Bandpass Subwoofer: You Are Doing it Wrong. Bandpass MYTHS BUSTED!

611 comments

(APOCALYPTIC BASS CREW LT Tony) Hi, great video. How do I calculate the formula to adjust port according to sealed side? Thanks

(ModernBassheads) When it comes to 4th orders from my experience I’ve seen shrinking sealed chamber leads to better low end and stronger output overall, this obviously goes against all logic but it’s true in 9/10 applications. I’ve spoken to numerous box designers, heard countless builds, seen friends go thru it, read on forums, etc. but this is all dependent on power too, if you are overpowering your sub by a bit, you will have Better low end if you have a smaller sealed chamber vs under powering a speaker, then you’d benefit from making sealed chamber bigger. the loudspeaker cook book is wrong in a lot of senses too. Come out to some bass shows once in a while, you’ll hear 4th orders that play down to 20 and into the teens sometimes and up to the 50s. Quarter wavelength helps the big ratio theory also, the farther your subs and port load away from your listening position, generally the better for low end output because the quarter wave develops more

(michael mills) I two flat Pioneer 10 inch subs that I'm trying to do a flat bandpass is there such a way to do that also what is the best way to get I want all around good sound you know between rap rock I found tens move fast enough to hit the rock sub beats and they move slow enough as well or deep enough where you can get good rap beat out of it but the last time I had a bandpass box it was a it was sounded really good but I didn't have a lot of space leftover for tools and stuff like that in my truck so now I got a smaller SUV and I would like to get the best sound out of these two flat to Pioneer 10 Subs right now I've got him in a custom box that I built myself they sound fine but I want him to get a little bit more bass out of them any ideas on what I can do please by the way I have really little experience with building boxes I would giving Dimensions that I needed to go by and that's what I went by

(nate0) Maybe you can answer this question. I own a bandpass for a 15 and built one for an 18. Both I have the sub mounted with motor in ported chamber. Main reason is to know when too much power is sent. However, I was curious if it makes any difference whether the back wave or not is entering the ported chamber? I own Vance's book btw 🙂. Also, am wondering how much the sealed chamber resonance in itself acts on the ported chamber? Ideally, I guess we only get 1 wave off the sub? My 18" bnandpass was 1.6:1 more SQ.

(Minsa_Gamer) Nice N outstanding Info sir u solve my big problem thanks a lot n love you with great respect from Pakistan

(Dinithm) Thanks 👍👍👍

(Pankaj) Please sir !! Could you please make video on how to make cylindrical subwoofer (sono sub) and how to tune it properly

(luis colmenares) Hi! Thanks for this video. Could one build one of these for a bass guitar amp? Based in your experience, could that be an interesting experiment?

(lukas henchman) parralel 6th order, if you tune the second smaller chamber say 70-85hz it should have almost no impact on low frequencies, 4th order sucks lol

(C.N. H) Since you started digging into subwoofer enclosure designs let me rack your brain real quick if you take a subwoofer that has a high xmax and you put it in a 4th order bandpass and you cut two holes on a sealed enclosure side and you add two cones of equal size to the one inside the enclosure what kind of enclosure you left with? And what is the kind of performance would you receive? And what kind of enclosure have you created?

(Tim Lewis) Odd you should talk about small rear chambers and SPL builds. Craig Butler's car has these digital designs 18" subwoofers in these sealed cylinders and is hitting insane SPL at one note. I'm not sure if he shaped his entire cabin to act like a great big resonator and thus he is sitting (or maybe outside of the car when it's turned up to record breaking levels) in the ported chamber of a 4th order bandpass.

(Joseph Yartins) I have 2 15s in a forward facing 7.25cuft slot ported enclosure in my trunk. I would like to regain use of the back seat as it doesn't fold and has to be removed. Can I calculate volume of space between enclosure and back of seat and port the rear deck as a 6th order setup? Or would the tuning be jacked up by having the output be from the smaller chamber?

(Miguel M. R. M.) 20 years ago I build my own.... the BASS transform in something unallocated but you can feel. May be the best in quality I have heard in a system 2.1 for 3X50w RMS. After one years I selled for 250$. The box subwoofer, on amps system inside, still alive.

(Jason Hopkins) Can you do a video on 6th orders?

(Appalachian Craft Masters) Bassheads Bible Right Here!! Basically simply purchase 2 Deaf Bonce 15's and build the biggest box you can fit in your truck,buy the biggest Orion amplifier you can find and spend the rest on a battery bank and wires and turn it up/ WARNING WINDSHIELDS WILL SHATTER😏🍻

(Ghost Ship) I was always a vented box guy, and after watching this, I still am 😁 I listen to a lot of types music, i need that wide, flat response curve a vented box provides.

(ashtaman anil) Dear Sir 3in 1 means? 2.7 vas ( 2.7÷3)=0.9 0.9×2=1.8 That means 1.8 cubic Port side 0.9cubic seald side Please give a reply!

(Ramon 1974) Interesting! Very informative!

(jasonneal) Everytime I watch this video, I learn something. Would be awesome if you could make a part 2 to this bandpass tutorial. 🤘🏻

(Doublemanson) Can anyone give me their thoughts on 2 subs in a ported box with separate chambers with each side having a different tuning? Is there a name for that.

(dpgoverride) Who remembers the Thunderbox that MTX Audio had back in like the late 90s early 2000s?! Great box for 250-600 watts, very musical. I remember those Pyle bandpasses haha. Thanks for the video, looking into designing a 4th order for 4 8's, trying to find good information on how to model it. Might need to pick up that book you mentioned.

(Audio and whips) Old school team Alma Gates Lead Builder checking-in!

(somthin else) Hey can you build my box

(David Zaiter) Holly crap finally I get it.

(Stanley Nhongonhema) Hie please can you help me ...i have a kenwood wps1300d and i was thinking of putting it in a bandpass box .On its manual there is only two options thus sealed or ported...will it work well if i use the specs for the jbl p1220 bandpass box?

(Otto Bauner) I understand the formula for Fc but how does this effect multiple drivers in a single undivided seal section say 4 drivers in 4cuft would you use the vb/4 or vb=4 in the formula. In my case this can make a difference between 60.7hz and 48.7

(Charlie Lavalleur) So what are three premade and loaded bandpass boxes that area a good value? I don't want to build one.

