Multiple amps in a 5 channel setup?

Papajin · « **on:** 14 Jun 2006, 04:00 am »

Hello! This is probably a dumb question but... are there any rules of thumb that should be used if utilizing multiple amps in a 5 channel setup? For instance, how big a deal would different wattages make? Are there other factors that are important to look at when choosing amps? That sort of thing.

Specifically, I'm using my rig for both 2 and 5 channel right now. I'm using a pre-amp with a bypass switch, and a seperate pre-pro. I'm considering purchasing a used 2 channel amp primarly for the 2 channel side of things while wanting to probably use my current 5 channel amp for the other 3 channels. The current amp is only 135 wpc, whereas the new amp would be be 250 wpc and would likely be a significant upgrade.

I'm just curious if anybody has any experience with a setup like this and if there would be noticeable discrepancies between the different channels, or if the differences could possibly be evened out in the pre-pro, etc. 2 channel is where my primary focus on sound quality is, but on the flip side, I don't want to ruin the sound on the 5 channel side either. I have almost no experience with 5 channel right now, so my apologies if my question seems naive.

Levi · « **Reply #1 on:** 14 Jun 2006, 04:30 am »

I am currently using the same setup as you. This setup saves me an extra room.
Here is a diagram to help you get started. The preamp processor takes care of all the different gain levels from the amps.

Quote from: Papajin

Hello! This is probably a dumb question but... are there any rules of thumb that should be used if utilizing multiple amps in a 5 channel setup? For instance, how big a deal would different wattages make? Are there other factors that are important to look at when choosing amps? That sort of thing.

Specifically, I'm using my rig for both 2 and 5 channel right now. I'm using a pre-amp with a bypass switch, and a seperate pre-pro. I'm considering purchasing a used 2 channel amp primarly for the 2 chan ...

Papajin · « **Reply #2 on:** 14 Jun 2006, 07:59 pm »

Do you notice any difference when a sound pans across the front 3 speakers? I guess my biggest worry was having the 2 fronts on one amp, and the center on another amp. I honestly don't know how noticeable it would be without trying it.

Levi · « **Reply #3 on:** 14 Jun 2006, 09:15 pm »

In movies, I don't notice any difference. When the movie has music playing, I am in heaven.

Quote from: Papajin

Do you notice any difference when a sound pans across the front 3 speakers? I guess my biggest worry was having the 2 fronts on one amp, and the center on another amp. I honestly don't know how noticeable it would be without trying it.

Bob Reynolds · « **Reply #4 on:** 14 Jun 2006, 10:57 pm »

I think the issue comes down to having the EXACT same gain in each amplifier. If not, then you have to have some way to balance the SPL levels coming from each speaker. Even if the gain is the same objects in the room, like furniture, will affect the balance. The adjustment can not be made "by ear" -- it requires an SPL meter. Your pre/pro should provide the balance capability.

alpsy · « **Reply #5 on:** 14 Jun 2006, 11:54 pm »

i use 2 amps for a 5ch setup and it sounds awesome. helps that they are of the same brand and power i guess (4b & 6b)

once i sort out my pre section ill be very happy

cheers,

julie

geofstro · « **Reply #6 on:** 19 Jun 2006, 09:10 am »

Papajin,

This is interesting for me since, like you, my emphasis is on 2 channel and I'm only just getting into 5.1 channel sound.

Out of interest which speakers are you using?

Thanks

geoff

Papajin · « **Reply #7 on:** 19 Jun 2006, 02:10 pm »

Quote from: geofstro

Papajin,

This is interesting for me since, like you, my emphasis is on 2 channel and I'm only just getting into 5.1 channel sound.

Out of interest which speakers are you using?

Thanks

geoff

Geoff,

I'm using a pair of HT3's, an HTC, and a pair of sealed HT1's by Jim Salk, or at least I will be. I have the HT3's and the HTC, but the HT1's are still being built.

Currently I'm using a Blue Circle BC32 5 channel amp, and a BC21.1 pre-amp. I haven't purchased a pre-pro yet, but will have to decide on something soon. I also have a Modwright SWL 9.0SE Tube Linestage pre-amp due to arrive here today which may or may not replace the BC21.1 in the main system. We shall see which pre-amp wins out.

Currently the only source is a Bolder modified Squeezebox 2.

geofstro · « **Reply #8 on:** 19 Jun 2006, 03:15 pm »

Well, at least all your speakers come from the same stable and will have similar characteristics and presumably power handling requirements.

My surround and center channels are very different from my mains. The mains being Rethm 2nd and the Surround and Center being Maggie MC1 and CC3.

