Cabinet Resonance | HOW TO TREAT IT!

In this weeks Tech Talk, Mr. Danny walks us through the ins and outs of Cabinet Resonance and how to deal with it! While this episode is not a sales pitch, you can check out the No Rez that's mentioned in this video here: gr-research.com/norez24x27shee...
How do you treat resonance and what works for you?
Post comments below or check out: gr-research.com
www.audiocircle.com/index.php...

[@chuckwilliams999]

Thanks Danny for the good information as always. I have a pair of the CST-1's that you have installed the no-rez in and I don't have any resonance from these.

[@bentleygt3716]

as i'm new to this great hobby. this video provided a lot of information for me. THANK YOU.

[@svtcontour]

I also agree about the open baffle analysis. Once you get used to that, you cant easily hear a boxed speaker without hearing the box.

[@MichaelLivingston-me]

My previous solution to this problem was to use Dynamat, or Noico. Both products seem to eliminate cabinet vibrations.

[@ianjohnhorwood2605]

You don't want the aluminium foil stuff it's reflective of sound from the drive units.

[@j.t.cooper2963]

@@ianjohnhorwood2605 Not if it's covered with foam on top of it.

[@MFKitten]

​@@ianjohnhorwood2605 So is the cabinet it goes on.

[@anpier926]

Thank You. As clear as you always do

[@JesusISdaonlyway]

I Realizing once again I have never heard an open baffle speaker! I want to get that done at some point. The ones in this video just even looks amazing. Great insight here!

[@davidjudd951]

This article really resonated with me.

[@StephenBusch000]

GReat explanations..and suggestions to treat, ..thank you

[@chrisboylan4599]

I am taking long pieces of triangular cut HD MDF to reduce corner reflections, applied with contractors cement, then coating the entire inside of cabinet and braces with a liberal coat of liquid fiberglass. An engineer said that the cabinet strength will now equal over 5in of MDF! All this before my dampening procedures and sending 1 in for a custom high end crossover prescription.

[@lumntoob999]

Love this series, thanks for doing it. I haven't tried the No Rez but for the type of product and the size of the sheet you showed it seems like a very good price.

[@sirwavell]

Bubble wrap produces amazing results for damping inside speakers, use the small bubble type and multi fold it tight until it is about 1 inch thick then place it around the inner sidewalls of your speaker cabinets (bubble side outermost) A very cheap and effective upgrade.

[@ryeshyes2552]

and yoga mat....excellent....and around $3/piece

[@tomlademann2521]

ryes hyes for real?

[@rogerwalter2500]

I was planning the same, but bubble wrap looses it's air after few months

[@d.s.w7779]

Wont yoga mtt color sound?

[@j.t.cooper2963]

@@d.s.w7779 Only if you use pink or purple. 😅

[@NickP333]

Thanks, Danny for another interesting and informative video. Much appreciated!

[@nmnate]

Sounds like an acoustical impedance mismatch and damping can be used to attenuate the mechanical forces. Makes complete sense - you can do this to prevent mechanical structures from ringing. Have you tried to quantify how well any of these options work with something like an accelerometer on the cabinet?

[@stevelueb7787]

Stumbled upon you doing the Klipsch 600m upgrade. You are Extremely Knowledgeable. What is your feeling about mounting speaker on spikes (cone). I also place 2 bags of lead shot (50#'s) on the top of the speaker cabinet to absorb & deaden cabinet vibration

[@jediknightdiscomike22]

Hey Danny - I just discovered your channel and subscribed. I really enjoy watching your videos that you upload. I've made crossover upgrades for 10 years now - mainly caps and resistors. I use Mills Resistors. I dont just use Sonic Caps, but I also use Mundorfs and Jupiter caps. I keep the same values of the caps and resistors I replace. The only thing I really do not upgrade in my crossovers are inductors. You mention about upgrading inductors. Does this make an improvement ? And what wire size should I upgrade to when it comes to the woofer section of the inductors ?

