bi amp

David7544

Dennis, Hi, You're right most AVR's can't output their rated power into 7 channels at once. But maybe this new one can. You're also right about my attitude. I apologize for that. Like I said, I'm still not convinced I'm right. If it turns out I'm wrong, I absolutely will apologize to everyone. The schematic I was shown by a service tech at best buy clearly shows seven separate amplifier configurations, and each one said "80wrms output" I even emailed the Audio Engineering Society, but they don't answer peoples questions(I was told) Pittdog, It doesn't mean all your audio mag reviewers are wrong, it just means they haven't put this particular AVR on a test bench yet. I hope they do.

Dennis Gardner

Just because an AVR can't meet the rated specs doesn't mean that it won't sound good. You must realize how ratings work and the fact that you most likely can't even hear the difference in 80 watts and 120 watts. 120 watts will only be 1.5 decibels louder than 80 watts. This is barely noticeable in a dynamic music passage.

I would rather have an honest underrating given that I can trust to be delivered over the full spectrum than the more common overrating at a single frequency that most of them give. I don't listen to music with only a single frequency in it.......

Some makers have been getting better about rating their products partly due to forums like this and reviewers calling them out on these practices, but others continue to cut quality and stretch the truth.

One avenue that hasn't been brought up during this thread is that many makers are going to a digital switching type of amp design that doesn't require huge power supplies and heavy weight anymore to make power. These receivers weigh much less than their earlier models yet still produce good sound and ratings. Pioneer started this trend in their lines a few years back with the line of ICE amps in their receivers. But that is a discussion for another day........

David7544

actually, the only thing I use it for is stereo. I don't want surround sound. And I don't care about movies. I've got 4 amp output channels active, 2 to each speaker. one amp connected to each driver. my speakers are Polk Rtia5's.

tonyb

What you really have is one amp connected to 2 speakers in a bi-wire configuration. There is not 7 amps in that receiver, only one. You have 7 different ways to slice up one amp is all.

voltz

I had a Denon 1911 I think that said it had 7 discrete amps in it. that is why it is sitting under the bed collecting dust while my NAD T-758 runs the show now my NAD's manual say in plain English that if I run it in a 7.1 setup that its 110 WPC with 2 driven will fall down to 60 wpc... they openly tell you the truth with no bull.
that is why I added a Adcom 5503 which is a 200wpc x3 amp that runs my 2 front speakers and my center thus leaving my NAD to run the 2 rear channels and can give them the full 110 wpc .

F1nut

The receiver is capable of a total output of 1225 watts

Must be some new math as it's maximum draw is 460 watts and it's not a digital switching type.

F1nut

One avenue that hasn't been brought up during this thread is that many makers are going to a digital switching type of amp design that doesn't require huge power supplies and heavy weight anymore to make power. These receivers weigh much less than their earlier models yet still produce good sound and ratings. Pioneer started this trend in their lines a few years back with the line of ICE amps in their receivers. But that is a discussion for another day........

My Pioneer Elite AVR weighs 50lbs. and actually puts out its rated 135wpc with 5 channels driven, just slightly less with 7 driven. It was also a lot more money that the $499.00 list of the OP's Denon.

David7544

I hear what you guys are saying. 30 years ago I had an SAE power amp which put out 300 wpc, 2 channels driven. It was so heavy you could hardly pick it up.It had two big black steel handles bolted to the front panel at each end. It must have weighed at least 40 lbs. Go to Pioneers website and look at the SC-81 AVR. This could be my explanation.

David7544

ZLTFUL, yes, I agree. but what if I've got seven buckets full of water, and a siphon hose in one of them,siphoning the water out, with the other six sitting there with all that water in them going nowhere. Then I add a second siphon into a second bucket. Now I'm getting twice as much water. I realize there's only one power supply, so I see what your saying.

David7544

I don't understand the internal configuration of the amp. Does it have seven power supplies? I don't think so. There is a menu in it for "amp assign" which features an option "bi-amp".I was assured by a Denon tech and a best buy tech that I have doubled the power being delivered to the speaker by connecting a second amp output channel to it, by I'm not sure I believe this. I think you're probably right that I'm not bi-amping. I'd love for someone to put this AVR on a test bench and measure the output power from each output channel. Does one amp channel draw power(when required) from another? I don't know. If it has truly separate amps, then there is a siphon hose.

Dennis Gardner

No one has mentioned what happens when you decouple terminals. Does the 8 ohm speaker now show 2-16 ohm loads since they are now separate? If so, then the amp just lost volume by 3dB for each load, so the power gained by bi amping was lost in impedance, so no gain was made. You would have 2 amps potentially capable of both putting 80 watts into each new speaker terminal, but since they are 16 ohms each, the level of sound remains the same. IE: 80 watts into 8 Ohms is the same and 160 watts into 16 ohms.

This is dependent on the crossover working in the manner assumed......I could be wrong, as I have never taken the time to measure separate post loads.

David7544

This is probably a dumb question, but wouldn't powering only one driver (tweeter) instead of two(tweeter and woofer) result in reducing the impedance rather than increasing it?

Dennis Gardner

David7544 wrote: »

This is probably a dumb question, but wouldn't powering only one driver (tweeter) instead of two(tweeter and woofer) result in reducing the impedance rather than increasing it?

The answer to your question is odd in that a higher impedance number means reduced load. 16 Ohm speaker is an easier load to drive than an 8 Ohm load.

