bi amp

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.