Stereo system with Subwoofer, How to do it?

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Hello every one out there,
I want to build a stereo system with a sub for my home. I will use a crossover to send bass signals to the sub. For the other speakers I was wondering if it was better to send full signal or only the hipass signal of the crossover? And finally how can we determine the best crossover point for a given set of speakers?

Need practical advice to start my project!!!
 
I use sealed satellites with an F3 of about 90Hz and a Q of .7.

The diagram below outlines the concept. I use 2 woofers per channel but you could use a single sub for the sake of economy if you sum the bass channels from the crossover.
 

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To continue . . .

For the satellites, there are many tried and true 2 way designs out there. Most all will be of the vented variety with either a 5" or 6.5" woofer so I would download WinISD and model the suggested woofer in a sealed enclosure to see if you can get a Q of .7 at around 80-100Hz. I will post links to some of these designs later today or this evening.

For amplification, one of the choices is a plate amp which most often includes a crossover. The problem is, I have never run across a plate amp with a 4th order low pass and a 2nd order high pass. I'm not saying there isn't one available, I just don't know which one it is.

I use 2, 2 channel power amps, which in my opinion is a better solution over a plate amp anyway. The following outfit has electronic crossover boards.

http://sound.westhost.com/

You could use the one with 4th order lowpass and 4th order highpass and take the output between the 2 cascaded highpass filters to get your 2nd order.


Also of concern is the placement of the woofer(s). For the satellites and woofers to sum properly the woofers should be at about the same distance from the listener as the satellites. To reduce the standing wave problems between the side walls, I have my woofers somewhat out from the side walls.

Just for the record, I prefer woofers in sealed boxes with a Q of .5 or so. Room gain will bring up the low end response so in my opinion there isn't a very good reason to use vented enclosures. I use 2, 12" woofers per channel. Previously I used 1, 10" vented woofer per channel but wasn't happy with the performance.
 
As promised, here are a few links for you:

http://www.gr-research.com/performer/av1plus.htm

http://speakerbuilder.net/web_files/Projects/peecreek/pcrkmain.htm

http://www.quadesl.com/okara.shtml

http://kahuna.sdsu.edu/~tucker/diyaudio/aerogel.html

http://home.hetnet.nl/~geenius/Proteus.html

It's up to you to determine if the drivers in each of these projects is still available. It will also be up to you to download WinISD and determine if the drivers will be suitable in the sealed enclosure abovementioned.

I have more links but too many choices could become a problem for you.

There also is the option of a full range driver for the satellites. Fostex in in vogue at the moment. What you gain with a full range driver is the absence of the mid to tweeter crossover which results in a more coherent sound presentation, so say many. I have no personal experience with these drivers so am unable to comment. You could pursue this in the Loudspeakers/Full Range forum.
 
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