diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Subwoofers (http://www.diyaudio.com/forums/subwoofers/)
-   -   ~50 lb tapped horn, woofer under $100, high efficiency, low power? (http://www.diyaudio.com/forums/subwoofers/217695-50-lb-tapped-horn-woofer-under-100-high-efficiency-low-power.html)

turbodawg 10th August 2012 05:16 PM

~50 lb tapped horn, woofer under $100, high efficiency, low power?
 
I'm interested in building a ~50 lb man-portable sub to be run off a battery powered amp, around 50-100w. What is the sweet spot between extension and efficiency here? For outdoor use.

I'm curious if using an efficient 12" pro audio (non-sub) woofer in a tapped horn is reasonable, considering the lower power and excursion.

Would probably be made from 1/2" cheap birch plywood.

I need to get horn resonse software and learn it.

You thoughts? Thanks!

jbell 10th August 2012 06:12 PM

ss15 with the kappa pro 15lf2 is exactly in line with what you are asking.
Look in the single sheet TH challenge thread.

turbodawg 10th August 2012 06:26 PM

Quote:

Originally Posted by jbell (Post 3121769)
ss15 with the kappa pro 15lf2 is exactly in line with what you are asking.
Look in the single sheet TH challenge thread.

Cool, thanks! Would something like an Eminence Delta-12LFA 12" be workable in a scaled down version...?

Eminence Delta-12LFA 12" Low Frequency Driver 290-416

turbodawg 10th August 2012 07:25 PM

How about a Dayton 12" PA310-8...?

Dayton Audio PA310-8 12" Pro Woofer 295-032

turbodawg 10th August 2012 07:52 PM

THAM12.......? Seems like just the right size for me?

Martinsson's Blog - THAM12

jbell 10th August 2012 10:07 PM

2 Attachment(s)
I have a design for an eminence 2512 eminator... It's half the cubic volume of the ss15.

I use this design in dance studio's. The 4ohm driver works well with HTIB's and/or mobile amps that are typically voltage challenged and want 4ohm or lower loads.

I still say the ss15 with the kappa pro 15lf2 is the ticket....

NEO Dan 10th August 2012 11:43 PM

Light and LOUD
 
You could always get the 2Ω JBL 265F-1 15" to get the power up, also happens to be very light weight...
http://www.jacksmusicfactory.com/ima...ucts/91609.jpg

And possibly a small class D amp with adjustable subsonic filter...

jwmbro 11th August 2012 02:06 PM

Quote:

Originally Posted by jbell (Post 3122010)
I still say the ss15 with the kappa pro 15lf2 is the ticket....

Except for his 50lb weight limit!

My SS15 with the Kappa-Pro-LF2 weighs 34kg - that's a solid 50% over weight budget. After using the KPLF2, my personal conclusion is: definitely go Neo, it's worth the money. But your own conclusion may vary depending on the situation

Quote:

Originally Posted by turbodawg (Post 3121784)
Cool, thanks! Would something like an Eminence Delta-12LFA 12" be workable in a scaled down version...?

Eminence Delta-12LFA 12" Low Frequency Driver 290-416

Quote:

Originally Posted by turbodawg (Post 3121858)
How about a Dayton 12" PA310-8...?

Dayton Audio PA310-8 12" Pro Woofer 295-032

Hi turbodawg,
both of those drivers perform well in a Horn, both in the SS15 design and in the THAM12 design.

If you use the SS15 design, unshrunk, in its original size, you are looking at about 117dB, down flat to 40Hz, xmax limited at 20V (50W into a nominal 8Ohm load).

You can easily shrink the width of the SS15 by about a quarter, for a 16" external width, this hardly affects performance, you are losing maybe 1dB of output, and a couple Hz of low end.

If you use the THAM12 design with either of these woofers (Warning: the THAM12 is a very tight design, before purchasing, make sure the magnet assembly of your chosen woofer even fits!), you can hit it with 28V (100W of power at 8Ohm) and are looking at nearly 120dB, but definitely not to 40Hz, more like 55Hz. and if you are using any kind of electronic music with deep frequencies, you'll probably want a protective high pass, as excursion goes up rapidly below 40Hz.

Have a look
http://i.imgur.com/xzuYp.png

All 4 these designs should comply with your airline-like weight restriction, however the slim SS15 with Dayton PA310 only barely - the driver is cheap, but it's heeeaaavy. If you can stretch your budget a little, consider this B&C driver:
B&C 12CL64 12" Neodymium Woofer 294-694
at less than 2kg it is super light thanks to Neo magnet, and works well in the horn designs.



I also agree with the other posters here, that for mobile usage, there is some advantage to using a lower impedance driver, as with batteries you are typically limited by the voltage your amp can supply. If you are running off mains AC, disregard that.

turbodawg 11th August 2012 10:40 PM

Wow that's awesome and amazingly helpful. I like the airline luggage analogy..."I'd like to check this please..."

This is to be part of a battery powered PA, to be transported in the back of a sedan. Just took some measurements, and it appears that 16" is too thick to fit in the trunk. 32x30x14 is about the absolute max, and 30x24x14 by looks like it would be optimal - would you say that decreasing the width by those 2" would have minimal effect on performance, while slightly increasing power handling?

The dayton pro 12" seems like a good fit, this is a budget project and has already far overgrown it's original scope, so cost containment is good. 40hz extension is just about right, and the output is plenty - is that sim'd in free space or against a wall? I'm calculating that the width decrease reduces the wood used by about 8 square ft, so that should put the total weight of the box itself around 30lb, plus the driver?

I'm starting to get excited here, thanks again!

jbell 12th August 2012 01:30 AM

Well if 24x30x14 is your ideal -- build that.

As it happens -- a ss15 is 24x30, and if you build it 14" wide and put a Dayton Audio ST305-8 12" Series II Woofer in it... you can get 120db at 100watts with just about the exact same response profile (just lower total output) as the full size ss15 version.

You are good up through 200 watts so you've got plenty of headroom available on that driver. Highpass at 30hz.
(wonder if that config should be added to the singlesheet thread as a SS15slim)


All times are GMT. The time now is 01:23 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2