(Travis Abrahamson) So how do you use the equation?? I keep coming up with like 3.5 ish lol has to be wrong . I need to find the resonant frequency of my sealed side . Its 3 cubic feet and the fs of my sub is 24 Hertz and the vas of my sub is 206 liters. Any help would be much appreciated. 😎

(Waltzs budgetBumpin) Like 16 years ago I was pretty uneducated with the technical aspect of audio. I knew the basics had been messing around since I was a kid in 80s. But there wasn't hardly any easily found resources there are now. But I bought a visonik bandpass from crutchfield and it sounded terrible and muddy and I burned it up probably clipped hell out of it I'm sure but I didn't know about clipping and I couldn't hear distortion with it. They replaced it and I burned up another... I ended up going with a Polk db12 in prefab box worked great for years. I still have that BP enclosure (actually both) and now I know technical side it's a total piece of crap, it's small prob 1 to 1 but super small. I'm sure the sub that was in it was a cheapie.

(Peter Bobojcov) This is one of the best explanation on YouTube IMO. Not only on this topic but generally on acoustic laws and rules in box building and designs. So right to the point with such a control to stay on the topic yet not to miss any critical point in explaining the reasons why. Great video. Its funny how some people talk about bandpass designs as a new fashion thing around the block. It is actually because of those cheap and many bad sounding bandpass boxes with plexiglass panels and bunch of blinking led lights. They are very attractive when you listen to them with your eyes and with LED technology these days those enclosures are coming back to the spotlight again. Bose made them popular with their Acoustimass series in late 80's and early 90's (dual reflex boxes) and they were a big commercial hit at the time. With those cubes the whole system sounded much more powerful then they looked. They had a jaw dropping effect on home listeners and since then satellite/subwoofer systems became very popular. They got a very high approval from female members of the household and we all know they have a great influence on the choices when bringing something in the house. I know all that as those Acoustimass were my first home system with the sub. And everyone who came to my home were very impressed. Until I bought a 15" Velodyne Digital series sub. Then I realised how Acoustimass box sharply drops in low frequency. So loudness cannot fix the lack of bandwidth when you can compare the systems side by side. If you dont hear certain frequencies you will never know they are there (in the source) until you hear them on the system they can reproduce them. And on that topic how some designers put the sub inverted so they can smell the burning coil on the driver during the SPL competition. I must admit Bose found a very elegant solution to protect those 2 small 5-1/4" drivers in their Acoustimass boxes. They put in line a light bulb with a specific resistance with each driver so when the driver receive more than rated power it would start glowing at that point turning that extra power into the light (glowing filament in incandescent bulb). And if you keep pushing you will burn the bulb instead of the driver. Very clever but scary when you dont know this and you see the glowing light coming out of the port when you overload the box. Thanks again for this great video. Instant subscriber.

(Pentenfi) Very well done!

(Derek Matthew) Doesn't the bandpass box get louder at max watts/power and have half the size box than the ported box? I'm pretty sure them Dayton response plots are of sensitivity not max db output right? I would bet the loud or all the ported boxs would reach their mechanical limits far sooner than the bandpass box would. But the bandpass would reach it's electrical limits sooner than the ported. Seeing how most subs only do 1 or 2 octaves and we all like smaller lighter boxes, I don't know why we don't see far more bandpass subs. Also bandpass boxes have less or far less overtones and or unwanted higher frequency noise or distortion than sealed or ported boxes because they drop very sharply at there high bandpass frequency. I also feel like the bandpass plot must have been tuned to 40hz to 50hz? If so what's the plot look like tuned to a more reasonable 30hz to 35hz? I'm not saying the Dayton sub is best suited for a bandpass but I feel like there's more variables you didn't address. I like a sub to hit 30hz to 120hz or 20hz to 80hz for bigger applications.

(KnockOut_WJ) It just alot of hot air.

(Dakota Bever) I need a system that sounds good and is loud

(Morbid Man Music) Raise your level, audio person.

(Paolo Zak) Hi! I'm a bass player and have always been wondering how to design the best sounding but also efficient 30-70 Hz band pass to support a smallish bass amp that does not go much below 80 Hz. What would you recommend, 4th or 6th order? What would be the smallest possible size (for portability) for a power handling of say 300 WRMS? Wouldn't a sealed enclosure with rear-firing passive radiators be a better choice for minimizing enclosure size and group delay (good sounding deep yet tight and well defined bass)?

(Brad Bullen) I love bass.

(bassmachine00) On all the bandpass videos this one I understand it's well explained even to beginners like me thank you

(JohnnayJohneson) Extremely interesting video thx so much for the simple explanation and especially the Formula :D

(chris britz) What if you made a bandpass that could move where the sun was so you could get a good mix of noise and low notes and range?

(Mr&Mrs Couple) This guy is an engineer. Subscribed right away.

(Guppy Duppy) bandpass is great if designed correct. I also used WinISD and it's great the bass is frankly on some points better then lowQ closed box.

(Jim Brown) I'm glad you made the qualifiers that you did. Back in the 80's I tried every possible box design in numerous variations. They all stink. Give me 4 Lab-12s in a 4 cu.ft. SEALED BOX. It can't be touched for fidelity, and has equal Output with a Ported Box. (but needs twice the power).

(djweszone) Band pass systems sound better in a hatchback or suv/van, they have more low tone and less shake. Band pass boxes never seemed louder to me in SPL in any car Iv tried, and they don't project well outside the vehicle in comparison to sealed or small ported boxes. Your right that the old school boxes were not loud like the now big ports, but they seem like another animal all together tuning the car like a external port system. With sealed in the old school boxes under the power they used to If your projecting properly outside the vehicle, your going to want a sealed big port design. led or ported box. When you use a sealed box or smaller ported box the internal body of the car or truck becomes the band pass side of the box. Band pass boxes are terrible for trunks giving more air flow shake for rattlers. What I'm realizing fully after almost 30 years is it's all about the box and the reason my set up when I was in high school was so hot beating everyone's set up in my age group across the state of MD. with just over 1000w rms, it was not about the amp but my custom built box. As soon as I put the old set up in a pre fab box was junk in the next car. Ant I had ppl coming to bass off with me over and over with 2000w rms multiple boxes and not even close. Everyone told me my box was too big lol but then they got smashed. If your looking for amazing you need a custom built box that fits your speakers and amp all else fails.

(Jordan Crawford) What about when designing a series 6th Order band pass enclosure, do you just tune the ports to the volume of the part of the enclosure that it’s venting from? And is it true the tuning of one side also has an effect on the other sides’ tuning; sort of like the ‘equal and opposite reaction’ etc?

