Bi/tri-amping stereo speakers with a 5.1/7.1 receiver

[anm]

Bi/tri-amping stereo speakers with a 5.1/7.1 receiver

Hi,
I plan buy only 2 front floorstanders to start with that shall expand to 5.1 over some period of time.
To power these, if I purchase a 5.1 or a 7.1 channel receiver, in the meanwhile can I use the unused power channels to power the stereo system?

Suppose if the speaker is not bi-amp(tri-amp)able, then can I converge the output from two channels into one?
I know its a tough one, or may be no one ever did this before coz rich people don't need to play these games. However, I am strictly limited on funds. I do want a good system though. And more important, I want to play with all these options.

regards

 

[ParadigmDawg]

Many newer models of AVRs have an oprtion to "bi-amp" by assigning the back surrounds to be used with the mains. This however is not really bi-amping as you are using the same power source. If you are like the rest of us, there is no need to bi-amp.

What are you trying to drive?

Bi/tri-amping stereo speakers with a 5.1/7.1 receiver

Hi,
I plan buy only 2 front floorstanders to start with that shall expand to 5.1 over some period of time.
To power these, if I purchase a 5.1 or a 7.1 channel receiver, in the meanwhile can I use the unused power channels to power the stereo system?

Suppose if the speaker is not bi-amp(tri-amp)able, then can I converge the output from two channels into one?
I know its a tough one, or may be no one ever did this before coz rich people don't need to play these games. However, I am strictly limited on funds. I do want a good system though. And more important, I want to play with all these options.

regards

 

[anm]

I am considering hk 254/ 354 - they do have pre-amp outs.
So is it possible to run them in stereo mode, split front left/ right pre-out to avrs front and rear amp channels - and then biamp the stereo speakers.

I am assuming each channel is a different power supply to speaker, bi-amping this way should allow speaker to draw more current.

regards

 

[PENG]

This however is not really bi-amping as you are using the same power source.

This may be technically incorrect unless you want to define bi-amp yourself. Practically speaking, a strong 7 channel receiver (e.g. HK's top models), or amp that has one main power supply for all the amps could be considered huge if used to power two speakers only. Regardless of how many power supplies you have in your amp(s) you ultimately plug it (them) into wall outlet(s) and that is one single (huge though) power supply.

For best results, it is preferable to bi-amp using two separate amps and active crossovers. Using two separate amps only without active crossovers may also yield good results. Using the unused amps within a multichannel amp is not bad and may be worth trying but using the unused amps within a multichannel receiver is probably not a good idea in most cases, and will likely gain no audible improvements.

 

[anm]

PENG - thanks for your answer. I may be wrong as I do not have any experience with hi-fi - still some time before I board the train
Has anyone actually tried this - bi-amping front speakers with spare channels from avr ?
If yes, what is the experience? Is it comparable to bi-amping with different amps withOUT active cross-over?

regards

 

[zumbo]

Waste of time, and speaker wire. Pretty much the answer you will get.

All AVR's will run in stereo mode. While in this mode, the extra power you are looking for will be sent to the mains. No extra wires needed.

 

[anm]

zumbo, thanks for your reply. I can understand guys on this forum would be frustrated with this question being repeated so many times by so many users, and so many times over and again by me.
However, AVR 354 specs doesn't seem to say what you are saying:

Stereo Mode
Continuous Average Power (FTC)
75 Watts per channel, 20Hz–20kHz,
@ <0.07% THD, both channels driven into 8 ohms


Seven-Channel Surround Modes
Power per Individual Channel
Front L & R channels:
75 Watts per channel
@ <0.07% THD, 20Hz–20kHz into 8 ohms
Center channel:
75 Watts @ <0.07% THD, 20Hz–20kHz into 8 ohms
Surround (L & R Side, L & R Back) channels:
75 Watts per channel
@ <0.07% THD, 20Hz–20kHz into 8 ohms

 

[PENG]

He is sort of correct, you will always get more power for your mains if the power supply only has to feed 2 channels. However, HK receivers seem to be more amplifier limited (strong P/S, weak amps in relative sense) relative to similarly priced Denon and Yamaha products so you will get significantly more power by using the unused amps to bi-amp. Take a look of some of the lab measurements by H.T. mag, S&V, HomeCinemaChoice sites you will see what I am saying. So yes you will benefit from having more power if you biamp your 354.

