Eric Ha

SVS PB12Plus/2 or Adire Tempest/Tumult DIY?

I have the SVS PB12Plus/2, but want to try my hand at a DIY sub. Would a Tempest or Tumult equipped sub get me the flat-to-16hz extension that I'm getting now? I'll use whatever power is needed, but don't want to go any bigger than the SVS enclosure if possible. I also do not need ANY more SPL than the SVS. It's more than plenty. I've read that the Tempest actually has better extension than the Tumult. True? Any suggestions?

MikeLi

Stick with the SVS... I doubt your going to notice much difference... You have a great sub.

Eric Ha

I love the sub, but would like to make one for the fun of it, as well as being able to put a better finish on it than the textured black of the SVS. After building some Adire speakers, I've caught the DIY bug. I don't however, want to lose any performance.

Dustin B

The tricky part for your request is the enclosure size. Bass reflex enclosures are limited by the the output capability of the port around tuning. The larger the port, the more air it can move cleanly, the louder the sub can play around tuning. The problem is the larger you make the port, the longer it needs to be to maintain it's tuning frequency. Very quickly it will become too long to fit in the enclosure.

The Tempest is designed to work in rather large enclosures, and it will take more than one to beat a pair of SVS DB12 drivers.

What could be interesting would be a pair of Ascendant Audio Avalanche 15 ($299 each) drivers in a 5-6 ft^3 sealed enclosure goosed by 1.5-2kW (what this will cost could vary a lot depending on the amp you choose). Add a little EQ to bring up the bottom end and you should have something as loud as a PB12Plus/2 down to the bottom of the last octave that is a little bit smaller. Should also have the potential to sound quite a bit better.

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Eric Ha

Thanks Dustin. I could go with the SVS route of multiple smaller diameter port tubes to keep the cabinet size down, right?

Jack Gilvey

The existence of the SVS line makes it difficult to justify DIY from a money-saving standpoint. Unless you have the tools already, you're likely going to spend more for a given performance level, at least with the lower-priced/more modest performing subs. When I got into it, this was not the case. There was no PB10-ISD then.


There you go...that's why I do it.



Not from the perspective of port length. For a given port cross-sectional area (single large or multiple smaller), you need a specific length to tune a fixed box volume (Vb) to a specific frequency (Fb).

Eric Ha

Ah, I see. Thanks Jack.

dave alan

Dustin's idea...

"What could be interesting would be a pair of Ascendant Audio Avalanche 15 ($299 each) drivers in a 5-6 ft^3 sealed enclosure goosed by 1.5-2kW (what this will cost could vary a lot depending on the amp you choose). Add a little EQ to bring up the bottom end and you should have something as loud as a PB12Plus/2 down to the bottom of the last octave that is a little bit smaller. Should also have the potential to sound quite a bit better."

...is right on the money.

Jack Gilvey

That pair in IB would be even better. I'm running their more modest siblings, the Atlas 15's, as a pair that way and they're astounding. I'm running the 2 Ohm coils in series and have shorted the 4's giving me a 4 Ohm load and a Qtc of ~0.53. A little PE 150w plate amp gets me to 10dB below reference cleanly.

Dustin B

Ah, hail to the IB (Infinite Baffle). If you have an appropriate space and don't mind cutting the hole I'm definately with Jack on this idea. But I'd vote for 4 Atlas 15 drivers instead of 2 Avalanche 15 for this app.

This would be an extra $40 in driver cost, but the amp requirements would be way way less. Oh, and a side benefit if you have the appropriate adjacent space, this sub would be infinitely smaller in room than the SVS (literally :p))

Constant Area Screen - The Only Way To Go

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