500w feed vs 250w bi amp

[pinifinina]

Hello guy,
I have a maths/power question. Which way is better? Case 1- feed 500w single feed to 1 speaker. Case 2- bi amp speaker with 250w i.e. 250w to HF and another 250w to LF of the speaker. Both cases using speaker internal crossover. Or, is case 1 and case 2 essentially the same? Thanks guys!

 

[Kvn_Walker]

You'd have to have some incredibly inefficient speakers to ever need 500 watts per channel.

To answer your question though, bi-amping will have little or no audible improvement. You will also have the added hassle of level matching, if all four of your amps aren't the same brand and model.

There can be exceptions such as for speakers whose woofer section presents a very difficult load. Even in those cases the benefits will only be evident at very high volumes, when the bass is most demanding. For most passive speakers a single amp is the best solution.

 

[Leemix]

Usually one better amp is better but the only way to know in each case is to try.


Sent from my iPad using Tapatalk

 

[PENG]

In general, passive biamp likely won't provide audible benefits but in theory it may, but would depend on other factors such as the type of speakers, amps and how much "power" do you actually need etc..

I would suggest you ask the same question on the manufacturer of your speakers, but that would be meaningful only if the manufacturer is a highly reputable one such as the likes of Revel, B&W, KEF, Magico, Dyaudio, etc..

 

[ryanosaur]

Also, keep in mind that 250w + 250w does not equal 500 w. Passive bi-amping is not additive like that.
That there is seldom a reason to provide that much power to a single speaker is a whole other matter!
Best practice is commonly agreed upon to have your lows passed to a good subwoofer, and to crossover about 1 octave above the F3 of your Speaker. This allows what is usually the more energy demanding part of the FR to be handled by a specialized Speaker(the Sub) and allows the actual Speaker in question to utilize the power more efficiently where it makes a difference, in the mids and highs.

 

[pinifinina]

Wow... thanks guys!! A lot of information here to digest. So from what I’ve gathered above, 500w single feed is more...worthwhile than 250w bi-amping, as It does not have issues of:
1. level matching (in this case, it is not an issue because we are talking about 250w each to the HF and LF correct?)
2. More audible difference compare to 250w bi-amping
3. 250w bi-amp does not equal to 500w. Regarding this one, can I say single feed 500w to a speaker is actually more powerful than 250w bi-amping?
Thanks guys!

 

[PENG]

Wow... thanks guys!! A lot of information here to digest. So from what I’ve gathered above, 500w single feed is more...worthwhile than 250w bi-amping, as It does not have issues of:
1. level matching (in this case, it is not an issue because we are talking about 250w each to the HF and LF correct?)
2. More audible difference compare to 250w bi-amping
3. 250w bi-amp does not equal to 500w. Regarding this one, can I say single feed 500w to a speaker is actually more powerful than 250w bi-amping?
Thanks guys!

All of the above are wrong, except 3. that is correct, factually speaking.

1. and 2. depends on other factors, some of them already cited by others.

 

[TLS Guy]

Hello guy,
I have a maths/power question. Which way is better? Case 1- feed 500w single feed to 1 speaker. Case 2- bi amp speaker with 250w i.e. 250w to HF and another 250w to LF of the speaker. Both cases using speaker internal crossover. Or, is case 1 and case 2 essentially the same? Thanks guys!

No, it is not the same at all. If you passive bi-amp, one 250 watt amp will supply the high pass section and the other the low pass section. The low pass requires far more power than the high pass. So the 500 watt amp would be able to deliver far more power. In the bi-amp scenario the extra power provided to your speakers would be totally insignificant.

 

[Leemix]

What bi-amping can give is the midrange and tweeter not being affected a lot by the bass woofers on difficult load speakers.

On the nr 1. point, its about gain matching not watts. Different gain will give a different main volume “scaling” between the amps.


Sent from my iPad using Tapatalk

 

[Irvrobinson]

What bi-amping can give is the midrange and tweeter not being affected a lot by the bass woofers on difficult load speakers.

This is the only case for passive bi-amping. The number of speakers that really meet the "difficult load" criteria, meaning that the low frequency section is such a difficult load that it measurably affects amplifier performance into the higher frequency section, is very small. Pretty much it rounds to zero. I owned one of the examples that did qualify as truly difficult in the bass, the Legacy Audio Focus, and to my ears it benefitted from passive bi-amping even with a relatively powerful amplifier. Some people I know have claimed that various other many-driver speakers are in the difficult load category, but measurements don't back them up. Mostly I think the difficult load notion is more a state of mind than an actual issue for amplifier performance.

