Bi-amp or Bridged Mono?

silentsound

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Hello,

I have an old Nad 2400 THX (100W stereo / 200W bridged) amp and soon I'm getting another one. I'm going to use these to drive a pair of MA RS6s. The cdp is Marantz CD6002 and I'm using my Yamaha RX-V1500 as a pre. My room size is 20 * 18.

My question is, to Bi-amp or bridge the amps and use them as mono amps?

Thanks for your suggestions and opinions.

SilentSound.
 
Hi,
Sorry am not totally getting the question.
One way of biamping is to bridge ur stereo power amps and use one for each speaker. So ur stereo amp drives a single speaker hence doubling the power.(acting like a monobloc)This too is Bi amping!
Second is to Use one of ur power amps in stereo mode to biwire one speaker(if the speaker has the provision)
Third is to use one of the power amps in stereo mode to drive the LF of both speakers and the other amp is simultaneously used also in stereo mode to drive the HF of both speakers.

Are u asking which of these is the best solution? If i have missed out anything would love to hear opinions. Have never tried either vertical or horizontal bi amping myself but it definately has it proven benefits as against just bi wiring.
Regards.
 
Hi dinyaar,

Thanks for describing the options clearly. My question was between option 1 vs option 2 or option 1 vs option 3.

I think that there is not much difference between option 2 and option 3 assuming both amps have identical performance.

RS6s have provisions for bi-wireable, one for LF & another for HF.

SilentSound.
 
Dear silentsound,

I have never tried this myself but i feel option 2 should be best. Option 1 where u bridge the amp could increase distortion and option 3 would make the amp driving the LF work much harder than the amp driving the HF. Though apart from running hot i dont think thats a problem too.

Silent try it peacefully over a weekend and post ur comments.
Regards
 
Hi Dinyaar,

Thanks for the reply. I'm sure you are one of the members keeping this forum interesting and worthwhile.

As soon as I get the other amp I'll try it and post my comments.

SilentSound.
 
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Hi,

I have to agree with dinyaar here though he was bit lost himself :p but brought the point back with precision:D !

The most prefferd option is to bi-amp ( use 1 nad per speaker in stereo mode not bridged) then use the 1 nad in bridged mode.

the main reason is in the bi-amp mode you are giving more head room for both LF and HF to play to thier best ability by giving them separate amps and by dissconnecting them from each other as oppsose share the same power between them.this for this reason alone its worth the option ! though their are other benefits both in the speaker and amp,I dun wana confuse you with too much information !

Hope this is of some use to you ! as dinyaar said please share your experiance with US.

Regards,
Bye
 
Hi Soundsgreat/Dinyaar,

I'm still waiting for the second amp. But I've a question. I'm using my avr as the pre-amp and it has a single rca output jack for right channel and another single rca output jack for left channel.

In the option both of you've suggested, where each amp is used in stereo mode for each channel/speaker, how do I get the 2 output pairs for LF and HF. Yes my speaker is bi-wireable.

Should I use 1 rca to 2 rca cable to connect from the avr to the power amp? If so, how good is this? Won't the signal weaken when you split? Am I missing something here?

Thanks,
Silentsound.
 
Hello Silentsound,

Yes You are 100% right the signal will weaken when you split it ! the trick here is to use the output from the amp ( usually thier will be a pair of out put in the power block) this out is from the pre or buffer stage of the amp so taking out from this does not have major implications.

So I suggest you to connect the right channel out from the pre-amp Or in our case the AVR to the NAD 2400 and take the line out from it and connect it to the other channel of the same Amp ( hence using two channels one each for LF & HF). do the same thing with the left channel aswell with another 2400.

But please make sure that the interconnects that you use for amp ( one channel to another) is as short as possible to avoid any loop distrotions and other problems

Hope this solves your problem ! anything else you want just let me know

Regards.
 
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Hi silent,
Only 1 pair of pre outs is a problem. U cannot use record out for loss of volume control.
I would not use a 1 RCA to 2 RCA. That would make this entire exercise pointless.
I guess the only option is to bridge the amps and use for each speaker and single wire ur speaker. The only problem that can arise with this is that in bridging u definately increase power and also distortion but u are also lowering an amps ability to drive low impedance loads. By that i mean if ur stereo amp can drive 4-16 ohms in bridged mode it would drive 8-16. Am pretty sure of this but i suggest u also confirm with some technical person.

Am not sure of what Soundsgreat is saying as none of my power amps has an out! The bryston i am using does not, the nad and rotels i had did not. Unless i am not understanding what he is saying.

