Holy Crap!

[davef]

I heard a Denon 1907 (85W/ch) and 2807 (110W/ch) in the same room at the same -15dB level with all other things being equal (same speakers, same treb/bass, 2ch stereo, etc.). The 2807 sounded a lot louder than the 1907. Was this b/c of the better circuitry do you think, or was it that the extra power in the 2807 allowed the 2807 to sound louder at the same -15 on the dial? This is one of the larger reasons that brought me to the line of questioning above. I thought with the +25W more of power in the 2807 was the main reason and would better help the speakers to perform with less effort!?

What you heard has nothing to do with power, has to do with gain. Gain is the amount of voltage being delivered. Here is a good way to think about it. I have two water pipes, one is 1 inch in diameter and the other is 2 inches in diameter. The water in both pipes is moving at 30mph. The volume control can be though of as regulating the speed of the water and the speed of the water can be thought of as SPL. The actual force of the water moving (which would be determined by both the speed of the water and the volume of the moving water (volume as in liters) could be considered as the power. The 2 inch diameter pipe has much more power, or force, but the water is moving at the same speed (same SPL) between both.

A 50 watt receiver could have its gain set so that its volume control position at halfway equals 20 volts output. A 500 watt receiver can have its gain set so that it is delivering 10 volts at the 1/2 position of the volume control. Which receiver is going to sound louder with the volume control at halfway? The 50watt unit will. The volume control position when comparing one receiver to another is mostly meaningless.

In addition, most manufacturers use the same gain settings throughout a line of receivers... You should have heard absolutely no volume level difference between the two receivers if both controls were set at the same position, provided one was not delivering full power (which it wasn't). What you head is typical salesperson trickery to up sell you, he/she probably set the gain higher for the higher power receiver in the speaker configuration menu. You know, exactly as I explained to you before -- rather than set at 0db, probably set the speaker levels to +6dB so that you would hear a very noticeable difference between an 85 watt receiver and 100 watt receiver. Honestly, the max SPL difference between 85 watts and 100 watts is less than 1dB. Nearly impossible to hear.

Go back to the store, take the same demo, and then when the salesperson is not around, go through the setup menu of each receiver and see what the setting is for the speaker levels

[audibleconnoisseur]

If they did that... I will flog them into submission! Actually, I don't know that is what he did and they don't work on commission but still I saw the levels, saw -15 on both dials, checked the trb/bass @ 0 and thougth I saw the computer that showed no difference. He did say there was better circuity in the 2807 but I heard the difference. This is why I have three units at my home awaiting your speakers so I can test myself with one receiver and another pushing the same speakers! I am going to commit these things to memory and when I am out, help those that need it even if the salesperson is trying to upsell them. I get a few looks when I deny their sub tests telling them I have one at home that will kick their subs ass up and down for 1/4 the price - I always get questions from others then! Some of the subs they were trying to sell me don't even drop to 20Hz and were nearing $1,000-$2K! Rookies. Ok, really, bed time for me. Thanks again and chat tomorrow if you are online with support. Much respect!

[audibleconnoisseur]

Professor Dave, is the answer 6.71A/ch @ 4 ohm & 3.56A/ch @ 8 Ohm?

[Kingrsl]

Interesting read! I think my local A/V specialist store may be guilty of that. I've certainly heard a difference between their "budget" line and high-end line of Yamaha. I couldn't afford to hold onto multiple receivers to test side-by-side at home and the BB & CC stores here don't carry anything with decent features.

[audibleconnoisseur]

"Harman Kardon rates their AVR-245 receiver at 50 watts per channel, all channels driven into 8 ohms. However, they also rate the maximum current capability at 35 amps. 35 amps divided by 7 channels = 5 amps per channel."

Since I have read and digested your information last night and this morning, and with some quick math...

Current (Amps) = sq.rt.[Watts/Ohms]
5a = sq.rt.[W/8ohm]
(5a)(5a) = W/8ohm
8ohm(5a)(5a) = W/channel
200 = W/channel

...are you saying above that the equivelant W/ch in the HK example above would be equal to 200W/ch?

I hope I didn't do the math wrong here...

