Best DIY sub for 18" driver

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In general, 18s are too fragile to be used in a bass horn due to the pressure at the throat which tears the cone. Bigger doesn't really mean better.

If you had say... nine 8" MCM 55-2421 woofers you'd have a total Sd of 1872cc. With an Xmax of 8mm that's a Vd of 14976cm3. An 18" has an Sd of around 962cc, so that'd need 15.5mm of Xmax to equal this cloud-9 :cloud9: array. Power handling would be just short of 1kW.

Oh, and the MCMs can survive a really high compression ratio for use in very efficient horns which make a lot of pressure at the throat. Shhh... don't tell everyone.

With the MCMs at around $25 each with a coupon code, sell your 18" before others learn about this.
 
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Shhhhhh. I thought I told you this was a secret. ;)

Keep it down - now everyone will know......

Oh - wait - I posted all the details of my quad 6" driver powered (tang band W6-1139) tapped horn earlier... :D

Multiple small drivers in a high-compression ratio horn (or tapped horn) can certainly be a good thing. I know I certainly have plans for my version of a 6-pack.

Many hands make light work.
 
I'm a little confused, I've been told that big subs lagged so I was already pretty keen to go down the road of 4 x 8" or 4 x 10".

Some one on the Klipsch forum told me lag could be fixed an to go for a horn sub as they had big output to input an relatively low cost in parts.

The only thing was that I had seen smaller subs at fairly high costs an figured if I could get away with 1 bigger sub I'd go for it...

Was pretty set on a tuba 36" when I saw a the issue of wrong/different data than was displayed.
I don't mean to be rude but some of my audion mates split hairs,
How far off are the results to the BFM results?

Thanks to you all for replying, I've been trying to get my set up ready for new years all year and have had little luck until now even getting straight info.

For the $3000 that a Danley would cost I'm prepared to have a good go, Are there any more pics, or info on these multiple small sub setups?

Thanks again
 
Shhhhhh. I thought I told you this was a secret. ;)

Keep it down - now everyone will know......

Oh - wait - I posted all the details of my quad 6" driver powered (tang band W6-1139) tapped horn earlier... :D

Multiple small drivers in a high-compression ratio horn (or tapped horn) can certainly be a good thing. I know I certainly have plans for my version of a 6-pack.

Many hands make light work.

Thanks for the spill guys...

Davygavy do you have plans or pics that I could find to get my head around a design?

Always find it hard to visualize a project with just these projected graphs to work with.

Are these multipliles useful outside loud?
Thanks
 
My quad-driver sub details are all posted over in the collaborative thread. No IP here. It was a home theater based design, and does that very well.

Jim's subs are something you've seen already. Again - the info is out there, no IP at all.

Now for the fun part. 4 of the MCM 8's in a tapped horn with a 4:1 compression ratio and a 10:1 flare (a mouth size similar to Jim's) gets real interesting.

Almost as loud as Jim's at 1W, though there is 3 dB of ripple in the passband, and it definitely has the typical 1/2 wavelength step where the response rises. Steps are easier to fix than dips.

Nope - they're not perfect, but they do play below 30 Hz with authority, and they don't run out of linear excursion until 400 W is applied, though my experience with these drivers suggests that the bad noises and smoke won't happen until 800 W is applied (200 W per).

If you want them a LOT smaller, you give up 3 dB, buy they fit in a room without looking like a pair of wooden refrigerators.

Davy - Dual quads always outran the six-packs - right?

I need to stop pushing pixels and make some sawdust.

Would I use these in a ProSound environment - No

Will I build myself a pair? Ummm - Yeah, at least.

In fact, the big brown UPS van should be dropping my drivers off this morning.

I will provide designs, details and measurements once I get this project moving along. I will even try to get a 28V/10M number, though I do have neighbors close by.

Here is the hornresp export (THANK YOU DAVID):
 

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Here's something I did about 4 years ago. That's six 16" wide AutoTubas loaded with the HL10c driver. It looks small, but the sound was big. Fc was around 36Hz for the combined, -10 usable at 29Hz. MaxSPL calculated to 137db(SPL) @ 40Hz. Absolutely no one believed they were 10" drivers who heard it.

I was only just making a point about how numerous small drivers can exceed a big one. If you did make one big huge horn driven by nine 55-2421 drivers, it is still huge. As horn cabinets mutually couple wonderfully, I'd consider many boxes with a single driver. They move so much easier. Maybe the 14" titan 36 with a single 10", but six or eight of them arranged in a V-couple array? But an HL10c isn't cheap.

jbell is working his FLH cab with a single 55-2421. That looks promising.
http://www.diyaudio.com/forums/subwoofers/144589-dual-mcm-flh-3.html
 

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Fc was around 36Hz for the combined, -10 usable at 29Hz. MaxSPL calculated to 137db(SPL) @ 40Hz. Absolutely no one believed they were 10" drivers who heard it.

Maybe the 14" titan 36 with a single 10", but six or eight of them arranged in a V-couple array? But an HL10c isn't cheap.

jbell is working his FLH cab with a single 55-2421. That looks promising.
http://www.diyaudio.com/forums/subwoofers/144589-dual-mcm-flh-3.html

Ok thanks davy those look really nice, good job!

I'm after 30hz to 100hz, Spl greater than 100db 1w/1m so even your little beauties could do what I'm after.

I think I should work with what I've got so I'll try to find something to utilise my 400w Qsc...

I could probably afford 4 HL10c's but I'll have to look into what sort of power I'll need to run them, if I'm going up too high I'll have to hire a big sub amp, not overly desirable but I'd do it until I can afford my own gear.
I've been told Titans work better with live music an Tuba's are better for recorded electronic stuff.... (which I play)

Do you daisy chain your setup?

Look forward to hearing about jbell's new FLH....:cool:
 
Do you daisy chain your setup?

I ran two cabs in parallel per each amp channel. I rented two QSC PLX2402s with one channel left over for the drummer's monitor. So that was 1200 W per pair of AutoTubas. A little over the 1000W (500W each) music power rating and used the limiter of my x-over to prevent heat damage.

What's the max SPL you're after? Normal rock levels of 107 average 25 feet out?
 
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Cerwin vega makes an 18" folded horn? EL36B 18"

An externally hosted image should be here but it was not working when we last tested it.


Path length looks to be 6.75 feet based on scale of the driver's cone with apparently little of a compression chamber. It doesn't look front loaded to me. They say sensitivity is 106, but forgot to mention they measured where the horn is most sensitive, probably 110Hz. And no charts! Where's the IEC-60268 graphs? Every company and their mother does this.
 
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