Axiom Home Page Forums General Discussion Technical Questions Sub Woofer Crossover Question

I have a Pioneer VSX-D810s (100W 6.1) reciever.
M60Ti mains are powered a Bryston 3B amp (120W) via preouts.
VP150 center is powered by a Thomas Patterson amp (120w) via preout.
Passive P.O.S. sub that is powered by the other channel on the TP amp via preout.
3xQS8 surrounds are connected to the Pioneer.

BTW the room is 24x36x9 with vaulted ceilings.

mains set to large
center set to small
surrounds set to small
receiver crossover set to 100Hz (can only set 100/150/200)
receiver configured to send LFE to mains (large speakers) also

The system sounds great, except when pushed.
The M60s strain with the lower bass, causing the Bryston to clip.

However, given the size of the room, I want so add a powered subwoofer.
So I was thinking of getting an EP350, EP500, or something like an SVS PCi 20/39. I would use the high level inputs, using the subwoofer to set the crossover at something like 60Hz for the mains.

When subs are configured like this, do you lose the output of the sub between the crossover point and the sub's higher effective frequency response?

Would I be better off setting the mains to small, and let the new powered sub(s) handle everthing below the crossover point (100Hz)? In this case it would be a shame to lose the sweet sound of the M60s below the crossover point and their lower effective frequency response.

Ideally, the best solution would be to replace the Pioneer with a reciever that would allow individual crossover points for each speaker and of course powered sub(s).

My vote is get the EP500 (you've got a sizeable room there, I think the 350 is a tad small for your needs. Set all your speakers to small, cross over at 60hz, and let'r rip!

Even set at large though, the M60's shouldn't have given your Bryston any trouble. That's a curious bit...any ideas Alan?

Agree with the EP500.

The lowest crossover setting on my reciever is 100Hz.

The Bryston amp clips driving the M60s as indicated by a clipping light, with the sound distorting on the lower octaves. I'm thinking that if I had the crossover at 60Hz (or whatever), the Bryston would not be clipping.

Have you looked at the Outlaw Icbm,it can crossover each channel as low as 40hz.You can get one from b stock for $199.

Then honestly my first investment would be for a new processor. Since you wouldn't be using it's amps, I'd get a inexpensive Denon refurb, such as this AVR-2802 for $299 at Ecost.com.

Bart, I'm also surprised that the Bryston would clip even in your setup, but apparently the combination of room size, listening level, and feeding M60s both full range plus LFE is a bit much. If the sub is as bad as your "P.O.S." indicates, get a new powered one and run all your speakers, including the M60s, "small"(which will also remove the LFE from the M60s), using the 100Hz crossover if you don't get another receiver or separate crossover to allow for more options as to crossover frequencies. Since the crossover isn't a brick-wall cutoff, but instead rolls off the sub above the selected frequency, often at 24dB/octave, the sub will continue to have some output above the crossover area.

Don't be concerned about losing any "sweet-sound" from the M60s if they're rolled off below 80Hz or even 100Hz. Those frequencies alone are in no way "sweet" or "tight", they're dull and plodding. Any such qualities in bass instruments are a result of the harmonic overtones which the sub doesn't reproduce and which the mid-range drivers handle. To illustrate this, disconnect all the speakers but the sub, leaving everything else the same, especially the crossover to the sub. Then you'll hear what the stuff below 100Hz sounds like alone.

John, that's excellent advice. 90% of the spatial and sonic information in music -- and what gives instruments their characteristoc sounds -- comes from the upper ranges. Even an upright or electric bass procude sounds in the kHz range when plucking the lowest notes. Without overtones, music would be dull and lifeless.