Patrick D

I'm looking to build a new subwoofer for a home theater, to replace a now-defunct tempest (doh). It seems like the sub driver market has dried up!

I was hoping to grab an Avalanche 18". I'm very flexible on box size (IB is out of the question), and would like to stay under 1000w of power. The AV 18" I could wait for, but shipping to my location (Hawaii -- no ground shipments) would be over $150 bux via air (FedEx).

What's the best I could do for a ported sub that goes low (e.g. < 15hz with moderately decent SPL) with a driver that I can actually get right now?

I'm thinking I may have to use multiple smaller 15" woofers in a single box, but again, there isn't much I can find that is available outside the Dayton/PE drivers, which are looking overpriced right now.

Are there any other options I should look into?

Ryan Schnacke

First, why are you discriminating against the Avalanche 18 because of shipping costs? Isn't this going to be an issue for any woofer you order? Especially if you go with multiple 15" subs.

With the closeout pricing on the Ascendant woofers, you could get the Avalanche 18 for $275 + $150 shipping. That's only $425 and since they were selling for $400 until recently I think this is a good deal. But a vented box for this woofer borders on ridiculously large.

Otherwise, the Atlas 15's seem to be shipping quickly if there's any left. But with Fs=21.5Hz they're not ideal for <15Hz stuff.

Seems like AEspeakers is almost ready to start shipping woofers again, so you could consider contacting them to see what they've got up their sleeves.

Patrick D

The discounted cost of the Avalanche is certainly true enough, and I hadn't entirely considered that.

Although multiple 15" drivers may be more, I was thinking more along the lines of things like the Dayton DVC15, which is about 22lbs in (shipping) box. Two of them would still come in under the 18" ava, without any possible surcharge/weight expense for the crated Avalanche.

I also like the idea of a more moveable cabinet, but not at the expense of quality.

Ryan Schnacke

Okay, that makes sense.

Here's the comparison:
Avalanche 18: 6.5L displacement, 42lbs, $275 each
DVC15: 2.4L displacement, 20lbs, $127.50 each
Atlas 15: 2.9L displacement, 24lbs, $105 each

1 Ave can outperform a pair of either Atlas or DVC's. Though a pair of Atlas's comes close. So my next question is why would you even consider the DVC if there are still Atlas's available? The build quality is sooooo much higher. Plus they're cheaper. Plus they're higher excursion. Plus they're XBL2.

I hear the Atlas 15's are almost gone, so think fast.

Patrick D

OK, I guess I'll bite the bullet and grab me some 18" sub goodness (and consider the shipping to be "free" after the discount). At least I won't be able to say "I wish I had gotten the bigger driver." I'm probably going to pair this with the PE 1000w amp (why not, it's not a huge amount more than the 500w).

With that out of the way, I have a second problem, which is probably easier to deal with. What's a good buildout for this driver?

I think the 20 cu. ft. box as spec'd on the Ascendant Audio site looks good, but there is nothing as to how to stuff the box or what ports are required. I did read elsewhere about the port needs being pretty hefty, like 3 6" flared ports.

I'll fire up Unibox, but it would be nice to see what other people have done, also. Any other Big Box subs out there?

Ryan Schnacke

I haven't played with ported boxes for this beast and I don't have software at this computer. Sorry.

But if you're going for the 20cuft @ 12Hz alignment then you'll want to be aware that the PE plate amps have a high pass "rumble filter" that's going to hurt your output below 20Hz. Check out the frequency response graph on the PE page for that amp.

For a similar price I'd consider the Behringer EP1500 amp and BFD equilizer if you don't mind having a fan cooled pro-amp (with 40% more power).

Patrick D

I ran the Ava 18" and the Blueprint 1804 through WinISD, and it seems like the Ava 18" is just built for that super-low reach.

That PE Amp thing is weird, it really does roll off hard after 30-20hz. Considering it is supposed to be a "subwoofer" amp, did they just drop the ball on this one?

It's probably a safer bet anyway to grab the Nady pro amp as recommended by the Cult of the Infinitely Baffled. It wouldn't be as likely to toast the driver in a huge box (and it's cheap too). Hopefully I can work around the fan noise.

I saw that Behringer earlier... what a monster!

Ryan Schnacke

Most plate amps have some rumble filter built in to protect the woofer from over-excursion ... especially in the case of a ported sub at frequencies below the tuning point. Its a good feature to have when its designed to complement the woofer alignment.

But being a generic plate amp, it won't work with every alignment. And yours is certainly a bit on the extreme side. Few commercial subs are tuned below 20Hz, much less below 15Hz.

The PE 250 watt plate amps implement this filter with a simple Sallen-Key Op-Amp circuit that can be easily modified for whatever frequency and rolloff Q you want. But I haven't yet heard of an easy mod for the 500W and 1000W amps.

Yeah, the Nady is probably a better fit for this application than the Behringer. I was thinking about driving a PAIR of Ave's for some reason (too much time spent on the Cult forum).

I think someone posted a fan mod for the Nady 1100 amp that should work just as well for the 900 amp. Look for it on the "Steals and Deals" section of the Cult of the IB.