BM mkIII dimensions

[Electrodynamic]

I think you're looking into this a lot more than is necessary. First, no, you do not need to have any clearance behind the driver. It has plenty of venting around/behind it to negate the need for X amount of distance from the rear of the enclosure. Secondly, simply shoot for a 0.5 ft^3 internal enclosure requirement, whether it be with or without stuffing. Just meet the 0.5 whether that measurement is after stuffing or before stuffing and you'll be good to go. As always, we recommend lining the walls with fiberglass insulation and then lightly stuffing the inside of the enclosure with polyfill for the best results. You may read otherwise on other forums, but that combination is what works best to smooth out the response and make the driver think it's in a larger enclosure.

As for a grille, the standard Madisound grille will work just fine. Any standard 12" grille will work with the new BM mkIII's. See this one: http://www.madisound.com/catalog/pro...roducts_id=715 We'll need to verify fitment with that one though since it isn't flat.

[zacjones99]

Overthinking it is the fun part! Almost done though.

I just reread your post about the Qtc not being too important and the target F3 being the goal. It sunk in a little better this time as I focused on that when modeling in winISD.

So whatever box I end up building I'll line it with fiberglass insulation and lightly stuff it with polyfill, aiming for an F3 in the mid-forties. It looks like my .424cf box will work out just fine. Thanks. Zac.

[Electrodynamic]

Yep, that will be just fine. Our test box was right at 0.43 ft^3 without anything in it. Then we lined it with fiberglass insulation and lightly stuffed it with poly.

[kelrog]

Originally Posted by Electrodynamic

Here is a technical drawing of the BM mkIII's basket for all of your mounting depth and cutout desires. All the dimensions are in mm.

anyway we can get this back up. Its not showing up anymore.

[Electrodynamic]

Try it now. It's showing up for me now. I don't know what was going on because the link looked the same.

[kelrog]

Originally Posted by Electrodynamic

Try it now. It's showing up for me now. I don't know what was going on because the link looked the same.

Thanks. BTW On the website This link on the MKIII page isn't working.

"For a technical drawing of the BM mkIII Click Here "
http://stereointegrity.com/images/BM_Basket.pdf

and this one as well.
"Click HERE for more technical information."
http://stereointegrity.com/technical.php

sorry, just want to help out.

[Electrodynamic]

Don't be sorry - I appreciate the feedback. Without it the site wouldn't get fixed. I'll fix the errors today. If you see any more please post it on here.

I fixed the basket dimension pic, now onto fix the technical page link.

[usa414]

Originally Posted by Electrodynamic

Yep, that will be just fine. Our test box was right at 0.43 ft^3 without anything in it. Then we lined it with fiberglass insulation and lightly stuffed it with poly.

Hi Nick, I'm going to finally finish my audio system this month. Man, was it a long winter here in the northeast (especially without a garage to work in). I noticed you said that you used a 0.43 ft^3 test box. What kind of power handling does that yield? I really hate to beat a dead horse here, but It looks like my box will be 0.9 ft^3 for two drivers (so 0.45 ft^3 shared air space per driver). I want to make sure I retain maximum power handling on the drivers though, and you said 0.5 ft^3 is what you need for 450 watts RMS. Anyhow I can probably make the box a little bigger, but the current dimensions work really well under the back seat of my 2005 F-150.

Also, what's the minimum/recommended amount of room needed between the bottom of the enclosure and the floor of the truck? I'll be using a down-firing configuration. Thanks again for all of your help!

[pinktaco]

what db does it hit?

[usa414]

Originally Posted by pinktaco

what db does it hit?

A pair is apparently capable of hitting 148 with a little tweaking. I think Nick was able to get 144 out of a single driver out of the box with some "extra power". There's a thread on DIYMA called SI BM MKIII 12" SPL FUN!

If you Google that, the thread should come right up. There were all kinds of things that needed to happen to get those numbers, like modding the box, and 2000+ watts of power... I think under normal conditions though (recommended RMS, sealed enclosure, etc...) a single BM MKIII can push somewhere in the mid 130's - at least, I think that's what Nick had said.

Hope that helps.