Baffle Diffraction and Edge Treatment | What Happens

Ever wonder why some speakers have angled or round edges around the baffle? Ever heard the expression baffle diffraction, but not sure what it is? In this video I make several similar baffles with different edges (chamfer, straight, offset, etc.) and measure to see what happens. I describe the results and provide some feedback about what baffle diffraction is and how to control it.
In another video sometime in the future I'll discuss baffle diffraction.

[@alexw890]

I’m glad I revisited this video. I forgot how much I learned from this guy a couple years ago. If you are out there, bro, thanks!

[@ImpulseAudioSpeakers]

I’ll be back one day 😉

[@loudspeakerchefOriginal]

The infinite baffle was correct response of tweeter. The extra meat on the bottom around 200hz on the infinite baffle is the baffle resonating a bit at the frequency.....The fill in at 4khz-5khz by the rounded baffle is due to the tweeter being very near the top and only having 3 surfaces instead of 4. Due to lack of surface, you will notice you get a boost in that same area when placing the tweeter on top because of lack of surface, that is how you got the nice fill in at 4-5khz.....that said, the infinitate baffle will give you the most accurate response of what the tweeter is actually doing.....A+ video.

[@owentroyer]

I didnt know anyone on youtube cared about sharing this type of information. although it may just be that i'm not too good at searching on youtube. I really appreciate your videos they teach me alot

[@sc0or]

It is shared on google also, but you have to skip 10-20 pages of search engine optimized results of web stores. I remember old times when google returned just an information rather than advertisements. Greedy stakeholders slow down our progress :( PS And this is a good channel with graphs, sure.

[@Projacked1]

Just met you, and I'm a fan.....this is what matters, reality.

[@skandahle]

Great stuff! This is gold. Let me also add to your results, that in addition to a flatter frequency response, reducing diffraction also has a positive impact on imaging. Ideally, we would want perfectly reproduced sound emitted from a single source, right? That's how we make our ears really believe in what it's picking up, not being able to tell where the speakers are, etc. With diffraction, however, like you said: the soundwave is re-emitted at the baffle edge. This is, in practice, introducing a second sound source. Your ears and brain will be able to tell that "Hey! This isn't natural!", and in turn, the immersion will be less convincing. Take a look at what Bowers & Wilkins does to their 800-series, for instance. Listening to those things is baffling (pun intended). Even with my eyes open, looking straight at the speakers, my ears are not able to tell where they are. It's all just ... soundstage. Something to strive for.

[@GeorgeTsiros]

DML radiate from their entire surface and yet the stereo image they create is quite good?

[@luminousfractal420]

Single source for a single sound, we want virtual positions for all sounds.

[@fearwolfbrewery5014]

Very good video with great explanations on an advanced topic! Looking forward to the baffle step video!

[@jenniferwhitewolf3784]

I bought a huge 2" radius, 1/2" shank corner rounding bit. Its a monster, but the big curve edge is sure nice. It must be used in a heavy router table, and with small bites over several passes, no hand holding the router. Have also found over the years that adding a radius roll back around sharp edge terminated horn waveguides is useful as well. Bottom line, sharp edges on speakers suck.. they wreck imaging cues. As far back as the '70s there were some great AES papers on mitigating edge diffraction effects with spherical, egg, and rounded edge baffle/cabinet shapes.

[@LifeofBliss]

This was a great video... learned quite a bit. Thanks!!

[@Malakyte-Studio]

Very interesting! I would never have imagined the difference would be so obvious.

[@SuperLeoSG]

Thank you! Very informative, waiting for another tutorial videos

[@davidg0901]

This is great thanks for explaining this so clearly

[@seano51]

Excellent job! Thank you!

[@fabricegrard1001]

Bon boulot très intéressant. Merci .

[@MarcelOoms]

Great information! Thanks

[@JosephCrowesDIYSpeakerBuilding]

Great video! Horns often suffer from edge diffraction as well. That’s why I’m a fan of the jean michel cleach horn profile.

[@CyrilleBoucanogh]

horn edges' diffraction latency is so minimal that it's not a case to put into account compared to the horns dispersion itself.

[@miloradpapic3298]

Thank you for this informations and test

[@nelsongracia]

Great video . Thank You

[@kozkoz7776]

No one explains it better I too was of the other understanding thanks for clearing that up

[@romanyaremko8729]

Great job!

[@enzofiero2924]

Thanks for taking the time to do the tests and making this video. There's great information here for all to use! I'm wondering what your opinion would be on my tweeter mounting setup.

[@Toid]

Great Video! And nice hat. I grew up in Illinois watching the Big Hurt, aka Frank Thomas. By far my favorite team growing up.

[@ImpulseAudioSpeakers]

I didn't realize it was sideways until I was editing the footage :P

[@Toid]

@@ImpulseAudioSpeakers haha, I was wondering why I was taking audio advice from this Canadian thug 😁

[@dublininnis9695]

let me know how it works out man

[@trort2714]

I just discovered your channel. Great stuff! You’re doing what I was doing in the 1980’s as we spent countless hours and thousands of $$ on loudspeaker design. A TEF was not in our budget as it was big deal in 1986, but we had limited access to one from a sound engineer in the Bay Area of SF. Our primary focus was on phase coherency. Effects such as diffraction as described here and driver alignment using as little crossover electronics as possible was the goal. We went through a lot of driver combinations to find the right formula. We eventually developed a sweet sounding loudspeaker that yielded a few, now since expired US patents. But, venture capital dried up and ......... Since then, the market caught up to us and I haven’t done much with design since. Looks you have a great shop with the right tools.

[@ImpulseAudioSpeakers]

Tro Rt hey thanks for watching. The tools available are definitely way better and easier to obtain than they were in the 80s. Must be very cool to think back. I used a CD with prerecorded tones and my ear when I first started. Couldn’t afford an SPL meter to check my ears. I think it sounded good, but probably sucked!

[@scotterickson6332]

Interesting stuff! GR Research is another great speaker building channel on KZbin.