[@jimgardiner1558]

As DYIer the last pair of transmission line speakers I designed and built used 3/4 msd laminated with 3/4” hard maple (1 1/2” total thickness) and I lined the inside with self adhesive lead sheeting. Seemed to work well. I also rounded all inside corners using wood angle pieces and epoxy with “micro balloons” (fibreglass spheres I got from local boat builder). This was more for reducing sound wave distortion but probably helped stiffen the cabinet as well.

[@hi-fihaven2257]

Thanks for another great video Danny. I really appreciate your helpful tips. I have a pair of speakers that I think would benefit greatly from the use of No Rez. Will be ordering some shortly. See you next week!

[@file1man]

So how did your no rez do... why not use dynomat

[@hi-fihaven2257]

@@file1man Replaced these speakers instead. Massive upgrade! Have a great day!

[@andrewmanus5686]

Thanks!

[@brandenwaite]

In a rectangular speaker cabinet, would it help against resonance to put 45° pieces of wood in the corners. Making it more egg shaped on the inside. I have heard egg shaped cabs are better for that reason, but harder to make. Awesome video, I'd appreciate any help you can offer.

[@Nightjar726]

Danny, what measurements can we take to see what we have done with adding internal bracing etc? Are RT60 decay time measurements from the seating area good? Can you link to an accelerometer we can buy and use with REW?

[@paulb4661]

Hi Danny, Have you ever had a chance to evaluate the effects of lining the internal walls of the enclosure with lead sheet ? What I did was to employ a matrix type bracing with apertures allowing for air movement, lead sheet is fixed with hundreds of screws and a compressed layer of slightly elastic, yet strong adhesive. Self adhesive, engine room type sound deadening mats go on top of it and then glass fibre fills inside each matrix shell "cell" with progressive density as you move away from the speaker. I know it's hazardous and politically incorrect choice of materials, but for sealed enclosures you can scream at your heart's delight facing the driver aperture and remain barely audible. I use lead sheet between half inch and and inch thick, deadening matt is a dual layer affair of about 12mm in total with rubber underside and thick open cell foam layer on top.

[@rothgartheviking858]

Have you tried Decidamp as a solution for resonance? If you have, what are the pros and cons compared to No Rez Foam?

[@srimanthkumar]

I have a 2 cube speaker box with 12" woofer MCM brand 120 RMS, 6" midrange Fital PRO 150 RMS and 3" tweeter Tymphany 120 RMS and the depth of the box is 14". I introduced polyfill mat with 8mm thick and a port. The diameter of the port is 2" and length 9inches. Just got fascinated with ported speaker box designs on youtube. Woofer is having 41Hz and Mid is 61Hz. For low volumes the bass is good, when I increase volume the bass of woofer is impacting the vibration of mid in the enclosure. Do I need to reduce the length of the port or should I introduce another hole on the right side lower to woofer without impacting my good bass. I am dedicating the speaker boxes to a small church and should they should go long way. Amplifier I use is 100 watts RMS. Please do help me.

[@treyhorn5645]

Good afternoon Danny, great info.. Out of curiosity, I used cork to line the inside of my cabinets , they have great internal bracing. I don't know if that was a good move . They sound good. Just wandering your thoughts. Thanks again.✌️

[@dannyrichie9743]

Cork doesn't really add mass or damp resonances very well. So not effecting these too much.

[@treyhorn5645]

@@dannyrichie9743 , okay, just had materials so did it on a whim.. thank you sir

[@johnpolk5345]

I've been looking for something my sub box build has weird sound from 40 to 6p hz seems peaky. It's 2 p312 in a weird angle shaped box . Was looking at quiet bat 30 until I found this can you use both or is it necessary

[@Newrecordday2013]

Hey Danny, I have a question about this one. If a speaker (sealed or ported) has sufficient bracing to control resonance, is something like norez still needed? Would there be any added benefit of using norez if the sweep looks clean from the get go? Thanks for the video!

[@dannyrichie9743]

Bracing can minimize wall flexing and resonances, but can shift the resonances higher up in frequency. However, the higher frequency resonances are easier to damp out. So a product like No Rez is still very effective. In the case of a well braced speaker, instead of just tightening up the bass region it may more significantly improve the vocal region. And resonances don't always show up on an impedance sweep. Smaller resonances may not show up at all or only show up as output levels increase.

