bi amp

F1nut

avalanche wrote: »

soundfreak1 wrote: »

Marketing

file:///C:/Users/George/Downloads/web_YG260B0_EN_RX-A3040_RX-A2040_om_UCRABGLF_En%20(1).pdf

Yamaha manuals do not make any power benefit claims, but they say this setup offers better sound quality! Also it clearly says it is using four internal amplifiers. Are these false claims?

My ears seem to confirm these claims. Hope its not placebo..

The issue is all those channels (notice I didn't say amplifiers) are drawing from the same power supply, so they are really not separate amplifiers and as such one cannot truely bi-amp. It would best be described as ghetto bi-amping. What many folks don't understand is the more channels you use in your AVR, the less wpc it is capable of providing. It's not uncommon for an AVR to be rated at say 120wpc, but that's with only 2 channels (sometimes only one) driven. By the time you have 5 channels driven the wpc drops to 70, for example. 7 channels driven will drop it down even more, say to 50wpc. There are some AVR's capable of putting out their rated power with 5 channels driven, but they are far and few between. Unfortunately, yours isn't one of them.

True bi-amping requires separate amplifiers, each with its own power supply and very important, the use of active crossovers.

Gatecrasher

avalanche wrote: »

soundfreak1 wrote: »

Marketing

file:///C:/Users/George/Downloads/web_YG260B0_EN_RX-A3040_RX-A2040_om_UCRABGLF_En%20(1).pdf

Yamaha manuals do not make any power benefit claims, but they say this setup offers better sound quality! Also it clearly says it is using four internal amplifiers. Are these false claims?

My ears seem to confirm these claims. Hope its not placebo..

It's not a 100% false claim but rather more of a matter of semantics. Basically you are using two driven channels from the receiver to drive one speaker array. Some of the people on this forum will attempt to belittle you but the bottom line is what you are most-likely accomplishing is send more power to each speaker depending on your receiver setup. Is it really true "bi-amping"? No, not really because you don't have an active crossover but it can make a noticeable improvement and that is why Polk offers the option on almost all of the speakers they sell and almost all electronic companies offer it too. Using the term as loosely as they do is part marketing gimmick but there is still some possible benefit by running two driven channels from a receiver to the same speaker depending on how the receiver is operating.

I used to have my Polks set-up to the Pioneer Elite "bi-amp" feature and they did sound better. An improvement that you don't have to convince yourself of, unlike bi-wiring or "breaking your speaker wires in" which requires a little imagination to convince yourself that there really is an audible improvement. Any so-called improvement that you have to convince yourself of over time or one that people claim can only be heard by youngsters because ears of people over 40 can't detect it, isn't worth pursuing. That's the real "placebo".

So to end the marketing gimmick aspect of it and not to further "offend" some audiophiles in this world who seem to get their panites in a wad over the subject, the industry should probably call it something else to differentiate passive bi-amping and using two separate channels from a receiver to drive one speaker array from true bi-amping.

Basically you are just wiring up your receiver differently and if you can hear an improvement who really cares what anyone else thinks. The same goes for baking your speaker wires in an oven. If it works for you that's all that really matters. I'd rather have a set-up that I think sounds great and I enjoy than to build one just to win the approval of anyone.

avalanche

Thanks for your replies!

I do "think" there is a difference in SQ especially in the midrange. I also definately did not observe any loss in loudness. I live in an appartment so I rarely play music higher than -20db. I am gonna keep it like this.


Theoritical discussion:

Even though I get your point about "true" bi-amp I do not understand why bi-amp is only when you use active crossovers. I had a car system where my mb quart speakers passive xover could have two input channels. So i had one amp for the tweeter and one for the woofer. Why this is not bi-amp? The only difference in an active xover system would be (excluding configurability) to avoid the losses in the passive xover, correct?

soundfreak1

The point of "biamping" is control of freq to each driver. A woofer can not reproduce high freq, it is designed to roll off at say 1500 k ( diff with different drivers) tweets at different and higher freq. In my system I set the external xover at 1k and under to the woofer going to one amp and 1k and over to the tweets thru a different amp. This way the woofer doesn't even see any freq above its range so it doesn't have to deal with "sound it can't deal with" same with the tweets. The result is control of the sound each driver is capable of reproducing and not with the sound it can't deal with. Without an external and adjustable xover this is done by the speaker xover and is static and not controllable and your stuck with what the original designer wanted and it may be correct for your amp, room, pre, not to mention like and dislikes. With the active xover I can experiment with freq that work best for me and my equip. In each driver. When done this way the results are nothing short or amazing.