[@martinenstrom8206]

I find good results with a smooth spread of diffraction by placing the tweeter all the way to the top edge of the baffle an keeping that unchamfered. Then only doing a smaller chamfer on the sides of the baffle. Nice work, very edgeucational. :)

[@johnbravo7542]

Very interesting video,found you by accident,watched two of your tweeter videos,and also I have half a sheet of the same veneer you made the bookshelves with,which I was considering making myself,only with Fostex fe126en drivers.

[@noobulon4334]

Afaik if you want to measure multiple drivers in an infinite baffle you can cut out a square in your baffle and nest a small square baffle in your infinite baffle

[@ImpulseAudioSpeakers]

Yes that is a way I have considered doing it, but haven't bothered. I think Zaph did it that way if you've ever looked at his site.

[@gregvanpaassen]

Great video that illustrates diffraction effects really well! Thanks for taking the time to make and measure the different baffles, and to make the video! Just a nitpick about terminology, and a few suggestions. ;-) Infinite baffles really are infinite - there's no way for sound to get from one side to the other. Indoors, mounting the speaker flush in a flat wall or ceiling gives you quite a good infinite baffle. But, driver manufacturers use an "IEC baffle" rather than an infinite baffle. (It's specified in IEC 60268-5, section 11. 268 also specifies test methods and conditions.) The IEC baffle is annoying because it's just a bit wider than a single sheet of ply (of the most common size). The IEC baffle specifies position offsetting, similarly to what you intended to do with your offset baffle, and for the same reason, mitigating diffraction reinforcement. (At its size, more so for mid-woofers than tweeters.) Of course neither the IEC baffle nor your infinite baffle are a realistic size for speaker boxes. For one-shot tests/mock-ups, drywall is cheaper than plywood or MDF and will work fine at low power levels for tweeters - or even for woofers if you brace it. Mount the speaker in a piece of MDF and then flush-mount that in the drywall sheet. :-) For off-axis measurement it's better to move the mic rather than the speaker, otherwise the changing distances between the speaker and nearby surfaces (the bench, the window) will affect the measurement, because of reflected-sound induced resonances in the structure of the tweeter. Moving the "listener" also matches real life better. :-) Room "liveness"/"brightness" is important when evaluating tweeters. If you want to know about the tweeter itself, a "dead" room is useful. If you want to know about the tweeter in your living room, test there. I'm glad the KZbin algorithm suggested your channel to me. Subscribed!

[@ImpulseAudioSpeakers]

Yes you are correct about the IEC baffle. Just being lazy calling it infinite. As for moving the mic rather than the speaker, I have to disagree. You said this will change the relative reflections, but it’s moving the mic that would actually do that. Reflections in a measurement setting are all about distance. If you change the mic then you’re moving the mic a significant distance. Turning the speaker only changes the distance of the drivers less than about 10cm.

[@Rastapapulus]

10:46 That wiggly part on red made by your ALMOST square baffle. if the width and height were very different the space between those waves would be more. Thanks for the video by the way. EDIT: And you don't need a sheet of polywood for every test. you just need one sheet and a changeable square in the middle.

[@nikolympiysky]

Thank you.

[@mackemacchiato3238]

That is why I build my round sphere speakers. And they sound marvelous. Have video of it in my channel

[@BasvanHeelRoseboom]

infinite baffle, just make 3inch a hole in a wall and make a small removable baffle from 3 inch to do infinite baffle testing proper and just use 3 inch plywood/mdf for each test. Great test, learned a lot! Thnx!

[@ImpulseAudioSpeakers]

Bas van Heel Roseboom I’ve considered doing testing that way, but it would take up so much space haven’t a big wall board around. Handling it would be a pain too. Even my small IB was a pain to setup and it was too small. Glad the video helped.

[@johankarlsson6]

I love your channel. Now to my comment. I try to smoothen the edges of the baffle but also the inside edges behind the driver can be soften or chamfered. Atleast with woofers I think inside treatment should be compulsory. Another thing I have done on recent projects is that the baffle is covered with cork or felt to soften diffraction close to tweeters. Maybe baffle treatment or absorption can be covered in some upcoming video. Thank you.

[@djscott9207]

I agree. I hope he does something like this. I bought some F5 felt to place around the circumference of my dome tweeter extending out to about the edge of the baffle. Hope to hear an improvement.

[@Steveleebdutoit]

I have a lot of time for your video's.

[@joeygonzo]

gold!!!

[@robertbenton2804]

How about trying this with thick felt on the front baffle similar to Dunlvay, and see if it corrects it altogether.

[@jeremyphilander8833]

Can you do a compression driver with a 90x60 short and long wave guide. Thanks for the info

[@mikeleahy5283]

Nice vid., have been wondering about the felt you stick on the front of tweeter or the blocks on each side of the dome has a positive effect.

[@ImpulseAudioSpeakers]

mike leahy others have experimented with that concept but I haven’t done much in that way because I think it looks ugly.

[@tarekz9992]

Excellent video. Use foam on the "infinite" baffle. Also, I'd really be interested in a video on Parts Express new RST28A and F. For the price it might be a giant killer

[@ImpulseAudioSpeakers]

Tarek Z that one actually may be on the list very soon. Probably the F version.

[@exif6839]

The best situation is: chamfered baffle and wave guide tweeter like Seas DXT 😁

[@markd4292]

Man, this is my forth video back to back on this stuff. Fantastic info. Thanks. Any advice on how to get started with this hobby? Any books to refer to? Equipment I would need? Well first, I definitely have to practice my woodworking skills! But what I finer way than building my own speakers? Peace

[@ImpulseAudioSpeakers]

I would suggest building someone else’s design and trying to figure it out. Use someone you can engage with. You’ll get a pair of speakers, learn something, and help you decide how you want to progress. I would also join a forum or Facebook group. KZbin is great for one way communication, but hard for asking questions.

[@rndclown]

Do the frames for speaker grills have an effect as well?