[@pabloosvaldopenizzotto1098]

Hi Danny. Is there any limits in terms of how much damping material you add inside the cabinet? In my case I have added polyfil on top and bottom of my towers speakers. Before to do that, I notice a big resonance of the walls about 400 Hz. After adding the damping material the resonance clearly has gone, ….and I also realized about many details in mid and high frequencies that I suppose was masked by the resonances before. The problem is now that low frequency response is too loud starting from 50 hz till 200 hz,with it maximum about 100 hz. Is it possible that this has been caused by excess in damping material? Thank you!

[@rotorfix]

I tried open-baffle speakers with 3" thick HDF baffles. They had some strengths, but produced a very audible resonance and an inferior midrange to my loosey-goosey Spendor cabinets. The heavy-braced speakers I've owned sounded least good overall. Have you read any of the white papers the BBC wrote on this topic?

[@bigjay1970]

1000% agree some of the worst sounding speakers that cost huge money are braced so good that they do not sound remotely good! Just was at a store that sells $80,000 speakers and was taught this very valuable lesson. Guy has over 40 years in the business! Sometimes a speaker can have no magic so to speak because of this desire to dampen the heck out of the cabinet. Wouldn't have believed it myself unless I heard it as I just did. That's why speaker manufacturing is more art than science sometimes!🤓🤔🤗😉 and ofcourse I am talking about over damping. A cabinet that is well designed from the start really doesn't need most if this damping material!

[@rotorfix]

@@bigjay1970 agreed!!!

[@terrysetter817]

@@bigjay1970 You might be describing two different things here. 1) is the damping of reflected energy inside of an enclosure. It converts acoustic energy into heat and does away with (much of) the rear wave energy in a sealed box. I believe the video is more about damping the actual cabinet walls so that they don't shake audibly when the speaker is playing. The difference being that you might have a cabinet that is so stiff and well built that it has extremely low resonance at any frequency, but you'd still have to add absorptive material (foam, fiberglass, etc.) to control the rear wave energy. Otherwise, the rear wave energy interferes with the speaker movement and, in very bad situations, can even be heard coming out through the diaphragm of the speaker.

[@oldschoolwc]

cone filtering and cabinet resonance. I'm running for cover

[@loudspeakerchefOriginal]

Tar works great

[@quant2011]

how about panels of slate glued to the walls? slate has good damping factor by itself. it also makes walls stiffer

[@yannick930]

Can we buy No Rez if we live in Europe, France ?

[@mojoneko8303]

I have considered using a layer of heavy wool felt 3/8-1/2" thick instead of foam on top of dynomat or industrial floor tiles. Has anyone tried using felt? It seemed like it would have the right properties for dampening cabinet resonance.

[@mjcorser]

Troels Gravesen uses felt to line internal surfaces in his designs. Specifically, I've seen it on the SBA-741. Then he stuffs with wool (or other suitable dampening material).

[@mojoneko8303]

@@mjcorser cool thanks for the info. I may "build a pair" this winter. : )

[@LCRLive687]

That looks like a front baffle and open back speaker with side walls and front wall. Not a full out open baffle speaker. But thanks for your info about controlling resonances.

[@audiokees4045]

I dod bought some old magnat,s and discover it has no damping material in it. It is a kind of box what is behind you, a smal tower with 3 6 inch woofers and a tweeter.

[@reubengeorgemathai7329]

Any way to measure TS parameters of passive radiator?

[@bradisley517]

Curious as to your take on polyfill/Dacron fiber fill's effect on resonance? As for a suggested topic I would like to see a video on how to do a basic Thiele and Small Parameter on the Clio. Thanks and keep up the great work!

[@BoRerunn]

Dynamate work just as good

[@kencohagen4967]

Before any of the current sound deadening materials were available, I added 3" fiberglass insulation to the walls of my 3 way cabs. It seemed to work well. No more boomy bass. The bass became tight and punchy and seemed to be lower in pitch than without the insulation. One question though, when you use a product like black hole five, does the thickness of the pad or no res subtract from the volume of the cabinet. Not volume as in sound pressure, the area in the cabinet. And as far as deadening material goes, what about rubberized undercoat like you spray under cars to keep them from rusting back east? I have no experience with the stuff living in the desert southwest.

