The traditional wisdom says that if the driver is close to the back panel of the speaker box, you'll get very obvious reflections back through the cone that colour the sound. While this is now widely accepted as true, I thought it would be interesting to actually test it and see first-hand how much of an impact it has. The two boxes are nearly identical internal volume of 12 liters (the deep box is very slightly bigger). That volume works best for the driver I'm using for the test, a Seas coax H1144. The deep box is 8" from the back of the front baffle to the inside face of the back of the box, while the shallow box is 4" deep. I used the same driver (I only have one of these), crossover and test setup for each box. The shallow box is just deep enough for the driver to fit - the back is just 1/4" from the back panel. Measured first without stuffing, the tall shallow box shows a disturbance in the 300Hz range. This can be the "back through the driver" reflection mentioned above or it can be a standing wave. Adding stuffing (I used the same piece of rockwool in each box) shows no significant change for the deep box, but has smoothed out that 300Hz wiggle in the shallow box, proving that it is a standing wave problem. The standing wave happens up in the shallow box because it is taller and the distance from top to bottom is great enough to support a standing wave in that 300Hz region. The rockwool is damping material that absorbs sound energy, breaking up that standing wave. Tangentially, this also demonstrates that standing waves are only a problem when the box is big enough inside to support a standing wave in the lower midrange frequencies. Note that the deep box shows no improvement when stuffed, indicating that there are no standing waves of any significance to damp. So making a small speaker box with rounded or angled sides won't be effective for preventing standing waves, when they wouldn't be there to begin with. Finally a listening test using both boxes. The mic is set up around 20" from the speaker on tweeter axis for both boxes in my listening room. I deliberately withheld which box is which, leaving you to decide based on listening only. Give it a try and leave a comment, and I'll reveal the results in a future video.

@doctorscoot

Жыл бұрын

I could hear no real difference

@act.13.41

Жыл бұрын

@@doctorscoot Same here, but I am old.

@dcuccia

Жыл бұрын

New to HiFi, but have a physics & engineering background: Is the standing wave precisely the same as what others call edge diffraction or baffle step? Does the RockWool essentially dephase the initially-coherent standing waves? How far can we push this? Can we stop worrying about long and narrow subs and engineer in-wall pancake enclosures?

@act.13.41

Жыл бұрын

@@dcuccia I'm not an engineer, but I do know that Monoprice has a selection of in wall speakers. You could probably get some measurements from their site.

@pablohrrg8677

Жыл бұрын

@@dcuccia I imagine the box as a pool with water: you can make waves in a pool; depending on the size of the pool and the frequency of the waves you can make them standing wich amplifies the peaks. Of course in audio the variability of the frequencies make it hard to desingn a speaker that doesn't resonate at afrequency but end up resonating at a different one. Sound systems have so many variables playing that are almost chaotic systems Think about butterfly effect.

I love that I couldn't hear a difference. This is a great channel btw. Thank you

@Den-r

4 ай бұрын

Use your ears idiot

I'm so jealous of that workshop

Seriously I could enjoy just watch you build boxes all day :) You are like the Bob Ross of speaker cabinet building.

Man, short and absolutely straight to the point

I think for those kind of tests it might be fun to have A, B, C and D, two of them being identical just to triple check people can *actually* hear a difference (let alone which is superior)

My "Guess" speaker B is the shallower box.

@drewthompson7457

Жыл бұрын

I'm listening on my tablet, but I agree with you.

@pcno2832

4 ай бұрын

My first though was "A is the deep one.", so it seems we agree. B sounded "boxier" to my ears, like those cheap speakers they used to put on Lloyed's all-in-one compact stereos of the 1970s.

@Freekniggers

3 ай бұрын

My guess is both at different frequencies and

@SoldierJ613

3 ай бұрын

Which is it ? What a waste of 6 mins of my time. Thanks buddy🤦‍♂️

@pointnemo369

3 ай бұрын

@@SoldierJ613 To my knowledge John has not followed up on this video. He is the only one that and tell us as he asked us to guess. If he did follow up in another video it has been months if he posted it in this comment section please let me know.