This is only true for speakers wired in parallel, the reverse is true if the speakers are wired in series. 2- 8ohm speakers in parallel = 4 ohms and 2-8 ohm speakers in series = 16 ohms.

David7544

I thought an amp that delivers 50 watts into an 8ohm load will deliver 80 watts into a four ohm load, therefore lower impedance means less "resistance". (?)
Does anyone here own the pure audio blu-ray disc of Neil Young's "Psychedelic Pill"?
Or the SACD of Pink Floyds "Wish you were here"?

Dennis Gardner

David7544 wrote: »

I thought an amp that delivers 50 watts into an 8ohm load will deliver 80 watts into a four ohm load, therefore lower impedance means less "resistance". (?)

You have it correct.

tonyb

The impedance of the speaker doesn't change however using just the top or bottom post.

Dennis Gardner

tonyb wrote: »

The impedance of the speaker doesn't change however using just the top or bottom post.

The top posts on a speaker that I tested, don't register any resistance. The bottom showed the same whether strapped to the top or not, so it really is simply the crossover's load that you are measuring, not driver resistances.

tonyb

ZLTFUL wrote: »

Still 8 ohms in the case of the RTiA5

Exactly, which is why I don't understand the OP's concern over it. At my age though, understanding certain things isn't my strong suit.

David7544

so ZLTFUL, if I've removed the jumpers on my Rtia5's, the impedance remaines 8ohms at each of the two pairs of input terminals on the backs of the speakers?

tonyb

Correct David....I'm wearing my ZLTFUL hat at the moment.

Msabot1

Those metal jumper strips at the binding posts are nothing more than conductor paths...you are better off without them....if you have to use...make some with some good gauge speaker wire...that has been mentioned before.....

F1nut

If ya want more power, pay for it.

That's sig material if I ever saw it.

David7544

I think this AVR has a new class of amp. "D3" I was told by a bestbuy tech , who brought up the electrical stuff about it on his computer screen, that it has a total output power capacity of, get this, 1225 wattsrms. Even he couldn't believe it. Also, it's supposed to be stable into any impedance load, and require a power supply much smaller than conventional A-B amps.I'm still not clear about the "seven power amps" claim. Maybe it really does have seven little power supplies in it(?)

BlueFox

Hasn't it been made clear yet that many times the power rating used by manufacturers could be bogus? A cheapo Denon is not going to have 7 power supplies in it, nor will it have much power.

ken brydson

BlueFox wrote: »

Hasn't it been made clear yet that many times the power rating used by manufacturers could be bogus? A cheapo Denon is not going to have 7 power supplies in it, nor will it have much power.

Especially at 18#...

jeremymarcinko

David7544 wrote: »

I think this AVR has a new class of amp. "D3" I was told by a bestbuy tech , who brought up the electrical stuff about it on his computer screen, that it has a total output power capacity of, get this, 1225 wattsrms. Even he couldn't believe it. Also, it's supposed to be stable into any impedance load, and require a power supply much smaller than conventional A-B amps.I'm still not clear about the "seven power amps" claim. Maybe it really does have seven little power supplies in it(?)

Dream on Alice.

F1nut

David7544 wrote: »

I think this AVR has a new class of amp. "D3" I was told by a bestbuy tech , who brought up the electrical stuff about it on his computer screen, that it has a total output power capacity of, get this, 1225 wattsrms. Even he couldn't believe it. Also, it's supposed to be stable into any impedance load, and require a power supply much smaller than conventional A-B amps.I'm still not clear about the "seven power amps" claim. Maybe it really does have seven little power supplies in it(?)

It's class AB, not D3. It weighs 18 lbs. It's an entry level AVR. It has one really small power supply. It cannot drive any impedance load. It cannot output 1225 watts.

THE END.

Thorton

Listen to the guy in the funny hat above. He knows his stuff. Actually, all the members have been spot on. This is an easier one to figure out. I can't believe it's taking 3 pages of posts.

tonyb

D3 or what is commonly referred to as "ice amps" in receivers are a different animal. You would be correct in your assumption that ice amps hold their power ratings better when all channels of the AVR are used. Those avr's cost more money usually though, but you can still find them used for around 600 bucks. Pioneer SC series used like the SC25-SC07, but they won't have the networking capabilities of more current models....if that interests you.

They also are not stable at ANY impedance load, and are no replacement for a separate quality amplifier in harder to drive systems. They will drive a good majority of your average HT systems with speakers that aren't all that power hungry though.

Your RTIA5's are not a hard load to drive anyway and your Denon is fine in that task. To further improve your sound look into better cabling or source gear. If you plan on never doing surround sound, then I would question why you bought a surround sound receiver to begin with.

nickster

I'm new to this world and do not know very much. But I have just purchased the floor-standing Polk A5s with Polk Center and Polk A5 Surrounds (in SIDE position). I am using a Denon AVR X3100W.

My question is this. What do you guys think is better for my overall experience out of the following 2 options...

1. Use my older BOSE 301 as the REAR Surrounds...? My room is big enough to add these.

2. OR is it better to use those REAR channels on the AMP to bi-amp the floor-standing A5s. (Use both the L/R and Surround L/R to the A5s).

Seems like from the rest of this post that your answer would be to go with Option 1?

Let me add one more question... as the Denon can handle 2 Subs do you recommend this and should i use my old Sub as the 'rear sub' even though it is a different make/model from my main polk sub?

Thank you for considering my questions...

I would much appreciate your thoughts....