[@djscott9207]

I hope he replies to your great question with an answer. Would like to know this myself.

[@petethegreekre]

Nice one, hope I don't have to start over again.

[@petethegreekre]

If it's a non elastic it works. Here's an interesting scientific take on building a speaker that includes some interesting examples for damping including a non elastic material that works efficiently when spread in a thin layer rather than thick. kzbin.info/www/bejne/e3bLYWSGjZKkb6s

[@tee-jaythestereo-bargainph2120]

Thanks ! I use a similar product that's twice as thick behind my speakers on the wall 4 pieces total for 2 speakers I hate what I call off the wall hall effect !,But I've used thick wool inside my speakers since my hpm 100s came stock like that I use it in all my speakers works pretty good but I'll keep you in mind if I ever find a good deal on some really good speakers nice stuff appreciate your time and education in audio

[@cgirl111]

Since adding damping material reduces the effective size of the cabinet, and assuming the cabinet wasn't originally designed with the material in mind, will this effect the performance of the speaker?

[@dannyrichie9743]

Actually adding a foam layer can slow down the airflow in the box and make the box act as if it is larger. So product like No Rez can be added without really effecting the box volume very much.

[@lio1234234]

@@slomo1010 you can get non flammable alternatives. Rock wool works too, pretty sure you can get non flammable for that

[@NotSure723]

How about some opinions on bracing?

[@AudioMaverickcom]

An amazingly complex issue most 'speaker people' continually grapple with! I've tried some crazy things, and the midrange bleed has been more difficult to manage than bass. This topic could be an entire class.

[@dannyrichie9743]

I may have to do a follow up with this one as there was a lot more I could have said.

[@svtcontour]

I'd imagine also something like Dynamat on the walls would help add mass to the walls to help reduce resonance

[@johnloupis2347]

How about Dynamat used in car audio applications?

[@Quetzalcoatl0]

what about adding bracing ?

[@FSXgta]

yes bracing is important, but if you have a high quality speaker it should be properly braced from the factory

[@RennieAsh]

Why can't they tell us if it is indeed a mass loaded vinyl or butyl constrained layer damper? It's almost like they are trying to be mystifying by calling it "heavy damping non resonant material". It sounds like MLV to me with a viscoelastic adhesive, and open cell foam on top.

[@markshields6732]

Any ideas how cork works as a damper? I use it on my speaker stands and have wondered about it for cabinets. Thx.

[@dannyrichie9743]

Cork would be a good material to sandwich between layers. Layers of different densities are poor conductors of resonances. By its self it really wont add sufficient mass to control the resonance of a larger panel. And ultimate example or layers of difference densities is the use of sand. See a good example here: www.ebay.com/itm/264376946847?ViewItem=&item=264376946847 Sand is also great for filling up stands.

[@evansstudios]

Hey Danny, great video. Quick question about No Rez, I just got in a pair of Zu Omen Dirty Weekends. I haven't taken them apart yet but I don't think they have any internal bracing, if anything there's just a pillar of foam centered in the cabinet similar to what's used in the regular Omens. If I try out some No Rez, is it best to line all the walls completely or just place a few pieces strategically?

[@dannyrichie9743]

For a speaker like that I would line all of the walls with it. And the No Rez will make more of a difference in a lightly braced or un-braced design like that.

[@MartinHAndersen]

Ain't there a chance that you move the cabinet resonances to where you can hear it

[@rotorfix]

Regarding bracing, yes, that's a common phenomenon. Typically what happens with poorly implemented bracing is the resonance moves to a higher frequency where our ears are more sensitive. This is why you can't build a cabinet all willy-nilly and expect good results. Though products like No Rez do not typically move the resonances upward. In fact I've never experienced that from any remotely similar damping material.