Guessing B is the tall one, and A is the deep one!

Sound fantastic I can't tell

I did the same thing many years ago with a guitar speaker cabinet using a single 15" musical instrument speaker. I was looking to fit a space at a local venue. The only thing I noticed was off axis performance was noticeably different. To use an analogy, the shallow cabinet was like a floodlight while the deep cabinet was more like a spot light. This was observed at the other side of a large room.

@superjervis

6 ай бұрын

good info

I noticed a difference in bottom end one had a slight loss to the bottom end which screems the shorter but longer box. Now if you glued small 45 degree angles on the back of the thiner box behind the speaker wouldn't that help from reflections?

Love hearing them Nail Gun barrages, very very informative vid!

Thank you for testing the theory

Well, for me is A shallow and B deep. A has more high-frequencies and distortion it seems to me. B has a more reaxed sound. So you can caculate the distance behind the speaker by formulas from Bailey and Rogers they used in their TLs since the sixties.

@MauriceHo

3 ай бұрын

I can hear the same differences even with my android phone. I agree with your conclusion and I love the deeper box sounds.

@not12listen

3 ай бұрын

My ears mimicked your guess as well.

This is incredibly interesting and had fun just watching you build the box, but got the added bonus of trying to hear the difference between the 2 speaker boxes. If I had to guess, it would be that B is the shorter/deeper box. When I get home, I'll give another listen as my speakers are home are much better than the ones I'm using currently.

B has less harsness in the sibiliance range and the brass sounds better. Which box it is will be interesting to see.

A = Deep/short box B = Shallow My guess

I once built speaker cabinets that were several feet deep in the back. A 5 and a half inch driver needed no sub. More cabinet volume does result in deeper bass. What is more important than what cabinet it is, is that if the cabinet edges, especially the ones near the tweeter, be rounded. You don't see really serious speakers anymore being made without that rounding off of the corners. Many noted speaker designer say how adversely it affects the sound if they're not.

@gzubeck3

Жыл бұрын

Rounded or 45 degree router cut. Both will yield similar results especially as the volume goes up!

Is the voice coil vented on the back of the speaker magnet? If so, allowing only a 1/4" space would also be a factor.

great video , i've wondered about this for a while. why did you put the crossover inside the box ?? would be better out side

Like a few others said, I think “A” is the shorter, deeper box. Looking at the frequency response, it had slightly more output in a lot of the low end range, and I could hear that the kicks sounded more meaty on speaker A. So that’s my guess. Either way, I thought both sounded good and there really wasn’t a significant difference to my ears, on my equipment, on this content.

I built a set of speakers a few years back that have very shallow boxes, and have a passive radiator as well. I've been really enjoying them but now I want to get out the measurement mic and see how even the response really is! I was going to do that after designing and building crossovers but they sounded really flat to my ears and I called that good enough at the time. Really enjoying these simple tests of commonly held beliefs, and very cool to see how much of a difference stuffing made (looks like I have a place for the leftover rockwool from renovations)

@lyntedrockley7295

7 ай бұрын

just put white noise through them one at a time. You'll soon hear the difference.

@missingremote4388

7 ай бұрын

I'm confused; putting stuffing in a closed back speaker won't hurt the sound. but does it help it? Let's say a 20" X 20" single speaker (12) cabinet. This thing is for my bass guitar, or subwoofer

Just a quick question re cabinet design, if i may. After watching a few videos, i notice the drivers are always recessed. I understand this may be for aesthetic reasons, however would the full thickness of the cabinet not be better right where the driver is supported?

What will really blow ur mind is positioning the driver a 3rd into the length of the long box and how it can null out nodes and such.

Generally speaking the deeper speakers are better (to a point). Most important is that the cabinets are dense enough to not vibrate. I have built my share of speakers over the years. The speakers I have right now cost very little to make and the sound stage is incredible. It's fascinating that so many are into horn type speakers now (had some a few decades ago and would not have them now). A good system will sound good no matter what the sound level is. It's interesting how audio (as other things) seems to have gone full circle. Who would have thought that records would make a come back (still have some Sheffield Lab albums in storage).

