11 replies to this topic

[br85]

So with these SR6500's, I intend to just put one layer of dynamat xtreme on the inner and outer shells of the doors (dynaplate for the holes? Or is there something highly effective much cheaper since I'm not gonna to be pushing ridiculous spl) as well as tacmat over the dynamat on the inner shell behind the trim.

I know that most people who know what they are doing when they say that dynaxorb is rubbish for diffusion, particularly for midbass, and that diffusion channels need to be a LOT deeper than dynaxorb's are. I understand that it is useless for midbass, but the XOvers on my Polk SR6500's are at 3.1khz, so I'm thinking for mids they might provide some of the benefit they claim to.

Thoughts?

If it's still no good, is the tac mat and dynamat extreme (along with spacers/pods) ample enough to make my SR6500's sound as good as they are supposed to?

Edited by br85, 19 February 2008 - 10:07 PM.

[Pulse-R]

I found the 'acoustic foam' from jaycar works quite well for diffusion of rear wave. at the frequencies in question (500Hz and above) the acoustic foam is great. make sure the pods/spacers are solidly built, and maybe apply some dynamat there too. leave space around the back of the woofer to breathe - this will affect lower frequencies.

I used 3mm MDF for the holes, attached with gaffer tape to the door, and dynamat over the lot together to seal up amd deaden the doors. you may want to wrap tape around the door's control rods too - to stop them rattling, and put closed-cell foam on the parts where the door trim rests on the door inner skin, and near the top where the window slot is.

IMHO, for normal use, one layer of dynamat extreme is sufficient.

On the subject of DynaXorb - it works (in theory, at least) the same way a fresnel lens, google it, works as an optical prism.

Edited by Pulse-R, 19 February 2008 - 10:35 PM.

[Dual Mono]

I havent used the Dynaxorb myself before so cant really comment.

I normally recommend the Focal Plain Chant. Its a bit more expensive but is good stuff.

[br85]

Pulse-R, on Feb 19 2008, 10:33 PM, said:

I found the 'acoustic foam' from jaycar works quite well for diffusion of rear wave. at the frequencies in question (500Hz and above) the acoustic foam is great. make sure the pods/spacers are solidly built, and maybe apply some dynamat there too. leave space around the back of the woofer to breathe - this will affect lower frequencies.

Well, the tac mat is a semi-closed cell foam already, so the dynaxorb in question would already have the foam and the dynamat extreme under it.

Quote

I used 3mm MDF for the holes, attached with gaffer tape to the door, and dynamat over the lot together to seal up amd deaden the doors. you may want to wrap tape around the door's control rods too - to stop them rattling, and put closed-cell foam on the parts where the door trim rests on the door inner skin, and near the top where the window slot is.

Awesome. 3mm mdf is MUCH cheaper than the plate, would adhesive silicone (i.e. roof seal) work instead of/as well as gaffer tape for the MDF attachment? Yeah and again I think the tac mat would do the job in bewteen the door trim and inner skin too.

Quote

IMHO, for normal use, one layer of dynamat extreme is sufficient.

On the subject of DynaXorb - it works (in theory, at least) the same way a fresnel lens, google it, works as an optical prism.

Hmmm, still sketchy about it. Don't want to waste my money on marketing hype, but nobody has reported on the sonic or measurable difference that it makes between 1kHz and 3kHz, and it sounds like there is a chance it might be enough of a difference to justify the cost.

[br85]

Dual Mono, on Feb 19 2008, 11:53 PM, said:

I havent used the Dynaxorb myself before so cant really comment.

I normally recommend the Focal Plain Chant. Its a bit more expensive but is good stuff.

Hmmm, "good" you say? At doing what, exactly? I just ask because I can imagine the dynamat ex and the tac mat would already be doing a massive amount of dampening, I can't see why I'd want another layer unless it can successfully diffuse the mids, or at least make the audio sound "cleaner" in some obvious way.

[~thematt~]

Whilst below 600-odd hertz, the benefits of Dynaxorb are merely physcoanalytical, above this range they are quite evident indeed. Actually, I really enjoy listening to a midrange with rear-wave dispersion (or IB/OB) and would highly recommend it.

[br85]

~thematt~, on Feb 20 2008, 08:43 AM, said:

Whilst below 600-odd hertz, the benefits of Dynaxorb are merely physcoanalytical, above this range they are quite evident indeed. Actually, I really enjoy listening to a midrange with rear-wave dispersion (or IB/OB) and would highly recommend it.

Thanks for that. That's exactly what I wanted to know. Looks like I'll be shelling out after all. Goodbye, savings =(.

Dynamat extreme - $280ish per bulk pack (probably need at least 2 bulk packs for all the bombadore doors alone)
Tac mat - $140ish per piece (need 2 or 3 for all doors)
Dynaxorb - $170ish for the 8pack (I'll probably use 4 and sell/give the rest away)

And that's before I even think about doing the floor/firewall with dynamat ex and dynapad, or doing the roof with dynamat ex and dynaliner!! (That might have to wait until after I get my tax return this year I think)

Somebody just kill me now, I want out =P

Edited by br85, 20 February 2008 - 11:05 AM.

[MatS]

You should be able to buy the Dynaxorb in a pack of 2. that's what i put behind my speakers. one on each side. No idea on the effect as i did it the same time i deadened/sealed my door. I tried some cheaper sound deadners and after a while they fell off, they also needed to be heated prior to application. A bulk pack of Dynamat extreme can be had ~$250 (esspecially if your buying 2).

I used 3 bulks in my VS, for a refrence. front doors (innner and outer) rear doors (outer), floor + parts of firewall, roof, boot, parcelshelf.

Edited by MatS, 20 February 2008 - 02:27 PM.

[BlackIce]

Not that I have any interest in this... but, Jaycar egg crates cheap and effective.. just treat it with liquid latex to stop it trapping water in your doors.. it all does the same thing, so why pay more ?

And its CONTROVERCIAL

[philz]

Quote

And its CONTROVERCIAL wink.gif

controverSial

Just use Dynamat for the doors, and Dynaxorb, then use Carpet underlay for the floors [which is more effective than Dynamat at stopping road noise for the floors].

Though if you have the cash, do both!

[br85]

MatS, on Feb 20 2008, 02:23 PM, said:

You should be able to buy the Dynaxorb in a pack of 2. that's what i put behind my speakers. one on each side. No idea on the effect as i did it the same time i deadened/sealed my door. I tried some cheaper sound deadners and after a while they fell off, they also needed to be heated prior to application. A bulk pack of Dynamat extreme can be had ~$250 (esspecially if your buying 2).

I used 3 bulks in my VS, for a refrence. front doors (innner and outer) rear doors (outer), floor + parts of firewall, roof, boot, parcelshelf.

Well my VS (that I'm getting in the next week or two) is going to be a wagon and I'll need a bit more than you would for a sedan, but it's comforting to know that I won't need the 5/6 that I dreaded having to get for all that. sounds like 4 packs will do the job, with enough left over to give my "jewish" friend for putting behind his front after-market coax's. =P

I would get the xorb in the 2 pack but I want to put it behind my rear fill speakers, thinking of getting the polk mm650 coax's from the states (don't care about warranty on a pair that are on special for $119US!!) and I hear they're a very high quality coaxial, ESPECIALLY for their price, so I might as well go the whole hog for rear fill/staging as well (look, it's not like I skimped on quality with my fronts to buy rears, so you know where you can take your "you don't need rear fill" comments =P)

[Pulse-R]

doors and roof and boot/cargo area should be sufficient, unless the car is real noisy then do the floor as well.