Cabinet Resonance | HOW TO TREAT IT! 

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.

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

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.

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.

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.

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.

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

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!

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.

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

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!

This article really resonated with me.

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

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.

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?

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

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.

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.

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?

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.

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

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

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!

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.

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.

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

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

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.

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.✌️

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?

Thank You. As clear as you always do

“Slide it in your woofer hole” 🤭

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.

Dynamate work just as good

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?

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

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!

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

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

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 ?

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.

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.

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.

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????

How about some opinions on bracing?

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

How about Dynamat used in car audio applications?

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!

what about adding bracing ?

Any way to measure TS parameters of passive radiator?

Tar works great

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

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

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

Thanks!

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.

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

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

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?

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

*60hz

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

Hi Danny these look like the NX-Treme !

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

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

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.