(Jose Lopez) Is it just me or he wore a black shirt??

(Doug Tond) This, by far, the best explanation of bandpass enclosures I've ever seen/heard

(Rick G) Bandpass sucks dont waste your time

(Arno Deinum) 80% en of this video is about 4th order bandpass, the last 2 parts are about a 6th order, or the dog ears, there is a difference

(Mortality Rated) The sub itsself isn't bandpass, sealed, or ported. The enclosure is what can be sealed, ported, and bandpass.

(DBT CAR AUDIO) Hi!! I have a question, what about parallel vs series 6th order bandpass ?? cause the only option in the programa is parallel. How can I calculate a series 6th bandpass??

(110% America Loving PATRIOT) Back in 1987 a friend and me built a box out of 3/4" plywood that barely fit in the trunk of my 78 Buick regal from side to side, we put four 12" woofers side by side and we had no port holes it was air tight and I drove it with a Kenwood 920 amp and it thumped like crazy.

(Audiogear) My friend... You are using a low Qts 10" driver optimized for ported enclosures when modeling a 4th order BP. If you had used a 6th order BP for the RSS265, you'd get better results.

(stanley steemr) I was able to solve this problem with 4000 Watts and 12 Woofers. Concrete cracked and glass shattered but nobody was worried about the band-pass. lol

(Gardevoir Dude) For someone who knows so much about audio, you can't manage to properly level the audio in your videos?

(John Viera) Great video. Exactly correct on every point

(Exclusive HF) This is great info! Can you elaborate on best polarity for a powered subwoofer?

(Mad Scientific) Informative video. I know several people that should watch this

(GudMusic4Lyfe) Great video! I love bandpass! Back in 2004 I had a 01 ford Taurus with two 12 inch pioneer impp TSW305Dvc subs in a 1:1 bandpass I built myself. Front&back chambers was 0.9cuft and I use pvc pipe for the port which was 3" x 5" each if I remember right. It's was Amazing! Had that longthrow bass and I used an audio control epicenter too. Sounded Beautiful inside and outside. People would ask me, "how you get your bass to be so deep and low"? Bass is just air and you want to move alot of it. Your sub is an acoustic air pump! So Now I have a jeep grand cherokee with a kicker zx2500.1 and a Soundqubed 15" HDX3 in a ported enclosure. It's beats stupid hard but bandpass have this certain sound that I'm addicted too. I been trying to order another one and build a 4th order wall but their sold out so I'm going to wall it with two Dayton Audio ultimax 18s. I have a 4th program on my PC that I already punch the numbers in and the results are impressive, better than any sub I seen probably because their fs is 19hz. Their louder and more efficient on lows. I can't wait to buy them!

(Queen audio Blitar) Nice information sir ..from indonesia🙏

(Hillonetwork Informatica Seguridad Comunicaciones) i have the sixth edition from 2000

(Nico Löser) The best bandpass design comes from Germany and is called Fortissimo Bandpass. This was designed by Dietmar Carle and is in my opinion the best variant to build a bandpass. To briefly touch on the subject, it uses a chassis that plays well in closed cabinets. Best examples are: Arc Audio Black 12 or JL Audio 12w6v2. The closed chamber is first tuned to about 45Hz. In the case of the chassis just mentioned, that would be about 30-35Liter. The ventilated chamber is now tuned so that it corresponds to about twice the volume of the closed chamber. For a 12" chassis, or for the chassis just mentioned, that would be about 60-65 liters. The port area is then calculated from the air displacement volume of the chassis: in the case of the JL 12w6v2 this would be 500 cc x 1.65 cm = 825 cc air displacement volume. This value is multiplied by 0.4 - in this case 825 x 0.4 = 330 ccm port area. The port is then tuned with the length to approx. 65-70Hz. In this case, the port length should be 20-25cm. In the simulation now a peak of approx. 10-12db results. This is simply pulled down with a deep and steep low pass filter of about 40-50hz at 18-24dB/oct. The big advantage of this design is that the chassis in the range between 55-65/70 Hz has to make only about 1/10 of the stroke as comparable chassis in a closed cabinet. This results in a very crisp, fast and punchy bass in this range. In addition, you have at the same time a steep drop in the upper frequency response and downward out the same drop of 12db/oct as in the closed. The only disadvantage is the size of the cabinet. However, in contrast to the closed housing, you have about 3db greater efficiency and the aforementioned fast upper bass. For 8" chassis a 10 liter closed to 20 liter vented or for 10" chassis 20 to 40 combi would work. Chassis from JL Audio, Arc Audio and Hertz Audio are best suited for this purpose. The case also works very well in cars m. Especially in sedans or convertibles with ski bag highly recommended. In the car but necessarily pay attention to the fact that adjacent surfaces port lengthens and thus the real length must be somewhat shorter to achieve the tuning frequency of 65-70Hz.

(BENNYBLANCO14_916) Burp boxes have to be the DUMBEST SHIT IN CAR AUDIO...its not even car audio...its just loud asf and pointless

