Jump to content



Sign up for a free account!

Signing up for an account is fast and free. As a member you can join in the conversation, enter contests to win things like this Logitech Harmony Ultimate Remote and you won't get the popup ads that guests get. Click here to create your free account.

Photo
- - - - -

SVS PB12Plus/2 or Adire Tempest/Tumult DIY?


This topic has been archived. This means that you cannot reply to this topic.
35 replies to this topic

#1 of 36 Eric Ha

Eric Ha

    Stunt Coordinator

  • 146 posts
  • Join Date: Sep 27 2004

Posted February 14 2005 - 01:10 AM

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?

#2 of 36 MikeLi

MikeLi

    Supporting Actor

  • 945 posts
  • Join Date: May 06 2003

Posted February 14 2005 - 04:12 AM

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

#3 of 36 Eric Ha

Eric Ha

    Stunt Coordinator

  • 146 posts
  • Join Date: Sep 27 2004

Posted February 14 2005 - 05:52 AM

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.

#4 of 36 Dustin B

Dustin B

    Producer

  • 3,128 posts
  • Join Date: Mar 10 2001

Posted February 14 2005 - 09:52 AM

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.
Constant Area Screen - The Only Way To Go

My Home Theatre Page

#5 of 36 Eric Ha

Eric Ha

    Stunt Coordinator

  • 146 posts
  • Join Date: Sep 27 2004

Posted February 15 2005 - 12:49 AM

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

#6 of 36 Jack Gilvey

Jack Gilvey

    Producer

  • 4,952 posts
  • Join Date: Mar 13 1999

Posted February 15 2005 - 01:15 AM

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. Posted Image

Quote:
I love the sub, but would like to make one for the fun of it...

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


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

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).
SVS Customer Service
http://www.svsound.com
sales@svsound.com
techsupport@svsound.com

#7 of 36 Eric Ha

Eric Ha

    Stunt Coordinator

  • 146 posts
  • Join Date: Sep 27 2004

Posted February 16 2005 - 12:29 AM

Ah, I see. Thanks Jack.

#8 of 36 dave alan

dave alan

    Second Unit

  • 256 posts
  • Join Date: Aug 30 2002

Posted February 16 2005 - 09:02 AM

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.

#9 of 36 Jack Gilvey

Jack Gilvey

    Producer

  • 4,952 posts
  • Join Date: Mar 13 1999

Posted February 16 2005 - 03:18 PM

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.
SVS Customer Service
http://www.svsound.com
sales@svsound.com
techsupport@svsound.com

#10 of 36 Dustin B

Dustin B

    Producer

  • 3,128 posts
  • Join Date: Mar 10 2001

Posted February 17 2005 - 12:48 AM

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

My Home Theatre Page

#11 of 36 Eric Ha

Eric Ha

    Stunt Coordinator

  • 146 posts
  • Join Date: Sep 27 2004

Posted February 17 2005 - 12:57 AM

I'm curious. What would make the Avalanches sound better than db12's? Does anyone know the XMax or other parameters on the db12 driver? What is it's closet comparable competition?

Down the line I may do an IB. I just added on to this room and don't want to start cutting into the floor. My brother may try an IB set-up within the next year, I'll keep those ideas in mind. Thanks.

#12 of 36 Shane Martin

Shane Martin

    Producer

  • 6,017 posts
  • Join Date: Sep 26 1999

Posted February 17 2005 - 03:05 AM

Quote:
drivers in a 5-6 ft^3 sealed enclosure goosed
Does anyone have a pic of how roughly big that is? I'm having a hard time imagining that.

#13 of 36 Edward J M

Edward J M

    Screenwriter

  • 2,031 posts
  • Join Date: Sep 22 2002

Posted February 17 2005 - 04:07 AM

IB is easy and fun. I recommend it if you have basic DIY skills and the adjacent space.

FWIW, a Vd of 2.5L is a good bet for the dB12. Regardless, as we used to say at the drags, there is no replacement for displacement. If you are going IB, my vote is also for the quad Atlas combo.

Quote:
infinitely smaller

Good one, Dustin - pun intended I take it? Posted Image
Ed Mullen
Director - Technology and Customer Relations

SVS

www.svsound.com

"What we do in life, echoes in eternity."


#14 of 36 Dustin B

Dustin B

    Producer

  • 3,128 posts
  • Join Date: Mar 10 2001

Posted February 17 2005 - 04:26 AM

SVS dual driver box subs are pretty close to 6ft^3.