Infinity reference and kappa were very good and used shallow boxes.

What happens if you put the stuffing directly behind the speaker ? It looks like you put it up in the topside of the box ? Would be cool to see how much of a difference more or less stuff makes

A longer dimension also means that you may have to deal with standing waves and use stuffing regardless.

Does not appear it was revealed in a future video, or we are not yet far enough into the future. My guess was A was the deeper box. Which one was it?

I listened using regular headphone and I didn't hear any difference at all. But I do believe there must be differences!! Good test. Thank you for the opportunity !! Alberto

@Mart77

4 ай бұрын

Box A sounds a tiny bit more open and wider

@Justwantahover

3 ай бұрын

The bass wasn't as sharp on A. The voice sounded a little bit colder on B but sounded better with a bit more detail in the high med in the voice sound. Everything was a little bit more muddled together on A and on B everything sounded more separate (especially the voice sound). I heard it on my made 5" open FR driver plus 6" boxed woofer speakers.

both sound good and to me the same, I couldn't tell the difference at all, in fact your transitions were so good if not looking at the screen I wouldn't know that it happened.

@richarddube3647

6 ай бұрын

Same with me, I think that there was simply no switching at all.

Interesting. Thanks for this. I have a personal interest in this because I have been thinking about subwoofer build in my (too) small home theater. And the reason for shallow box is obvious: there is no room for large boxes. Tried to search something on the topic but pretty soon found out that no one is builind shallow woofer boxes. Thought there would be some reason for it. So this got me thinking, if reflection is the problem, I guess it would be easy enough to put a angled wall behind the speaker element to reflect the waves up.

@sudd3660

Жыл бұрын

hello i am no one, i built a shallow subwoofer box. 6" deep for a 10" shallow mount subwoofer driver. i got great results, below 200hz its fine. i also ran it up to 2000hz a little while, i liked that also but i would not recommend that.

@Renrondog

Жыл бұрын

@JaniLahtinen Shallow subwoofer boxes are fine. Use some absorption on the back wall to help diminish reflections. The wider the baffle the better. As long as you have enough room behind the driver motor's rear vent (hole in the magnet structure) you won't have any problems. Roughly 2"to the absorpbtion material is a decent guess The length of the sound waves from a subwoofer are so long that reflections thru the cone aren't really a problem with smearing the sound. That happens in the upper octaves.

The trouble is thou because the baffle is different, the baffle step has changed, and that will overshadow the reflection u hear, plus by adding extra damping to the back reduce the reflection in a shallow box anyway. I think the shallow box may sound a bit better in this test as the baffle is longer, hence more sound directed towards the mic at front at lower frequencies.

@EricBrettJones

18 күн бұрын

Shakespeare has chimed in?

Did we get which one is A/B ?

The two sound very close to each other in my headphones, but A has a little better sounding bass, and I would guess that it's the deep box.

@peterbaugh51

Жыл бұрын

A is my guess also, deeper box. Cheat: how many good speakers have shallow boxes?

Listening to this on my headphones I thought that A had a slightly fuller bass. I guess that A is the deep box but it is almost impossible to hear a difference.

@Justwantahover

3 ай бұрын

A has fuller bass but B has more detailed bass with a sharper attack.

I have two 8" subs. they're rectangular with the speakers being on the top half of the box. would'nt they be better on the bottom closer to the floor?

Good work man!! To make it a more fair test it would be cool if you could strap a 'fake' baffle extender on thr shorter deep cabinet. The baffle itself will affect the LF range

@tonybuccolo8555

8 ай бұрын

Agree! I was thinking the same thing. The shape ans size of the front baffle can have a very large effect, all other things being equal

@gunterhackstock4480

3 ай бұрын

For sure. Can please you argue in short how the longer or greater size baffle will affect the sound?!

