Should I combine the amps i have?

[timoteo]

OK so i have been around the block a bit when it comes to setting up my home theater system. I understand that when you have an AVR that is capable of "bi-amping" the mains, you are not ACTUALLY bi-amping them since the watts are coming from the same power source. I had tried it a few years back & gained no improvements in the audio quality.

However now my situation is a little different & im wondering if i am making good use of all the power i have available to me. Before i start moving cables around, i want your thoughts & advice on what i should do.

As you can see from my sig my Receiver is a Yamaha RX-A2000 & my external ampmis the Emotiva XPA-5. As of now i am using the Yamaha as a processor & ONLY using the XPA-5 to power my 5 speakers. The other day i started thinking that by not using at least a couple of the amps in the Yamaha i was waisting some of my systems potential. So here is what i have been thinking may make best use of all i have...

Would i gain headroom in my system if i hooked things up this way?...
2 channels from my receiver to power my 2 surround speakers
1 channel from my XPA-5 to power my center &
4 channels from my XPA-5 to bi-amp my mains

My thought is that instead of waisting my receivers amps, id use them for my rears & use the 5 amps in my Emotiva to power my front 3.

Would this be better than only using the Emotiva to power my system?

Thanks for your help guys!!!

 

[MidnightSensi2]

Your receiver is stable to 6-ohms, and your rears dip to 3.7-ohms according to B&W. I think stick with the Emotiva.

Your speakers recommended amplifier power is 25-100W. Your emotiva is putting out 200@8-ohms and 300@4-ohms. Generally I recommended doubling the IEC (100W is IEC in your case, so 200W is ideal), which makes your Emotiva perfect for running those speakers.

Are the speakers sounding strained/stressed at the volumes you listen to? If so, you might consider a speaker with better power handling and greater sensitivity.

 

[highfigh]

OK so i have been around the block a bit when it comes to setting up my home theater system. I understand that when you have an AVR that is capable of "bi-amping" the mains, you are not ACTUALLY bi-amping them since the watts are coming from the same power source. I had tried it a few years back & gained no improvements in the audio quality.

However now my situation is a little different & im wondering if i am making good use of all the power i have available to me. Before i start moving cables around, i want your thoughts & advice on what i should do.

As you can see from my sig my Receiver is a Yamaha RX-A2000 & my external ampmis the Emotiva XPA-5. As of now i am using the Yamaha as a processor & ONLY using the XPA-5 to power my 5 speakers. The other day i started thinking that by not using at least a couple of the amps in the Yamaha i was waisting some of my systems potential. So here is what i have been thinking may make best use of all i have...

Would i gain headroom in my system if i hooked things up this way?...
2 channels from my receiver to power my 2 surround speakers
1 channel from my XPA-5 to power my center &
4 channels from my XPA-5 to bi-amp my mains

My thought is that instead of waisting my receivers amps, id use them for my rears & use the 5 amps in my Emotiva to power my front 3.

Would this be better than only using the Emotiva to power my system?

Thanks for your help guys!!!

Using Speaker A and Speaker B is a problem for receivers because they're both fed by a single pair of channels an, while low or moderate SPL listening is OK, cranking it will cause a problem for the amp because of the impedance drop. If the receiver has a Zone 2 and it can be conficureg specifically for Bi-Amping, like Denon, you would be feeding the woofers with one pair of channels and the mid/tweeter with another.

I doubt the sound will be much different at just about any level if you bi-amp using a receiver, although you will have a bit more headroom and that's always a good thing. However, true bi-amping places the crossover ahead of the amplifiers and the benefits from that include: increased control of speaker level matching, more control of crossover points, slope, notch filtering and there's no insertion loss caused by passive crossover components. In this configuration, the insertion loss can be well more than 3dB and if the power is doubled, that adds even more, so the dynamics would improve and the amplifiers don't need to work as hard or see a roller coaster-like impedance curve.

 

[timoteo]

Thats a good point about the impedence dip. Thanks

Highfigh:
I think you may have misunderstood my question. I have no plans to bi-amp using my receiver. I know that sort of bi-amping is worthless. Im wondering if using my receiver to ONLY power my surrounds. This would free up 2 channels in my XPA-5. Id use the XPA-5 to bi-amp my mains & the 5th amp to power my center.

