BL 15 spl enclosure

[kjmass21 7]

I am running a fullyloaded bl15 off a planet audio bb2400 making about 1600rms. Electrical- big three, 1/0 throughout, second battery in rear, voltage stays around 14.3, drops to 13.6 for tones. My first enclosure was 5ft^3 tuned 36, 60 sq" port, with bracing, angle boards and routered port edges. Sub faces drivers seat while port fires up behind passenger seat. I hit a 143.8 meca style. Built a new box 3.5 ft^3 tuned 45 with all the bracing, angle boards and routered port edges and dropped to 141.7.

I wanted to find out what box changes I may make to increase score, and if I was crazy trying to reach a 150 with a bl?

Edited March 30, 2011 by kjmass21

[bassahaulic 155]

You don't have enough power to do a normal SPL box. The woofer was using the power more efficiently in the larger box.

[kjmass21 7]

What kind of power would you sugget, keeping in mind its a single bl?

[bassahaulic 155]

Well if it's only for SPL, I'd have no problem burping 4,000+

[Notorious97200 339]

Wow ! 4000 on a 15" bl ? It can handle that much on a burp ?

[thor02 2]

It should handle 4k (on a burp) no problem, as long as the enclosure is properly built. Use aeroports for adjustability and changing the tuning/box volume slightly. For high power burps, you want a smaller box volume. Your first box was good for the amount of power you were throwing at it, but the only this i would change about it was adding more port area. Closer to 80 or 90 sq inches.

[RAM_Designs 25]

Agreed, with all posts.

[ford302redneck 15]

What vehicle you got?

I've did a 146.3dB sealed in a trunk with 1 15 BL and a SAZ1500d at 1ohm dropping to 12volts.

Outlaw was 147.6 I believe.

This was in ~3.2cuft with 3, 4inch aeros tuned to 46hz or so. Burping at 51hz I believe. Its been a while.

I wanted to try 4 4inch but never did. Also would of liked a little bigger box, just this was the biggest the opening of the trunk would fit. I had to actually cut it up after I built it because the original didn't fit.

[ford302redneck 15]

And I think they'll handle 4k on a burp pretty easy. That is if you know how to.

It was laughing at the power I was giving it.

One thing about burping is, rolling up the volume. Even though a lot don't do this. I found in my setup, rolling up the volume gave me a few extra tenths. Than just having it wide open and just pressing play.

[shizzzon 461]

i ran a DC Lvl4 (1000wrms driver) off 7kw for burps and never had a problem...

Hell, Clay ran 24,000w to a single Dc Lvl4 XL and didnt have a problem.

Point is, just throw however much power u want to and see what happens.

Remember, burps should only be done long enough to get the score.

build the box so the sub doesnt fold when running lots of power either.

[Adrian_D 520]

You don't have enough power to do a normal SPL box. The woofer was using the power more efficiently in the larger box.

INdeed.

MOAR volume. Your drop in score is related to the enclosure volume.

I'm using a single BTL 12. Tried 2 cubes, couldn't go over 147dB. Went to 2.8 with more port area and got an extra 2dB. And I have no mercy...it gets everything my Z1 can muster. Whenever I drop the volume a little, I lose.

[shizzzon 461]

volume isn't everything..

Loading in cabin is key too...

One of my buddies who is also a judge set the record last year with a 155.x at the headrest on 4 15s in only 7cuft NET. Everything below the window line and entire install ONLY in cargo area.

He recently switched vehicles and took this street box with 4 15s and threw it into a prebuilt van with a 6thorder shell and broke 161 with no tuning @49hz.

[Adrian_D 520]

Well, in the OP's case, when going down in volume showed a drop in score it's obvious what happened.

As for loading and box / car relation, I remember I used to have a huge box for my xxx18, 10cubes or so, couldn't get anything decent out of it so I cut it down to 6 cubes and gained a little.

[shizzzon 461]

yea, i mean in my testing, i always gain by increasing volume...

But you gotta be careful.. if trying to use the same box for music, you might bottom out the sub at all frequencies above and below tuning if it gets too large.