Getting the last drop out of my system.

eagertrader

I would like to make the most efficient and best use of my system:

I have the following setup:

Amplifier: ADCOM 555-II High Current 2 channel @ 200 watts each channel

Receiver : Yamaha RX-V890 5 Channel @ 100 Watts fronts (being by-passed since I am using the audio-out front outputs to connect to the Amplifier above). 80 Watts for the Center and 60 Watts each for the rears.
The Velodyne HGS-18 is connected to the Low-Pass output which filters out at
200 Hz.

Front Speakers: Polk LS-90's tower type with the following specs:

Driver Complement:
Midrange: 4 - 6-1/2" Diameter (16.51cm)
Tweeter : 1 - 1" Diameter(2.54cm)dome tweeter
Electrical Overall Frequency Response:
20Hz - 26kHz
Lower -3dB Limit 35Hz
Upper -3dB Limit 25kHz
Nominal Impedance 8 ohms
Recommended Amplifier Power: 30-250 w/channel
Efficiency: 90 dB
Dimensions:
Cabinet Size: 40" H x 12-1/4" W x 14-281/500" D
(101.60cm H x 31.12cm W x 36.99cm D)

Subwoofer: Velodyne HGS-18

Center Channel: Canton: 40Hz to 22 KHz
Rear Channels : Polk In-walls

Althoutgh the system is set up as a home theater, by far, most of my listening is 2 channel stereo.

Here is my question: Using the above system as reference, am I better off using the low pass output of the receiver to connect to the Velo sub as I presently am, or would I be better off to connect the output terminals of the ADCOM amplifier to the input terminals of the Velodyne HGS-18 sub, and then the output speaker terminals of the sub to the speakers (I assume that the Velo has its own internal crossover, and would filter out any low frequencies that belong to the sub, thus the main front speakers can be driven more efficiently since they would not have to work as hard).
I am presently going bi-wired from the amp to the main fronts upper and lower range drivers. I guess If you recommend in favor of using the speaker terminals in the sub, I could keep the high range drivers connected to the amp directly and the low range drivers going through the sub connected to the amp. Another twist would be connecting the High range drivers on the speakers to the 100 watts front channels on the receiver, thus Bi-amping the front speakers.
By the way, the HGS-18 is located against a corner behind and to the left of the Left-Front Polk LS-90.
Any light that you can share as to how can I extract the maximum potential from my modest set-up would be greately appreciated.

gidrah

The first thing I would do is to set receiver "sub-out" as low as possible. 80Hz outta do it. This will relieve much stress on your sub. Also, most subs don't do too well at that high a frequency. I'd also probably set the mains to large and the center and surrounds to small. This should get you in the ballpark.

eagertrader

I got a phone call from the folks at Velodyne that proved immensely helpful. This is what I ended up with, which in my humble opinion made my Polk LS-90's (circa '93) sound spectacular, to the point that the music coming out of these speakers sound effortless, satisfying and with depth even at low volume.
I connected the YAMAHA RX V-890 receiver PRE-OUTs (left and right channels being true) to the Velodyne HGS-18 Ultra 2 subwoofer LINE-INs using Radio-Shack's Fusion RCA cables (which have RFI filters at the imput end), I used another set of the same cable to connect the LINE-OUTs (keeping left and right channels true) to the LINE-IN's on the ADCOM 555-II amplifier. This connection allowed me to use the High Pass crossover in the subwoofer to filter out any frequencies below 80Hz going to the main speakers, so the midrange would really come alive at 200W. The speaker outputs on the amplifier were connected to the speakers midrange and woofer sections only on the Polk LS-90's speakers.
In addition I connected the 100W left and right front speaker outputs on the YAMAHA receiver to the tweeter section on the main speakers.
The end result is that this set-up allowed me to truly Bi-amp the Polk LS-90's and in reality the system is TRI-AMPED, since the 1250W (3000W peak!) amplifier on the Velodyne subwoofer handles all the lows from 80 Hz all the way down to 15 Hz!
The accuracy, soundstage, sweetness and just gut wrenching satisfiying sounds that were hiding in my older Polk's are simply awesome.
Thanks Polk Audio and thanks Velodyne.