(mmatsman D300HC) HOW and WHY Bandpass is louder than Sealed or Ported- I am writing this to help anyone who is puzzled, curious, or unsure, to understand the reasoning behind bandpass and actually physically what is going on that doesn’t meet the eye. I am not pretending to be a know it all or to try to school anyone, especially since I am an oldschooler who competed back in the 90s for about a decade and has not been active in the hobby since. The last 20 years I’ve focused mostly on theory and just enjoying watching the modern crowd do their thing and break numbers that were totally unobtainable in my time. I guess you could call it fantasy SPL. I have a very strong love for the hobby, but neither the money nor time to be involved currently. I am now into vinyl analog and vacuum tube sound quality home audio. This brought me to a place where I designed back loaded horns that take very low power vacuum tube amplification like under 3 watts RMS and give you a kick of bass to the chest like a small subwoofer. And that’s how I learned about what I’m about to explain. So anyway here we go - Bandpass enclosures achieve higher SPL through efficiency. For over two decade no one could or would explain to me exactly what is going on behind the scenes so through research and talking with various acoustic engineers I put the puzzle together and would just like to present it. 1. The method through which the efficiency is obtained is called Acoustic Impedance Matching. This simply means creating a “drive train” of similarly physically matched density materials between the speaker cone and the air/your ear/mic. Energy transfer always works the best when all the materials in this chain share a similar physical density. 2. A poor Acoustic impedance match, a.k.a. a hard woofer cone and the soft air are exactly the same as a hard metal baseball bat to a soft cotton ball. Test it out in the yard. The cotton ball won’t go far. Now substitute the cotton ball for a golf ball. The baseball bat and the golf ball are both rockhard so the energy is transferred efficiently and you’ll most likely take out a window a half a mile away! 3. The top chamber of the bandpass enclosure, the one vented into the cabin, forms a median, like a psychic transferring the energy in between two different entities. The compressed air chamber is halfway between the density of the cone and the density of the cabin air, so it absorbs more energy from the woofer cone and resonates like a piston through your big walk in port. Now that packed air mass is closer to the cabin air density then the woofer cone, and transfers that energy to the cabin better. 4. I would like to conduct an actual test in efficiency with let’s say an 8 inch woofer cone versus an 8 inch port and figure out the exact percent efficiency increase, I would guess 50 to 75% better. That is why you see bandpass boxes with small ports yielding louder results than a bare woofer cone. And ones with large port yielding out of this world SPL scores. The guys that really got this principle working on an extreme scale are the “High Ratio” guys who have a low count of woofers, a very large front resonator (compression chamber/air packer) and achieve an extremely high score. Although this does not constitute a cool looking build, or lots of wind or air movement. Think Project SPL versus EXO or Chris Lee. All F*cking Sick builds in my humble opinion, different purposes. All use bandpass properly just some more extreme in efficiency department which yields lack of musicality bandwidth and playability fun/hair tricks etc. 5. On the other hand there are tons of benefits to sealed and ported and by simply loading against a tailgate or the corner of the room, you can create that compression wave which acts as the median intermediary to transfer that cone power also, but it is not quite as efficient as a dedicated tightly reinforced and braced compression chamber into which the woofers load (bandpass). 6. Sixth order is louder than fourth order for the simple reason that you are using both sides of the woofer cone to energize the compressed packed air mass in the top chamber. The downfall is you lose the tight control of the sealed chamber which allows the stupid power levels you guys use now. Running the woofers inverted in a fourth order will yield better cooling but less surface area then mounting standard. The motor noise and the back of the cone are two downfalls because it is not quite the surface area as the front but very damn close. But there is no doubt that standard mounting with the cone pointing into the compression chamber of a fourth order will always yield louder results than inversion even though it may be a small difference, the woofers may overheat and it looks boring. The front of the cone yields a larger cleaner piston to energize the air than the back with frame in the way and voice coil taking up 4 inches of the cone. This is not to anger the inversion people, most likely you are running power levels that absolutely require it and negate the small gain that may be only percent of dB. A sixth order would not matter because both sides of the cone are being used anyway. Take care and have fun! I hope I’ve been able to help someone understand bandpass better. I absolutely love the progress and crazy builds happening out there! Peace Love Bass! Mike PS- I took down my original post and tried to make a more concise post, thank you so much for all the info in this awesome video, I am always learning new things!

(Ruger909 San Bernardino) Been wanting a good video on bandpass boxes it's like their a thing of the past...I'm going to find one that I can put a scar audio 12 in it

(Alain Pratali) good 4 order work well and sound good

(Eric Salyer) I have a ultra audio 6.5" sub in a 2:1 ratio 4th order It freaking slams most people think i have a big 15" woofer for my home audio setup

(Neil Snow) My first bandpass box was a 2x12 with plexiglass front from best buy. Put 2x12" soney xplode subs and a 900 watt xplode mono block sub amp. It hit so hard that I couldn't hear my other speakers. So I added component speakers front and rear from crutchfield powered by a clarion 4 channel amp. By the time I was done, my truck was a small extended cab Toyota pickup, I couldn't see out of any of my mirrors. Lol sounded great though. Went to the drive-in and everyone hated me lol

(London The Littlest Hobo) So with this video I've come to learn that the Zenith 4th order BP "subwoofer" is really more of a one-note wonder than anything else. Large vented chamber, tiny sealed chamber, long vent tube that likes to fart and a 6-½" Quadral woofer that fires into the sealed chamber. Very low end HTiB "Sub". You can see a few videos of it on my channel if you scroll.

(Rowland Buck) I had a bandpass with the led lights. For $100 it was pretty decent pass.

(Patrick Beaty) did 1 it peek at +14 db at 45 hz back to 0 db at 120 hz. wall saw makes boxes ez

(MikeMcChiken) I remember a friend that had a bandpass enclosure with 2 12's and a cheater Autotek 80 watt amp . I never heard 2 12's that loud . This was about 1990

(Necrochrist) I don't know why I wasn't subscribed to this channel yet. Not only are your videos informative, but you respond to comments as well...which is a huge deal. Thanks!

(Aito Blitz) 4th order bandpass closed1:2reflex :) is good yes

(Eric McGinnis) Purchase a band pass box in the 90's with two 10's! Years later I forget the brand but it was a medium brand in its time like pyramid I think but anyhow it seemed to have a constand gun to it! Honestly I only purchased sealed boxes after that! Would like to try a ported box next system I build! Looking into purchasing 2 of the down for sound jp 23 amps and two subs and well that's as far as I've gotten to so far but back in the day I ran a cadence electronic crossover with a 7 volt line driver and it made a world of difference cause older head units only put out like 2 volts out the RCA's but now I think the average is close to 5 volt but now they have larger line drivers so though people seem to have forgotten them in going to use one! One amp per sub wired down to either 1 ohm or .5 we'll see!

(Carl Thornton) Very Good!..

(a 6) I never realized that those prefab plexi boxes were bandpass

(DrunkPisces) I love the fact at 9 minutes and 25 seconds you mentioned the smell of coils. When you're smelling your coils that means that the show is about over. Time to choose push it and have to recone your s*** or turn it down and take your score.

(DrunkPisces) I have a 16 cubic foot band pass made out of inch and a half thick Birchwood plywood with two scar audio zvx V2 18 in. Sealed side is 4 cubic feet ported side is 12 cubic feet. 3 to 1. Pushing 80 volts at 2 ohms. In the cargo area of my 2005 Chevy Tahoe. At 33 HZ it'll score 168 DBs. This is only possible because I used half inch thick lexan for my window on the band pass construction. Also I have (4) 4" ports that are 9 in Long. If you want to get loud your box has got to be rigid. Acrylic is for chumps. Polycarbonate is where it's at.