Im just thinkin, with the receiver sitting there twiddling its thumbs is a waist of good amplifiers. I could be wrong...thoughts?

 

[agarwalro]

Would i gain headroom in my system if i hooked things up this way?...
2 channels from my receiver to power my 2 surround speakers
1 channel from my XPA-5 to power my center &
4 channels from my XPA-5 to bi-amp my mains

Purely theoretically, it may help since the speakers are being driven with higher potential for power delivery. That said, I do not know if it is any better/different than simply using a more powerful amp, say 400W @8ohms.

I also doubt there will be any perceptable improvement in SQ because...

However, true bi-amping places the crossover ahead of the amplifiers and the benefits from that include: increased control of speaker level matching, more control of crossover points, slope, notch filtering and there's no insertion loss caused by passive crossover components. In this configuration, the insertion loss can be well more than 3dB and if the power is doubled, that adds even more, so the dynamics would improve and the amplifiers don't need to work as hard or see a roller coaster-like impedance curve.

Could not have been said better. This configuration would be considered "active"...

 

[timoteo]

As of now im not noticing any distortion or strain at high volumes. Im not planning on getting a more powerful amp for these speakers but was thinkin, if i set my syem up right i want the most headroom available to me. Its more a matter of optimizing what i already own.

Before buying my Emotiva, i had an ATI 3004 amp hooked up to my front 3 giving each channel 300 watts. I was borrowing it from a friend for a week. The bass seemed a bit better than the Emo but that could have been in my head because i couldnt do a side by side comparison. Ive read that if your speaker has a power handling rating of 200watts then its ideal to hook up a 400watt amp to it so it will never even get close to running out of juice or clipping at high reference levels.

Im thinkin the best thing to do is try it out to see if i notice any improvements. Even if i dont hear anything different ill know ive got plenty of juice.

One more question though.

Would it not be recommended to have 200watts going to my center & 400watts to my mains? Does that effect the way things sound as they pan across the front 3 speakers?

 

[agarwalro]

Im thinkin the best thing to do is try it out to see if i notice any improvements. Even if i dont hear anything different ill know ive got plenty of juice.

In fact, you're not an Audioholic if you don't do it . Look forward to reading your comments for pre and post switch.

Would it not be recommended to have 200watts going to my center & 400watts to my mains? Does that effect the way things sound as they pan across the front 3 speakers?

Just like using a 3ch amp for fronts and letting the receiver drive the surrounds, once you level match, it will be a non-issue.

 

[timoteo]

Haha your not lieing!! Screwin around with different settings, placements & anything else we can do makes us an Audioholic. In fact, one of my favorite things about my new VTF-15H sub is the 5 different modes i can set the sub. (3 ported & 2 sealed) its fun to flip a switch, turn a knob & swap a plug then get a totally response! So i definately like tweaking.

I will post back on my thoughts & response once i chNge up the way im using my amps. Im not expecting much if any audible difference but hey ive been suprised before. I can speculate & ask a lot of questions but i wont know for sure to i just do it!

Any more thoughts from you guys are totally welcome.
Thanks again for the helpful comments!!

 

[PENG]

All those talks about true biamping or not truly biamping are opinions. Who are we to dictate what the definition of biamping should be? One could say that as long as you are using two separate amplifiers it fits the definition of "bi=2" amping literally but that would be just one way to define it. So until someone can post an official (and tell us why is is official) definition you should feel free to do it and call it biamping regardless what other people are telling you.

Now back to the topic, your thinking is logical but you have to actually do it to find out if there is a perceptible difference to you. You may perceive a difference due to Placebo effect, or you may in fact hear a difference even in a blind test. No one can know for sure. In theroy there will be differences physically and electrically speaking but there may not be, and I would say not likely be audible differences one way or the other.

I also don't think one can assume the 3.7 ohm impedance dip will make an audible difference because:

1) We don't know where that dip is, and for what bandwidth?
2) We don't know if the dip coincides with a large phase angle (between the current and voltage phasers, commonly but inaccuratekly referred to as vectors).
3) The AVR will understandable be stressed by a low impedance relatively speaking but if it has to feed only two surround channels it may not be stressed at all depending on 1) & 2) above, the size of your room, and a few other factors.