[@mrfancypants9873]

“Slide it in your woofer hole” 🤭

[@changappalarny4701]

3/4 " particle wood is the best with little layer of pillow poly fill is good enough. olden days they use to put in glass wool. MDF boars are too dense box resonance is not that good. same with wood and plywood etc. cabinet resonance is must because the woofer alone can't give that kickdrum effect so the box resonance helps in. its not colorization. when you make the box walls too thin then the colorization kicks in.

[@jajessee]

Thanks. Does putting weight on speakers work to reduce resonance? Bookshelf speakers? Any suggestions..

[@dannyrichie9743]

Adding mass to a panel does change its resonance frequency and reduce resonances.

[@jajessee]

@@dannyrichie9743 Thanks.

[@sudd3660]

in the case of sealed cabinets, since they are filled with acoustic stuffing, i am thinking that cabinet Resonance also are reduced. bass reflex cabinet might have less pressure inside at some frequencies but much less sound absorbing material inside.

[@dannyrichie9743]

Whether the cabinet is sealed or ported will not change what goes on regarding cabinet wall resonances. And the internal damping material can slow down air flow and pressure changes, but does little to nothing for cabinet wall resonances.

[@RennieAsh]

Acoustic stuffing is an absorber, not a damper :) Generally to dampen a structure, constrained layers with different densities and viscoelastic glues work well.

[@minho4575]

Mr. Richie - will you have your products on display at the upcoming RMAF?

[@dannyrichie9743]

I am not planing on exhibiting there this year.

[@minho4575]

@@dannyrichie9743 TY!

[@charleskatz2606]

I used to sell B&W and nautilus was interesting in bracing tech to make cabinet more inert.But wht I find intriguing these days is Magico.The whole line even the least expensive uses aluminum panels with aluminum bracing that is screwed together from side to side.Of course with Magico least expensive is still $10K!!!.I wonder if the bracing with torsion rods have to be screwed down as tight as one can or if it has some "tuning" sweet point?And of course I wonder if it could be used with DIY or more resonably priced speakers like GR.Thoughtz????

[@dannyrichie9743]

I've designed speakers that were made from milled Aluminum. You can see some photos of them in our pics: facebook.com/pg/grresearch/photos/?ref=page_internal Aluminum is very solid and shifts the resonance point up much higher in frequency. However, the higher frequency resonances are easier to damp out. It's just really expensive to use.

[@bc527c]

Torsional rods would likely vibrate like a guitar string.

[@charleskatz2606]

@@bc527c well maybe I am using wrong descriptive term but look at cutaway of Magico A3.Could be that the tight screwing together reduces that effect while deadening inner frame./outer panels.The lus would be rigidity while allowing for more room to resonate and not being an interior dampener.Kick myself as I was at T.H.E last summer and did not hear them but they got a few rave reviews.Given Magico line starts usually at $30K and goes to ten times that I thought worth a listen if they share that aluminum cabinet and bracing.Next time

[@bc527c]

@@charleskatz2606 Yeah, it sounded to me like you were talking about a rod or wire, like a shroud on a mast on a sailboat... and on a diagonal inside... The A3 is thick aluminum plate with areas cut out, that will vibrate differently. No one is going to exterminate cabinet vibration 100% for any sane amount of money, so you have to make it so what is there is not harmful. The Magico M3 cabinet vibrates a little, a very little... but still some. That minimal vibration along with isolated drivers does allow Magico to accomplish some fine sound. Very dynamic, the near perfect amount, actually, and sound utterly divorced from the cabinet.

[@charleskatz2606]

@@bc527c well here we have a youtube where the title description is dead on kzbin.info/www/bejne/g2bLZptqhqaHi9E

[@haveaseatplease]

Cabinets: get rid of them and go for open baffle.

[@mykeldg]

can we use this damper on the outside of the cabinet?

[@dannyrichie9743]

It is designed for inside use. The foam layer would be of no use on the outside, but the damping layer would still be very effective. And it wouldn't be very pretty on the outside of a speaker.

[@mykeldg]

Danny Richie thanks! How about adding another layer of wood outside the cabinet? I somehow see this common from sonus faber where there is additional wood trim on the outside of the cabinet sides. Would that help cabinet resonance and dampening?