[@artvandelay3823]

Thanks for the video, always informative! I’m getting ready to actually do a semi-custom build using some parts from DIYSG. I was planning on also using this as an opportunity to work on my woodworking skills as well. I’ve read that a spherical speaker would be best since there wouldn’t be any edges, but that would be much too difficult for me. So, I was thinking of doing a build that would look almost like a Google Nest Doorbell. This would be using a concentric speaker, so the compression driver and woofer would be together. If I was continuing with the Google Nest Doorbell example, I’m planning on putting the speaker where the camera is located and potentially a port where the button is located. Based on the video, the issue would be that the center of the driver would be equidistant for the top half of it. But I was curious if rounding the edges enough or putting a 45 degree chamfer would negate this?

[@ImpulseAudioSpeakers]

Yes I wouldn’t worry about the equidistant location if there’s a healthy round over. Good luck!

[@guitarchitectural]

I would love to see two other profiles tested - rounded corners and a bowed speaker front! Bonus round: what happens when you stick a grille on the front of it...

[@1ralton1]

Many thanks for your great videos. I really enjoy watching them. Do you think you could do a video explaining your test and measurement equipment? Which particular hardware and software you use and why you prefer it? Perhaps a few tips and tricks you have learned to get good results too...?

[@ImpulseAudioSpeakers]

1ralton1 I’ve been thinking about a REW tutorial or something like that.

[@1ralton1]

Great, I'll look forward to seeing it. I'm presently pondering over purchasing such gear for myself. I really like the Dayton equipment but here in the UK it is almost double the price as it is in the states and I guess Canada too probably due to the import duty. I have noticed you use the Dayton DATS v2 for impedance tests. But what about frequency response tests? I guess you're using a UMM-6 or Omnimic? But then there's the software.?..I was thinking of using ARTA but it looks rather complicated and time consuming to set-up or is it? Are there equally as good alternatives which are simpler to use? Thanks again for the reply.

[@1ralton1]

Ah there you go you see. I hadn't yet discovered the REW software. At first glance it looks already to be more straight forward than ARTA. Thanks

[@benthomas4196]

Thanks. Really educational. What about surface treatment (e.g., felt, etc) around tweeters. I sometimes see this in speakers. Why?

[@ImpulseAudioSpeakers]

Ben Thomas the idea is that the felt will absorb the sound energy on the baffle and reduce diffraction related sound. It works, but now all that well. Wilson Audio does this a lot. And they make it look ok. Don’t expect miracles from it though.

[@satriany31]

Hello, What seems to work well and comes from the BBC speaker ls35/5a is just putting some absorbant around the tweeter, like 4 lines of thick wool stuff

[@ImpulseAudioSpeakers]

Yup that sort of thing can work as well. Felt, cotton, even leather. Tough making those things look good though.

[@ross9263]

Have a infinite baffle with a square cut out to make inserts for different sized drivers. So youll only be wasting a small amount of wood each time. You just insert the driver into the infinite baffle

[@ImpulseAudioSpeakers]

Ya I’ve considered that. Mdf is cheap and keeping an IB around the shop is a pain.

[@rndclown]

I see that the 1099 you designed originally was offered at diysg with rounded edges but now only comes with square edges. Were any adjustments done to compensate for the difference (if that's even possible)? I'd imagine with square edges it wouldn't measure as well due to the added diffraction?

[@mikeables]

Thank you for this video. A question came up as I watched it and looked at the speaker in my living room playing your audio. They have a screen on them. The speaker covers are framed with about a quarter inch of plastic all the way around the box. What does this do to your test results? Would it help to put a strip of foam around the inside of the cover, like the old century JBL tweeters used to have. My concern is your best result can from a shampered edge but my speaker covers are sorta the opposite

[@ImpulseAudioSpeakers]

mike ables yes that is not ideal for sure. Speaker grills generally make the sound quality worse and this is the primary reason. Adding foam will help. Or taking them off when doing serious listening. Or, don’t worry about it because it’s not the end of the world. Any option is acceptable :)

[@iowaudioreviews]

Have you tried covering the baffel with materials that absorb sound? Could this possibly help store bought speakers that people may not want to take a saw or router to the front.

[@ImpulseAudioSpeakers]

IowAudio Review I haven’t personally done this but I know of people who have used thick felt material and seen improvements. Kind of looks ugly though.

[@user-tk1tf8wq1s]

even if you did a small mistake in offseting the tweeter he was steel not in the middle .. we saw no differnce so im wondering does it even do the job?thx

[@vincentkoster6291]

Hey there! I've discovered your channel a while ago and I really like it! It's super informative and detailed. I do have one question though. When I watch a video of either you, or 123toid designing a passive crossover in Xsim for example, you seem to go for a super flat response. But why don't you take baffle step into account when designing a passive crossover? 123toid claims it to be super important in fullrange systems (and I agree) but it looks like it doesn't apply to 2-way systems as I don't see you guys taking it into account in your videos. I can't imagine baffle step not affecting a 2-way speaker because the physics behind baffle step remain the same right? Won't your sensitivity be much lower below, say 500Hz, if you are not taking baffle step into account when designing a crossover? Please enlighten me because it really confuses me.... Thanks again for sharing your knowledge and test results with us

[@ImpulseAudioSpeakers]

Vincent Koster hmm I’m not sure if we are understanding each other. I certainly do add baffle step compensation. Even my desktop speaker build, the Life S5, had nearly full BSC. My preference is for a full BSC design. Possibly just my messing around in video tutorials gave the wrong impression?

[@vincentkoster6291]

@@ImpulseAudioSpeakers I'm sorry, I must have missed it then. Maybe I should just watch more of your videos. Especially those desktop speakers. I really liked those speakers but I've got to be honest with you, I did not watch all of them yet so maybe I commented too early ;) Thanks again for sharing your videos with us and replying to my question! Best of wishes

[@jimconard5889]

Thanks for the Great videos! Is there a specific angle you cut the baffle?

[@ImpulseAudioSpeakers]

Jim Conard I just did 45 degrees for this test but other angles, or multiple angles can be used.