The claimed benefits of biamping are plural, more power is only one of the several claimed benefits, and for that one only you could do better with a more powerful amp as others have suggested. Regarding the crossover thing it is more of an opinion than facts. There are reputable amp manufacturers, Anthem being one of them, who will tell you the "right" way to do it is passive biamping, not active biamping. Obviously rightly or wrongly, and whether you choose to believe them or not, they have their reasons. I am neutral on this controversial topic and I am only trying to tell you not to take opinions. I do not know what the facts are and I doubt many people really do. For all these reasons, I believe one should try different ways and stick with the way you like best. Your have all those amps on hand, the only thing you need to invest on is time and a few pairs of interconnecting cables.

 

[highfigh]

Thats a good point about the impedence dip. Thanks

Highfigh:
I think you may have misunderstood my question. I have no plans to bi-amp using my receiver. I know that sort of bi-amping is worthless. Im wondering if using my receiver to ONLY power my surrounds. This would free up 2 channels in my XPA-5. Id use the XPA-5 to bi-amp my mains & the 5th amp to power my center.

Im just thinkin, with the receiver sitting there twiddling its thumbs is a waist of good amplifiers. I could be wrong...thoughts?

I don't think it's totally worthless- it would still add a little headroom but that's about all.

Personally, if I was going to use the XPA-5, I'm not sure there would be a large benefit gained by bi-amping other than, again, more headroom. Assuming you don't drive the system to the point of clipping or deafness, you should have a good amount of headroom, anyway. I'd think about just using a preamp/processor instead unless you really like/prefer the features of the receiver you have.

 

[timoteo]

Peng:
I read your post twice because i not only enjoyed what you had to say but i also had to actually THINK about some of the points you made. I appreciate those type of responses, it stated some valid opinions but also incorporated facts. I enjoyed that so thank you! Gives me something to chew on

Highfigh:

Thats an interesting suggestion you have of going to a dedicated Pre-pro instead of using my receiver to do the job. On one hand i do love all the features & flexability i have using the Yamaha, but since audio quality is #1 to me, your making me think about an actual pre-pro.

What benefits (if any) would i gain from switching out my Yamaha for a dedicated processor from another manufacturer?

 

[highfigh]

All those talks about true biamping or not truly biamping are opinions. Who are we to dictate what the definition of biamping should be? One could say that as long as you are using two separate amplifiers it fits the definition of "bi=2" amping literally but that would be just one way to define it. So until someone can post an official (and tell us why is is official) definition you should feel free to do it and call it biamping regardless what other people are telling you.

I also don't think one can assume the 3.7 ohm impedance dip will make an audible difference because:

1) We don't know where that dip is, and for what bandwidth?
2) We don't know if the dip coincides with a large phase angle (between the current and voltage phasers, commonly but inaccuratekly referred to as vectors).
3) The AVR will understandable be stressed by a low impedance relatively speaking but if it has to feed only two surround channels it may not be stressed at all depending on 1) & 2) above, the size of your room, and a few other factors.

The claimed benefits of biamping are plural, more power is only one of the several claimed benefits, and for that one only you could do better with a more powerful amp as others have suggested. Regarding the crossover thing it is more of an opinion than facts. There are reputable amp manufacturers, Anthem being one of them, who will tell you the "right" way to do it is passive biamping, not active biamping. Obviously rightly or wrongly, and whether you choose to believe them or not, they have their reasons. I am neutral on this controversial topic and I am only trying to tell you not to take opinions. I do not know what the facts are and I doubt many people really do. For all these reasons, I believe one should try different ways and stick with the way you like best. Your have all those amps on hand, the only thing you need to invest on is time and a few pairs of interconnecting cables.

OK, let's call it 'bi-amplification with passive crossover' and bi-amplification with active crossover'. Either way, the amount of power delivered to the HP and LP can be whatever we want it to be, for whatever reason necessary. If max SPL is needed with a given power, an active crossover is needed because of the passive crossover's insertion loss- a passive crossover will never work without changing the level of the signal and an active crossover has the ability to achieve 0dB signal loss because it has gain stages.

