Box Modification SPL Gains

[sundownz]

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.

[sundownz]

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.

[cj407]

good to know some foil tape isnt going to help my car...

[sundownz]

good to know some foil tape isnt going to help my car...

I've gained 0.1 in a vehicle doing 158s with a single piece of foil tape before So it is always worth a shot!

[cj407]

crx and modding the car isnt a great mix from what i hear...

[2003F150]

I may need to go inside my box and try some pieces in the corners.....watching and learning....you are a good man testing this for us all to see.

[sundownz]

crx and modding the car isnt a great mix from what i hear...

Might be surprised - look up Terry Brocks' thread on Termpro :

http://audioforum.termpro.com/topic/8/27273/4.html

He said he gained alot putting the Dynamat Extreme in

[ABSOLUTEAUDIO]

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.

I first looked at the pic of the TL readout WOW Your woofer hit's every note Then i read your last line

[Lakota]

In street boxes corners usually don't give too much, if at all. I've always lost score from them, even as much as 0.5 dB.

[fearof85]

By box mods are you agjusting the port length too. When your competing having that "it's not gonna make me louder" mentality will do just that. Keep making those gains for everyone to see.


Drew

[Xprime4]

good read. Waiting on the corner. I'll do a box tomorrow and don't know if i should put corner or just gain some more airspace

[sundownz]

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.

[oh2tahoe]

I'm ready to see the resin put in, I got about 3 gallons in mine and I could tell a difference when I did it, but didn't meter before or after.

[Lakota]

I can defiantly see that pvc helping.

[Xprime4]

is the pvc tube the port? or just a pvc tube at the bottom