(Abel Catalan) Toby speakers one of the best band pass boxes

(not yo biz) i've already built the box and never knew all these crazy specifics! could you tell me the fc of my box? sealed section is 2 cu ft but i have 2 subs and my fs is 41 and my vas comes to 1.009 cu ft. it's a 2.65 to 1 ratio (before displacement) box (5.25 ported 2 cu ft sealed) tuned to 42 hz. thanks much in advance

(Murray Sheckleberg) OK, but I still don't know if a hamburger is a sandwich or if cereal is soup.

(Proud Fire Dad DelFrate) You need to stop moving the 3d pic around so it can be looked at

(kurup suresh) Hi, amazing information, Please give me a best bandpass enclosure sizes / ratios for 8inch 400 watts subwoofer.

(michael voltron) What type of enclosure + subwoofer do you recommend for playing Hans Zimmer style of music?

(MaNNeRz Laguna) I built a box a couple years ago for my alpine r series. Sounds great at 30hz but 40hz seems to take off and ring right through me... Does that mean my box is tuned to around 40-50hz? And how if possible can I lower the tuning by 10hz or so? I'm half debating starting a new box from scratch with the type of design in this video.

(Matt Steel) You the real mvp! So glad there's someone explaining the science in a way we all get! Feeling alot more confident about starting an SQ build now. Was always dubious since most info tailors to SPL.

(Erik Gee) Can you expand on tuning ports? Nothing on you but I (personally) am confused by the spl turning aspect of a speaker. How do tune ports or a speakers potential to an outcome not defined?

(0steri) the rule with the EBP need to be over 55, but is it ok if the EBP is just 55 and not over it?

(Logan Freed) First video here, I thought I heard “ THIS, is a big ass subwoofer” All right all right my kinda channel. Subscribed.

(GoblinPhreak) Transmission line or quarter wave are my favorite. Because if you make the "line" get smaller towards the "line exit" you can gain QUALITY. If you make the "line" get bigger as it reaches the "line exit" you get LOUD. And if you keep the same size throughout the "line", you get a mix between quality and loudness. The only downside is available space. The bigger the speaker, the bigger the box. However, you can make a 6" or 8" sub sound like two 12"s. I know, because I was the asshole who put a 12" into a quarter wave. Giant box was a downside, but..... sure enough, it bumped loud as !@#$.

(Jason D'Onofrio) I just got the TX-WX1210AH and it hits hard. Sure you can buy separate components that will beat this but for convenience to take out in 5 seconds and put back in and have some serious hard hitting bass ........well there really is nothing so convenient.

(1 Brotherlove) I bought a Bandpass system back in the 90's, because I wanted to hear the bass on my reggae music at low levels, here it is 2021 and my JVC Bandpass system is still pumping out quality bass at low levels just like I like it.

(JUNKYARD GTO) Damn my 4th order truck wall is 3:1 ratio 🤣 please subscribe

(SuperKanuuna) What's up nerd?

(Jamie’s Car Audio Channel) What CAD software were you using there with the duel ported band pass box?

(Awestruck Audio Hertz) Great video man! Great watch, informative, to the point, honest. Thanks for doing it! +1 like

(hobart666) Ya know. any "regular" ported box is technically a 4th order...

(block force mod menu xp lobbys all day live steram) Could I just make my own sub box without doing all this bullshit 😂😂I’m a stoner I don’t understand all this shit I’m trynna make a box for my house inside but I wanna make it huge could I do it with just plywood or whatever I want 😂and I got another question how the hell you set ur amp 🤣I got mine good rn but still goes to protection every now and then it’s not anything to deal with wires or anything it’s the gain and I have no clue how to set smh 🤦‍♀️

(Izaak Gray) You're quite wrong sir, bandpass literally means bad sound. Bandpass = limited pass band = high q = high resonance = time domain distortion = the kind of distortion that is most obvious = bad sound. Bandpass = bad sound. You can polish this turd, and yes your turd may be then become the shiniest amoungst turds, but a turd it shall remain.

(Gio arteaga) Well said👍

(Ric Bachman) How do you feel using an isobaric back to back setup with this? 1 sealed chamber 2 ported.

(Audio_Phill) Regardless of ratio or driver used for a 4th order bp, the vented side will always be smaller than the sealed side in proper design if looking for the best freq range for sq builds. If the driver is well suited for 4th order, dog ears can be avoided. If the center is @ 0db, then eq's the peaks down will flatten and maintain a more natural sound than trying to boost the lower output range. Cut is always better than boost.

(TragestyX) I am hoping the DIY Audio Guy or someone else can answer this question. I have a dual 8 inch bandpass box, similar to the one at 2:10 but only one port on each side. What I'm wondering is for the size of my subs should they as much as possible be smaller to not have the driver directly under the port, does it not matter, or should I change the plastic port to be not as deep?

(cheddar shredder) Just subbed. you explain things in a dumbed down enough even way i could understand it lol. Superb knowledge though, i will keep learning!

(john myers) Thank you for a great informative video. I am also a professional audio trainer and I would like to ask a favor. I teach people in my classes another common misconception. A band pass enclosure is not a 4th order. As you know, a 4th order is 24dB/ octave roll off. A band pass has an average roll off of 12 dB/ octave on both the high and low pass. That's a second order. You cannot add the two together to get a 4th order because one is high pass and the other is low pass. Technically, a band pass enclosure is a dual second order. Furthermore, a vented enclosure rolls off at 24dB/ octave low pass so it's actually a fourth order. Can you help me to try to encourage that we do not classify enclosures by order and use the type to describe them. Thank you. Feel free to give me you thoughts. Jmyers@kicker.com

(Sebastian Stallings) My JL Audio prefab band pass box from 1995 sounds amazing and is super loud. I wouldn’t have it any other way. The plexy glass doesn’t affect sound whatsoever

(D S) I once built a 4th order band pass as recommended by Kicker for the two 12” comp series. After one week, I made a ported box and it sounded 10X better.

(Hookers Terminal Tackle) Did you do vids on sealed enclosures? We just did a sealed at 1.5ft per sub. Vega series 12s. High frequency response isn't great but around 28hrz is insane. 4 12s at 2250w rms. 2ohm mono.

(katie Barber) hopefully videos like this will result in better speaker boxes in the future,, altho capitalism has a tendency to sell shitty products as long as they create profit despite product quality

(Timothy Thomas) Make an Auto tuning algorythem driven Namd Pass Box. That computer moves the size of the Port by moving the speaker depending on the next note of the song.

