A couple of output questions

[Rorschach138]

Hi all,

I had a few questions about output for some speakers I wanted to use. I have a set of floor speakers that are rated for 80W continuous at 8 ohms. I wanted to buy this cheap 200W Yamaha R-S201 for them as a stopgap until I could get some more power. Sorry first post so I cant link anything.

I tested them out with my Yamaha RX-V471 5 channel, which is also supposed to be 100W per channel and they sounded good, but to really crank them I basically had to turn it all the way up.

From looking around a bit, I suspect that neither of these amps puts out a true 100 watts, but is there any reason to think the 201 may have a higher ceiling than the 471?

And beyond that, would the Yamaha R-S700 produce better results output-wise than either? Like a more legitimate 100W? The 100W for 150 bucks on the 201 seems too good to be true, even though there's no phono stage etc.

I'm partial to the Yamaha stuff because I'm retiring one that I've used daily for over 22 years. Actually still works great. Just won't push these speakers.

Any help would be greatly appreciated. Thanks!

 

[markw]

It may well be a "true" 100 watts but that may be when only two channels are driven. If you drive more than two channels, then the power to those two amp/channels will be less. Remember, a receiver only has so much power available to drive the amps and the more amps/channels involved, the less is available to each amp/channel.

And, don't expect a major increase in your average listening level by upgrading to another receiver that has a few more watts.

If you double your amp power, you get about 3 decibels increase in loudness and, in the real world, that's hardly noticeable. If you want to double your apparent loudness, you would need about ten times your current power.

 

[Rorschach138]

Thanks for the quick reply. Ouch. It's crazy how expensive pushing large speakers can be.

I think I'm just going to pull the trigger on the cheaper one and see how it sounds. I can go back to my old speakers if I need to. I'm really only using two speakers and I'd be upgrading from 65w total to 200w. I'm just kind of wondering if the 'stereo receiver' is able to push the speakers harder than the AV receiver did in my test.

One more question. If I have the floor standing speakers as speaker A and my bookshelf speakers In the other room on speaker B, would it just split the power by four and thus pump more (or too much) volume out of the smaller speakers, or does it handle the power to keep a level volume?

Thanks again

 

[markw]

It's not the size of the speaker that matters, it's it's "sensitivity" rating. That pretty much tells you how loud a speaker will play with a certain voltage/power level. If one has a higher rating, it will play louder than one with a lower rating.

As for the power divide between the two speakers, that will be determined by their individual impedance. A speaker with a lower impedance will draw more power than one with a higher impedance. So, a lower impedance causes an amp to work harder.

So, you can see that two different speakers running opff the same amplifier can both be playing at different volume levels.

These aren't numbers you can feed into a calculator to give you an exact answer but consider it a general guideline to work with.

One thing to keep in mind when running multiple speakers: When you run two speakers off one amp, the amp "sees" the total impedance as one half of the two. i.e, two 8 ohm speakers present a 4 ohm to the amp, and a lot of amps might not like that. Read your manual on this.

 

[Rorschach138]

Hello,
Bumping this thread because I finally picked up my new receiver. I ended up getting a Yamaha R-S700 rated for 100w x2 RMS.

The specs on the speakers I wanted to use are 80w-200w at 8ohms 95db sensitivity.

Am I in danger of clipping here at medium high volume? Anything I should test first or watch out for if I try them? The receiver already sounds miles better than my old one through smaller speakers, but I do want to try the larger ones out if I can without damaging either end.

This probably means nothing but my max volume (the loudest I'd consider listening at) on the smaller set of speakers is -15db and those are rated 10w -140w at 8ohms. I have no info on the sensitivity, but google seems to think they might be 85db. Any chance I can hit that volume on the larger ones without destroying them or the amp.

Thanks again.