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View Full Version : Resin vs. Non-Resin test (spl results inside)



PSturmer
12-10-2007, 07:49 PM
for everyone into spl i thought i would post these results

so my first test was birch vs. mdf.

box was 1.25 cubes net and it came out to be they had the same db output.

here is the thread:

http://www.caraudio.com/forum/showthread.php?t=274407



so in this test there were 2 identical box's. one had 3 layers of resin in the inside, the other did not.

http://i24.photobucket.com/albums/c8/psturmer/100_0029.jpg

http://i24.photobucket.com/albums/c8/psturmer/100_0030.jpg



results:

non resin:
~800 watts.....140.9
~2200 watts...144.1

resin:
~800 watts.....140.6
~2200 watts...144.1

i did multiple trials with the 2200 watt setup and got consistent 144.0-144.2. i did not have another dmm on hand so i was not able to see whether the reactive load changed.


it is hard to make conclusions about these results. what i learned is on small box's resin does not increase output. with larger box's resin could help just because of the fact it will add strength. on the scale my box is on, strength is not a concern.

Canaan
12-10-2007, 08:18 PM
Nice post.

Just wondering, what freq. did you peak at in these tests?


I have gained a few 10ths from resin before, but that was always in 4cuft+ boxes.
Also, my note usually went up ~1hz...so that could account for the gains.

Edit:
Also, I see your #'s came up alil since the last testing you posted.
Are these test boxes the same as the other test boxes?

And, did you roll/paint on the resin...or pour it in?

PSturmer
12-10-2007, 08:30 PM
Nice post.

Just wondering, what freq. did you peak at in these tests?


I have gained a few 10ths from resin before, but that was always in 4cuft+ boxes.
Also, my note usually went up ~1hz...so that could account for the gains.

Edit:
Also, I see your #'s came up alil since the last testing you posted.
Are these test boxes the same as the other test boxes?

And, did you roll/paint on the resin...or pour it in?

i played 50hz. i dont peak there though. the numbers being any higher then last tests is not significant. there are many other variables that have changed since.

ngsm13
12-10-2007, 08:31 PM
it is hard to make conclusions about these results. what i learned is on small box's resin does not increase output. with larger box's resin could help just because of the fact it will add strength. on the scale my box is on, strength is not a concern.

Simple adding resin, does not add any strength what so ever. :fyi:

R-tard.

nG

mrogowski
12-10-2007, 08:35 PM
I was just going to post that. I believe you can get resin with fibers in it which would add strength though.

Informative post nonetheless.

97cavy
12-10-2007, 08:37 PM
I just dont really understand your tests. First off, ive never seen anyone say that birtch is "louder" Its justed used to save weight and for its strength...so im not really sure where that came into the test?

And I know mulitple people who have seen gains from smoothing the interior/port opening but its much more then just resin'ing and calling it a day thinking your going to gain....

mrogowski
12-10-2007, 08:43 PM
Perhaps this is the thread to post this question:

Has anyone performed SPL testing on enclosures with a highly reflective interior to see if there is a gain in output? I was chatting with someone who had aluminum tape covering the outside of his SPL box. Just curious if this would have a similar effect in the inside...

JimJ
12-10-2007, 08:45 PM
In much the same way that standing waves aren't as big of an issue in subwoofer enclosures as they are in, say, bookshelf monitors, I'd think it wouldn't make as much of a difference...

Although Snoopdan had good luck with that marble port, so who knows :)

ngsm13
12-10-2007, 08:45 PM
It all has to deal with making the interior of the box smoother, less friction... allowing the air to flow at a higher velocity...

So, whatever you use... it doesn't much matter.

nG

mrogowski
12-10-2007, 08:46 PM
Ok, thanks.

AudioXtremes
12-10-2007, 09:03 PM
In such a small box with a external aero resin shouldn't help much.

In a large box with a wood port smoothing it helps. My van has a few gallons.

sundownz
12-10-2007, 09:05 PM
My box = needs resin... it's rough as heck :)

AudioXtremes
12-10-2007, 09:28 PM
Drive to indy and we'll work on it Jake.

sundownz
12-10-2007, 09:30 PM
Drive to indy and we'll work on it Jake.

It's not ready to drive very far yet :) I need to replace the rear axle seals... they are leaking grease all over my rear drum brakes so it doesn't like stopping that much *laughs*

AudioXtremes
12-10-2007, 09:38 PM
Sounds exciting. My brakes in the crx went out at a drag show and I hit a truck.

:)

sundownz
12-10-2007, 09:41 PM
Sounds exciting. My brakes in the crx went out at a drag show and I hit a truck.

:)

Dang, that *****! I did have it out driving yesterday, though, but it has the stopping distance of a loaded 18 wheeler going down hill right now.

My Dad helped me fab up a new alternator bracket... and lots of work was done to re-do the rats nest of wiring that was in there. Batteries moved to the sides of the box from the back, and all kinds of other little stuff (new power steering pump, new door pods, etc).

I am looking forward to getting it to some shows finally! Once I get my Nightshades in I'm going to try to cram eight 15s in there and make it loud, we'll see how that goes when the time comes :)

Lakota
12-10-2007, 09:43 PM
I told you it wouldn't make much of a difference :)