One sub, two systems

[Carl]

I am interested in purchasing the VTF 3 sub. My goal is to use it with my 2 channel system that consists of Martin Logan Ascents which are driven by a Krell 300i as well as a home theater system containing a Denon 3803 and M&K sats. I was simply wondering how to integrate both systems in a user friendly manner with one sub.

[Sasha_G]

There are two main challenges to integrating a high and mid-fi system together:

1) crossover
2) volume levels

The crossover is the hardest. The Krell doesn't have a subwoofer crossover. For the Krell, you need to use the crossover on the subwoofer.

The Denon does its LFE and crossover work in the digital domain, on the other hand, allowing for a greater feature set. These features reduce the demands on the subwoofer's features.

So, we have two apparently conflicting setups. The Krell system demands that the subwoofer's crossover be used.

ONE solution we have found is to create a system where the user must switch two switches to go between the two systems.

For this system, a switchbox is connected to the subwoofer's RCA-type line level inputs. A stereo interconnect is connected the the "A" setting on the switchbox to the Krell. A mono interconnect is connected to the "B" setting on the switchbox to the Denon. Now, when you listen to the Krell system, you set the swtichbox so the subwoofer uses the Krell's signal. When listenign to movies on the Denon, you switch it the other way so the subwoofer uses the 'subwoofer output' on the Denon.

The Krell system requires the subwoofers crossover to be "IN", or engaged. The Denon system requires the subwoofer's crossover to be "OUT" so the sub can get the 120 Hz and lower bass from the LFE track.

Now, on to challenge #2.

This one is simpler. Just set the volume on the sub to best integrate with the Krell. Then, on the Denon, you can adjust the subwoofer level to the desired volume level. Many people prefer the sub to be louder on the home theater end, so this works out perfectly.

One last note: some people have reservations about using a switchbox. We respond by saying that the switchbox does not switch the signal for your main speakers! It only switches the bass, which is a less critical signal. Radio Shack has a line level switchbox.

[Sasha_G]

I was just thinking that one limitations with many surround sound receivers today is that the subwoofer level and crossovers are set under the "speaker configuration settings" only once for the entire receiver.

It would be better, for subwoofer setup at least, to have these settings adjustable for different sources or modes, instead of following a "set it and forget it" philosophy.

That way, there would be more setup options for Carl. If Carl didn't mind having the bass crossover handled digitally, the Denon could take the Krell's pre-out signal and send out appropriate bass signal for his high end main speakers.

Just a thought. I would guess that some people would prefer the subwoofer to switch between the signals, but that would add a lot of cost and complexity in the analogue realm that most people don't want.

[Rob Babcock]

There probably is SOME reciever out there that allows a different sub setting for each input instead of setting levels globally, but unfortunately I haven't seen it. I agree that this is something all mfgrs should have done years ago, and it's vexed my for a long time.

I'd like a unit smart enough to allow me to at least have a level setting for 2Ch and a separate one for PLII.

[Dr_Hsu]

Actually some receivers do have this feature, but their product literature do not make it clear that it can. The cheap Pioneer receivers I get from Costco (VSX-D509) does allow you to set the subwoofer level separately for each source. All I have to do is to set each channel's level for each selected source.