How To Dramatically improve speaker sound quality for £40 (Dynamat)

[Munro]

I wasn’t too happy with the bass from my speakers, even after the excellent Infinity Speaker upgrade the bass was still weak. After applying Dynamat Extreme the sound quality is dramatically improved.

The problem, as noted elsewhere on this site, is the doors don’t make very good speaker cabinets. This is mainly because the thin metal sheet vibrates with the speaker. This can easily be improved by applying a damping /sound proofing membrane to the doors, paying particular attention to the area around the speakers.

I chose Dynamat Extreme as it seems to be best on the Market (Easy to apply and claims to be at least twice as efficient as its competitors). It is a @ 2mm thick bitumen like sheet with an Aluminium backing. Guides on the product are here:
http://www.bbg-av.com/mobile/bbg_car_07.asp?id=5

I have applied it to all the hidden sides of flat panels of the door which are prone to speaker vibration. Both sides of the panel were treated around the speaker Area. I used about 4square ft to each door (8 sq ft in total) which costs about £40.
Some tips to help installation are shown on the photos below:

The photos only show the area around the speaker, but I applied it where ever I could access a panel, including the hidden face of the outer panel.

Tweeter mount also shown.

[m4rky]

Thanks for the post Munro - I have already bought some dynamat in anticipation of picking up my Civic. Looks like a wise investment now. Did you line the outer door skin as well (from the inside obviously)

[Munro]

Originally Posted by m4rky

Thanks for the post Munro - I have already bought some dynamat in anticipation of picking up my Civic. Looks like a wise investment now. Did you line the outer door skin as well (from the inside obviously)

Yes , I managed to reach @ 50% of the outer door skin. There are lots of things like window lift mechanisms and side impact bars in the way. I didn't want to put too much in for weight reasons so used just less than 1 x 4sq ft pack per door (@ 750g). Plenty around the speaker area and patches (not full coverage) on the biggest flat panels elsewhere.

It is a really easy mod with a good improvement in sound. The next step would be a sub and I didn't want to go that far.

On a rating basis (building on the rating for the infinity speakers elsewhere).
Standard speakers...4/10
Infinity Speakers.....6/10
Inf + Darmat Doors.. 7.5/10

[m4rky]

Cheers - How did the dynamat stick to the panels? Was it as good as they reckon?

[Munro]

Originally Posted by m4rky

Cheers - How did the dynamat stick to the panels? Was it as good as they reckon?

Dynamat will stick to anything very securely ! The main trick is to get full contact and avoid trapped air bubbles. I found sticking the middle of the dynamat patch first then working out to the edges was best. Any remaining bubbles can be punctured with a stanley Knife

Further Tips as follows:

I found the best way to find the areas needing treating was to put the stereo on with a track with plenty of bass and then feel for the worst panel vibration areas with my hand. The picture below shows the worst area in green, which received a triple layer of Dynamat Extreme both sides of the panel.

I also put a bit on the plastic door panel - see silver stuff at the bottom of the second photo.

I am really pleased with the improvement - So yes I reckon Dynamat Extreme is well worth it.

[m4rky]

Great advice thanks again

[Munro]

After a bit more researching I have put some “Skins acoustic sound wave diffusers” in my doors. It sounds highly technical for what is basically foam cut like an egg crate with a sticky back. It Cost £20 for 2 x 250 x 250mm sheets which seems quite expensive for what you get, but worth it as there is a definite improvement in speaker sound quality.

There are other similar solutions, but I chose this product because it is a purpose designed acoustic diffuser, waterproof for car door use and has a sticky back for ease of application. Further details on this link:

http://www.caraudiodirect.co.uk/skinz-acoustic-wave-diffuser-p-5482.html

“Acoustic sound wave diffuser

Reduces back waves, ensuring a tighter punchy mid/bass speaker performance.

Skinz wave diffuser is an ultra dense foam damping material used extensively to control acoustics in the recording studio industry. Now specially treated to reject moisture its benefits can now be achieved in car door applications.

Skinz Wave Diffusers sinusoidal profile helps elimate rear sound waves from reflecting back through the speaker cone causing sound cancellation. By attenuating unwanted sound waves from behind the speaker, greater sound and energy is gained. Thank to its excellent elasticity, flexibility and damping properties, Skinz Wave Diffuser will help deliver a far more open dynamic midrange with a much tighter mid/bass performance from any speaker system.”

It’s dead easy to install – simply stick the 250 by 250 panels on the outer door skin behind the speakers. I had to trim the corners off the panel for a good fit. I also cut the panel into halves to help pass it thru the speaker hole and manoeuvre it into the correct position.
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Some other useful links:

Another similar product “deflex”:
http://www.deflex.co.uk/cgi-bin/deflexshop/deflexshop.cgi

Sound proofing – Comparison of products on the market:
http://www.sounddeadenershowdown.com/

And of course Rasmus thread on soundproofing if you get really serious about soundproofing:
http://www.civinfo.com/forum/how/5241-sound-isolation.html

Some pictures:

[FWH]

Could this affect water flowing through the door?

Or in fact just get wet and cause more rust?

[Munro]

Originally Posted by FWH

Could this affect water flowing through the door?

Or in fact just get wet and cause more rust?

The skins stuff is water proof so it doesnt soak up water. I also kept it about an inch above the bottom of the door to avoid it daming any water trickling down when you open wet windows etc.

The stuff in the bottom picture is from an American site where a guy actualy used egg crate foam to save money. Maybe he lives somewhere where it doesn't rain! Or maybe he will end up with mouldy smelling rusty doors ! But at least he will have saved £20 and be enjoying better sound quality for a while!

Does anyone know if Honda galvanise the doors ? Your getting me worried I will end up like Clarkson and co in this weeks top gear!!

[Munro]

The Dynamat guides have disappeared off the link below, so attached again as pdf docs below:

Its also worth considering using Second Skin Damplifier as an alternative to Dynamat Extreme. It gets a good write up and is a bit cheaper:

Car Audio Direct - The UK's leading car audio and stereo resource. Second Skin Damplifier Pro Door Kit - Second Skin SEC-DPRODOOR
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