Well, it's a far cry from your stated performance goal and with a 1500 W rating it's pretty much a given that the extra power will be burned up as heat, raising the cab's effective Qtc and in some cases I've seen/read where it raised it so much that it had less peak SPL at the higher power than at the driver's half power rating; so IME one needs to design based on half power rating and use as many drivers as required to meet the SPL requirements, though have enough power on tap to ensure the amp won't clip.
GM
The ideal sub setup "for you" really depends heavily on what you want out of it. If you are strictly going for high impact sub 50hz frequencies for home theatre, than one of the cheaper built subs from Exodus might be the way to go. If you're looking for more high fidelity bass - you are on the right track with Peerless or maybe a 15 inch SB. These will give you added flexibility to cross over higher to integrate well with a high fidelity midbass unit. Of course, that kind of system can produce nice results down low too - maybe not as cheap as a high SPL Maelstrom though if you were to assemble a couple of Peerless woofers to get the same overall output. But then you'd have much cleaner bass down low and up high. The key number you should look at is the moving mass spec - this is a very important quality indicator for determining who is making a low distortion bass unit. Anyone can throw a rock on a spider and rubber surround and get it to oscillate at very low frequencies. If you want a sub that does more than make "that monotone thump sound" - focus on subs in the moving mass range of 200 grams or less.
Hi Thims,
My suggestion is to give four Peerless 12" XXLs sealed boxes a try. Very difficult to beat for cost, size and-particulary-ease of build. For example, there was a realy nice write-up on a sealed 12" sub called the Thrifty Thumper, by Robert Trim in 1997. Four "end tables" maybe with corner loading would be something, and the sealed box has an excellent impulse response. But, if you are looking for maximum low end impact, tapped horns should be better.
Luckily the Peerless XXls line of 12" woofers models very well in a 300 liter tapped horn, and a dual driver (maybe push-pull?) 600 liter tapped horn maximizes the use of the 830847's Xmech v. distortion, and power. So, with a bit of OSB you could easily build sealed and TH boxes, and see which one is the better compromise for you.
For an all out attack on the low end Tom Danley's recent gift to the DIY community-the DTS-10 -would be very, very hard to beat for the price; with any sub. They are still available at the introductory kit price (quite possibly? a loss-leader), and there is a monster thread already in the AVS Forum.
Regards,
My suggestion is to give four Peerless 12" XXLs sealed boxes a try. Very difficult to beat for cost, size and-particulary-ease of build. For example, there was a realy nice write-up on a sealed 12" sub called the Thrifty Thumper, by Robert Trim in 1997. Four "end tables" maybe with corner loading would be something, and the sealed box has an excellent impulse response. But, if you are looking for maximum low end impact, tapped horns should be better.
Luckily the Peerless XXls line of 12" woofers models very well in a 300 liter tapped horn, and a dual driver (maybe push-pull?) 600 liter tapped horn maximizes the use of the 830847's Xmech v. distortion, and power. So, with a bit of OSB you could easily build sealed and TH boxes, and see which one is the better compromise for you.
For an all out attack on the low end Tom Danley's recent gift to the DIY community-the DTS-10 -would be very, very hard to beat for the price; with any sub. They are still available at the introductory kit price (quite possibly? a loss-leader), and there is a monster thread already in the AVS Forum.
Regards,
Attachments
What exactly is your criteria for high fidelity bass anyway?
I've heard a number of Exodus Audio subs and I think that they certainly sound as good as (or better) than the Peerless...as they should, having a SOTA XBL2 motor, which the Peerless does not. The Peerless isn't a bad design, but it is dated and the Shiva or Maelstrom will out perform it. BTW: It isn't so much that the Exodus Audio drivers are cheap, as it just so happens that the Peerless are quite expensive, in any sort of cost/performance comparison.
Best Regards,
TerryO
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Rather than repeat myself, you can get a better understanding of my take on Exodus here
HTGuide Forum - Top Sub Driver
I'm pretty sure I was just banned from HTGuide because of criticisms I've leveled about their buddy's (Kevin Haskins) sub - the Maelstrom. No real loss anyway, that blog site is good if you want to be hounded by people trying to sell you on their design or their wares. Say a critical thing about any of their stuff and they attack - full force.....LOL. The thread above gives a glimpse into that.