(Anthony Ellison) I wish I paid more attention in algebra. Seems like imma need it

(dick beninya) im only here because soundman sent me here as he makes fun of this channel lmao

(Mike Powers) I've never understood all of the debate about "port tuning" and "box size". It's math. You calculate those parameters by using the specs measured from the speaker you are using. Period. It works every time. The math isn't that hard, and it's all in the Loudspeaker Design Cookbook you showed. You use that or software. Once you learn what the sound signatures of the box Q sounds like, you will learn your preference and build accordingly.. A box Q of .707 sounds great to most people. If you use the math, you can't go wrong. The only way you can go wrong is buying a woofer that doesn't sound good in the first place.

(Jonathan Lopez) I never like them

(AdamantForce) Don't say that, that sub did not out perform the bandpass box. The ported box had a horrible range. Not low enough. And got to much unwanted high end bass response. Bandpass got lower freq, and better crossover range

(Mughees Mohiuddin) hello, wanted to ask for your opinion as it will be my first build ever. Had a spare klipsch k27k woofer with BIC subwoofer amp plate rated at 240 watt rms lying around so thought of giving it a build. i could not find any parameters for this woofer. if you dont have any parameters how to design a ported box? thanks

(Richard Alvis) Not the brand, the shape.

(Richard Alvis) So again. Pyramid enclosures. What do you think?

(Richard Alvis) Just did this to see if my comment had to go through a leftist.

(Stanner) 9:17 I thought it should be pointed out that when the woofer is "Inverted" the voice coil also tends to cool better, especially over longer periods of play, because fresh outside air can enter the open chamber and is exchanged with heated air whereas if the voice coil vent (typically through the rear of the magnet structure) is installed into the sealed chamber the inner air continues to heat and becomes a less efficient cooling system.

(DIY Audio Guy) For more info on how to use WINISD check out this video right here:. https://youtu.be/yZNeYBYGRKk

(askela superior) That was good. Thank you.

(DLcarburetor) You may not have won the Sound Advise boom box build but your the guy I'd want to design my subwoofer box. Nice video

(Jamie Brown) I’m about to try and do my first sq system I want a lot of bass but want to be able to hear everything don’t want the bass to drown out everything else is there a ratio as far as Mids and highs to lows?? And example would be if I have 1000 W of power going to my Subs should I have 500 W going to my mids an highs

(Bass Jasinski) Great video! Does this box have a 24db roll off since you called it a 4th order? I was taught you get 6dB roll off per order. Seems the graph shows a 12dB low pass and a 12dB high pass roll off.

(Joseph Beltramini) Huh?

(Siana Gearz) How can you by looking at driver's TSP determine whether it's well-suited for a bandpass enclosure or not?

(Chris McMurray) I'd love to build a 4th for my 2 immortal 12's but I wouldn't know where to start lol

(Branimir Bicanic) Build a Bass Van! Join the Bass Wars! 😀 Fido! Make a noise!!

(b1782w) I've noticed higher qts values with low fs seem to be best Ina bandpass for achieving low end but a relatively wide passband but not necessarily great sq

(Chris Lapp) Nice tech. Until it rolls past your house at 300 dB at 2 a.m....

(Greg Blau) Great video. Now where’s the van?

(DJ WRAITH) @9:49 So if you build the box for the sub your using that is both good for ported and sealed enclosures and you do the 1:1 Ratio what i would do is add the sealed enclosure withe ported enclosure and where the two boxes meet I would put the sub so it is most efficient for sound quality and range of sound or maybe just move it a little closer to the sealed side just to get a little more low end and just a little more power because the pressure side would help keep cone stability more stable and keep the voice coil in it's space inside the motor.

(Jeremy Meyer) Is this going in the bass van?

(gizmoochi) Finally a channel with facts instead of 'buy my product' . Thank you from a new subscriber.

(TheRattleSnake3145) T-Line boxes ftw!

(ChaosHusky) For cheap installs for friends, with maximum perceived 'loudness' along with a nice sound, i'll use a ported and a sealed box with woofers of the same size, sometimes even a 10" sealed and a 12" ported.. Works quite well! ;) I have one of those exact shitty sub enclosures that's scrap, too..might as well burn it? I could have blown its original 10" "woofers" with a head unit lol speaking of frequency response, if you want some great reference speakers that can go down low and way up high (very high bandwidth) look for some KEF Coda III speakers, also Mission 731/750SE Gold and Gale G20 Gold.. I tend to prefer my Rotel or Yamaha amps to drive them all, though i have a few good JVCs and a Kenwood amp too.. And no EQs! And an EVGA Nu Audio Pro 7.1 sound card!

(Ile Stojanov) What about building a double volume box (for example-600mm width,300mm height and 300mm depth)with driver mounted in the middle of the box and mounting one equal port on each side.i'm thinking to built one like that so advise will help!

(Rasta Storr) Whoaaaaaa man this is knowledge I got two toro force eight inch 800 rms and for some reason my speakers be making popping sound when I crank it up I do believe box is the issue

(Na8 Tha Ska8) Dude your tight ill be getting T ya about so boxs

(Michael Rinkle) WHAT?!?!

(bass guy19) I have 1 12" kicker l7 solo baric sub in a small q bomb box it beats now but I have been told to put it in a bigger box is a q bomb box good enough or should I build a box whats you recomendation

(Matt Roadfeldt) Could you do a video on the series tuned sixth order bandpass?

(Ivan Iñiguez) The best bandpass box I've ever had is called toby speakers/box by mr toby, what a legend. With only one single 10" sheriff 200w speaker and a 160w amp sonds like 2 12" 2000w system

(Dylan Suiter) 6th orders tend to work best with a 4:1 with the ports tuned a half octave apart. Should've dove into those as well because bandpass.

(B Bailey) Bandpass have always been my favorite. I never knew how to design one correctly but when I found an installer/builder who did know what they were doing it always turned out great. Nice to see someone in the modern scene trying to eliminate misnomers about bandpass. Now if I could find someone to design me a bandpass for the 15" B2 X2SIX I just picked up that would be amazing!!!

(Ritch Schut) Great video! The bottom line is, ( I don't care if your goal is SPL or sound quality ) every single install is unique. Therefore there are no magic tricks. You have to decide what your goal really is, and design and build the install based on all of your unique variables. Every single install is a series of compromises bar none.