That being said, it also depends on the speakers you have. If they are 2 ways, the tweeters use very little power so the extra power you get from the other amps will not be very well utilized. In that case you could have just bi-wire and get the same results. Most people will still tell you it is a waste of wires to bi-wire.

 

[anm]

I am considering speakers (Dali Ikon 7, or may be Dali Ikon 6) that specify
Recommended amp. power [Watts] min 25
Recommended amp. power [Watts] max 200

In this case, what is the power in watts recommended? I would use them in a room that is 20ft by 30ft - my listening position normally would be 9 -12 ft from the fronts. With that kind of distance, the SPL levels would be different than what they would be if I stick my ear close to the speakers. On a normal day, I would not hear at very high SPLs, but once in a while when I want to take it to high volume, it should not die mid way.

Of the following two options which one do you recommend:

Option 1 - I buy 3490 (120x2) along with two fronts. Buy a 5.1/7.1 later when I buy other speakers for 5.1.
Option 2 - I buy 254 now, use them in stereo till I buy other speakers. But 254 may not have adequate power for the fronts.

Option 2 may turn out to be cheaper in long term if I can biamp. Will turn out much more expensive if I have to buy extra amp for fronts.

 

[zumbo]

Click the link below, and scroll down to This Receiver is more powerful than the other one.


http://www.audioholics.com/education/frequently-asked-questions/common-misconceptions-in-audio-part-i/

 

[PENG]

I am considering speakers (Dali Ikon 7, or may be Dali Ikon 6) that specify
Recommended amp. power [Watts] min 25
Recommended amp. power [Watts] max 200

In this case, what is the power in watts recommended? I would use them in a room that is 20ft by 30ft - my listening position normally would be 9 -12 ft from the fronts. With that kind of distance, the SPL levels would be different than what they would be if I stick my ear close to the speakers. On a normal day, I would not hear at very high SPLs, but once in a while when I want to take it to high volume, it should not die mid way.

Of the following two options which one do you recommend:

Option 1 - I buy 3490 (120x2) along with two fronts. Buy a 5.1/7.1 later when I buy other speakers for 5.1.
Option 2 - I buy 254 now, use them in stereo till I buy other speakers. But 254 may not have adequate power for the fronts.

Option 2 may turn out to be cheaper in long term if I can biamp. Will turn out much more expensive if I have to buy extra amp for fronts.

Based on the specs of the 3490:

Stereo Mode :
Continuous Average Power (FTC) Per Channel : 120 Watts per channel, 20Hz – 20kHz @ <0.07% THD, both channels driven into 8 ohms
150 Watts per channel, 20Hz – 20kHz @ <0.2% THD, both channels driven into 4 ohms

and the 254:

Stereo Mode
Continuous Average Power (FTC) per Channel : 65 Watts per channel, 20Hz – 20kHz, @ <0.07% THD, both channels driven into 8 ohms
Seven-Channel Surround Modes, Power per Individual Channel,
All Channels Operating at Full Power :
Front L & R Channels : 50 Watts per channel @ <0.07% THD, 20Hz – 20kHz into 8 ohms

I recommend you go with option 1. If I understood correctly the 3490 can be used as a power amp so it will not be totally wasted if and when you are ready for a 7.1 system. Even if you bi-amp, the 254 will likely not do justice to the basically 5 to 6 ohm rated speakers.

By the way, I read a review that suggested you use a subwoofer with those speakers so if you find that you are not getting enough base do not blame the receiver too soon.

 

[zumbo]

With such a nice speaker choice, why are we looking at low/mid-fi equipment?

 

[anm]

Quote from the article

The fuse rating on this receiver is 11 amps. It is common practice in engineering to derate a fuse to 75% of its maximum sustained current ratings. Thus the Receiver should not be able to deliver more than 0.75*11 amps = 8.25 amps.

Seems there is an error in the calculation. If fuse is rated at 75% of maximum sustained current - max current should be 11/0.75= 14.7 AMP - and so it seems it can use entire 15 A of current from the power supply.

