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Discussion Starter · #1 ·
I'm interested in how speaker builders here add damping materials to the enclosure walls. I've read about special materials, developed for submarines, and simple things such as roofing felt. Weigh in with your method(s) and results. Thanks for your OnT responses!
 

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Quote:
Originally Posted by gsmollin /forum/post/18152013


I'm interested in how speaker builders here add damping materials to the enclosure walls. I've read about special materials, developed for submarines, and simple things such as roofing felt. Weigh in with your method(s) and results. Thanks for your OnT responses!

I don't use anything to damp vibration; a well designed and built cab doesn't need it.
 

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Discussion Starter · #3 ·
OK, I know this is AVS Forum, and being on-topic is never a concern, but that isn't the question, so Bill has nothing to add. There are at least two ways to build a speaker enclosure, (1) is brute-force materials thickness with internal bracing, and (2) encompasses (1) plus it employs a built-up process that includes composite layers that add damping to any enclosure. I am asking about (2) in this thread. As before, your on-topic responses are welcomed.
 

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For the structure, I simply use a clone of the B&W Matrix . Simple single wall construction of modest thickness is all that's needed.
 

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For subs I'm not too worried.


For my LCRs, I use the 3-layer sonic barrier stuff from PE. It mass loads and absorbs reflections. I built my enclosures solid with 3/4" MDF and bracing, and they are only 7.5" x 12.5" x 21.5". Before I did any internal treatment (minus polyfill) I could always hear some ringing, and it really bothered me. I was kind of disappointed. So I worked on treating one speaker while listening back and forth with the untreated one, and it improved the midrange clarity quite a bit.


After I got done treating the speaker I had friends listen back and forth to each speaker (without telling them which one I did anything to or what I did to it) and they all picked the treated one as sounding much smoother. So I was convinced that it wasn't just me hearing things. What I think is going on is that the treatment prevented the sound waves from bouncing around and getting back to the cone, which was causing some ringing at certain frequencies.
 

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I used egg crate foam to line the inside of my ported boxes. It worked well to smooth the mid-bass. My sub was already lined with fiberglass insulation like you'd find in house walls. In a closed box you fill the enclosure lightly with poly-fill.
 

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Quote:
Originally Posted by XanderMoser /forum/post/18154068


Before I did any internal treatment (minus polyfill) I could always hear some ringing, and it really bothered me. I was kind of disappointed. So I worked on treating one speaker while listening back and forth with the untreated one, and it improved the midrange clarity quite a bit.


After I got done treating the speaker I had friends listen back and forth to each speaker (without telling them which one I did anything to or what I did to it) and they all picked the treated one as sounding much smoother. So I was convinced that it wasn't just me hearing things. What I think is going on is that the treatment prevented the sound waves from bouncing around and getting back to the cone, which was causing some ringing at certain frequencies.

Apologies to the OP, but for those who are interested most cabs need lining to absorb midbass and higher frequencies, otherwise they will reflect back to the cone and cause irregular response, as was the case here. But that's a totally different situation from using high density materials, like Sonic Barrier, to damp resonating panels. Well built and braced panels don't vibrate, so they don't need damping, though some prefer to use damping instead of bracing, and some prefer to do both. Some also prefer to wear both a belt and suspenders. To each their own.
 

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Discussion Starter · #9 ·
"Ringing" sounds can be caused by internal reflections, or by panel resonances. Speaker cabinets have problems with both. So here I am trying to find out what people have done with the damping materials available. Xander had these results without using polyfill, so the Sonic Barrier damping materials were having effect.


Without going OT myself, well built and braced cabinets do vibrate, but at a higher frequency and lower Q than those that are not as well built, or braced. The science of sonic control depends upon construction details like dampers to manage the Q of the walls, after they have been built and braced. This is the topic of this thread. So Bill, apology accepted, but really, if you don't have anything to say about damping, please try to refrain from becoming a stereotype-AVS-Forum-nay-saying troll, and respond to another thread. I think there's a good cabinet construction thread that needs your input.
 

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proper bracing and then OC703 or similar.


But dampening will not do squat if the bracing isnt there.
 

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as has been already said, it really depends what you are trying to dampen.


panel vibrations should be damped with bracing or more inert materials.


reflections should be damped with something like fiberglass.


whole cab vibrations should be damped by adding weight or decoupled from the structure with foam.
 

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Quote:
Originally Posted by gsmollin /forum/post/18156231


"Ringing" sounds can be caused by internal reflections, or by panel resonances. Speaker cabinets have problems with both. So here I am trying to find out what people have done with the damping materials available. Xander had these results without using polyfill, so the Sonic Barrier damping materials were having effect.