[@teleharmonic]

Thanks for the video! I'm curious, if I wanted to construct a baffle with a curved front could I still use baffle dimensions from plans that were intended for a square edge baffle? Or, at a certain point does shaping the front (as opposed to just rounding the edges) require an entirely new design approach? I suppose another way of phrasing this would be, at what point does edge treatment become baffle re-design?

[@ImpulseAudioSpeakers]

Gregory Fowler good question. There is a point that would change things enough to warrant a redesign, but I think it would have to be pretty significant. I don’t know how far is too far.

[@Schnippen_Schnappen1]

lol i"ve been battling with tweeter EAR RAPE in my beater car system. i've tried different tweeters and now have focal inverted dome tweeters and isn't as bad anymore. But now i realized it's diffraction. Thanks for these great videos!

[@gravitystorm61158]

I’m dying to build speakers. I built woodworking table, included table and miter saw, dremel router base, and want to try my hand at a speaker set.

[@ImpulseAudioSpeakers]

Go for it. Very rewarding. Just pick a kit that is well designed with measurements and someone who knows what they’re doing.

[@gino3286]

hi thanks a lot for the very valuable video have you ever tried felt pieces around the drivers? felts would prevent sound from reaching the speakers edges Some main manufacturers have used them i guess with success

[@ImpulseAudioSpeakers]

I haven’t done much with felt personally, but have seen it done and it does work. Not sure how to make it attractive, but if you have a way, I would do it.

[@gino3286]

@@ImpulseAudioSpeakers hi thank you for very kind and valuable advice Its quite challenging to make felts attractive But I think it's a different approach That is to limit the side emissions of drivers where they start At the driver end It has been used already in the past like in AR9 and 93 speakers In this way no signal will reach the cabinets edges Moreover in many home situations acoustical treating of ceilings and side walls can be problematic If we limit the speaker h and v dispersion boundary reflections could be less impacting Of course the sweet spot will be also much smaller Thanks again and kind regards gino

[@luminousfractal420]

Im so glad the bose im updating atm have floating tweeters on metal brackets Dont need another layer of headaches 😂

[@decentblue1]

How about mid-range or bass units, are those affected by the diffraction? And what if we use a baffle muffs like the westlake audio suggests , the sound wave travel along the baffle plane but absorbed on the edge between the speak baffle and the baffle muffs around the speak. Thanks!

[@ImpulseAudioSpeakers]

Wei-tsung Chang yes they are, but to a lesser extent. Tweeters really show it the best. The shorter the wavelength and the more omnidirectional the driver, the more baffle diffraction is a problem. You can use felt and different absorbers to reduce diffraction. I personally find them to be more work than necessary and tend towards edge rounding and things like that. Nothing wrong with trying to absorb them though.

[@user-tk1tf8wq1s]

thx for the tests and making this video ...as i see it the only way around this issue is to use kerf bending on the sides of the front baffle. seems to me this will solve the problem .and then placing the tweeiter not in the middle of the baffle .the only thing is...the baffle even with glue and filling metirial will still be not so rigid.whats your opinion on the subject? thx man.

[@ImpulseAudioSpeakers]

Doing a curved edge is an extremely good way to deal with diffraction, but adds lots of construction complexity. Maybe worth it if you like the look and enjoy building speakers.

[@user-tk1tf8wq1s]

@@ImpulseAudioSpeakers thx man ....as i see it if done correctly .i.e placing the table saw blade at just the right hight is the only issue .which looks not so complex .i realy wonder if speakers on the market use the same method when i see the speakers do rounded and nice/? the roundover bit cant give so much of a curve . thx for all your help.you r the best🙂

[@johnsorrentino6630]

Great video, as you always incorporate measurements. I will be doing a chamfered baffle on my next build. Then a build after that I am pushing myself to use a sphere enclosure to continue the thought of no diffraction. I don’t imagine you would be doing a video and measuring the results from a sphere enclosure would you? 😜

[@ImpulseAudioSpeakers]

John Sorrentino sphere no, but there are papers out there showing the results. Google sphere speaker diffraction or some such thing and you should get some good into. It can work really well but make sure it’s a decent size and don’t allow the edge of the tweeter to diffract. Make the transition from faceplate to enclosure very smooth and round.

[@pliedtka]

John, another John Otvos (Scandinavian) build Waveform speakers in collaboration with Clouds Fourtier years ago - they used NRX chamber. The tweeter and mid was placed in egg shape enclosure on top of woofers enclosure - Peter Aczel did review in Audio Critic. Also not long ago someone did egg on top high piramid - the pics appeared in Audio Express

[@pliedtka]

Sorry, damn clouds www.torontoaes.org/claude-fortier/

[@stevenswall]

This dude in a blue polo looks like the quintessential dad... And he does woodworking! I am curious what a genelec style cabinet would do diffraction wise. Rounded should work even better than with the angular chamfer.

[@raymondcooke5506]

Excellent, informative video! One question/comment: what's your thought on chamfers or roundovers when using waveguides? I think there's a distinction to draw, because a waveguide throws less energy onto the baffle. But there seem to be opposing viewpoints: Earl Geddes seems to want a speaker cabinet with a narrow throw waveguide to look like a bar of soap that's been left under a faucet for a few hours. Wayne Parham has written that he can't hear a difference, but I've never seen measurements. JBL uses small chamfers on the M2. Infinity had a speaker with a prominent ledge over its tweeter waveguide! Thoughts?

[@ImpulseAudioSpeakers]

Raymond Cooke in my experience, the waveguide helps but does not eliminate diffraction. I’m not as obsessed with it as Geddes, but do try and minimize it. It’s obvious here how much a 1.5” chamfer helped and that’s all I feel is needed. I should add that I have not used many horns that are exceptionally directional. Usually the 90degree or wider variety.