Silent why not buy a used Nad C162? Most dealers in mumbai are stuck with a few and will happily discount. I know it has 2 pre outs (one is variable) and is a decent stereo pre and will obviously mate brilliantly with ur power amps.
Best regards.
 
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Hi Dinyaar,

The NAD 2400 THX which is the point of disscussion here has an line and lineout (I've attached the Pic of the same) so I think this clears your doubts.

Also My NAD Multichannel Amp 906 has lineout !

with respect to your suggestion of using NAD C162 which has 1 preout with volume at the back. how can you control the volume of that ,same level as the other which is controlled from the front constantly ?

Regards.
 

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Hi sounds great,
U are right. I have never seen line outs on power amps but i guess i learn new things everyday. Thanks for pointing it out. Are these pics of models for asia or for the EU? If i remember correctly the back panel of my nad pre was not exactly the same as the one in the picture.
The variable pre out(preout 2) on the 162 matches the output of the fixed (pre out 1) when turned to the maximum position. Basically so u can use non identical power amps.
My suggestion to look at a dedicated stereo pre like the 162 is firstly to improve the sound as compared to an AVR as the pre and secondly to have the convenience of having 2 pre outs.
Silentsound now u have all the options available to experiment!!!!!!!!
Regards
 
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Hello Dinyaar,

First of all thanks for being considarate,before posting it I was bit hesitant to point out thinking where I might offened you:p ! but then I thought its my duty to point out certain things as we both are trying to help,so did it.

the Amp is Asian ! as for the Pre, I tried to look it up yaar but they've not specified whether its the asian are what,So I dunno !

And with respect to your comment on keeping the 2nd pre-out volume full, how does it works with main volume ? Am not very sure, coz the very reason of providing an volume control is to control independently from the main, atleast this is my understanding.

please shed some light on this :) !

Regards
 
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Hi Soundsgreat/Dinyaar,

Thanks for your valuable suggestions and taking time to do so.

Soundsgreat,

My Nad 2400 THX power amp back panel looks like the one you've attached. But the rca jacks you've highlighted labelled as 'LAB'. What does this mean? I'm not sure whether these are preout jacks. Let me know.

Dinyaar,

The main reason I prefer the avr over a stereo pre-amp is, I'm using this setup for movies also. This way I don't have to switch the wires when I switch from movie to music vice versa.

About the preout volume knob, when its at maximum level, its as if there is no difference between the two pre-ins. Thats what I understood.

SilentSound.
 
Hi Soundsgreat,
Why would i get offended buddy? U have pointed out something that i had overlooked and did not know. In fact i am grateful for u correcting me.

Ill explain what i understand it as soundsgreat. I had this pre for a year but never used the variable pre out. Suppose i am using the pre with say one amp which is 100 wpc and the other is 120 wpc. I would connect the 100 watter to the fixed pre out and the 120 to the variable and then while i set the master volume at whatever level would raise the variable volume to match the output/sound pressure level of the other stereo amp.

Once again if i am wrong please do not hesitate to correct me as otherwise our dear friend silentsound might end up blowing something!!!!!!!hahaha

Regards
 
Dinyaar., you are right ,
The pre 1 and variable pre 2 can be connected to different power at the same time and both the pre outs will be controlled by the main volume control. And if you want the volume to match the other power you can adjust the variable volume control on pre2 . I have used NAD C 160 to my Rotel Power 980 and 960 for bi amping.

regards
 
HI soundofmusic and dinyaar,

Thanks for bringing clarity on this issue !

The main reason why I this doubt in the first place was,I have seen many high-end P.A booster amps with the 2nd pre out where its volume is controlled by the volume control thats it has and its not related to the main volume in any way ! thts why I had this doubt !

anyway lets not deviate from the main disscussion which is to help our friend !

As with your query regarding the lab input. the pic I've attached is the asian version which had line out as dinyaar was mentioning the Asian and Europe Version, your's might be europe version ( oh god why they do this !:mad: ) so I checked this out, infact I just got a NAd 2100 from a friend which has same lab input.
after checking out and trying diff things I came to conclusion that this might be a premitive type of balanced inputs that we find in todays date ! so they are not lineouts !

Now we are left with very few or nill options for Bi-Amping !
Am just trying figureout a way around this issue please wait(any how you are waitng for the 2nd nad to arrive )


Reagards.
 
Hi

IMO its not possible to Biamp using a AVR receiver , even if he uses a Y separater , the quality is compromised. the best possible way is to bridge the 2400 into Mono and use one amp for each speakers.

regards
 
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