Just a guess but wouldn’t the deep box be what you want in a sub and a shallow but tall for the upper range equipment?

Curious about the inverted config on each?

B seemed to have a clearer top end, odd though considering the measurements weren't altered up that end. Unless, efficiency is maybe slightly increased in whichever box that was, presumably the shallow box as possibly had an effect on the loading maybe...🤔

Equipment lust! I feel it!

B all day long. Don't care which is which. I prefer B (I think B is the deeper box b/c the low bass extension) Side note the highs in this song were very harsh and distracting.

Amy Lynn & the Honey Men. Good choice for test music!

I’m 79, wear in-ear (larger) hearing aids. I closed my eyes listening to your test. I could not hear a transition, and indeed saw A and B items. I would like to hear TV and Movies / Netflix as well as might be possible, and suspect I need not get audiophile quality speakers. I live near Toronto. Can you provide a recommendation? Pretty sure I’m not alone in this quest. Recent Sony receiver plus PSB speakers from about 1990 .

A more wider.. Just a bit tiny diff.. But still A for me... Nice information I got from u.. Thanks for sharing.. Love from malaysia

Wow what a great royalty free song. What is it?

A is the one that measured to have a tad more low end?

i heard for bass reflex subwoofers optimal depth is 60 cm because of the wave length of the bass frequencies. i wonder if that’s true

I built some subs in boxes that were very tall but very shallow to get within the depth of LCR. The ports are so far away from the drivers that it's like spreading subs around the wall to excite different nodes instead of crowding them all in a similar location. I initially wasn't going to bother with stuffing until I calculated that a quarter wave within the low pass tail off range could stand up within the box. Alright fine, have some denim fluff.

Did you ever plot the difference between the two freq responses?

Seas of Norway! Didn’t know they still operate. Pretty close from where I work.

sir which type microphone used to measure the speaker parameters

Iam planning to build a 2 way speaker using ribbon tweeter and a 6 inch mid bass, I would love to get your assistance/advice on how to build a picture frame 🖼️ speaker

I noticed that you have one of the cool "remote arbor tightener" tools...

I like A more, but I'm hoping it's the shallow box. When will you release the results?

@jfs70ss

3 ай бұрын

Nine months later I guess we'll never know. Does this guy respond to questions??? 3/10/24

I think this is a good starting point but it's what you do with the back wave from the back of the speaker that counts. I found that with quality acoustic foam on the side walls combined with real wool yields very good results for deep clean base.

A sounds like it packs a bigger punch. Was that the thin box?

I thought you always had standing waves and I suspect the deeper box just has them at higher frequencies and more grouped together, because the three dimensions are more similar

Trying to determine which speaker sounds better by the sound that was crunched up by YT compression and then reproduced by my somewhat questionable audio setup is not an easy task. To me they sounded almost the same. BTW what would be the perfect speaker box shape? Spherical? I understand why it's not common - manufacturing becomes way more difficult. I heard that some speakers are designed to avoid 90 degree angles (by making side panels trapezoidal instead of rectangular) - supposedly this reduces standing waves. Would be interesting to see a comparison.

@ItVex

9 ай бұрын

Yes in physical theory spherical would be the best shape for the inside of the box.

I am very jealous of your shop too. Love your videos! Would you make some baffles for someone (me)? I would pay for wood and time and wear and tear etc

you are the king .

Interesting. This reminded me of something I came across 40ish years ago. It was stating a certain size speaker needs a certain volume of box and then the dimensions ought to be 0.6 units deep, 1 unit wide, and 1.6 units tall, then acoustic insulation on the back, one side and bottom. Now, this was 40ish years ago and I am relying on a memory that can't recall names and birthdays, so take it at that. I may be totally out to lunch...lol.

@IBuildIt

Жыл бұрын

The golden ratio is supposed to reduce standing waves in the box, but that's something else I'd have to try before I add it to my list of hard and fast rules.

@FOH3663

Жыл бұрын

Dipole is the golden ratio!