[@raymondcooke5506]

I absolutely agree that it's obvious HERE (a small tweeter flush on a baffle) that the chamfer makes a huge improvement. Based on your data, not chamfering the baffle when using a flush tweeter is negligent design. However, a flush driver that small will throw a lot more energy onto the baffle than most waveguide tweeters will. I've seen another of your videos with a 10" SEOS waveguide. I could not find a sonogram for that one, but a tweeter in a 12" SEOS waveguide will be about 10dB lower at 2kHz at 90 degrees referenced to axial, and by 4kHz probably 15-20dB lower than a flush 1" tweeter at 90 degrees. Logically, that means diffraction should affect frequency response less. Whether that "less" is enough to negate the obvious reduction in diffraction due to a chamfer is, I think, still unresolved. If you are so inclined and build up enough scrap wood to do a round 2 with a 90 degree waveguide, or have a waveguide that lets you reuse these baffles, I think testing a waveguide with different baffle edge treatments would be just as interesting and informative as this video was.

[@ARDigitalMastering]

Very interesting. One question: Does the depth of the chamfered part of the baffle matter? What if you only made a 45 degrees angle on a piece of 0.71 inch of wood instead of gluing 2 of those together?

[@ImpulseAudioSpeakers]

The bigger the chamfer or round over, the more effective it is at reducing diffraction.

[@richardpuller2468]

can you not use a double thick baffle with the first baffle having the speaker offset or flush mounted with a cosmetic baffle on top with the chamfer?

[@ImpulseAudioSpeakers]

Richard Puller the problems shown in this video will still be an issue. If you’re comfortable tackling the issues, then no problem.

[@walterg4025]

Excellent video! Can you recommend a reference text on this subject for further study?

[@ImpulseAudioSpeakers]

About diffraction or speaker building in general? Sound Reproduction is good.

[@jordanwartortle2849]

So what's the best chamfer? 45°? Or something that rolls off more gradually? Is a rounded edge better again? Awesome video!

[@ImpulseAudioSpeakers]

Jordan Wartortle I haven’t tested them all back to back so couldn’t really say. Bigger is better. I’ve even made huge chamfers on the table saw. Generally a big round over is probably the best option.

[@Quetzalcoatl0]

How does this affect tweeters that have it's own "horn" even if it's a really small one like the Hi-Vi TN25 ?

[@ImpulseAudioSpeakers]

Quetzalcoalt if the horn is directional it will keep more of the sound directional and off the baffle edges, but not all.

[@MrFrobbo]

Out of interest, what are you using to measure the drivers with, software/hardwate combo? Would be really interested in some type of review of these components. Great video and so many thanks.

[@ImpulseAudioSpeakers]

MrFrobbo I have a shop tour video that would be helpful. About half way through I discuss the tools I use.

[@MrFrobbo]

@@ImpulseAudioSpeakers awesome, thanks, will go search.

[@bnaudio7813]

new subscriber. do you have a video showing all your test equipment and software that you use? i have a upcoming project and i do not have ts parameters of the speakers i am using. so i need some direction on how to get the ts parameters.

[@ImpulseAudioSpeakers]

BN Audio thanks for joining. If you have the manufacturers TS parameters these are generally pretty reliable. In any case, the only video I have like that is my shop tour video. Has a lot of info about tools but also some about measurement equipment.

[@jimspc07]

Can diffraction be reduced by A. sticking a sponge material around the speaker on the baffle at say 2" away, using the self stick door draft excluder type that about 1/4" square. B. Routing a dado channel in the baffle around the speaker at say 2" away and gluing in a strip of sound deadener. C. Using a dado channel as at B instead of sound absorbing material, put in a circle of hard wood or plastic that is rounded over with a slight protrusion and polished or natural, like a speed hump for soundwaves. But the height above the baffle may need tuning depending on frequency, irrespective of height it might be worth a try.

[@ImpulseAudioSpeakers]

A. Would likely work. Maybe B. but I don’t think C. would work, unless I’m not understanding correctly.

[@thepirateswirled]

How it would have been with a kind of combo of two drivers without baffle, which would have interested me the most, like as you would not only put the tweeter at the top of the mid/bass driver + enclosure but also put the mid/bass driver in a like cylindrically shaped housing, so both of the driver (tweeter + mid/bass driver) would work in a kind of "without baffle system", and actually the edges of the lower enclosure wouldn't be bothering for the tweeters anymore, because they don't exist this way anymore, what do you think about that idea?

[@ImpulseAudioSpeakers]

It pushes the diffraction point higher in frequency, but makes it far far worse. The baffle becomes the edge of the driver which is not rounded and it is equal distance at all points from the center of the driver. Generally not a good idea.

[@rydn2lo]

Hi is it useful to use ferrofluid on a high output subwoofer?

[@ImpulseAudioSpeakers]

Doug G I don’t think it would be a practical application on a subwoofer. Air venting is the most practical way of controlling heat because the cone can move a lot of it on the backside.

[@sweiss042]

Hi Luckily I just found your KZbin Channel. I have just started to look into Open Baffle speakers and am very interested. In particular the use of a 15" full range Open Baffle Speaker set up. An recommendations for a 15" Full Range speaker i.e. Lii Audio Fast 15 (awesome speaker) and the dimensions for a Open Baffle or how to calculate the size/shape of one. There are at least two companies that are making Open Baffle speakers using this Driver, their baffle is not round but looks oval with the ends sawn flat off. Any recomendations for how to calculate the size/shape that would work well? Thanks for putting all of this great information out here online so us noobs can learn - THANK YOU!

[@ImpulseAudioSpeakers]

Stephen Weiss I don’t know if you can still get it, but there was software called EDGE that was free and could be used to calculate baffle dimensions, even for OB application. I don’t tend to do much OB work so I’m not the best resource. There are two schools of thought, big baffle with big drivers to extend the bass as low as possible and not worry about the side effects of diffraction. The other is narrow with many drivers. Like a 4 way with 10”, 6”, 3”, ribbon. All crossed low with dsp crossovers. This is much more complex but gives you all the benefits of OB including a dipole radiation pattern. For a beginner I would stick to the first option to play and learn. Something 20” wide with a pro audio 15” and a 4” full range driver would be nice. Or just a full range 15” with a wizzer cone. But expect a different sound signature than you are use too. It won’t be clinical and clean. It will emphasize the mids and be light. At that size the shape of the baffle isn’t that important and probably more about aesthetics than anything. The bigger the more bass that will be transmitted forward. But this has diminishing returns unless you like a 4ft wide baffle. Thanks for watching. I hope to do something OB in the future.

