Is today's power different from yesterday's?

[Shadow_Ferret]

I have a 25 year old Pioneer SX-780 stereo receiver. It has a power rating of 45 watts per channel. I have a pair of Sansui SP-6300s. Not sure what their efficiency is. Yet, at my home I hardly have to turn the volume knob to get those things to levels that will disturb my neighbors and make you shout to be heard.

Now, I'm looking at these A/V receivers and there is nary a one that has less than 75 watts, some are typically 100 watts.

Why is that? Are todays speakers less efficient and need more power to drive them? Are the receivers' power output measured differently than it was 25 years ago? Is it because they are going into 5 speakers instead of 2?

It seems to me when I finally get my home theater with the 100 watt receiver, I'm barely going to be touching that volume knob and I'll be getting levels that will blow out windows, right?

Thanks.

 

[gregz]

Shadow,

I started typing in a long winded response to your questions, but then remembered there are quite a few articles on this site. Rather than re-create the wheel, I thought it would be more efficient to post a few links:

For the volume knob setting vs. volume:

http://www.audioholics.com/FAQs/equalvolumelevelsreceivers.php

For the power rating comparison of today vs. a decade ago and the games manufacturers play to "cook" the numbers:

http://www.audioholics.com/FAQs/equalpowerratings.php

Hope that was helpful. In general, audio gear from two decades ago seems to be more conservatively rated than today's gear. But you know what the saying is - you can NEVER have too much power! LOL!

 

[Audioholics]

I started typing in a long winded response to your questions, but then remembered there are quite a few articles on this site. Rather than re-create the wheel, I thought it would be more efficient to post a few links

I think I love you.

 

[gene]

You guys forgot this article which indirectly addresses the topic at hand:

Product Managing Receiver Platforms

 

[Buckeyefan 1]

If you've ever tore into one of the old 12" 3 way floor speakers of the 70's and 80's (Technics, Sansui, JVC, AAL, Pioneer, Kenwood, etc...), you'd find the magnets on the woofers weighed about 2lbs. You'd also find the entire speaker weighed about a third of todays towers. With such a small magnet on the woofer, there was little resistance and thus great efficiency. It didn't take much to max out those speakers with a 40 watt 2 channel receiver back in the day. If you ever checked the receiver after running it for hours, it was extremely hot. I don't think the new receivers are any less powerful, but that the speakers are simply less efficient. IMO I think mfg's do this for better warranties and to handle the higher power. The big goal of mfg's is to rate the receivers at 100 watts - however they can get to it. Most do put out 100 watts, but some at high distortion rates. Nevertheless, if speaker mfg's didn't lower the efficiency on speakers, they'd be replacing drivers left and right.

 

[mustang_steve]

As far as receivers getting hotter back then, that was mainly due to the poor efficiency of the components/design of the amp. That has been the single greatest point of improvement for amps IMO is better FETs, and better more effficient power supplies.

As far as speakers, look back to the 60's....Square magnets....can't get much lower power than that.....man now I want to hit EBay in hopes of finding another Sansui SP-35....my god those things could run nice off one watt!

 

[Shadow_Ferret]

Well, my Sansuis aren't light, that's for sure. So maybe what they supposedly lose in weight in "cheap" magnets they more than make up for in nice solid wood (or particle board) cabinets. They certainly seem more solid and heavier than the floorstanders I've seen.

And my Pioneer has never run "hot" even after hours and hours of loud music in the Navy dorm. And that's with the turntable on top of it blocking the top vents!

 

[MacManNM]

As far as receivers getting hotter back then, that was mainly due to the poor efficiency of the components/design of the amp. That has been the single greatest point of improvement for amps IMO is better FETs, and better more effficient power supplies.

As far as speakers, look back to the 60's....Square magnets....can't get much lower power than that.....man now I want to hit EBay in hopes of finding another Sansui SP-35....my god those things could run nice off one watt!

I'd have to disagree with that. Amp design hasnt changed much in the last 30 years (save Bob Carver and class D amps). If anything, todays components aren't as well built. How many of todays components will still be running strong in 20-30 years, not too many IMO. The older stuff was over built as in, if a 1 watt resistor was needed a 1.5 watt was used. I think todays stuff isnt like that, to save more $$$$. 2 Chan Amps back then weighed as much as 5 chan amps do now. The design is roughly the same, so why are they different? Power supplies arent as beefy, not as many output transistors, not as high of current. Thats my 2c.

 

[Buckeyefan 1]

Well, my Sansuis aren't light, that's for sure. So maybe what they supposedly lose in weight in "cheap" magnets they more than make up for in nice solid wood (or particle board) cabinets. They certainly seem more solid and heavier than the floorstanders I've seen.

And my Pioneer has never run "hot" even after hours and hours of loud music in the Navy dorm. And that's with the turntable on top of it blocking the top vents!

My friends dad had a complete Sansui system. You are right, the speakers weighed a ton. I think they were 4-way with the chrome voice coil covers. The tweeters had an aluminum type fan directing the highs downward for some odd reason. System was loud. We weren't allowed to get near it because it was so "hi-fi". I also remember a lot of the speakers had controls on the midranges and tweeters.