Help with a tapped horn.

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It is this design in the pic below. I hope someone can help me adjust this design and resize it for the 8" MCM driver. I did do a search but the link posted for a design for the MCM driver didn't work. I don't understand Hornresp.

The specs for MCM 8" driver:

Specifications:

•Power capacity: 120W/240W RMS/peak
•Frequency response: 25Hz ~ 1KHz
•Nominal impedance: 4Ω
•Voice coil diameter: 2"
•Magnet weight: 47oz.
•Sensitivity: 87dB W/M
•Fs: 25.7Hz
•Re: 3.4Ω
•Le: 2.47mH
•Qms: 14.0
•Qes: 0.22
•Qts: 0.22
•Vas: 30.43 liters
•Mms: 59.78g
•Xmax: 8mm (one-way)
•Magnet gap height: 8mm
•BL: 12.99
•Piston diameter: 163mm

Dimensions:


•Overall frame diameter: 8.25"
•Required cutout: 7.125" diameter
•Mounting depth: 4.5"

An externally hosted image should be here but it was not working when we last tested it.
 
Your right DJK
I actually wrote TH 115/ Mini and then removed the mini portion. Go figure why my brain did that.

I am finishing up my second 2nd TH Mini clones tonight.
All I have left is to screw on the side/top. Then I get to paint those and the Lab 12 reflex cabs. Can't wait to hear 4 of them! (mini clones) :D
My basement will eventually look like Danleys demo room !!!!!!! ::spin:

Mike
That driver will take a redesign. It does not work to well in said design. (using my TH Mini clone parameters which is 106 lt internal) A dual driver setup works ok for this layout in about 220-250 Lt (forget what it was). Which is between the sizes of the 2 cabinets in your images. So DO you HAVE to use that particular driver? And what will the sub be doing? IE PA or Home?

Which can you please post a link to where you got
these from?
 
Easier said than dun

A design like you posted is not to easy to re-size and have work out well. Believe me I'm working on a couple right now. If you are determined to use the plan why not knock up one with the same proportions but down sized to meet the smaller horn. Other wise there are some plans for 8 inch horns on the forum.

Some names to search
jbell
mwmkravchenko

There are others just I thoroughly checked out jbells work and it is good.

Mark
 
Jbell it will be for PA use. I am looking to build several (6 or 8) small, light weight subs using 8" or 10" speakers. Still want the thump in the chest from the kick drum, but easy to carry. We play small bars and clubs.

I had the MCM 8" driver on hand. No big deal though as I can get Eminence speakers at dealer cost. Could you give me some idea's on cabs for the MCM front loaded? Also what small Eminence driver would do good in a tapped?

Thanks Mike
 
Mike
Other night I played with that 8" driver. The only way I could get anything good from it was to make it a dual 8" which defeats the purpose of an 8" in the first place.
I have 2 options right off the bat for you.
Either the B&C 12PS100 or the Eminence Kappa Pro 12A. In a box that is 24" T x 22.5" D x 15" W. The B&C cuts off at 42 Hz. The Kappa at 38. The B&C is about 3Db louder though. 126-129 Db Vs 123 Db. 50-200 Hz
IF I hadn't already built a set with the 12PS100 I would have used the Kappa as it is cheaper and uses less power to get there.

Thanks for the link.
Funny I didn't see that thread of there. I kinda wasn't around for a bit and then everyone over the pound was dissing the TH a bit so I didn't keep up with it.
 
Thanks Flip for the info. Your right, dual 8's defeat the purpose. Oh well it won't go to waste, I'll use the MCM 8" in a Autotuba or a DIY subkick.

I have a couple Eminence 3015lf drivers, I wonder how they do in a tapped horn?

I don't have any of the Eminence Kappa Pro 12A on hand, but can get them about $50.00 below retail price. How many 24" T x 22.5" D x 15" W boxes do you think I would need for live band PA in small clubs (200-300 people)? We play 80's to current rock and metal? We run everything thru PA and looking for that thump in the chest kick drum...
 
Mike:
3015lf's are fantastic in TH. Go search screamerusa's cabinets for them. That's your absolute best bet. I used 4 of them in a very large TH, for a football stadium project. Yea, 3015lf works well in TH.

GM:
Check out my outdoor measurements on my dual 55-2421 FLH... average 103db @2.83v, drivers in series for 8ohm cabinet? wow... If you've got any hornresp sims that come anywhere close... I'm all ears. I used a pair of them for a PA in the Park event... Outdoor, PA, FLAT TO 40!!!! out of an 8" driver that costs $25... blasphemy... driven with one channel of an xti1000, worked beautifully. (btw, a zed14 to a xti1000 is a killer cheap setup)
 
yea, about 100db in 400l for TH, or 103db in 270l for FLH. Some drivers just like FLH, and some like TH.

I had to use a compression chamber, and a very high compression ratio to get it, but it works. Of the cabinets I've made, I think this one impresses me most, because cheap-o MCM 8" drivers are not supposed to be able to do PA duty.

The concept that I had, that I never completed, was a 'bass stick' A FLH for a 55-2421, that would be the speaker stand for a pa top. (Think up and back FLH) I thought that would help me out in small venue's.. but then, it seems that anything small, I need to wall or corner load the sub(s), and everything else is outdoor or needs more than that would give, so the bass stick idea kinda died.

Another thought, is a BFM T18, dual driver, 24" wide, with a big inductor (10-12mh) That gives respectable output, and is reasonably flat. 4-8 of those would be downright impressive, and easy to carry.
 
I read the 67 page thread of screamerusa's. My poor little peanut brain is swimming. :spin: Whew! I don't even know where to start. lol :D

I was trying to shy away from a big cab and the 3015lf. What I am looking for is a small light weight cab and a cheap driver. Something I could build 6 or 8 of to give the thump in the chest from the kick drum.

It doesn't have to be a tapped horn, I just thought the pic of the cabs I posted at the beginning of the thread would be about the right size for me. How would a 10" BP102 do? They can be had pretty cheap and are for bass. Would 6 or 8 of them in a TH do any good?
 
bp102... hmm sounds like you are getting the T39 suggestions in BFM land.
Well here's a couple pics that you might find interesting. One of them, is the T39s, ready for hot dog duty... (roasting) I just don't like -13db@ 40hz, vs 100hz.... Just like bgavin, I like flat to 40. I just don't want to have to eq my subs down to 95db efficiency across the board, to get it. (BFM faithful will tell you, that gives you more 'headroom' when you eq down the upper freq... Well, I've never had a need for more 100hz headroom on a sub...) I have ZERO bass eq on my little (21x23x33) mcm FLH subs, and with just 2 of them, they are flat to 40.

so... take that as my 2c...

If you want a BFM design, build 24" wide dual T18's. ounce for ounce, cubic inch per cubic inch, it's the best sub BFM has. I actually don't think Bill has a good appreciation of how good that sub really is, especially with an inductor added. The second picture gives you a good reference on how much bigger T39's are, vs the dual T18.

good luck.
 

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