Without going OT myself, well built and braced cabinets do vibrate, but at a higher frequency and lower Q than those that are not as well built, or braced. The science of sonic control depends upon construction details like dampers to manage the Q of the walls, after they have been built and braced. This is the topic of this thread. So Bill, apology accepted, but really, if you don't have anything to say about damping, please try to refrain from becoming a stereotype-AVS-Forum-nay-saying troll, and respond to another thread. I think there's a good cabinet construction thread that needs your input.

the walls of the speaker should be built in a way so that the rear wave does not reflect back through the woofer. Other then that, its not all that hard to figure out.


- make sure rear wave does not reflect back through.

- make sure there is proper bracing.

- line the walls with carpet pad, OC703 or whatever floats your boat


In the end if these are done you will have ZERO concern about SQ effects and you should be focusing on the crossover anyways since that is 90% of the SQ anyways.




As for you nay-saying troll comments. Im not sure why you are posting such stuff in DIY. Its a damn good forum for building speakers.


Go back to those other forums you like to argue in if you do not understand this. Okay Mr. Knowitall



Get back to us when you actually build something too....I will enjoy your replies for sure
 

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Quote:
Originally Posted by gsmollin /forum/post/18156231


"Ringing" sounds can be caused by internal reflections, or by panel resonances. Speaker cabinets have problems with both. So here I am trying to find out what people have done with the damping materials available. Xander had these results without using polyfill, so the Sonic Barrier damping materials were having effect.


Without going OT myself, well built and braced cabinets do vibrate, but at a higher frequency and lower Q than those that are not as well built, or braced. The science of sonic control depends upon construction details like dampers to manage the Q of the walls, after they have been built and braced. This is the topic of this thread. So Bill, apology accepted, but really, if you don't have anything to say about damping, please try to refrain from becoming a stereotype-AVS-Forum-nay-saying troll, and respond to another thread. I think there's a good cabinet construction thread that needs your input.

I use the vinyl peel and stick stuff sold by PE on centers or mains. I figure it can't hurt, and I don't mind spending the extra $15 or so if the speaker is a keeper. I've heard that floor tiles can be effective too. As to the nay sayers, I'm really surprised that this thread has been going almost twelve hours, and no one has told you that you should build a proven design!
 

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Quote:
Originally Posted by Bill Fitzmaurice /forum/post/18155673


Well built and braced panels don't vibrate, so they don't need damping, though some prefer to use damping instead of bracing, and some prefer to do both.

That's certainly true for sub boxes; do you assert same for full range?
 

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Quote:
Originally Posted by noah katz /forum/post/18158183


That's certainly true for sub boxes; do you assert same for full range?

I've never found any need to use mass damping on my full rangers. I can't speak for others.
 

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Quote:
Originally Posted by gsmollin /forum/post/18154178


Xander, did you have any problems with the adhesive falling down after a time?

Actually, yes. When I took the drivers out a few weeks after I finished with the sonic barrier, the pieces that were upside down were starting to come off. I used some epoxy to stick them back up, checked a few months later, and all is good.
 

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Discussion Starter · #17 ·

Quote:
Originally Posted by LTD02 /forum/post/18156402


as has been already said, it really depends what you are trying to dampen.


panel vibrations should be damped with bracing or more inert materials.

What kind of "inert materials" do you mean, and how do you use them? How effective are the results?
 

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Discussion Starter · #18 ·

Quote:
Originally Posted by kbgl /forum/post/18156727


I use the vinyl peel and stick stuff sold by PE on centers or mains. I figure it can't hurt, and I don't mind spending the extra $15 or so if the speaker is a keeper. I've heard that floor tiles can be effective too. As to the nay sayers, I'm really surprised that this thread has been going almost twelve hours, and no one has told you that you should build a proven design!

Do you mean vinyl floor tiles?


Please don't give them any ideas.
 

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Quote:
Originally Posted by penngray /forum/post/18156434


As for you nay-saying troll comments. Im not sure why you are posting such stuff in DIY. Its a damn good forum for building speakers.


Go back to those other forums you like to argue in if you do not understand this. Okay Mr. Knowitall



Get back to us when you actually build something too....I will enjoy your replies for sure

+1



I'm not sure the OP knows who Bill is. Here's a clue for you gsmollin . His opinion does hold weight, you may want to listen to him.



dbl
 

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"Do you mean vinyl floor tiles?


Please don't give them any ideas."


Vinyl is used in many commercial damping products.


Also, many are confusing mass and damping, which are two completely different things.


Adding mass can seem to have the same effect as damping, but it the mechanisms are different.
 
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