Sound absorbing, carpet or cork? or??

[Jase4224]

Hi guys,

I've been wandering around this forum for a while now researching my first DIY speaker build. I've learned alot! My goal is to make the best speakers I can using a pair of MB Quart 5 1/4" Premuims (mid range driver + tweeter). These are the OLD German made MB Quart not the crappy new Korean made models. I will also be making a small subwoofer using a 6" Yamaha sub driver from an old surround sound system. All will be sealed boxes as I prefers a tight sound and dislike the sound of most ported speakers.


I have come to the conclusion that the speaker cabinet is crucial to good sounding speakers and I have put a lot of thought into how I will build mine.


I'm going to try multiple layers of sound absorbers and dampeners to soak up and prevent sound waves reflecting back into the driver cone as much as I can.


I'm thinking I will go with something like this (in order from inside to outside):


1. Filter wool behind driver (to keep it clean of fibreglass)
2. Stuffed with fibreglass
3. Acoustic pinboard
4. Carpet OR cork
5. Lead sheet
6. Curved MDF (all insides of the driver enclosure will be curved)
7. Cement


My question is what would be the better option for the 4th layer? I want it to absorb sound and not bounce it back.


Cheers, Jason

 

[tinitus]

may not work exactly like you imagine

I suggest you search on 'matrix bracing'

 

[Jase4224]

Hi tinitus,

I have seen the matrix bracing used by B&W and would like to make larger speakers using this technique however my current project will only be 24" tall maximum with a minimum 1.5" thick reinforced cement. So it will be sufficiently rigid.


My concern is.. where are the internal sound waves going to go, and how can I create an I closure to soak up this energy?

 

[sippy]

You can simplify the 'Matrix' style bracing ie: less of it.
Or you could search for Planet10 on this very forum, Very simple and effective.