 

[Leemix]

This is the only case for passive bi-amping. The number of speakers that really meet the "difficult load" criteria, meaning that the low frequency section is such a difficult load that it measurably affects amplifier performance into the higher frequency section, is very small. Pretty much it rounds to zero. I owned one of the examples that did qualify as truly difficult in the bass, the Legacy Audio Focus, and to my ears it benefitted from passive bi-amping even with a relatively powerful amplifier. Some people I know have claimed that various other many-driver speakers are in the difficult load category, but measurements don't back them up. Mostly I think the difficult load notion is more a state of mind than an actual issue for amplifier performance.

I had to bi-amp a pair of infinity kappa 80 before, they really needed it.
No idea if my current speakers would benefit but only one set of binding posts so not possible anyway. They probably dont need it at all and the cost/benefit would be horrible but damn that “what if...” feeling lol.


Sent from my iPad using Tapatalk

 

[Irvrobinson]

I had to bi-amp a pair of infinity kappa 80 before, they really needed it.

Whatever you say, but "really needed it" is unlikely, unless you were using a tube amp. The Kappa 80s were rated for 6 ohms, so I'd be surprised to see some 2 ohm load or lower frequencies, and given their simplicity it seems unlikely they had a problematic highly capacitive phase angle in their load. Solid state amps with a reasonably low output impedance just aren't that delicate.

 

[Leemix]

Whatever you say, but "really needed it" is unlikely, unless you were using a tube amp. The Kappa 80s were rated for 6 ohms, so I'd be surprised to see some 2 ohm load or lower frequencies, and given their simplicity it seems unlikely they had a problematic highly capacitive phase angle in their load. Solid state amps with a reasonably low output impedance just aren't that delicate.

They played ok with a good amount of power but why settle for ok when bi-amp made me smile. It didnt cost anything extra either because i just ended up using a slightly older amp i already had for the surrounds instead of all on the bigger 5ch amp.


Sent from my iPad using Tapatalk

 

[Trell]

You'd have to have some incredibly inefficient speakers to ever need 500 watts per channel.
...

Or sitting far away in a very large room

 

[PENG]

I hate to admit it, I used to think even bi-wire made a difference too, until later when I knew better. Then I read about DBT experiments and then Dr. Toole's, especially what he said in the often linked video, about it must be done blind. All of those support my own experience gained after having spent a lot of money on electronics that didn't do much for "sound quality" improvements. Good thing I love electronics regardless.

 

[Irvrobinson]

They played ok with a good amount of power but why settle for ok when bi-amp made me smile. It didnt cost anything extra either because i just ended up using a slightly older amp i already had for the surrounds instead of all on the bigger 5ch amp.

Ok, that is a different issue altogether. I have often said on this forum there is a difference between making a sound technical case and making a buying decision. If it made you smile the technical facts are not the only criteria.

 

[lovinthehd]

Might want to review this article on bi-wiring/bi-amping https://www.audioholics.com/frequent-questions/the-difference-between-biamping-vs-biwiring

As was mentioned the 500wpc amp would give you the larger advantage (altho the difference between 250w and 500w is only 3dB spl). Bi-amp terminals are largely about marketing....

What speakers are they? 250wpc is likely just fine in any case.

 

[pinifinina]

Thanks for all the input guys. It is not really about how much power speakers needs, i am considering 2sets of amplifier (second hand) in very similar price. First option is 2 mono amps, each of them is 500w on 8ohm, the second option is a multi channel amp, 200w x 5 on 8ohms. So if i go with option 1, the pair of mono obviously power the mains with 500w. If I go with option 2, the multi channel can biamp the mains with 1 channel to spare, this will be 200w to the HF and 200w to the LF. So, which option would people go for? Thanks

 

[mtrycrafts]

I hate to admit it, I used to think even bi-wire made a difference too, until later when I knew better. Then I read about DBT experiments and then Dr. Toole's, especially what he said in the often linked video, about it must be done blind. All of those support my own experience gained after having spent a lot of money on electronics that didn't do much for "sound quality" improvements. Good thing I love electronics regardless.

Yep, gaining knowledge can be very expensive.

 

[lovinthehd]

Thanks for all the input guys. It is not really about how much power speakers needs, i am considering 2sets of amplifier (second hand) in very similar price. First option is 2 mono amps, each of them is 500w on 8ohm, the second option is a multi channel amp, 200w x 5 on 8ohms. So if i go with option 1, the pair of mono obviously power the mains with 500w. If I go with option 2, the multi channel can biamp the mains with 1 channel to spare, this will be 200w to the HF and 200w to the LF. So, which option would people go for? Thanks

I would skip the passive bi-amping altogether. If it is a 2 ch system go for the higher power from the two mono amps if the same price and you have no use for more than 2.0 speakers....