[audibleconnoisseur]

Dave, others,

Ok, spoke with Denon about their systems, 1905, 1907, 2307 & 2807. They were very friendly and took the time to discuss, as Dave does, some technology. I will break it down from the 15 minutes we talked:

-1905 = 80W rms
-std testing for denon units is 6ohm - 16ohm
-"typical spkrs installed are 4ohm - 8ohm"
-it is considered and is published as a "high current amp" but he did not know or could not tell me how high in total b/c denon does not test for that such as HK does. he did say it would be more of a comparison if the current that is rated had a qualifer of time (this makes sense as a pico second is not a long time in electrical time - i can curl 125-130lbs, but not more than 1 or 2 times... i am with Dave and say this with respect to HK or others that rate using current/amps and their equipment!!), i have respect for all of them!
-also said that at all 5,6,or 7 channels running full out, which almost never happens, you might could assume a 10dB drop/ch. mainly your sound comes from the front three channels anyway unless you are listening to 5/6/7 ch stereo.
-said if you are listening to SACD's via analog discrete, it would jump to 90W/ch!
-compared to the 2307 and 2807, the 1905 does not have the same higher quality and newer components and as well, it has a weaker power supply as the 2807 so there would be a difference in the sound and quality of sound at the same level from the 1905 to the 2807, even from the newer 1907 to the 2807. "technology and power and internal parts are simply better but to truly know, use the voltometer at the speaker connection to agree that BOTH systems are producing the same volts to compare apples to apples (adjust the gain to match the output of course)."

So, Dave, he agrees with you fully and used a lot of the same terminology and ideas that you did and I didn't feel he was hiding anything which was refreshing. Even said to reset the system in the comparison as you mentioned to me in your example while at the store, testing the 2807 v/s 1907.

anway, you weren't sure about the above in relation to denon so there are the answers. glad to do the research for you and the others if they are in the same boat. fyi, he really likes the bryston amp as well...

[Kingrsl]

The 170s are pretty big for surrounds! It really doesn't kick in until you unpack one. I have all my speakers mounted now and the Omnimounts seem sturdy. The only thing is you can't turn the speakers inward 90 degrees. I have mine turned in as far as I can and they still "intersect" about 2 feet in front of the LP. I really haven't had the chance to do a proper calibration (it was already 9:30pm when I finally had them wired up) but it doesn't seem to affect it TOO much. Does anyone have any ideas? My LP on the couch is about 1 foot in front of the wall and I can't really move it up in my living room. Tomorrow is movie testing day! I played a few favorite scenes with the volume turned down low and I'm amazed how many sounds I had never heard before! I get to play with the new receiver and set my levels correctly tomorrow. Pics to follow.

[audibleconnoisseur]

You can try to cut a piece of 2x4 at a sturdy 45deg angle and use that for the extra angle that you can't seem to get from your brackets. just make sure to use drill holes and screws that are appropriate length. The cut piece of 2x4 needs to be solid so everything will hold. Oh, I would pait it the color of your walls as well!

[HP666]

Hey guys, I was hoping I can get some input on a mounting dilemma I have run into. Please look at the attached sketch. This is a top view of my listening area. The small boxes marked 1 and 2 represent where I would like to place my 2nd set of surrounds. I would like to use 170SE's but I'm concerned about # 1 due to location in the corner. The thicker black line behind speaker 1 is a louver door so an omnimount can't be put there. I was hoping to mount # 1 on the wall it's next to in the picture, but if it can't be turned at 90 degrees toward the listening area then that kind of defeats the purpose. I will be placing my speaker order shortly and I'm trying to plan ahead. I really would rather not go with the 200's. My fronts are 340's my 1st set of side surrounds will be 170's. Any suggestions or ideas??

[Kingrsl]

You can try to cut a piece of 2x4 at a sturdy 45deg angle and use that for the extra angle that you can't seem to get from your brackets. just make sure to use drill holes and screws that are appropriate length. The cut piece of 2x4 needs to be solid so everything will hold. Oh, I would pait it the color of your walls as well!

Good idea. I'd definately need to paint them. My wife already isn't happy about the size of the 170s. I think being able to turn them in 90 degrees might actually look better as they wouldn't stick out quite so far. I'm sure she'll get used to it though....she once thought the 61" DLP was too big when we bought it.