[@sweiss042]

@@ImpulseAudioSpeakers Thank you for the advice/tips! Much appreciated - happy holidays, all the best! Regards

[@davefred3]

Any idea how to reduce the 3K "bundling" I always run into? See 11:50'ish mark with chamfered baffle. Andrew Jones answer was very large baffle or cross with a mid 3K+ (I have not tried either).

[@ImpulseAudioSpeakers]

Yes a different sized baffle like Andrew said could help. A very large round over can also help. The best approach in my opinion is to use a waveguide.

[@user-tk1tf8wq1s]

hi does ithave to do more with the tweeter.....cut in 2000hz ? or the midrange as well?i have a 3way speaker bc i can offset the tweeter but the mid??? its a problem thx man

[@ImpulseAudioSpeakers]

More a problem with tweeters, but mids can be a problem depending on their radiation pattern.

[@steveleucel1056]

Hi, what a fine job you're doing! An excellent and very informative video! But I may ask this question - What’s your opinion, does it make sense to combine speaker offset and chamfer when designing a baffle? Or would it mean generating some new problems in the end? Greetings from the old world ! Regards Steve

[@ImpulseAudioSpeakers]

I think that is totally fine. Thanks for watching.

[@steveleucel1056]

@@ImpulseAudioSpeakers Thx - you're fast as a lightning! Sorry, I'm just standing on the wire. You've said:" I think that is totally fine". So if I get you right it sounds to me, that it really makes sense to combine speaker offset perhaps in a 2 to 3 ratio and chamfer?! Geetings from germany and a nice weekend! Regards Steve

[@ImpulseAudioSpeakers]

@@steveleucel1056 yes that can be a very effective way to reduce diffraction. I would say the driver offset depends on what aesthetic you like. And don’t forget that as you move off axis the offset actually doesn’t help.

[@steveleucel1056]

@@ImpulseAudioSpeakers Thx - really great explanation of edge treatment as to be seen in "Elements of Acoustical Engineering (First Published May 1957 and Reprinted August 1960) by HARRY F. OLSON, PH.D." on page 22 - 23 like the "TRUNCATED PYRAMID ON PARALLELOPIPED" which was very close in less difraction to the ideal "the Sphere"! so i guess that is genius that everyone can see that it works in real! Nice job! Regards Steve

[@garyl5128]

Late to the party, but what are your thoughts on foam? I found that it helps a lot with detraction and measures a lot better just adding some 1/2 inch foam to the face of the speaker around the tweeter - some manufacturers have been doing that for years and even MK do it. Have you compared it to rounding over which seems a much nicer way of doing it.

[@ImpulseAudioSpeakers]

I haven’t played with foam but it does work. Just difficult to make it look good for DIY. It works well though. Round over and chamfer are about the same. No performance difference. If you like the round over you can do that. Has to be large though.

[@pliedtka]

Hi, very important issue the Diffraction. How closely your measurements follow simulations done by diffraction calculators, let say in SE, Vituix ? My biggest PITA are big wobbles around x-overs and 2-6kHz where hearing is very sensitive and small differences make big changes in sound. The chamfered baffle seems to cure that pesky dip - sexy flat, should sound good. What angles did you use. Also the tweeter is quite high on the baffle and might cut the diffraction effects more than one with the regular 104mm face plate. Of course BSC video is welcomed. I think, next time, I will devide the baffle, with tweeter having its own chamber, so I can try different locations for the tweeter, and to check real vs simulations freq resp.

[@ImpulseAudioSpeakers]

pliedtka in my experience the diffraction simulators are very accurate actually. My preference is a program called Edge. There’s a few though. I used a 45 degree chamfer 1.5” deep. The tweeter location is important, but it’s also important to keep the tweeter close to the woofer. So keep that in mind.

[@benjoe999]

People forget that a baffle is also reflecting sound back that is reflecting from walls and objects in the room

[@owentroyer]

Hey i have a question, would putting foam on edges help catch the sound wave before it could diffract? It would be obtrusive but for the people with speaker covers it could be an option.

[@ImpulseAudioSpeakers]

Owen Troyer yes this can work although I haven’t experimented with it much. From what I know, a dense layer of felt is pretty effective. Good thought 😉

[@owentroyer]

Impulse Audio Felt seems like a much better material, it also looks alot better than foam. Appreciate the response!

[@linandy1]

What about wool felt? Does that diffuse edge diffraction?

[@ImpulseAudioSpeakers]

Yes it can. But I haven’t tested how good it is.

[@leif8436]

Why exactly don't you use a capacitor while measuring the tweeter? I always thought that the low frequencies can damage the driver. Or do you simply set the starting frequency of the sweep higher?

[@ImpulseAudioSpeakers]

2.8V won’t hurt most tweeters. Unless it’s a ribbon that drops to 0 ohms towards low frequencies. It’s the same excursion at 20hz as it is at 400hz.

[@leif8436]

@@ImpulseAudioSpeakers huh that's very good to know thank you for the quick answer. In general I wanted to give you a huge thank you for all the great videos you put out. They are the best source of information on KZbin! Hope everything goes well for you at the moment. Take care!

[@JTranDung]

hey u guy. please help me how to get that application. i need test my speaker pls pls pls...

[@ImpulseAudioSpeakers]

Sorry, not sure what you mean. The software?

[@jimmyramirez8844]

What’s the best router bit to get that nice smooth edge on speaker boxes

[@ImpulseAudioSpeakers]

jimmy ramirez I think what you’re looking for is a Flush Trim bit. Get one with the bearing at the bottom. Over size the baffle slightly so you have an 1/8” all way around. Then run the flush trim bit counter clockwise around the baffle and that 1/8” will get routed off perfectly flush with the speaker box.