Re: your #1 point- the impedance "dip" is easy enough to determine using a Dayton WT-3 or something like it. It also shows the phase plot, so the angle can be seen. Whether this will be audible depends on the amplifier, as you posted.

 

[PENG]

OK, let's call it 'bi-amplification with passive crossover' and bi-amplification with active crossover'. Either way, the amount of power delivered to the HP and LP can be whatever we want it to be, for whatever reason necessary. If max SPL is needed with a given power, an active crossover is needed because of the passive crossover's insertion loss- a passive crossover will never work without changing the level of the signal and an active crossover has the ability to achieve 0dB signal loss because it has gain stages.

Thanks for understanding my point, I know it matters little other than for clarification purpose.

Re: your #1 point- the impedance "dip" is easy enough to determine using a Dayton WT-3 or something like it. It also shows the phase plot, so the angle can be seen. Whether this will be audible depends on the amplifier, as you posted.

I have seen plots from various sources such as Stereophile magazines that show those dips sometimes occur in the higher frequencies and for a rather narrow band that also coincides with relatively small phase lags. Anyway, I also understand the simple rule of thumb that more power on hand is always a good thing regardless.

 

[DD66000]

If you are NOT running near 0 db on the volume control, then your amp has more than enough power for your system. Passive bi-amp is therefore a waste of time. On the other hand, if you are at or near 0db, then you do need more power.

 

[Mad Norseman]

Hi Timoteo!,
Yes, I understand what you're suggesting (Home Theater magazine had a quick article in their August 2011 issue on this very topic!), and since your A-2000 delivers 2 x 130watts (I think) into 8 Ohms across the full spectrum, that's what would then be available - at a minimum - to your two rear/surrounds.
The comments following about your B&Ws 'dipping' to 3.7 Ohms are legit I think, but since your receiver's amplifiers would be loafing driving just the two, and since those 'dips' would only occur very infrequently, I would expect no issues from that, and wouldn't worry about it (set your A-2000 to 6 Ohm loads - see manual).
The XPA-5 would then drive your bi-amped fronts, and center channels.
You'd need to make sure you setup your A-2000 to output the bi-amped signals at your pre-out jacks (but they will if you've already set it up as if bi-amping the receivers own amplifiers).
What you will have to do once its all connected (because you'll be utilizing two different amplifiers with slightly different gains) is run a test audio disc, and set the levels for equal volume output given the same signal inputs for each channel.
(But I wonder if running the receiver's own YPAO will do this for you? - Might ask Yamaha...).
But if needed, your A-2000's separate channel output levels can be adjusted for this in 0.5, or 1 db increments I believe.
Your final result will be:
Front channels (bi-amped) will receive 200w x 2 each, (400w total each), from the XPA-5.
Center at 200w, from the XPA-5.
And rear/surrounds will receive 130w each, from the A-2000.
Sounds great to me - good luck, and report back!
The Mad Norseman

 

[Adam]

The Mad Norseman

Welcome to the forum! Awesome screen name.

 

[Mad Norseman]

Its nice to be welcomed - Thanks!

Nice forum, great posts!
I'm looking forward to participating more now.
Thanks again for the nice welcome!

 

[GranteedEV]

There are reputable amp manufacturers, Anthem being one of them, who will tell you the "right" way to do it is passive biamping, not active biamping. Obviously rightly or wrongly, and whether you choose to believe them or not, they have their reasons.

Anthem... a passive loudspeaker manufacturer first and foremost? ...

 

[walter duque]

Ive read that if your speaker has a power handling rating of 200watts then its ideal to hook up a 400watt amp to it so it will never even get close to running out of juice or clipping at high reference levels.

Don't be so sure about a 400 amp not clipping at high reference levels. I run 350 watts with 3.2 db headroom and I do manage to slightly clip the amp at +6 db.

 

[GranteedEV]

It also depends on the speaker sensitivity, seating distance, preout headroom, and available line voltage too. Raw speaker wattage ratings are meaningless, beyond "feed it a sine wave with more than this number, and you'll blow these speakers son"

I've got around 500w on tap, but only ~88db sensitive speakers, 15a line, and ~7vRMS preouts and i've seen the clip light go off around -3... i think it was during some movie. Nothing audibly offensive at least, but the light indicates something was inadequate.