Who uses ONLY Receiver with no amp/preamp? Is good sound possible?

[kexodusc]

I hate to disagree with Kex since he has technical knowledge and I don't.
But my argument is that in heavy bass peak music at high volume approx. 95 DB these big effcient floorstanders suck up all the available watts. I had my Bryston 3B-st hooked to my main outs on my Yammie. This amp is rated at 120 watts. So lets say I have 60 watts of clean undistorted power before clipping. Now according to Kex's figure my Studio 100's have a 91 DB effiency, So I should be using somewhere around 15 watts with 9 DB headroom. And guess what my 3B-st will clip, meaning its using at least 60 watts in heavy bass peaks. Steve's Yammie has 40 watts of clean power at best before clipping. So his av/receiver is using the majority of its power when he has 4 other speakers to drive, thus the reason it sounds like crap. Even if you use a better floorstander speaker it'll still sound like crap cause there's not enough power to go around. So an external power amp will take this heavy bass load speaker off his receiver solving his problem.

A few things going on here...

First, I don't disagree that more power makes the sound cleaner at louder volumes. If you'll all read my original post I asked about room size and desired volume. This is critical. My assumptions used a 20 X 20 room, the figures apply to that scenario.
Also I only included 2 speakers in the assumption. Read the OP...it mentions 5.1 as an afterthought. I assume stereo listening is stereo listening - as in 2 speakers only. If other speakers are added, volume is increased by their output too...depending on the room, this can actually make it easier on the amp. Perhaps worse. No sub considered either, which if used with a crossover, really eliminates any "bass power sucking" problems.

Second. Your Bryston should not be clipping at 60 watts, especially a Bryston rated for 120 watts. There should be ample headroom there. I'm guessing well over 200 watts for bass peaks...How do you know it's clipping? If it's cliipping, I'm guessing your using more power than you think.

I just did a little experiment.

I have a 40 watt NAD integrated that I just ran to my bookshelf speakers - measured 89 dB sensitivity. I get in room bass transients in mid/high 90's on Crystal Method's Vegas CD no problem. The NAD 3140's power meters show mostly above 5 and rarely above 25 watts. When the 50 lights up I know I'm into dynamic power, above it's average rating. This is tops for my ears in my living room, and my SPL measures 89-97 dB, eyeballed. The needle's bouncin'...The bass isn't breaking tectonic plates, but it's plenty loud....That's a 40 watt NAD integrated amp. These are the peaks that are hitinng the 97 dB range...but it happens every second a few times. I hooked up my Adcom GFA-535II...the distortion meters don't light up - I can't see the power usuage, but if there's no LED, I"m good. Now, 97 dB is a long way from 89...

I can't speak to what's going on in your setup without being there, but it could be a number of things.

Again, how loud do you listen, and how large is the room?

I used the 4 watt example in Steve's setup earlier, is near the limits, but it's an average 100 dB volume with 110 + dB peaks...110 is what would show up on the SPL meter...nobody is going sit in a house and listen at that level (I hope).

My intention was to use a ridiculous scenario to point out basic concept. If Steve only needs the odd 100 dB peak, more power isn't going to be demanded by the speaker if this is his listening level...Doesn't matter how big the amp is...it won't be sending the extra power.

Turning the volume up to get more bass or better sound is a common practice, but that's really an indication of a speaker's limits in terms of high-fidelity. And I'm going to argue that the louder his speakers go, they worse they WILL SOUND. Those aren't really long throw woofers. The drivers don't like too much power. These CV's were around $300-$400 (I think they replaced mine) when they came out, and were marketed to sell with Pioneer, Kenwood, Technics gear, etc...$400-$500 receivers back in the day. The likes of NAD, Adcom, Bryston etc are rarely used with CV's

I'm not opposed to adding more power - but I'm also thinking of the big picture here. His receiver doesn't have pre-outs, getting another one, or adding an amp is going to be expensive. The most it's going to do is show a tiny bit of improvement at the extreme volumes. I think there's a more effective allocation of his resources to be made addressing the speakers, if improved sound is the goal.