@disklamer

7 ай бұрын

I am pretty sure that the idea is/was to limit standing waves to one dimension and thereby reducing resonance peaks etc. by using these recurring fractional ratios or derived dimensions. (0.618...1...1.618 is the mathematical sequence). In this context people also considered the cabinet resonance to correspond to a musical frequency to hopefully potentially enhance harmonics - or not. It seems lot of it had to do with driver response. IIRC by contrast the pythagorean ratios (3...4...5) are susceptible to standing waves and harmonic resonances. The basic idea is to avoid the ratios of scale harmonics, ie avoiding dimensions that correspond to the proportional wavelengths. Some cabinet ratios produce crazy wolf tones or other anomalies for no apparent reason, which adds to the fun.

I am going with B but my hearing is affected by years of playing in bands.

In my car audio days. You could buy a silcone type round piece with lots of 45 degree concentric circles that you stick on the back if the bass box to difract sound away from passing back through the cone imagine a rubber lp with deep ridges. Was this snake oil? Dont know never bought one.

I can't hear much of a difference with my PC's speakers. (2+1) I was trying to detect whether one was muddier that the other but can't sense enough to determine if the sound was better or worse.

Something to consider is that the crossover for the shallow box is mounted right next to the driver, possibly interfering with the air space at that end

When I started in Audio retail some 50 years ago I was selling the Rectilinear III speaker. They then introduced the "Low Boy" version of it. As I understood it, same drivers and cubic cabinet space. Just different cabinet dimensions. While they shared the same general characteristics, they did sounded noticeably different. I preferred the original Tall Boy. But that could have been familiarity.

The only way of isolating this test is to make a large box with same identical outside dimensions and baffle, but have sliding internal panels that change the depth but keep the same volume of chamber inside to see if you can hear the difference, consider looking at stored energy response and try the adding damping to back to see if you can get both deep and shallow to perform the same. Make sure the panels are solid with bracing, as any vibration of the box walls will overshadow the tests. This is actually very very hard to do.

Is that some sort of a full range? If so why the crossover? Is that a mid woofer? What kind of a speaker is that? Talking about the driver.

I don't know which one is which, but "A" has a very, very small (almost indistinguishable) bit tighter bass. But for all intents and purposes they sounded the same to me.

I think A is the deep box and B is the tall shallow box, as most others also think. This lines up with the graphs , with the deep box having more low frequency output and the tall shallow box stronger in the mid range. I think the 2 different boxes together would sound good but most people wouldn't like the look of this.

I be more worried about the dip at 10K and peak at 12K but its a great test!

What about isolation bass rerflex tube?

I have heard a lot of speaker box design best practices and all of them are for a ported or vented design... when looking at sealed, 'same volume' designs the speaker should have the same results. Knowing you don't want to go thin on the material, brace or frame areas that might flex with large low frequencies... but for the most discerning ears it will be the same. Great channel by the way!

I could hear a difference and prefer A. But which box is it?

Didn't hear a single different anywhere 👍✨🙂 BUT GREAT VIDEO

I have a sundown sd3 10 d4, it requires a sealed 1cf enclosure. The enclosure i built is rather shallow (shallow sub). I thought it needed to be shallow but do you think a shallow sub would do ok in a deeper box?

@shopmunkey

Жыл бұрын

Sub bass has such long wavelengths it's not going to be a huge difference. Just like in the video, you'll get more benefit from using rockwool or polyfill stuffing to break up the standing wave inside the box. That said, it won't hurt the driver at all to go with a deeper box if you can fit it, as long as you're not increasing the airspace beyond what the driver is intended to be put in, and all that's going to change is what frequencies of standing waves are created (again, put rockwool or polyfill in the box to reduce the effects of that). I would also ask that you double check your enclosure specs for that driver. It's intended for a sealed box between 0.5 and 0.75 cu.ft. The 12" is happier in 1.0 cu.ft, though going larger box with the 10s will help them play a bit lower, just looser, and sadly with a little more risk of damaging the woofer at high volume, assuming you can power it past what the suspension can control. (I do car audio for a living, 10 years professionally, 12 more unprofessionally, if that at all backs up my information)