[@dannyrichie9743]

Yes a decorative but heavy wood layer adds mass and is usually a different density from the material used to make the box. So it can be very effective.

[@mykeldg]

Danny Richie thanks a lot!

[@RennieAsh]

@@mykeldg If adding another layer of wood, I'd consider putting a layer of mass loaded vinyl between it and the cabinet, and/or using some viscoelastic glue (usually ones that stay tacky) You could also use lead sheet

[@christopherbass4521]

I tried this with my old technics speakers...ended up hating them for over a year...removed the damn stuff I put in there and understood that they were designed to sound good with basically nothing in the cabinet. "Never again" - Not saying your component upgrades are not a great idea and I know I give you shit for some of the woo woo, but ultimately, when you give a FR graph showing results, I will listen.

[@mag290]

My cabinets just don't resonate to begin with, they are casted using volcanic ash.

[@petergordon931]

Hi Danny these look like the NX-Treme !

[@Newrecordday2013]

They are, I forgot to add in text to correct him.

[@dannyrichie9743]

Yep, I called my own speaker by the wrong model name. It is the NX-Treme. Good catch. I'll have to give you a discount on your pair. See them here: gr-research.com/nx-treme.aspx

[@TektonDesign]

I couldn't agree more with Danny. Danny also talks about the "muddied up midrange". This is so true.

[@sarahbrenay9324]

Eric Alexander I don’t think I’d consider myself a “damage control troll”, but I’ve been called worse. I’d recommend laying off the comments and just talk to your attorney. Or write your feelings down in a journal to look over later after all this dust has settled.

[@mrpositronia]

Seems like you just want a reaction. it's just a video about a hobby.

[@sarahbrenay9324]

Eric, ok sounds good! I’m glad you and your attorney are on the same page.

[@clausolsen856]

This is so sad.... With out pointing fingers.....take it down!....come on man, it's on the internet...nothing ever goes away...! But this will certently atract even more attention.... Let it go....move on both of you😉

[@sfhifi2304]

@@TektonDesign Didn't you refute the idea that an impedance sweep could even show resonance in the comments of the other video? Now you accept it but think NRD's is fake? You keep changing your tune buddy, makes it seem like you don't know what you're talking about. You appear to be the only one lacking integrity, and you still haven't provided any proof.

[@michaelstark7962]

Hi danny thanks for you talk on zero rez and antiresonance control ilike theidea of vinyl floor cob Vering as well as no rez together isthisa also benefit besides just zerorez sheets do you knowfor sure i wouldlike tomak akit using the bestideas on youtube i see tomodify cabinet crossovers dampening etc inside our side fully to bring about through cheaper diy a good bookshelf loudspeaker kit intoits best possible an interest of mindd since i first heard oodifying loydsoeakers in the 1970 with the radio shack minimus seven mods but for my sister im researching in time through diy youtube informations and any otber path ileRn ofnew usefulinformation from successful approaches to speaker enhancements buildings so one is to send yourself a c not bluetooth loudspeaker to improve on modify crossover and orany suggestion in you exoeriences life throughyourprofession to bring out eak out every littlebt improvements at all that would possibly inevetively be audibleadded together or individually thanks you you help and ihope you arehappy and well in you being

[@johnpolk5345]

*60hz

[@dogpoundoatthetube7756]

What about the stuff that's been used in car's for decades? I think it was called Dynomat or something .

[@dannyrichie9743]

Good stuff. It was designed for steel surfaces but works well.

[@johnloupis2347]

Did you happen to try Dynamat ?

[@bobnevala5218]

@@dannyrichie9743 Jute Padding that was placed underneath the carpet in cars? I have some that came factory installed in my Technics SB-G800 speakers and was thinking about adding some the all the surfaces inside the cabinet? i know this video is old so...

[@dannyrichie9743]

@@bobnevala5218 Make it easy and just use No Rez.

[@ianjohnhorwood2605]

No-rez, = no resolution ability, his product is a an expensive waste of anyone's money. To damp cabinet resonance all you need is bitumen visco elastic pads, and do a far better job than his expensive foamed no-rez crap.

[@Newrecordday2013]

I’d love to agree with you but then we would both be wrong.