F1nut

avalanche,

This will address any and all questions you may have about bi-amping. Enjoy!

http://sound.westhost.com/bi-amp.htm

tonyb

Avalanche,

Bi-amp functions on avr's .....eh, more marketing gimmicks than real world use. F1NUT explained all that need be said.

I'll add though, what ever you try in audio, if it makes a difference to you, perceived or not, roll with it. Don't listen to the naysayers, they can't hear with your ears. It's about what you enjoy, not what someone else says you should or shouldn't.

Experiment a bit, try different things....brands, cables, gear...etc., until you find what works for you and is pleasing to your ears.

[Deleted User]

Stick to the subject and leave the personal jibes out of it.

avalanche

https://www.youtube.com/watch?v=mzTV_vABhSQ

Listen after minute 9. If this guy is for real he is explaining how bi-amping in AVR started.

Side question: How can I compare the power supply capability of an avr receiver from the specs?

tonyb

"Side question: How can I compare the power supply capability of an avr receiver from the specs? "

....as compared to what ? Pay attention to specs first off. In AVR's, lots of gimmicks. It may list a receivers power as 100 WATTS per channel, but only one or 2 channels driven. Anyone buy a surround receiver to only play 1 or 2 channels ? Some may list it as "all channels " driven, even that is suspect. Look at the build, if it uses a 450 watt transformer, which a lot of AVR's do, how can it put out 100 watts to 5 or 7 channels ?

All those channels, as explained early on, use one power supply that they all share. The more channels you use, the less power each channel is able to receive. There's more to it than that but generally speaking.

Some may also say they can drive 4 ohm speakers. What that means in receiver speak is that they limit the current provided so the power supply doesn't overheat. Well, speakers thrive on current, especially 4 ohm speakers, so that is too a marketing gimmick.

You have to kind of wade through the B.S. with marketing and whats real world knowledge. A manufacturer wants to sell stuff, bottom line.

When it comes to receivers, the higher up the model chain you go, the better the power supply, usually, but that comes at a cost. You always want to buy a receiver with pre-outs that would enable you to add a separate amplifier should you feel the need for more power.

txcoastal1

Most tests are done at 1khz

avalanche

tonyb wrote: »

When it comes to receivers, the higher up the model chain you go, the better the power supply, usually, but that comes at a cost. You always want to buy a receiver with pre-outs that would enable you to add a separate amplifier should you feel the need for more power.

That's true! Having a pre-out is a very nice feature to have. Unfortunately I realized about this after I bought mine.

tonyb

avalanche wrote: »

tonyb wrote: »

When it comes to receivers, the higher up the model chain you go, the better the power supply, usually, but that comes at a cost. You always want to buy a receiver with pre-outs that would enable you to add a separate amplifier should you feel the need for more power.

That's true! Having a pre-out is a very nice feature to have. Unfortunately I realized about this after I bought mine.

Yes Sir, as long as it has pre-outs you need not worry about how much power the receiver has. You can always add some. However without those preouts, your handcuffed. Way too many good amps too on the used markets for 350-600 bones that would leave any receivers power supply in the dust.

tonyb

Yes and no x, current limitations is what enables most to list them as 4 ohm capable. It's not necessarily indicative of the power supply, just how they go about handling the additional load.

That's more the case with entry-mid line receivers. TOP ones do have better power supplies and can probably drive a fairly efficient 4 ohm speaker to reasonable levels but still nowhere near what a separate amp is capable of.

Point being, stop worrying about the receivers power, and worry more about if it has preouts or not. Without them, your limited to what speakers you can run with.

avalanche

How does this look for an amp? Looks to me 4 ohm capable since it almost doubles its power at 4ohm.