I think 2.5L is pushing it a bit for the DB12 displacement. I'd say the Ultra is closer to that than the DB12 is. I'd guess the DB12 at closer to 2L than 2.5L.

The Avalanche drivers are capable of a little over 4L of displacement and incorporate Adire's XBL^2 motor topology which many people are reporting results in very low distortion all the way to the drivers limits. Dan Wiggins, Adire head hauncho has stated a number of times that it would take 3 Tempest drivers to match the clean output of a single Tumult, even though it only takes 2 Tempests to match the Vd of a Tumult. Also sealed enclosure vs ported for my Avalanche recommendation.
Constant Area Screen - The Only Way To Go

My Home Theatre Page

#15 of 36 EdwinK

EdwinK

    Agent

  • 38 posts
  • Join Date: Oct 29 2004

Posted February 17 2005 - 10:04 AM

Dustin B, are you saying that two cheap Avalanches in a 5-6 ft^3 sealed enclosure could equal (or better) the performance by a PB12-Plus/2 or a PB12-Ultra/2?

#16 of 36 Dustin B

Dustin B

    Producer

  • 3,128 posts
  • Join Date: Mar 10 2001

Posted February 17 2005 - 01:15 PM

Yes. It's no secret that one can build a sub that will beat any commercial design for less money. You just can't be concerned with enclosure size, need the right wood working tools and the time. SVS is the closest you can get to that value level, and if you don't have the time they easily become your best choice IMO.

The Avalanche drivers are anything but cheap. Drivers equivalent to the DB12 in the Plus series subs would retail for well under $200 each. The TV12 driver in the Ultra is an exercise in excess and would likely retail for over $400, but it's still a 12" driver. The Avalanche is a 15" driver and the displacement advantage that affords is not small. If you don't limit enclosure size to 6ft^3, you could build a dual Avalanche 15 that would easily outgun PB12 Ultra/2. And the XBL^2 motor is not trivial either.

Also don't forget that would be $600 for just the drivers, you'd need another $100 for the enclosure, $750-$1600 depending on the amp you choose, and then you still need to add a finish to the enclosure which can vary a huge amount depending on what you go for. SVS has succeeded with their dual driver box subs (specifically the PB12ISD/2 and the PB12Plus/2) in making DIY a tough sell. Building a sub that size of comparable performance will be damn near the same price. But when you don't have to limit yourself to <6^ft3, you can do some wild stuff at significant cost savings with DIY.
Constant Area Screen - The Only Way To Go

My Home Theatre Page

#17 of 36 Jack Gilvey

Jack Gilvey

    Producer

  • 4,952 posts
  • Join Date: Mar 13 1999

Posted February 17 2005 - 04:18 PM

Quote:
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.

Would have loved to, but don't have the Vb available in the closet I'm using. I barely make the "legal" definition of IB with a pair. Posted Image
SVS Customer Service
http://www.svsound.com
sales@svsound.com
techsupport@svsound.com

#18 of 36 Dustin B

Dustin B

    Producer

  • 3,128 posts
  • Join Date: Mar 10 2001

Posted February 17 2005 - 04:56 PM

Sorry Jack, didn't mean to imply you should have used 4, although I know you would have if you could have Posted Image

I just thought 4 Atlas 15 drivers would make a better IB than 2 Avalanche 15 drivers. Cost is almost the same but the Atlas would have more Vd and way more wiring options.
Constant Area Screen - The Only Way To Go

My Home Theatre Page

#19 of 36 Jack Gilvey

Jack Gilvey

    Producer

  • 4,952 posts
  • Join Date: Mar 13 1999

Posted February 17 2005 - 11:44 PM

Quote:
I just thought 4 Atlas 15 drivers would make a better IB than 2 Avalanche 15 drivers. Cost is almost the same but the Atlas would have more Vd and way more wiring options.

Absolutely agree! More sensitivity, also, so you really could run a plate amp and get insane levels. Since I only have 3600 liters to work with, though, I was actually considering two Avalanche 15's. This would necessitate more power and some boost in the low end, so I need to decide if the extra Vd is worth it. Your thoughts?
SVS Customer Service
http://www.svsound.com
sales@svsound.com
techsupport@svsound.com

#20 of 36 Shane Martin

Shane Martin

    Producer

  • 6,017 posts
  • Join Date: Sep 26 1999

Posted February 18 2005 - 12:01 AM

so how does the avalanche compare to the Timult which was initially mentioned?


Back to Speakers, Subwoofers & Headphones



Forum Nav Content I Follow