I decided to do a little experimenting to see if I could find more bass in my system. My trunk setup consists of an amp board mounted as far into the trunk as possible with a beauty board covering the sub. I have attached photos below.

I wanted to see what difference in db it would make if I removed them, and had the pass-thru open. For the test I had the car running using a 50hz test tone, and kept a consistent volume to keep all things equal.

First I just removed the beauty board in front of the sub. This made a mere .5db difference.

Next up, I dropped the amp board flat and ran it again. Bingo...5.5db increase just by allowing the bass to clearly pass through to the cabin.

My plan now is to cut out as much wood as I can in both the beauty board and amp board, and then cover them with black speaker cloth. From the front it will look like it's a solid board, but from behind you will see plenty of "open space" for the air/sound to easily move through to the cabin. Just imagine a removable speaker grill from your home speakers...just an outer frame holding it all together with cloth covering it up.

On top of that, I plan on removing the stock sub from the rear deck so that sound pressure can move up through there as well. On top of that, I will cut a hole out in the upper trunk lining just underneath the sub hole in the rear deck. So it doesn't look like a big hole in the trunk lining, I will also cover that up with black speaker cloth so it has a nice, clean finish. I'll take db readings before and after to see how much more one can gain by removing the stock sub.

Stay tuned...

Current amp board setup:


Current beauty board setup:

 

I always wondered if those boards would act as a bass blocker or isolator.

 

Again - learning from your lead and experience. I was already planning on removing my stock sub.

I'm going to have to mount my NINe.5 in a similar fashion to your DLS. I was thinking a board barely big enough to hold the amp bolted to the angle supports. I haven't yet taken my trunk apart so I don't know if this is even possible.

Keep going - the more work you do the less experimentation I'll have to perform!

 

I see how you are...letting me do all the work!

 

At this point I WISH I could be doing some work. Still waiting for my amp and sub/box...

 

Well I modified my amp and beauty boards, covered them in speaker cloth, and got great results. I installed everything in place (finished system photos to come later), and got the exact same meter readings as I did with everything removed! So my theory worked even better than I thought it would.

You'll notice the cutout in the amp board...that is for access to some switches that are located on the bottom of my amp. I can now get to them without having to completely remove the amp from the board.

Cut up frames before cloth:




Backside:




Finished front side:

 

that looks great! Glad you got the result you were looking for.

 

TSC17, how do you measure your levels?

 

I have a Radio Shack SPL Meter, and use it with a Rives Audio Test CD...it has tones that are calibrated to work specifically with the Radio Shack meter. I use it for all of my home audio tests and adjustments as well.

 

Which model are you using? What weighting?

 

33-2050 analog. C weighting, slow.

Rives Audio Test CD