The Rethm 2nd is very easy to drive, being a horn loaded Lowther DX4 based design, whereas the Maggies are notoriously difficult, being a 4 ohm impedance.

For the Rethms I mostly use a First Watt F1 and for the Maggies a JVC F10 acting as a 3 channel receiver.

Apart from these obvious differences the Rethms and Maggies do share some important characteristics in common, one of which is "speed", and I like the way they work together. Although I admit it probably isn't the last word in seamless Multi-Channel surround sound.

I also actually like having so much flexibility in adjusting the volume of the mains completely independently of the surrounds and center. I adjust by ear until I get a balance which is to my liking. I like very subtle use of the rear surrounds. I realise I'm effectively re-mixing the balance from what was intended on each disc, though it seems to work well for me.

I have an SPL meter, so I may try balancing the mains and center with that and see how I like the result.

For crossing over to my TBI Magellan subwoofer, I'm using my HTPC with a software digital crossover solution.

What has been tricky to deal with is all the different Multi-Channel formats I've encountered. For example:

3 Channel
4 Channel (SACD surround)
5 Channel
5.1 Channel

...and this list may not be exhaustive.

For the 3, 4 and 5 channel disks I need to XO all channels to the sub at the same frequency (I use 85hz).

The 5.1, of course, has a dedicated bass channel, so that gets sent straight to the sub.

geoff

Papajin · « **Reply #9 on:** 19 Jun 2006, 03:38 pm »

Quote

For crossing over to my TBI Magellan subwoofer, I'm using my HTPC with a software digital crossover solution.

What software are you using for this? Just curious, as it may be worth looking into for me later. I plan to build an HTPC for my system soon.

geofstro · « **Reply #10 on:** 19 Jun 2006, 04:32 pm »

I'm currently beta testing "Allocator". You can find it here:

http://www.thuneau.com

I'm very happy with the results on a 2.1 channel set-up. There are some issues that would need to be addressed before I could use it in my multi-channel set-up, though.

Hope it helps!

geoff

Levi · « **Reply #11 on:** 19 Jun 2006, 05:26 pm »

The front, center and right speakers are the most critical in HT setup I agree. It is highly recommended and it is most enjoyable if they have all timber matched.

Levi · « **Reply #12 on:** 19 Jun 2006, 05:36 pm »

That's where I started. Until there is a need to sit on the side other than the sweet spot. There would be a perceived loss of details when switching to 5.1 but a good Pre-pro will cure that.

Quote from: geofstro

I'm currently beta testing "Allocator". You can find it here:

http://www.thuneau.com

I'm very happy with the results on a 2.1 channel set-up. There are some issues that would need to be addressed before I could use it in my multi-channel set-up, though.

Hope it helps!

geoff

Steve Vol · « **Reply #13 on:** 19 Jun 2006, 05:43 pm »

Levi, any comments on the difference between your Bat and Bryston amps. I am looking at the Bat or Bryson to run my front speakers in a 5.1 set up also. I'm leaning toward the VK500, but was wondering how you would compare the Bat to the Bryton.

Levi · « **Reply #14 on:** 19 Jun 2006, 06:41 pm »

I hope this doesn't fall into the 2ch audio circle. I like the sound of the BAT VK-500 in 2ch specially when they are connected fully balanced input to output with BAT preamp. Although it is compairing apples to orange I can summarize to you my findings in 2ch listening. VK-500 vs 9BSST that is not fair! {snob}

Similarities:
low noise floor
Fast transient response
nuance
low level intelligibility

Difference: favor's VK-500
better bass control
3 dimensionality/layers/colors - put emphasis on this.
palpability/natural sounding
immediacy and delicacy

I hope this helps. The VK-500 is good but needs synergy with the rest of the system. If you are in the NYC area, please let me know as i can accomodate you in.

The success in having the best of both worlds is the preamp with unity gain or HT Bypass.

Quote from: Steve Vol

Levi, any comments on the difference between your Bat and Bryston amps. I am looking at the Bat or Bryson to run my front speakers in a 5.1 set up also. I'm leaning toward the VK500, but was wondering how you would compare the Bat to the Bryton.

lonewolfny42 · « **Reply #15 on:** 20 Jun 2006, 06:29 am »

Levi....From your photo, that BAT 500 is really ...BIG.......compared to your old BAT 200.....

Levi · « **Reply #16 on:** 20 Jun 2006, 01:51 pm »

Yes. That is correct.

Quote from: lonewolfny42

Levi....From your photo, that BAT 500 is really ...BIG.......compared to your old BAT 200.....