Dynamic Power per Channel (8/6/4/2 ohms) 165 / 210 / 285 / 405 W

soundfreak1

Need more info, damping factor and slew rate.

Nightfall

avalanche wrote: »

How does this look for an amp? Looks to me 4 ohm capable since it almost doubles its power at 4ohm.

Dynamic Power per Channel (8/6/4/2 ohms) 165 / 210 / 285 / 405 W

That's not WPC.

F1nut

avalanche wrote: »

How does this look for an amp? Looks to me 4 ohm capable since it almost doubles its power at 4ohm.

Dynamic Power per Channel (8/6/4/2 ohm 165 / 210 / 285 / 405 W

That's a deceptive spec as many like you don't understand it and think it's 4 ohm capable, heck it appears to be 2 ohm capable. The dynamic power rating simply means it can output that rating for less than a second or so, it is not continuous or as Nightfall stated, the wpc rating.

To re-enforce what Tonyb said about AVR's and 4 ohm ratings. Almost all AVR's rated for 4 ohms do so by LIMITING current, which is exactly what you don't want.

As for those Audioholic's videos/postings....you'd be best served by ignoring them unless you want to settle for mediocre.

Nightfall

I ran three pairs of 4 ohm speakers on a lesser RX-A1020 - no issues. I also ran them on an EVEN lesser RX-V667 - no issues. I'm not saying you'll get the best performance out of them but I have yet to have an issue where I'm damaging something or tripping protection circuits.

Edit: Don't get stupid with the volume knob though. Maybe that's why I haven't had an issue. When the speakers start sounding shrill and forward, you're going too far. That happens long before audible distortion.

avalanche

Interesting discussion on amps.
Yes, this is copied from a yamaha 2040 which is near top of the line AVR.

I understand that continues power rating is good for comparisons but do we really need it when we play music?

Also the link shows that the yamaha 2000 has been tested to 4Ohm.

This graph shows that the RX-A2000’s left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1 percent distortion at 170.5 watts and 1 percent distortion at 189.3 watts. Into 4 ohms, the amplifier reaches 0.1 percent distortion at 236.1 watts and 1 percent distortion at 287.4 watts
Read more at http://www.soundandvision.com/content/yamaha-aventage-rx-a2000-av-receiver-ht-labs-measures#lG4fQKRQcJ3OzzDu.99

F1nut

I understand that continues power rating is good for comparisons but do we really need it when we play music?

What one really needs to know is the peak to peak ampere (current) rating, which you'll never find listed for an AVR. Anyway, because music is very demanding, much more so than HT, the continuous rating matters.

Also the link shows that the yamaha 2000 has been tested to 4Ohm.

For a very brief period of time. It does not mean that the AVR is rated to drive a continuous 4 ohm load.

Yamaha specs show the following, "Rated Power (watts per channel): 130 into 8 ohms, 2 channels driven"

Since it does not mention a 4 ohm rating, it is not rated to drive a 4 ohm load.

tonyb

Good point Ken.

Many older, and certainly vintage receivers had some darn fine power supplies in them despite their power ratings in watts. An old Sansui or Marantz 60 watt'er had more power than todays 100 watt receivers easily.

Point being, watts is not the sole indicator of a good power supply, but it sure sells stuff which is why it has become the leading indicator to those who simply are not that in tune to the industry.

When it comes to power supplies and todays receivers, it's probably best, if you don't want to get in the weeds and think too much, to associate it with model lines within a brand. You can break it down into 3 categories....

entry level...which all brands will have the same weak power supply

mid-level- will be a tad better, but some will also include pre-outs to add power.

Top of the line- is where you'll find the best power supplies and gives you the best variety of speakers to use with them. All will have pre outs also.

Obviously, if your on a budget, the mid line option is best with pre outs. That way you can add more power should you find a deal on speakers that need some. Entry level is fine if you never plan on going larger than 8 ohm bookies or small 8 ohm floor standers.

tonyb

xcapri79 wrote: »

[In the end, specifications give you a baseline for comparison, but the real test is with your ears in your room with your speakers.

X.....

Have to send you the bill for the Doc because you just made me fall off my chair.

True words.....for sure.