what to do with 12 mcm 8" speakers

[soundhead]

I have twelve mcm 55-2421 8" driver what to do with them. Confuse here. looking for 30 to 200hz.

[jbell]

which mcm's ???

hopefully 55-2421's.

[soundhead]

yes sir

[TerryO]

Originally Posted by soundhead

I have twelve mcm 8" driver what to do with them. Confuse here. looking for 30 to 200hz.

That's almost subwoofer territory, sounds like you've got a set of good woofers.

Best Regards,
TerryO

[killa12222]

Put it all into a big ol ported box!

[NEO Dan]

Originally Posted by jbell

which mcm's ???

hopefully 55-2421's.

My thought's exactly, every other MCM driver I've tried was total rubbish in the TSP department.

***

jbell is modest, he has posted a couple nice horn variations for this driver.

[18Hurts]

JBell built horn loaded subwoofers out of a pair of those 8's. It rolled of at 40Hz but might work for you with a redesign.

Dual MCM FLH

Do you want 12 subs, 6 subs or one giant sub? How large can you go?

[ByronInLawrence]

Hi Soundhead,

There's an awful lot one could do with 12 woofers like that. Here is what I would do if I had 12 of these woofers:

Option 1, easiest:

1. I took the liberty of finding and attaching the data sheet on your woofers. Save it to your computer.
2. Download one of the many free box design programs available. Here are two really simple ones that you don't even need to download: http://www.mh-audio.nl/ReflexBoxCalculator.asp and http://www.mh-audio.nl/CBC.asp
3. Play around with alignments, sealed vs. vented (I think your driver is designed for vented), box sizes, etc . . .
4. Choose your design and build an awesome subwoofer!

Option 2, harder, but more fun, with better chance of good results:

1. Save attached data sheet to your computer.
2. Go here: SPL Tools and download SPL tracer.
3. Use SPL tracer to make at least a *.zma (impedance graph) file. You could also make an *.frd (frequency response) file.
4. Download free software which will allow you to use your *.zma and *.frd files to model a box. I use Speaker Workshop (SW), which can be found here Speaker Workshop I don't like SW, but it's the best thing I've found for free.
5. With the help of the many online tutorials, learn to use SW just enough to design a subwoofer.
6. Design, then build, the ultimate subwoofer!

Option 3, probably not worth the effort unless you're really hard core.

1. Don't bother with the manufacturer's data sheet, because it may not be accurate.
2. Download SW, and learn how to use it to measure impedance.
3. Build yourself a Wallin Jig. Instructions are here Eric Wallin's Internet Homepage. Don't worry, it's not expensive, but it is time consuming.
4. Use the Wallin jig, along with an external amplifier, and Speaker Workshop to generate *.zma files and calculate T/S parameters. If you want to be obsessive, make a separate file for every driver.
5. Don't bother with *.frd files - too difficult and expensive, and not necessary for a subwoofer.
6. Use said *.zma files to design a box or boxes for your speakers!

That's just what I would do. I'm sure you'll get lots of suggestions.

-Byron

[soundhead]

A tapped horn design four mcm per box will do.
box size 20x32x45

[ByronInLawrence]

one more thing . . .
If you don't want to use all 12, I'm sure you could find people at the swap meet forum who would be willing to buy a few from you.