[@jimmyramirez8844]

Impulse Audio thank you for the help

[@abhinilbose24]

Thank you for the information that you shared. How to get the distance which you mentioned that should kept from the centre of tweeter and sides of the baffle ? Is it speed of sound divided by crossover frequency or 20kHz ? Thanks in advance.

[@ImpulseAudioSpeakers]

Abhinil Bose you just want to top and sides to be unequal 1/3s. Google the golden ratio. That’s what you want. So say 3cm 7cm and 10cm roughly would be one example off the top of my head.

[@abhinilbose24]

@@ImpulseAudioSpeakers Thank you, one question though. If my design have a front rectangular port then should I include it in the above length calculation or exclude it ?

[@ImpulseAudioSpeakers]

Abhinil Bose is the port next to the tweeter? If it is then possibly. It could add diffraction to the tweeter. I would be tempted to put it below the woofer.

[@abhinilbose24]

@@ImpulseAudioSpeakers I am trying an mtm configuration, with the port below the woofer. It is a rectangular port. Planning to chamfer the age along with placing drivers non symmetrically following the 1/3 rule.

[@ImpulseAudioSpeakers]

Abhinil Bose sounds like you’ll be fine.

[@quant2011]

Will covering the baffles with felt help with diffraction?

[@ImpulseAudioSpeakers]

Yes it can, but I’ve never seen it look all that good. Some leather wrapped baffles look ok, but I’m not sure leather works. That would have to be tested.

[@reubengeorgemathai7329]

Which software is this? For the frequency response?

[@ImpulseAudioSpeakers]

Reuben George Mathai SoundEasy. I don’t recommend it. I prefer HolmImpulse.

[@crackyflipside]

VituixCAD has a pretty good diffraction/baffle step calculator, not sure how close it is to measured data tho

[@ImpulseAudioSpeakers]

Chris most of the diffraction simulators I’ve used are quite accurate actually. I haven’t used that one though.

[@crackyflipside]

@@ImpulseAudioSpeakers it's good, a ton of functions available but no good tutorials, the user manual is kind of vague.

[@ImpulseAudioSpeakers]

Chris most of them are up to the user to learn.

[@itamarkas]

How important is to make round over baffle than a chamfer (45 deg.) baffle? I'm in the middle of a project and wondering if the extra effort to go to a friend shop worth it. I think in a design perspective the round over looks nicer.

[@ImpulseAudioSpeakers]

itoosh in terms of sound quality either is fine. They both deal with diffraction equally well. The bigger the better and a big round over can be tough. The bits are expensive. A big chamfer is easy on a table saw. In terms of aesthetics that is entirely up to you. So pick the one you like and go for it.

[@itamarkas]

Thanks men! Keep Rocking!

[@johantaljaard6722]

What degree is the chamfer or does it not make a difference?

[@ImpulseAudioSpeakers]

45 is probably best, but I haven’t measured various angles.

[@jamesswiggins]

Hi, was wondering, when you measure a tweeter, do you put a capacitor in series with it to keep from blowing it up? If so, how do you account for the phase shift in the measurements?

[@ImpulseAudioSpeakers]

James Wiggins no I don’t unless it’s a ribbon or something else I’m worried about. I actually decided to take it out of the video but I was taking these sweeps at a pretty loud level and had close up footage of the tweeter excursion. Was pretty incredible and the tweeter was fine. It’s a beast. Most dimes can handle 2.8V at all frequencies.

[@jamesswiggins]

Cool, thanks! Just curious now, if you put a capacitor in series with a ribbon, do you try to account for the phase shift or does it not really matter?

[@ImpulseAudioSpeakers]

James Wiggins it does matter. I usually try and use a large enough cap that the phase shift is mostly in the stop band, but it never is completely gone. So I will simulate a crossover then test and repeat more than with a dome tweeter that I feel confident the simulation is right.

[@js1545]

why not make a third comparaison with the same flat surface + 45° edge ?

[@BostonMike68]

If you have a 6.5 woofer how wide would you make your baffle. The reason I ask is I have a 1" thick by 7" wide piece of walnut I want to use for a baffle and I am trying to figure out what size woofers I should use

[@ImpulseAudioSpeakers]

The 7” width won’t accommodate a 6.5” woofer very well. Perhaps if you extend the side panels to sandwich the baffle. That would get you about 8.5” baffle. That’s reasonable for a 6.5” woofer. Is the walnut all trimmed and straight or will it end up even narrower?

[@BostonMike68]

@@ImpulseAudioSpeakers that's with a round over yeah but still it's not enough I didn't think it would be. I think 5.5 would be better. Have you ever tried silver flutes? That was a response btw 😂. Thanks

[@BostonMike68]

@@ImpulseAudioSpeakers I can extend the side panel like you said I haven't rounded it yet or anything but I just trying to keep the look of the walnut baffle.

[@ImpulseAudioSpeakers]

@@BostonMike68 I have used the 6.5” and 8” silver flutes. Can’t recall if I’ve used the 5.25”. They were easy to work with and sounded ok.

[@BostonMike68]

@@ImpulseAudioSpeakers thanks I appreciate it. That's why I was looking at the SB. I know you said good things about them and they will work with the baffle. I appreciate you getting back to me . I learned so much in the past 2 months just from your videos.

[@davefred3]

Have you discovered any ratio between X and Y positioning of tweeter on baffle? We know 1:1 is bad, say 6" from top and 6" from either side, but if it is 2" down, how wide should the baffle be? How wide is your test baffle in the video?

[@ImpulseAudioSpeakers]

davefred3 yes you should google Golden Ratio. That is the best choice of distances. So for a 2” the ratio is roughly 1.6 so that’s 3.2” on either side of the tweeter, so a 6.4” wide baffle. But that could also be a 12.8” baffle and other common ratios. The baffle in the test was 8” I believe.

[@davefred3]

@@ImpulseAudioSpeakers At the risk of becoming pedantic, Let's say you had a baffle that was 8" wide, divided by 2 and 1.6, you would have the tweeter 2.5" down. How would having a 1" roundover on the top and sides work into that? Same math? Or would you consider the baffle to be 6" wide, divided by 2 and 1.6, you would have the tweeter 1-7/8" down from the end of the top roundover?

