# SI BM MKIII 12" SPL FUN!



## sundownz (Apr 13, 2007)

Random pre-fab sealed box screwed down on top of my SPL box creating a 4th order band-pass *laughs*










First Try :










Second Try :










Adding some duct tape as it was leaking air BAD:










Little bit of power on tap :










First score with duct tape added :










Tried again :










Last burst and best score :


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## JayBee (Oct 6, 2006)

nice...what is left of the driver? a smokey crater? or does it still work?


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## sundownz (Apr 13, 2007)

It worked until that last burst of 143.2 dB... I added quite a bit of power from the 143.0 score but the sub was out of stroke so I ended up destroying the carrier assembly and mechanically beating up the coil. I did not smoke it, though.


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## sundownz (Apr 13, 2007)

I will add that NOBODY should ever have an issue with the coil or carrier assembly at anywhere NEAR rated power... I juiced it pretty hard with *two* 3500s on 18v to kill it like I did, LoL.


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## Electrodynamic (Nov 27, 2007)

That was some pretty sick testing today.  

The subwoofer was in good working order until the last burp with two 3500D's strapped to it. The carrier was destroyed, which in turn did a little bit of damage to the coil. Even though the coil and former got raped when the carrier let go, the windings were still in good shape. As Jacob said, with rated power, no one should have problems with the subwoofers at rated power. 

...test results today have me a bit worried that Jacob might be able to pull the 150 out of a pair of BM mkIII's.


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## JayBee (Oct 6, 2006)

This has got me considering picking up another pair to run in the false floor. But then i would have to get another amp...and god knows that car audio projects never go beyond the original plans.


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## ItalynStylion (May 3, 2008)

Wow, you guys are insane....and I like it! Sounds like it was a fun day!


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## Boostedrex (Apr 4, 2007)

What is the rated power on 1 BM anyway? I have never known that figure. LOL!


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## Lanson (Jan 9, 2007)

Boostedrex said:


> What is the rated power on 1 BM anyway? I have never known that figure. LOL!


I've learned it is limited by x-max plots relative to the box size. About 450 seems normal on a .5 cubic foot box, polyfill and insulation stuffed as instructed.


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## Electrodynamic (Nov 27, 2007)

We rate them for 450 watts RMS. We probably sent it 2500 to 3000 watts during that last burp which killed it. Man that was fun!


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## Electrodynamic (Nov 27, 2007)

BTW: Jacob and I have a bet going on. If he does a 150.0 with a pair of BM mkIII's, you will witness a video of me blatantly admitting that he knows more about how to get loud (i.e. SPL) than I do. The limits are less than 2500 watts and below the window line. 

Yes, ladies and gentlemen, the game is on!!!


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## mSaLL150 (Aug 14, 2008)

Electrodynamic said:


> BTW: Jacob and I have a bet going on. If he does a 150.0 with a pair of BM mkIII's, you will witness a video of me blatantly admitting that he knows more about how to get loud (i.e. SPL) than I do. The limits are less than 2500 watts and below the window line.
> 
> Yes, ladies and gentlemen, the game is on!!!


2500 per driver or total for both?

He might hit the 150, but the real question is: how many drivers will you let him blow up trying to get that number? :laugh:


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## Electrodynamic (Nov 27, 2007)

mSaLL150 said:


> 2500 per driver or total for both?
> 
> He might hit the 150, but the real question is: how many drivers will you let him blow up trying to get that number? :laugh:


We blew the driver in this testing on purpose. Other than that, he only gets a pair of BM's to attempt his 150. If he blows them trying to do the 150, I win the bet.


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## SQJEEP (May 14, 2009)

I'm tuned in. I wish I lived around there to see this cause man it would be fun to see. Good luck to both of you, but i think jacob can do it though.


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## ItalynStylion (May 3, 2008)

Electrodynamic said:


> We blew the driver in this testing on purpose. Other than that, he only gets a pair of BM's to attempt his 150. If he blows them trying to do the 150, I win the bet.


Ohhhh, I see...we've got money on this test


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## basshead (Sep 12, 2008)

with a box like this, i think it's possible





























this guy scored [email protected] with one 15 

in a Dodge Caravan...


