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Hey guys, just wondering if you could help me out. I've got a couple of questions.


First off, sorry about the SVS vs Shiva thing. The "this vs that" I guess is kind of a touchy subject around here, but I have no real means of listening to either, so I'm asking for opinions. I'm building a HT entirely from scratch, planning on mostly DIY, mainly because I enjoy doing that type of stuff. (and saving money is definitely a plus) The system will be 90-100% for movies. Not much music, I do that more when I'm on the computer.


Next, there's a guy locally who says he's selling a SVS ISD. I've never actually seen a picture of the original driver. Does anyone have any pics, or can tell me a way I can be sure this is the ISD, and not the original driver?


SVS's website states about buying parts from them:

"One note, these items available only to SVS customers, whether bought new or second-hand. All others will not be processed unless prior arrangements were made with our staff."


So that means I can't buy their amp? Since I'm not in their customer database? The "second-hand" kind of confuses me.


Finally, can anyone recommend an amp that would work well with that SVS ISD?


Thanks for all the help, I'm sure I'll think of more questions soon :p .
 

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Quote:
Does anyone have any pics, or can tell me a way I can be sure this is the ISD, and not the original driver?
pics

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So that means I can't buy their amp? Since I'm not in their customer database? The "second-hand" kind of confuses me.
Since you didn't buy the entire sub second hand, I don't think you qualify to buy the replacement parts.

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Finally, can anyone recommend an amp that would work well with that SVS ISD?
The 250w PE amp is very popular. Rythmik Audio has a larger amp also. Stryke , Adire and Acoustic Visions all sell amps.


If your ISD deal falls through, you might want to look at the BP1201 .


-Robert
 

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There are many excellent subwoofer drivers, all with the characteristics required for power handling and excursion: 2+ inch voice coils, 12+ mm XMAX, etc.


The most important thing is being able to get the Thiel-Small parameters for the driver and plug them into a box response graphing spreadsheet or or program. By plugging a number of drivers into the spreadsheet and adjusting the box size and/or port tuning, you can start to see the relationships between the parameters and the performance of the total system inclucing Q, the resonant freq of the system, and the -3 dB point.


Whether you build a ported speaker or a sealed speaker, you need to consider some form of active equalization. For a ported speaker, you almost certainly need a subsonic filter to keep from killing the driver. Most of the "plate" amps have such a circuit that can be modified by replacing capacitors and resistors. A sealed enclosure will also benefit from EQ at the extreme bottom end, although the ideal equalization circuit will be somewhat different than a ported speaker.


By far the easiest DIY approach would be a sealed enclosure, a separate amp, and a Linkwitz Transform Function EQ such as the Marchand Bassis (available in kit form) -- in large part because of the superb spreadsheet that lets you model any driver in any box with any target Q and response curve. See this page:

http://www.trueaudio.com/st_lkxfm.htm


If you want a mathematically intense discussion of a very well designed sealed-box subwoofer, see Sigfried Linkwitz's pages on his THOR DIY subwoofer project. This uses a very interesting low-Q Peerless driver that is ideally suited for a smallish box/Linwitz EQ application. These pages provide an incredible amount of detail on the behavior of closed box subwoofers, particularly things like impedance curves, amplfiier power, and excursion issues. This would be a very good DIY project in combination witht the Marchand Bassis, because one of the foremost mathematicians in audio has already done all the work. His spreadsheet "closed-box1.xls" is an incredible resource, with this driver and box already plugged in or for use with any other driver and box combo.


See the pages that start here and then work through the links at the bottom of the page:

http://www.linkwitzlab.com/thor-estim.htm
 

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If you have space permitting (these things are really big) this is about the simplest (really simple) subwoofer you could make.

http://www.t-linespeakers.org/projects/nick/index.html


basicly a 12 inch woofer on an 8 ft long 12" tube that sits on a milkcrate. Never heard one, but transmission line speakers do work, and making them out of tubing is dead easy.
 
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