In any case, my main issue is with the Maelstrom - not the Tempest or Shiva. And I can say with certainty without ever having heard a Maelstrom that it would be useless to me. Just look at the data posted above in this DIY thread by lBP1Fanatic. See any issues there? How about an efficiency that goes from .14 to 30 then back down to .6 % system efficiency in the span of 64 hz?
Clearly, this driver, with a mass of about 530 grams is very band limited and highly non linear with respect to response level versus applied signal level. Ever try to cross something like this over to a midbass unit at 80 to 100 hz ? Even if you were successful at level matching and finding a midbass driver or woofer with sensitivity to blend reasonably well - the dynamics are almost impossible to match. The Maelstrom is obviously a driver that was designed with low end extension and output in mind by throwing a lot of mass on a large coil/magnet assembly. In that design, its primarily the mass that's making the output once the whole thing enters oscillation. The drive signal in the coil gap that's supposed to do the driving gets lost in the proverbial sub bass sauce.
The unit is configured to oscillate without a lot of power applied between 20 and 60 hz. Outside that range - response falls apart in a major way. If you want a home theater slammer - this might be a good choice. But given the response plots and the design, it's anything but a high fidelity sub. There's no doubt in my mind that the impulse response and distortion measurements for such a sub in the range of 20 to 80 hz would be almost laughable - particularly at the more critical upper end where the unit would have to blend with a driver that is likely to be far more accurate. Ever wonder why these units don't get supplied with distortion measurements?
Take a long hard look at the graphs and data BP1 posted. Really, does this look like high fidelity to you?
They look like sims in hornresp for a tapped horn, not measurements. Can't say they are good or bad until it's built and measured. Seems like many THs simulate like this so nothing to make judgements on.
Notice I didn't say measurements? The little "hornresp" thingy at the upper left hand corner was a bit of a give away for me - maybe you noticed it too. Regardless, it looks like he plugged a fair amount of data in - and if hornresp is worth anything - it should give a rough approximation as to what to expect. None of the numbers generated surprised me in the least.
Shivas are the same money and have twice the displacement.
You should also have a read of Aaron's dual Mal 18 thread. He had the boxes made, but will give you some reference as to what a pair of them can do in what looks like a similarly sized room.
I have a Mal 18 that I'm going to build into a coffee table and will likely pop for a pair of Tempest 15's for the side walls a bit later as I'll also need another amp.
So you already know that the hornresp sims don't support your post. Why don't you just say that rather than quoting it adhoc.
What I read of the sims is that this driver may well not be suited to a tapped horn; not all drivers are. I would think running these drivers LLT or sealed as preferred by the OP might be a bit more apt. Not saying they are the best drivers for the job but worth investigating.
I used these specs. I let Hornresp calculate BL, Cms, Rms, & Mmd with the T/S parameters.
http://www.diycable.com/main/pdf/maelstrom_docs.pdf
Parameter: Series
Re: 3.8 Ohm
Le: 4.0mH
Fs: 17.4Hz
Qms: 3.62
Qes: 0.42
Qts: 0.37
Mms: 525g
Cms: 0.16mm/N
Sd: 1182 cm^2
Vas: 313L
BL: 22.9
X-Max: 33mm
Pmax: 1500W
Hornresp thingy
Post #32, villastrangiato: "... if hornresp is worth anything - it should give a rough approximation ..."
An extensive amount of work has been done in e.g.: the "Collaborative Tapped horn project" thread comparing Hornresp simulations to measurements. David McBean's Hornresp has been proven to be reasonably accurate, and data can be easily transferred into AkAbak for even greater simulation accuracy and additional evaluation. Without Hornresp and AkAbak the building of tapped horns would come down to trial and error. Hornresp is a heaven sent, no ifs, ands or buts about it.
Regards,
Post #32, villastrangiato: "... if hornresp is worth anything - it should give a rough approximation ..."
An extensive amount of work has been done in e.g.: the "Collaborative Tapped horn project" thread comparing Hornresp simulations to measurements. David McBean's Hornresp has been proven to be reasonably accurate, and data can be easily transferred into AkAbak for even greater simulation accuracy and additional evaluation. Without Hornresp and AkAbak the building of tapped horns would come down to trial and error. Hornresp is a heaven sent, no ifs, ands or buts about it.
Regards,
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