[@ImpulseAudioSpeakers]

@@davefred3 I would still view it as an 8” wide baffle. The reason you’re not sure is because the round over does change things. This is sorta why the round over reduces diffraction; the sound waves are hitting the edge at varying distances.

[@lepostral]

Could you please try midrange or fullrange drivers?

[@ImpulseAudioSpeakers]

lepostral they have a similar result if they’re small (3” or so), but I haven’t done any videos about it exactly. I do have a couple of driver test videos like the Morel mdm55 that show diffraction as an issue. The bigger the driver the less this matters. Little tweeters are affected the most.

[@adamloos1388]

What would be the result of an inset baffle (ie a 1/4” overhang all around it)? I am looking to build a sound bar, and found a design idea that looks good with a hardwood baffle and painted MDF that it’s slightly inset into. Would this just make the diffraction that much worse or somewhat cancel it?

[@ImpulseAudioSpeakers]

Adam Loos it would not be as bad as what I’ve shown here, but the diffraction will be quite bad. If the speakers will be for high quality listening, don’t do it. If it’s for asthetics then go ahead. It’s not so bad it’ll make them unlistenable, which I feel that’s what I’ve shown in this video.

[@adamloos1388]

@@ImpulseAudioSpeakers It will be for an anniversary present to my parents, and seeing as they are currently using no name mini speakers for left, right, and center speakers, I think a decent driver in a bucket might sound better haha. Thanks for the quick reply!

[@ImpulseAudioSpeakers]

Adam Loos ya just go for it then. If you like the looks, sometimes that’s more important than the last 0.1% of performance. Just don’t mount the tweeter in the rear of the baffle like this video!

[@ThPappas]

Why don’t you glue some sound absorbing material on the baffle,so as to absorb those unwanted sounds?

[@ImpulseAudioSpeakers]

Cause it’s ugly.

[@sicksigma74]

I'm sooooo glad I stumbled across this video (and clicked Subscribe). Here's a question - maybe you've already thought about - I'm in process of making some open baffle speakers for my living room, and was thinking of using approx 18" live edge walnut (1/4" thick). Based on what you've shown in this video, I'm guessing that the rough edge of the bark would really push the waves out in many different directions and be ok....thoughts? Thanks, keep up the great work!

[@ImpulseAudioSpeakers]

sicksigma74 the rough edge would probably just fine. The sharp edge of a box is less ideal. I don’t think you’ll have any issue.

[@CyrilleBoucanogh]

sharp edges also spread the sound energy in all the directions. The latency of this effect is the clue. The roughness of the bark is still not enough for diffusion of the mid frequencies. Round edges are a much better option.

[@kevenharvey9711]

What about putting the tweeter on the other side of the chamfered baffle, so instead of a smoother transition, you get a sharp edge. Don't know if it would apply to sound, but in car aerodynamics, it is often used to decrease drag. Instead of having a hard time following a 90° edge, the air just detaches sharply and creates less turbulence.

[@ImpulseAudioSpeakers]

Keven Harvey I also did a video about that, and it’s not a good idea.

[@kevenharvey9711]

@@ImpulseAudioSpeakers If you mean the video about flushmount vs inlay, that's not what I meant. I mean rotate the baffle 180° so that the back become the front and vice versa, and then flushmount the tweeter to that.

[@ImpulseAudioSpeakers]

Keven Harvey oh, ok I’m not sure if I have you 100%. But you basically mean turn the baffle backwards? That would not work well either as all the sound would be projected towards the rear (the back wall, back of the room, etc.). Is that what you’re referring to or am I just that dense today :)

[@kevenharvey9711]

@@ImpulseAudioSpeakers Almost, turn the baffle backwards as you say, but then reflushmount the tweeter facing the front, so instead of a chamfered edge, you have a very sharp one.

[@ImpulseAudioSpeakers]

Keven Harvey oh, that shouldn’t be really any different than a normal square edge baffle. I’ve never tried it but once it hits that edge the sound diffracts. The best is so have as smooth of a tradition from the front of the back to the sides of the speaker. That will minimize diffraction.

[@MajorTendonitis]

Just recently learned about diffraction . I have always wanted to build a pair of dream speakers for music . I wanted to try and clone Focals Utopia series , but I’m not understanding how there not getting diffraction issues, as they have large sharp horizontal edges on there separate enclosures ,including the tweeter ? You’d think for a quarter million dollars , they would know this lol . Obviously they’ve done tons of research and testing . I want my drivers aligned to my ear , so I’d be more inclined to build my front baffle more like there Kanta series now , as there’s no sharp edges to contend with . What do I need for test equipment. A laptop , mic , and software ? Can all drivers be tested at once after the crossover is installed . I’m thinking if a front baffle was built with all the drivers installed , it could be tested before building the entire enclosure ? Not sure if a temporary open baffle would effect the test outcome though , especially with larger drivers

[@ImpulseAudioSpeakers]

MajorTendonitis focal knows about this for sure. But sometimes aesthetics rule the engineering department. I’ve done it to myself even. My Life S5 speakers used a sharp baffle edge even though I knew a round over is better. You can measure one all the drivers are installed, and should. But open baffle changes everything. It won’t be the same. You’ll need a mic, amp, laptop, wire, and software. Most people use REW. It’s free and very good.

[@MajorTendonitis]

That software is interesting, and I’m wondering how the room effects the outcome of the response as you test ? Or is being one meter away with the mic the standard , and the surroundings don’t matter ? I mean , I’ve seen you do a test outside. Btw, I have no interest in open baffle speakers .

[@ImpulseAudioSpeakers]

MajorTendonitis the software uses a time length to test within. So it measures the sound from the time the sound reaches the mic to the time to sound from the reflections reach the mic. The further my setup is from any reflections the more accurate low frequencies are. This is why I sometimes measure outside. In my shop my measurements are only good down to about 150 or 200hz. Outside they’re good down to 80hz easily. This is a bigger difference than it seems.