(Eric Schulze) Keep it going man

(Eric Schulze) Thank you so sick of these guys spreading misinformation it ain't that hard TS formulas can't be changed but these guys think they can reinvest the wheel shut these hocus pocus dudes down

(Lance LeFevre) Once or twice a year I find a channel that gives me the old youtube excitement I used to get finding all the awesome content when I was new to the platform. It's rare anymore but still very exciting to find an awesome channel. I'm so happy to find your channel. You've got great content and seemingly a ton of knowledge. Thank you for your videos and channel.

(Thomas Brown) That did not come out right I'm looking for someone to build me a sub box or to help me with a cut sheet 4 4 Subs 12in the boxers I'm looking for a 9 cubic inches

(Thomas Brown) Do you build subwoofer boxes or where are you fan out cut sheets

(FreshAsFxck) Wow thats the most informative video ive seen in a LONG time. Subscribed. Would love to see videos like this on series and parallel tuned 6th orders, horns and 1/4 wave T-lines. Thanks for sharing!

(zoran kamcheski) I still have the pioneer ts - wx206, 8inch bandpass box,it's a true bomb

(Joey Holthusen) At least Pyle got their name right. 😄😆😅

(Condone yourself like a professional) Videos explaining how to use WinISd would be much appreciated. There seems to be a void in the internet concerning how to use WinISD or BassBox Pro 6. I can give you a copy of bassbox through google drive if you don't have one. I'm about to build a sealed box for two Skar VXF-15's with hopes of turning it into a 4th order ported through the rear deck of my crown vic.

(Michael 24) I personally have found a relatively small sealed side with about a 1/1.35 ratio is most musical. Tuned to 56 hertz, it’s quite flat throughout the response from about 26-56. Not best for SPL or super lows, but sounds musical, and still gets loud.

(Austin Tyler) @DIY Audio Guy  New Subscriber. I'd love to get some plans for 4th-6th order. 20-35 hz ? Morel Ultimo Titanium SC 12/2 Need to fit trunk 2014 chevy cruze. What ya think? Seem like u are very knowledgeable fellow. Thanks & God Bless ya brother.

(Ernj C) Toby enclosures anyone?

(Col Striker) I've installed many systems and setups my own way . An I have learned many ways how to adjust many frequency's based on the setup an what it can handle . As for instance back in the day I could use pioneer 6x5s an 4 1" tweeters a 12 " Memphis in a ported box with a heartbreak amp in a 2 door hatchback an bring the music to the party an it sounds just as good if the band was playing at the party . To using a Clarion in a regular cab truck with stock 25 watt 5x7s with just 2 pioneer 2-way 6x5s an have very little bass with crisp clean mids and highs without a sub . To upgrading to 4 3-way 6x9s at 150 watts rms per speaker. An sound dampening the doors the floor , firewall and back wall including behind the back speakers. To have crisp clean mids an highs with really good bass after adjusting the frequency's for with the kind of music I like . When you upgrade from 20 year old stock 25 watt speakers to bigger better speakers that can actually handle the power of a truly well built Clarion that was made to make it rock with the right setup . Honestly haven't had a need for a custom box or amp . But wouldn't hurt to add an would honestly readjust my settings to work with the sub and amp to produce more of the bass since I can also adjust my settings for just the sub through the Clarion and could still out do many. Including I eliminate all errors that could cause distortion . You want music to be crisp an clean with excellent bass that's not to little or to much . After all is said an done . You want to listen to anything you want to an be able to hear it at any level you wish . Without even having to adjust anything ever again.

(Gerald DiAngelo) I’m a oldschool audio head just subbed great video 🔊💪🏻💪🏻

(Turbo Duckhead) Think I have found a good informative channel

(BOSSLIFE BEATS) 👌🏾

(Thomas Gruber) someone knows the fortssimo tuning? does this work in home cinema. I think about to try... but not sure if the the principle work at home.

(Brainztorm Productions) that bandpass plot looks like the subwoofer wasn't designed for a 4th order, a 6th order would plot much better, your misleading people by saying the ported is better than the bandpass when infact your just plotting the wrong type of bandpass enclosure

(DJ Francisco Perez) Do you have any knowledge of tapped horns TH

(william killingsworth) sweet intelligence... subbed

(Audiolover20) I noticed you didnt talk about 6th orders in this video. I would very much appreciate if you made one.

(Chris S) Idk how I’ve never found your videos before. The way you explain stuff and relate it to real world is awesome! Going to search your videos but I hope you have something on designing regular ported or sealed boxes based off of sub/amp specs!

(BLINDSMURF) Can u do a video on how to read what frequency mid bass/midrange speakers play the best on are speakers? With out oscilloscope if there is away

(HTNHRD) To bad most car subs are only in mid 80's for efficiency rating. I don't know my 4th is pretty damn musical and low. lol... Next though is going to be 8 15's in a 6th order isobaric with around 6k of power 😎

(Scot&Tiffani McCord) You just made the best video on 4th bandpass, not sure that is a huge complement or a slam on the complete lack of info! All SB aside you did good job! no great, no good. If you watch American Dad you will get that..

(Steven) Can you do a video on 8th order? I built one on another guys design, for a 5.25", it sounds great, but I'd like to design one.

(trollslayer82) People need to know what the "theile" or small parameters of a sub means, that way they can use those numbers to dictate what type of enclosure they want to use. Alot of people dont know that certain subs are 4th order friendly,so imo, you should also cover the bases on the small parameters. If you have any luck explaining it in a simple , yet non boring way , i commend you lol.

(matt ekstrom) I’ve done 4:1 ratio bandpassed with huge range . Ratio can be less important with a well designed bandpass . I had the gain of the extra ported volume but kept the range . I could play 18-55 hz . I see some myths being re enforced in this video that aren’t true as well . There is a lot of physical changes that can be made in the design to combat that “peakyness “ that a lot of people think higher ratio enclosures can give you .

(Rax Pax) ported vs passive radiator please

(SLK 2020) Question can you do a video on a isobaric ported box

(enoX 2k) Check out maybe 6th order ?

(bkrgls) Cool video! Gonna hit da "Like" and da "Sub" for sure. Do you know if there's any major difference between LSDCB 6th and the 7th edition? I have the 6th edition.

(Electric Lettuce) My boy literally says there's no secret ratio, then proceeds to tell us the formula to get our secret ratios.

