Help me Understand Rated Output Power

[Zen Traveler]

23 hours ago, Youthman said:

My point was that the more speakers you add to your current receiver, the less power you will have to effectively drive each of them.  In my case, it was a Yamaha RX-V1800.  Looking at the specs....I was incorrect....it is a 130x7 (or so they claimed).  It sounded fantastic driving 5 speakers but after I added surround backs, I noticed I had to crank the receiver up quite a bit more and even increasing the volume, there wasn't the same dynamics that I heard with only the 5 speakers.  It wasn't until someone directed me to Sound and Vision's bench test of that receiver that I found out when you add all 7 speakers, you are no longer getting 130w per channel, but it dropped to merely 55wpc. 

I am curious--Were you using the RX-V1800 with RF-7s up front? The reason I ask is because I've developed a hypothesis after my research that it isn't necessarily the Watts per Channel, but the ability of lower end AVRs to cover the impedance dips of the RF-7s in a multichannel configuration. Without getting into the weeds, I noticed the same thing you described when I was happy with my Yammi RX-V 800 in a smaller room driving a 5.1 system and then moved the AVR to a larger room and it kept shutting down at louder volume...

 

...I then got a Denon AVR-4802R that was THX ultra II rated which advertised it was able to drive (ALL) speakers that dipped down to 3.2 Ohms in a 3,000 sq ft room, which was a major THX Ultra II spec. That was when I found not all AVRs were created equal and that the upper end units had beefier power supplies. I was disheartened when lightening struck and bricked the AVR-4802R and then received a AVR-4806 which also was THX Ultra II rated and loved both of those units....I kept an eye on the AVR-4311ci and was concerned it may not be able to drive my system efficiently but found it also was rated to drive 4 Ohm speakers all of the way around (I also have RB-75s on the side and rear and haven't seen their impedance curve but felt it's "8 Ohm compatible spec could be suspect because of that last word) Fwiw, I have been ecstatic with it and for the last 3 years, as before listen to material quite loud (80+ dB) on pretty much a nightly basis.  

 

Btw, here is the link to the Yamaha RX-V1800: http://download.yamaha.com/api/asset/file/?language=en&site=usa.yamaha.com&asset_id=35512 and on page 117 seems to confirm that using speakers that may be closer to 4 Ohm shouldn't be used or at least implied that by not mentioning it. I have also seen other manuals actually express not to use 4 Ohm speakers and those that can seem to use that as a selling point and are more expensive than their counterparts.

[Zen Traveler]

18 minutes ago, wvu80 said:

Because I am in experimental mode with the newly upgraded Khorns this morning I played the same high quality 5.1 source material with which I am very familiar starting with 2.1, then 3.1, then 5.1.  I then listened in reverse order from 5.1 back to 2.1

Did you also use an SPL meter to see what volume you were comparing?

20 minutes ago, wvu80 said:

Running from low to high my system sounded really good in 2.1, a little degradation in 3.1, and very smooth in 5.1.  I was listening to dynamic LOUD horns and drums.  Smooth isn't good in that case and the side speakers added little to nothing in terms of audio content.

Hmm. I listen to mostly multichannel music disks and have RB-75s on the sides and rear to match my RF-7/RC-7 front soundstage and I'm never going back to 2 channel.  That said, if you surrounds aren't as 'matched' to your front K-horns I could see where that could have diminishing results.

[wvu80]

1 hour ago, Zen Traveler said:

Did you also use an SPL meter to see what volume you were comparing?

No, I don't have an SPL meter.  My internal SPL meter tells me that as speakers get brighter, they tend to sound better.

 

Quote

Hmm. I listen to mostly multichannel music disks and have RB-75s on the sides and rear to match my RF-7/RC-7 front soundstage and I'm never going back to 2 channel.  

Nice setup.  RB-75's as sides and rears?  Outstanding.  Wow! 

 

That said, if you surrounds aren't as 'matched' to your front K-horns I could see where that could have diminishing results.

Good assumption.  The surrounds are Bose 301's and as such are much less efficient than my L/R.  The AVR does a good job of matching my mis-matched speakers, but when I add the 301's it really throws a wet blanket over the front sound.

 

And since you're stirring up trouble...  ...

 

I never really thought about this, but I do have another set of horn driven speakers and they are much larger than the Bose, but closer in efficiency and sound to your RB-75's.  In your honor, I may swap them out and see what happens. 

 

 

I still don't think I will be a fan of side surrounds.  It always freaks me out when sound comes from beside me or behind me. 

[Zen Traveler]

1 hour ago, wvu80 said:

Good assumption.  The surrounds are Bose 301's and as such are much less efficient than my L/R.  The AVR does a good job of matching my mis-matched speakers, but when I add the 301's it really throws a wet blanket over the front sound.

 

And since you're stirring up trouble...  ...

 

Thanks for responding, but I wasn't trying to stir up trouble--legitimately curious.  That said, I can also understand not appreciating multichannel music as much having completely tonally different speakers as surrounds (especially with K-horns as mains).

 

1 hour ago, wvu80 said:

I still don't think I will be a fan of side surrounds.  It always freaks me out when sound comes from beside me or behind me. 

I have heard this as well. Otoh, it was something I became accustomed to going from concert videos which I didn't like crowd noises in the surrounds as much as well placed vocals and instruments meandering seamlessly through my system. I started off with classic Rock albums that were re-mastered in 5.1 and then on to Steely Dan/Donald Fagen which I wasn't privy too as a kid and then came full circle finding Talking Heads were made for this format!

 

We started out watching movies, then concerts and now I primarily listen to DVD-As/SACDs with a few concerts mixed in.