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## Boostedrex (Apr 4, 2007)

Electrodynamic said:


> BTW: Jacob and I have a bet going on. If he does a 150.0 with a pair of BM mkIII's, you will witness a video of me blatantly admitting that he knows more about how to get loud (i.e. SPL) than I do. The limits are less than 2500 watts and below the window line.
> 
> Yes, ladies and gentlemen, the game is on!!!


Oh.... This could get funny.


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## basshead (Sep 12, 2008)

forget my last post... this is what you need to get mad DEEBEZ


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## ItalynStylion (May 3, 2008)

^Oh hellz yes!


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## Electrodynamic (Nov 27, 2007)

We got a 144 out of the 4'th order bandpass yesterday night.  I'm sure Jake will post pics pretty soon.


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## Electrodynamic (Nov 27, 2007)

basshead said:


> forget my last post... this is what you need to get mad DEEBEZ


Definitely need to add that to have the mad dee bee zorz!


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## Electrodynamic (Nov 27, 2007)

mSaLL150 said:


> 2500 per driver or total for both?


I missed this question earlier. He gets to use 2500 watts total for the pair of drivers to attempt his 150. 

...this is getting interesting because we keep doing very good numbers with a single sealed driver.


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## sundownz (Apr 13, 2007)

Pics of the loudest box position (we tried like 20 ways) and the score :



















Video Uploading now...


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## sundownz (Apr 13, 2007)

YouTube - Stereo Integrity BM MKIII -- 144.0 dB


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## JayBee (Oct 6, 2006)

Is that still with a single?


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## sundownz (Apr 13, 2007)

JayBee said:


> Is that still with a single?


Yep!


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## Boostedrex (Apr 4, 2007)

Electrodynamic said:


> We got a 144 out of the 4'th order bandpass *yesterday night*.  I'm sure Jake will post pics pretty soon.


Ummm? You developing your own local dialect around there Nick? LOL!


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## Electrodynamic (Nov 27, 2007)

Boostedrex said:


> Ummm? You developing your own local dialect around there Nick? LOL!


It's a technical term. I don't expect you to understand.


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## Electrodynamic (Nov 27, 2007)

We managed a 148 and some change tonight with two BM's. I'm sure Jake will try for the magic 150 tomorrow with the new pair of modded drivers.


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## sundownz (Apr 13, 2007)

Getting close


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## danssoslow (Nov 28, 2006)

Electrodynamic said:


> We managed a 148 and some change tonight with two BM's. I'm sure Jake will try for the magic 150 tomorrow with the new pair of *modded drivers*.


Care to elaborate?


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## sundownz (Apr 13, 2007)

First we made a REALLY small ported box... but the tuning was too high and extended the port messed up the phase relationship...




























Not much better than the single woofer at it's best so we quit on this box.

So... we modified one of my dual 8" woofer boxes to hold two 12s -- about 75% larger than the first :



















I forgot to take pictures yesterday... the port did have a flare on the end. MUCH shorter port.

This is what we got :


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## mSaLL150 (Aug 14, 2008)

148 legal is pretty damn impressive for two BMs.


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## sundownz (Apr 13, 2007)

danssoslow said:


> Care to elaborate?


Treated the surrounds with some flexible glue to stiffen them up.


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## albocruz210 (Feb 25, 2010)

when will another run of these happen?


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## dantonel (Mar 30, 2010)

Hey Nick!!! Quit Messing Around and Put Out Some Speakers for Gosh Sakes!!!! Lol.


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## sundownz (Apr 13, 2007)

albocruz210 said:


> when will another run of these happen?


Nick is working on it  I believe that all the parts are ready and they should be assembled shortly.


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## Electrodynamic (Nov 27, 2007)

I'll be sending out a newsletter this week, so be patient.


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## dantonel (Mar 30, 2010)

Nick, I hope you know I'm just giving you a Hard time. I know that Quality can only come after patience and care. I am so freaking excited to get my Mkiii it's not even funny... BTW did Jake hit the Magical 150 yet?


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