Anyways I am not comparing the insane ratings. I am comparing 55x7 (avr 254) and 75x7(avr 354) and in case I can successfully bi-amp - 110x2 for 254, or 150x2 for 354 with 120x2 of 3490. Both of these ratings seem to be far from ceiling of home power supply.

regards

Click the link below, and scroll down to This Receiver is more powerful than the other one.


http://www.audioholics.com/education/frequently-asked-questions/common-misconceptions-in-audio-part-i/

 

[anm]

Coz speakers have eaten into my entire budget.
Dali Ikon 6 would cost me about $1500.
HK 3490 would cost me $670 in India - and if I get it from the US it would cost me $675 ($300 + 200 shipping + $175 customs )
HK 254 would cost $800 ($400 + 200 shipping + $200 customs)
With 254 I get extras - HD audio, HD video, option of expanding to a 5.1 (if I keep on using rears for bi-amp) or 7.1 if I don't biamp.

Can you suggest something in $300 - 500 budget that would better suite? Cost in India would be x2.

My salary per month - $1150

With such a nice speaker choice, why are we looking at low/mid-fi equipment?

 

[anm]

oh, and I already spent a fortune (it costs a fortune in my Liliput world) in buying a Panasonic PT AX200.

 

[PENG]

Quote from the article



Seems there is an error in the calculation. If fuse is rated at 75% of maximum sustained current - max current should be 11/0.75= 14.7 AMP - and so it seems it can use entire 15 A of current from the power supply.

Anyways I am not comparing the insane ratings. I am comparing 55x7 (avr 254) and 75x7(avr 354) and in case I can successfully bi-amp - 110x2 for 254, or 150x2 for 354 with 120x2 of 3490. Both of these ratings seem to be far from ceiling of home power supply.

regards

As I said before it depends on the type of speakers but in general if you want more power you are better off with a more powerful amp than biamping because the low frequency drivers need much more power than the tweeters. Again, purely from power stand point your speaker will do better with 120WX1 than 75WX2 (bi-amp) because the L.F. drivers are limited by the 75W amp in the latter case. People bi-amp mainly for reasons other than justing wanting more power.

 

[zumbo]

Seems there is an error in the calculation. If fuse is rated at 75% of maximum sustained current - max current should be 11/0.75= 14.7 AMP - and so it seems it can use entire 15 A of current from the power supply.

To figure 75% of a number, you multiply that number by .75 (11 x .75 = 8.25)

Anyways I am not comparing the insane ratings. I am comparing 55x7 (avr 254) and 75x7(avr 354) and in case I can successfully bi-amp - 110x2 for 254, or 150x2 for 354 with 120x2 of 3490. Both of these ratings seem to be far from ceiling of home power supply.

regards

It's just not gonna happen. If you could get that kinda power out of such a receiver, none of us would have to spend thousands on amplification. Don't know how else to put it to you.

 

[anm]

Now it makes sense! If low frequency drivers take much more power than high freq. If that ratio is like 90%, biamping certainly isn't going to help.

BUT, are we saying that the bi-amp/ bi-wiring posts on speakers means 1 goes to tweeters and another to mid + bass? Shouldn't speaker makers give one binding post per bass woofer so that bi/tri amping can be done and give actual benefits?

Some other options that I can see in my budget are
Integrated amp - Rotel RA04, RA05
Power amp - RB06
Stereo power amp -RB1050, RB1070 (over budget, but can stertch)

What is the difference between stereo power amp and power amp??
Can I connect analog outputs from my cd player directly to a power amp? What is the difference in that case between integrated and power amp?

regards

As I said before it depends on the type of speakers but in general if you want more power you are better off with a more powerful amp than biamping because the low frequency drivers need much more power than the tweeters. Again, purely from power stand point your speaker will do better with 120WX1 than 75WX2 (bi-amp) because the L.F. drivers are limited by the 75W amp in the latter case. People bi-amp mainly for reasons other than justing wanting more power.

 

[anm]

I think it says 75% of Max = 11 amp which is written on fuse. So Max = 11/0.75

If it is the other way round, ie Max= 75% of 11, I stand corrected. But phrasing of the statement is confusing to me.

regards

To figure 75% of a number, you multiply that number by .75 (11 x .75 = 8.25)



It's just not gonna happen. If you could get that kinda power out of such a receiver, none of us would have to spend thousands on amplification. Don't know how else to put it to you.

 

[zumbo]

The power amp RB06 can be bridged to combine both channels to 1 channel @ 180w.

The stereo amps are 2-channel only.

The only way you can use your cd player directly with the power amp, or stereo amp, is if it has a gain control. You can find players that have this feature. My Yamaha CDC-645 does.

The integrated amp has a gain control, so it can be connected directly to a cd player.