(Bad Bass and Blowing :-/ Salaki Hz) I remade my own bandpass subwoofer out of a jamo bandpass sub, I GOT A NEW SUB DRIVER, NEW PORT, Tuned crossover for the lows. I will upload a video of it. Plus you got a new subscriber here. 😀😆😃

(Cruz Morales) So,happened that I just started in the audio world , have a front stage active and asking around everybody asked, told me that for S.Q. the best bass was a seal box , is that true?

(hooptastic_hippie 852) i need a box designed for a 12 inch DC level 4- it says Suggested Sealed 1.00³ ft Suggested Ported 1.50³ ft

(Josh Haimes) First video I've seen from this channel, and it was awesome, thanks! Subscribed! The other thing about bandpass boxes to look out for, with respect to sound quality, is group delay.

(Jerry Wright) Hey can you do a video on win isd. Where to download and how to use please

(mike phinney) Awesome content, thank you for the education! Off topic question, I have a sealed composite speaker box by Rockford Fosgate for my Polaris rzr. I loaded the RF RM110d2b 10” sub in it. I put sound dampening material in the RZR and went crazy and put some on the enclosure itself. Does this kill sound? Should I remove it?

(hyperdriverr) The best sounding band-pass I heard used a dayton dcs255 classic 10" really similar to a jbl gto 10". They are xmax limited so they struggle below 35 hz but they have some of the lowest group delay you can find in a band-pass without giving up efficiency. I ended up using it in a 6th order in my daily driver and sacrificing a tiny amount of sound quality for the ability to play some decaf when I feel like it. Another cool thing is they still play high enough that if you are on a tight budget you don't have to upgrade your mids and highs, the classic 10" can play mid-bass even in a band-pass.

(309 basshead) im one of those spl guys. thanks for the cool and informative video

(Lee Roxburgh) Man Justin, you made my day with this one. So if there is a sub, that has a sealed and ported application from manufacturer, can this be utilized as a reference? Or even worked in conjunction with each other? I know this will be based and the optimal power rating and not so much a high power dumping, which as you stated will require a smaller enclosure to control the sub.

(DecalsAndFriedChicken) Hey that's me at 2:28! That's some old pictures and videos from an event in 2018. Car is completely different now! It was a flat ported wall then and is well on its way to becoming a 4th order.

(Alessandro Chiodo) Great content !

(CoffeeConservative) You know what you get with a really well designed bandpass ? An enclosure that almost performs as well as a mediocre ported box but still doesn't as good as the crappy ported enclosure lmao

(chad leimgruber) I would always build my box with an under sized sealed section and about in spec give or take .5 cbft and tuned around 50

(philip harcrow) We have a legendary local shop called Toby Speakers. He only builds bandpass enclosures for vehicles using Dayton subwoofers. I have a dual 10” and a 3-12” enclosures made by him. The dual 10 is one of his production boxes called the Hitman. My 3-12s enclosure is a one off he did for me. And let me tell you, they get down

(Kilroy) So a down firing sealed box is kinda a big bandpass with large port side, like if its under the back seat of an ext cab truck

(J.Steger) Jacob from Audio Customs design me a 4th order for 2 8w7 and it plays 20hrz to 100hrz port Thru the ski hole of my lexus is250..

(Bassotronics) The dog ear analogy is perfect because woofers. 🐶

(Peter Towers) Wow by far you are the only one that gets in deep covers it all and keeps giving info. Please don't stop making videos.

(Travis Dilligaf) Nice! We'll put sir. The mythicals also say if the subs better suited for sealed box then it should play well in 4th order BP As a sub better suited for ported box plays good in a 6th order or something like that. Damn good video on 4th order bandpass!

(Ganesh Narayan) I have bought Kenwood Excelon Xr 901-5 amp with 2 12" kenwood excelon subs now the speakers are separate in a box and they are not ported i have spend lot of money but i'm not very happy with bass. i listen to lot of old rap music. what kind of ported box is good in your opinion.

(Shane Johnston) Love the simplocity and informal info

(rhkips) Waking up late on the first Saturday morning I've had off in a good long while, I find this video, buried deep within the typical tripe of YouTube's "recommended" wall. Liked, subbed, and I'll be spending the rest of my morning pouring through your channel! Awesome stuff! So refreshing to see some real technical talk actually based in reality. :D

(Sam Scharp) I remember hearing an Alumapro BP series 8" bandpass box back in the day that sounded like 2 12's. Was only like 1 cubic foot but that batboy dumped. I've been keeping an eye out for one ever since.

(Jesse Strahn) Great content and myth busting! "Myth Bustin' with Justin" maybe a new segment idea!

(BHanBeatz843) Very well made short and informative

(Tavar Sumrall) Leaning so much with videos! Thank you!

(ReDmAn) Very very well made video I learned allot Keep up the great work 👍🏽

(3RD ERA) Cookbook is a must in my opinion, filled with gems!!

(V13 Audio-JV) Hey Justin.......your vids are awesome. I really like the format/editing and I am trying to get my channel going. What editing software do you use??

(Paul Cooper) Thanks for sharing the truth I bought my LSDCB about 25yrs ago its the best source

(Audio) There is no 1 word about Group Delay.

(Huey) Very interesting and informative content! I just purchased a Dayton Audio 12” HO DVC sub. I’m trying to understand box designs. What box design would you suggest for the best SQ? I have a space 15”W x 32”L x 15”H. My 15”W is fixed but the other dimensions are flexible. This will be placed between my seats in my second row? Thank You in advance for your insight!

(SJC Audio Guy - TheSFFV) My favorite kind of subwoofer box!. Been rocking those since '94. I always used the fully carpeted ones back in the day.

(Jeff needs to give Jake a turn on the ps4 -) Thanks man, I really enjoyed this one. You're fast becoming the Mr. Wizard of car audio. 👍

(L Ry) Hey a bandpass series, awesome! I remember when I first started seeing the JL boxes at shops back in the day. Those were good sounding boxes! I picked up a box at a bazaar and put my Soundstream USA’s in it. That’s when I realized there’s more to it than meets the eye lol. Awesome video!

(MrConcord75) Does anyone else get really low sound/volume on this video?

(Colby laro) vewy twicky indeed..keep these good videos coming justin 👍

(Josh M) Wow thank goodness for programs like WinISD because math is confusing to me due to... choices in life. I follow along slightly but math in general just isn't my thing. But your explanations are really good that even though me big dum dum. It did make sense. Someday I'll explore bandpass and other fun box styles. 😁

(sugarmaker67) improper design has given the bandpass box the ugly nickname of the "one note wonder"