Combine four stereo amps to make a multi channel amp

[rahuln]

Hi,

I am redoing my AV room. Now a days I am using HK-AVR 635 as receiver. Unfortunately it doesn't support new HD/BD audio format and hence need an upgrade.

One option I am looking at is using Oppo BDP-103 (not purchased yet) as pre-amp as it supports 8-channel decoded output. It also support HDMI in, for upscaling. I can route my Tatasky HD through Oppo and get the decoding, with upscaled signal.

Now instead of buying a multi-channel amp, use 4 stereo amps. I already have two Norge amp and I will get two more for another 20K. So while listening music, I can turn on just one amp, for 5.1 3 and all four for 7.1 audio.

Do you guys see any problem with this setup?

Thanks

_Rahul.

 

[navin advani]

Now instead of buying a multi-channel amp, use 4 stereo amps. I already have two Norge amp and I will get two more for another 20K. So while listening music, I can turn on just one amp, for 5.1 3 and all four for 7.1 audio.

What you need is 7 channels of say 50-100W rms and 1 channel of 200-500W rms. You do realise that the .1 channel is for a subwoofer. Most subwoofers come with 200-1000W plate amplifiers designed for just that duty (bass takes a lot of energy).

The .1 channel in a movie (esecially sci-fi and action movies) contain a lot of low frequency energy (much more than in conventional music) and this puts a lot of stress on regular woofers and amplifiers. Amps like th BASH amps are capable of dealing with this abuse.

Additionally you do not need the preamplifier sections of the amplifers. Which Norge amplifers do you have (they make only one power amp that I know of, all they rest of their amplifers are stereo integrated amplifers). I dont know if any of the integrated amplifiers they have provide a "power in" input. The Aux/CD/Tuner inputs go via the preamp and volume control.

Hence what you would need is 2 get 4 stereo power amplifiers (I think is the Norge 1200) and mabe get Norge to supple one of these 4 bridged to mono mode. I do not know the topology of the Norge amps so cant tell if this is possible safely.

What speakers do you intend to use? For most surround sound systems it is preferable to use a similar speaker across at least the front 3 channels.

 

[trittya]

Exactly my thoughts, FM Navin Advani and OP.
All I'd like to add is suggest is to go in for a Dune HD prime in case you are hell-bent for blu ray, else go for Dune HD base as a near-total AV source-cum-processor-cum-media hub solution. I say near-total only because it lacks a DAC, AFAIK.
HTH

 

[Audio_Freek]

Ops This seems to Experimental.

The basic need for HT is clear surround effect and synchronization of speaker delays.
I have seen a person who used the same idea and the sound was really amazing, but the real time HT feel was not there as"Fronts and Centre and rear where playing good gear, But the dynamics were missing"

Matching a 5.0 to 0.1(Sub) itself creates lots of issues, And i wonder how you have such plans.

Your set-up would give GOOD SOUND but not apt one for movies. Eg" MONO mode in Stereo Set-up, though we know it sounds good,for sure it will not satisfy as like stereo.

You can keep one Amp for the Stereo, sell another and add some budget to get entry level Receiver .

This is my honest opinion

 

[spirovious]

It will be better that you use similar amps for front & center as sound signature of different amp may not give good effect.Also check if oppo has distance calculation,Bass management which can be needed for timing.

 

[navin advani]

You can keep one Amp for the Stereo, sell another and add some budget to get entry level Receiver

Yes this is what I would normally recommend. I too have done this for one of my systems. I assume the Oppo player you have has the ability to do all the processing and give you 7.1 channels of analog signal out.

I have a CD player and audio media player that are connected to a regular stereo integrated amplifer. All video soruces (Set top box, DVD player, Gaming machines, XMBC media Player, etc) are connected to the HT/AVR.

The Integrated amplifier has "Power in" connections and the AVR has pre amp out options. The Left and Right pre out from the AVR feed the Integrated amp. For Video sources the Integrated amp acts as only a power amp. For CD playback (and other audio only sources) the Integrated amp operates as it would normally be used for 2 channel playback.

This however requires that your front speakers be fullrange speakers.

In my case (it is a little outside the norm) the subwoofer amplifers have 2 inputs - one LFE input (used by the AVR) and one mono input (used by the Integrated) so either my AVR or my Integrated can drive my subwoofers. Both my AVR and Integrated have subwoofer output (in fact both have 2 subwoofer outputs so both my front and rear subwoofers can be driven from either amp - the AVR has Audssey SUB EQ HT so integrating the subwoofers is easier).

 

[joyous]

Hi,

I am redoing my AV room. Now a days I am using HK-AVR 635 as receiver. Unfortunately it doesn't support new HD/BD audio format and hence need an upgrade.

One option I am looking at is using Oppo BDP-103 (not purchased yet) as pre-amp as it supports 8-channel decoded output. It also support HDMI in, for upscaling. I can route my Tatasky HD through Oppo and get the decoding, with upscaled signal.

Now instead of buying a multi-channel amp, use 4 stereo amps. I already have two Norge amp and I will get two more for another 20K. So while listening music, I can turn on just one amp, for 5.1 3 and all four for 7.1 audio.

Do you guys see any problem with this setup?

Thanks

_Rahul.

I guess you already have the essential apparatus to experiment. What you need additional is an active subwoofer ( you need a subwoofer anyway, I guess you already have four speakers)

I suggest you to test with the two stereo amps you already have. Test for 4.1 setup with active subwoofer. If it works, go for more stereo amplifiers.

But in a multichannel receiver, you get lots of bells and whistles.

 

[Audio_Freek]

But in a multichannel receiver, you get lots of bells and whistles.

Bells n whistles" This is the major feature of HT, Surround music should be "Surprise" and needs to be heard when central is quite with low volume (most cases).If you use Stereo for all channels "the sweetness of surround"will be missed' due to other speakers impact.

Even though if you set up ,then need to keep "4+remotes" For operating all the equipment's volume (4 AMPS,MEDIA PLAYER,etc etc).this will make you tough time in home movies

 

[rahuln]

Sorry guys.. I was away for while.

@navin.. I already have powered subwoofer (HSU STF-1) and its a blast. I am planning to continue to use it. So I wont me loading the amp for .1 channel.

For speakers, I have a Polk Audio set. R50 for fronts, R30 for sides, R15 for rear and CS20 for center.

@spirovioius.. Oppo do have distance calculation and bass management.

But I get it, I guess synergy will not be there if I use multiple amps together.

Is there any simple 7 channel power amp available in India (I don't want to get power hungry equipment from US, I hate the converter noise)?

Thanks

_Rahul

 

[manoj.p]

Rahul,

I think your idea will work fine. Oppo does have level and distance adjustment + bass management. Plus, it has an HDMI input. In that regard, it can function as an HDMI pre-pro, offcourse without different DSP filters etc.

As for synergy, if you get same amp for all the channels, all are level matched, there is no question of the entire thing not working as a single system. You can even mix-n-match amps. Like same make/model for front speakers and different amp for surrounds. Remember, the biggest change in sound signatures is from speakers. And nobody uses same speakers as front as well as surround. Comparatively, an amp will make very little change to sound signature.