Box Modification SPL Gains

[sundownz 197]

I am going to start putting corner pieces in my box as well as adding resin. I will be tracking my gains from these things here.

I will do each corner with a 45 degree piece first (ripped 4x4 lumber). I will also try pieces that are cut into an arc (same 4x4 but with an arc cut) to see which is louder.

This will be done one corner at a time.

This may take a while but I am going to start today.

Base-Line score from the end of my dampener log :

155.2 dB @ 48 Hz

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First piece in place - screwed in with tape along the top as that edge was rough:

This resulted in a GAIN :

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I tested 49 Hz as well to make sure my frequency did not change - I metered 155.2 dB @ 49 Hz. I also gained 0.1 dB here compared to before but it is still not as loud as 48 Hz.

[3stagevtec 2]

this will be interesting..

[sundownz 197]

While I'm in the area I tried something random - metal taping all around the plastic trim piece at the bottom. I didn't have enough time remaining today to take the whole box out and do another 45 piece so I wanted to try something

No change... but at least my 155.3 is consistant :

There was alot of odd noise on the meter this time, though... not sure why, maybe a fluke.

[sundownz 197]

I wanted to see how much my internal port PVC piece was doing so I took it out this morning :

* With

* Without

Without - 154.9 dB (verified two runs 12 minutes apart)

With - 155.2 dB

So that piece is worth around 0.3 dB!

The score "with" is within tolerance since my speaker wires moved around in the port with the subs in and out... I need to get those out of the port - will probably do that today before further testing to eliminate that variable.

[Sir-Lancelot 216]

Interesting how such small things can change your set up. I guess when you are in competition, every little thing has to be taken into consideration.

Pretty cool and thanks for sharing.

[Aaron Clinton 2,372]

Nice work! Showing how smoothing air flow helps.

[sundownz 197]

Yesterday I put in another 45 degree piece:

Nothing really changed - did 155.2 dB.

Then I drilled holes to get the speaker wires out of the port... no change. BUT they were not sealed up - just holes.

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TODAY I got threaded brass rod, washers, and nuts to make a proper connection :

I should add that before I had a smaller wire jumping from one coil to the other to parallel the coils. Now I have two sets of wires going to the common point (this is probably part of the gain I saw).

So I am up 0.3 dB from my best score and 0.4 from the score I was doing yesterday consistently.

I would say part is due to moving the wires out of the port (this has always gained me in the past) and part was due to the superior connection of running two sets of large wires off the coil.

[efxtruck 0]

Nice numbers keep up the good work boys

[culzero 0]

nice numbers. question though. Aren't you also reducing the size of the box by adding the 45?

[sundownz 197]

nice numbers. question though. Aren't you also reducing the size of the box by adding the 45?

Yep - any sort of brace, corner piece, etc takes up box volume.

So far it has not been enough to significantly alter my frequency or score.

I am hoping when I make them into arcs rather than 45s that they will smooth out air flow a bit and add a tenth or two more.

[Aaron Clinton 2,372]

[sundownz 197]

Tried a few things with no success :

No change - 155.6

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LOSS - Down 0.2 to 155.4

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This has gained me in the past... but not today, did 155.5 dB this way.

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155.5 dB again

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So no more gains yet!

[Aaron Clinton 2,372]

Resin time?

[sundownz 197]

Not quite ready for resin yet.

[chad y 1]

Very nice. just goes to show you don't always need to spend a fortune to keep gaining.

A little time and effort can gain on the meter.

Chad

[bigjae1976 0]

I thought duct tape around the screw holes will gain a couple of DB's.

[mattd0344 2]

what size of speaker wire are you using?

[sundownz 197]

what size of speaker wire are you using?

I am using Stinger HPM 8 awg power wire for speaker wire.

[shizzzon 461]

Hey, unless i missed somethin in the post, if u have only been able to get up to 155.6, how did u get that 155.9 in your sig?

[Derrick824 4]

Hey, unless i missed somethin in the post, if u have only been able to get up to 155.6, how did u get that 155.9 in your sig?

That was a different setup. You'll see he has 4x saz-3000s listed in the sig where he's only using 2 right now.

[shizzzon 461]

oh ok...

Wow, that's impressive then.

How much power u gettin out of those amps? approx 5kw per amp?

[sundownz 197]

oh ok...

Wow, that's impressive then.

How much power u gettin out of those amps? approx 5kw per amp?

Not quite in this setup. I am at 0.45 DCR per amp with this setup - so I'd say more like 4k per amp tops.

[syzkomike 0]

hey like the box design anyway you could spec me a box and do some gain checks i dont have the equipment and box mats are getting real pricey. i have to tens @ 37hz 5.2cbs good for a 149.3db allso what track are you esting with??

[mattd0344 2]

what size of speaker wire are you using?

I am using Stinger HPM 8 awg power wire for speaker wire.

Did you have to trim the wire a little in order for it to fit in the push terminals on the sub?

[shizzzon 461]

maybe, maybe not. 8awg really isn't that large diameter-wise.

Even though most amps may state that the max speaker wire size they accept is 8awg... the insert is actually quite bigger as long as you do not expect the casing of the wire to fit in there as well.

I'm gonna be running a @$$&%$%* ton of wire for speaker wire in my setup soon just because wire is so cheap but also doin it for comps too so every little bit helps.