@gregkrueger331

Жыл бұрын

@@shopmunkey hey man i really appreciate the answer. Great info too. Yeah i was mistaken, if I recall correctly the box i built was a 1/2 cubic foot. But the frequency feels too high, the only way i can explain it is that the bass sounds hollow if that makes any sense. It’s completely sealed, no air movement whatsoever, i built with 3/4 MDF and i used poly fill initially but removed it because i can’t seem to get good sound from it. My goal isn’t really to have monster bass, i just want a punchier clean sounding bass to take the music to the next level. Going bigger isn’t really an option (changing from a 15” PPI sub) because i need the space in my Tahoe. Again, thanks for the good info bud.

Couldn't really tell. But if I had to pick one, I choose B as the shallow box.

I have found that the optimal rectangular box shape is a half cube with the driver centered on the square face. Why? My goal was to have all the reflections travel the same distance so the lowest box mode frequency would be as high as possible. Damping material is more effective at higher frequencies, so this mode is easily damped by filling the box with rock wool or fiberglass producing a resonance free result. Selecting drivers that need the smallest volume helps push this frequency higher, which is great. With this construction it is possible to low pass filter the woofer at or below the lowest cabinet resonance and have zero audible box sound. The free Hornresp software will model box internal resonances so you can try this concept before building anything. To extend the bass use woofers with sufficient displacement and equalize the system with a Linkwitz transform ( asymmetric second order shelf filter). Nice video, but without more stuffing I fear the listening result is not conclusive. The lowest mode of that long cabinet will likely color the sound even with lots of stuffing. It would be audible with a slow sine sweep or some vocal in that frequency range.

What if you put the driver so it fires down the longer demension of the shallow box?

@BenBuss

4 ай бұрын

Then it would be a very deep box…

It took a very close comparison to find a difference but I prefer A.

I think B is the shallow box

At the beginning B sounded quieter, but it could just be the section of music that was played on it. In the graphs the deep box was slightly lower in the midbass, so maybe that was B. Although 650-750Hz is higher on the shallow box, and that may be where the singer's voice is. They're so close, it would take a lot more listening to know if there was a significant difference and whether one was better. From what I read, the outside of the box can be seen as a waveguide and deeper boxes show better directivity in the midbass. Shallow boxes have a more abrupt transition from 1/2 space to full space.

I like the sound of B. It's tighter and more focused. A is a bit.......just a bit on the boomy side.

Standing wave reverberation can be reduced in a shallow box by using random size foam diffusers on the back panel.

@disklamer

7 ай бұрын

diffusers are the answer to many problems

The size of the walls of the different boxes could introduce different resonane frequencies

I figured that a slower sweep of the audio might allow more "settling" time for standing waves to really get going .. Thx...🇨🇦in🇩🇪

Speaker A has a more open and rich sound which make me guess it is the deep cabinet but I might be wrong hence the “surprising results” John mentioned in the video

You are using full range speaker, what frequencies are to be limited by using the crossover? Guessing the lowest bass.....

I prefered B for upper midrange/vocals and think it's the shallow box.

Did one of them detonate?😁

B sounds like a more controlled sound, whereas A sounds more lively to me. I would pick A for my speaker build.

Couldn't tell a difference on my computer, finally hooked up a decent amp and speakers to it. there's a difference, but I'm not sure which is deep or tall.

I feel that A is the deeper shorter box. The low frequency seemed crisper.

Why did you use plywood for one of the walls on the first box?

@IBuildIt

Жыл бұрын

Ran out of MDF.

What's the name of the song, please?

Used a headset. And believe that B was the shallow box, because of the booming 200-300hz that overshadowed the deeper sound.

Listening on some B&W's, B seemed to have some crunchiness to it that I did not like. Id guess somewhere in the mids.

My guess is A is the shallow one but I'm not really sure.