Update 3/12/03

I had been contemplating replicating my reference stereo system to my HT L/C/R and after Outlaw announced the 7100, I decided to go for it, with changes only to the bottom from the reference. So, I ended up with the following. Note that only one additional 7100 is required in this configuration, because I am only tri-amping the left/center/right, requiring 6 additional channels. 100 watts is more than adequate for the mid & high. While the above looks outrageously expensive, its really not. The speakers were about $500 ea for cabinets & elements. The xover adds an additional $60/channel and the extra amps add around $300/channel. So the total per speaker is still under a grand each. Not cheap, but not the most expensive speaker system you see either. (Note the B&W center I replaced retails for over a grand for example.) The principle down side is the overall size and of course complexity. This is not a small system, or the most attractive. Added to that the wiring nightmare of the extra amps and xover, which I don't think does well on the wife scale. On the upside, it is highly configurable with the ability to twiddle the xover frequencies and adjust balance of the driver volumes with a twitch of a knob. Moreover, woofer control is not compromised by the DCR of the crossover coil. Consider, even the very best inductors used for the woofer crossover are going to have ~0.1 ohms of resistance. That's like the same as 10' of 20 gauge wire. Imagine any serious audiophile sticking 20 gauge wire in the speaker path.


The exact enclosure detail is as follows in case anybody wants to build something similar. The Scan-Speak is mounted in a Madisound WS803 for the center and a WS123 for L/R. The Scan-Speak wants a minimum volume of 24 liters for a flat bottom, so the center box is just large enough. The L/R is twice the required volume, which allows the mid/tweeter enclosure to set on top of the woofer enclosure without requiring a speaker stand for either. I kept the center smaller to keep the size of the center down to a reasonable level. Wiring is of course straight thru and uses 14 gauge wire internally. A madi DB-CUP is used for the woofer and mid connection. Two additional holes were drilled to bring the tweeter wires out of the back of the mid/tweeter enclosure using a pair of BG-POST. The mid and tweeter share a madi WS802 enclosure.


The speakers were chosen for accuracy and flat response in the pass band. The Focal's are phenominal in accuracy. Focal didn't have a driver that appeared as smooth as the Scan-Speak, so I went with the Scan-Speak for the bottom. Note only the Scan-Speak is shielded, but I see no image problems on the TV. Probably because it is an RPTV and the speakers are some distance from the CRT's. For a direct type TV, I'd suggest a shielded driver for all elements.


The controller was probably the most tedious to design/build. The schematics for the controller are here and here. I had an old broken UPS box that I used to put it in. The box conveniently had power outlets for the xover 120V connections already which made life easier. It also had some LED's on the front panel which I used for status. The controller essentially uses the 12V trigger from the 950. For on sequence, the controller first turns on the power of the xovers. About 1 sec later, it flips on the first amp, another second it flips on the second amp. Finally, one second later it enables the tweeter relay. The controller reverses the sequence on power down, with the exception of leaving the xover on for about a minute. Note that Outlaw did a great job of controlling transient on both the amps and the 950. But, Behringer did not, so the xover must stay on until the amps discharge to avoid a nasty thump to the mid/woofers, which do not have relay protection. The controller also has power fail detection and will dis-engage the tweeter immediately on power fail. The mid/woofers will unfortunately see a thump in this case. You could add relay protection to these elements too. The controller will inhibit power for about 2 minutes after a power fail, so if the power is unstable, the controller will prevent multiple surges.

Ground loops should not be a problem with the controller. The 950 output drives a photo-detector, so make sure the 950 output is isolated from ground. The amps have photo-diode inputs so the amps do not see the ground of the controller.


So far, listening shows the system is capable of incredible dynamics. When played loud, it shows absolutely no compression effects. The articulation is incredible. Almost too good. I'm noticing the limitations of Dolby sound quality compression more than anything. I am anxiously awaiting the new Blue-Ray DVD system, which I hope includes upgraded sound data rates as well as more bits for video.