Does my receiver give me enough power? Specs and setup given

[usmcsoldriver]

My only concern is 2 Channel play back for Music.

The Receiver: Sony STR-DH700 7.1

Specs:

Minum RM Output Power (8 ohms, 20-20k, thd .09%) : 95w + 95w

Stereo Mode Output Power (8 ohms, 1 kHz, THD 10%) : 105w + 105w

Surround Mode Output Power (8 ohms, 1 kHz, THD 10%) : 140 W/ch

The Speakers: RF7's. Rated Sensitivity 102db @ 2.83 volts/1 meter

***********************************

Whle putting together this info, i noticed that the RF7's sensitvity is rated at volts/meter while other speakers I have noted are rated at watt/meter . What is the difference?

For Loud, but not pain inducing, listening, does this receiver provide enough power? Recently I auditioned some speakers, not sure the brand, using a Receiver, then a stand alone amplifier immediatly after. While they were small floor standing speakers, wth the stand alone amplifier they seemed to come alive. I would expect the same results at home, but the difference in effeciency rating from my understanding has to make a difference. While those were, I am fairly, ~88db thats a good 14db (if they were rated the same way) difference. I know that Klipsch typically need much less power tahn other speakers. Additionally, I was able to audition some Palladium's ran off some 2ch 250watt McIntosh's. Yum. Call me crazy, but I did not hear 8k$ difference between them and my 7's.

Using

http://community.klipsch.com/forums/storage/4/1385708/Amplifier%20Power%20and%20Klipsch%20Speaker%20DfH.pdf

I figure that the 7's are going to need a tad more power than the Heresys, so a +~5watt difference would be accurate? If it is, and i am actually getting 95watts, I should be good. Please tell me where I am wrong if I am.

I know that my ears are the final verdict. They seem to top heavy currently. I grew up with a pair of Heresys, so I am use to the klpsch "sound". There just isnt any punch in the mid/lows. Very unsatisfying. I am planning on adding some feet/spikes, hopefuly that clears some stuff up.

[tube fanatic]

Unless your RF-7s are in an enormous room which is filled with all kinds of heavy sound absorbing materials like rugs, curtains, hundreds of books, etc, 5 watts/channel would be more than enough! With the amount of power that your receiver provides you could create sound pressure levels that would break your eardrums before you would run out of "steam." Don't even give it a thought!!! 2.83 volts is equivalent to 1 watt into 8 ohms.

[usmcsoldriver]

ok. So even for dynamic music, dynamic power demands it is more than capable of providing the power needed?

About how much power does the RF7's draw at peak at high levels?

I ask because while watchng the Meters on the Mcintosh's while listening to the Palladiums, they were at a happy 5watts while listening to The Dave Mathews Band at descent levels. As soon as the drums and everything kicked in they started to spike at around 50 watts.

[tube fanatic]

To determine exactly how much power is needed you will have to determine the maximum sound pressure level you desire at your listening position. The easiest way to do that is with a sound pressure level meter (Radio Shack used to make a nice one for around 50 bucks- not sure if they still have them). Once you have that, you can determine the power needed. Your speakers can each produce approximately (approx, because the output will vary with frequency) 102db at a distance of one meter with one watt of power applied. The level at, say, 10 feet will be lower. But, with that in mind, you can still extrapolate somewhat by considering that you need to double the power for each 3db increase in output from the speaker. So, for 105db, you need 2 watts, etc. Considering that the auditory pain threshold is, if my old memory serves me, around 120db, you could achieve that with around 64 watts. But, we're talking about each speaker providing that level of output. So, in stereo, with both speakers driven, the power requirement per channel is far less. Also, don't compare the Palladiums to the RF-7s as they are not as efficient and will require more power for a given sound pressure level. So, I hope this helps you a bit. The bottom line, as mentioned before, is that you have more than enough power.

[RockOn4Klipsch]

I would suggest that you get a heft power supply to push the RF 7's. Most on the forums here will concur that the RF 7's need plenty of good power to push them well. The RF 7's will play fine with smaller and moderate power supplies easy enough but you will notice a great improvement with say 200 watts or more per side, or getting solid amps for the 7's.

The other most noticeable difference in comparing the Palladiums to the 7's is that the Palladiums have a nominal load of 4 Ohms vs. the 8 ohm load of the 7's. So the Palladiums will suck more juice from a given amp compared to the 7's. Also stated was the sensitivity difference between the 2 is 3dB.

2.83 volt /1m is 1 watt of electricity but that does not necessarily mean that 1 watt of electricity is 2.83v/1m. The 2.83v/1m is thought to be more accurate.

[usmcsoldriver]

so at 1 meter i need 1 watt to achiever 102db, we know that.

How do you calculate then how much power you need to get that same 102db at 3 meters?

[edwinr]

I'm beginning to lean towards the philosophy that the quality of the power is more important than how much power you have...

[willland]

For Loud, but not pain inducing, listening, does this receiver provide enough power?

Usmcsoldriver,

Truthfully, I don't see how a 17.6 pound Sony HT receiver can push your RF-7's at moderate levels let alone at loud levels. While the RF-7's don't "require" an amp with high power, they do need high current which your Sony will not provide. While I am not knocking the Sony brand, their non ES line receivers just won't cut the mustard with low impedence speakers. I would suggest you sell the Sony and get a mid priced receiver with preouts and add a high current amp to the mix. On the used market, there are many good deals out there to find. Here are a couple of examples.

http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1282055620&/B-K-Reference-4420-225w-X-2

http://www.audiogon.com/cgi-bin/cls.pl?miscrcvr&1281622410&/Marantz-SR7002-thx-select2-dol

Bill

[usmcsoldriver]

Believe me I will not get offended because of the Sony, not at all... ever.

I suppose I should read up more on High Current power. Can someone provide a quick definition or a link?

[twistedcrankcammer]

Believe me I will not get offended because of the Sony, not at all... ever.

I suppose I should read up more on High Current power. Can someone provide a quick definition or a link?

I own a Sony DA 777ES Receiver, wich is widely considered the best 5.1 channel receiver Sony ever produced, it is a tank, extreamely large transformer, and it still sounds like crap in the amplification section. My brother in law owns one as well, same thing. an outboard cheaper Adcom amp was a huge imrovement, and my Nakamichi amplifiers make the Adcom sound like chit!!!

Receivers are a comprimise of both space and money. Just because the amplifier in a receiver is rated at 95 watts per channel, and plays from 20 to 20,000 Htz, does not mean it will make 95 watts all the way from 20 to 20,000 Htz. Much like a sub, many amplification units are severely limited, especially on the bottom end. This was discussed less then a week ago, with a link to an article from Klipsch on the subject, where Klipsch said it was not company policy to recomend, but if you wanted to be able to hit the peak wattage to reproduce the propper dinamics at maximum spl without it lasting long enough to burn out the coil, they recomended an amplifier 4 to 5 times the continuous or RMS rating of the speaker. As an example, it showed that a Klipschorn, Belle, or La Scala, rated at 100 watts RMS, would need an amplifier capable of 375 watts RMS to be able to hit the propper momentary peaks while averaging 100 watts RMS and not taking out the speaker. These heritage speakers are obviously more efficient then the RF-7, and the RF-7 is notorious for needing a big amp for good bass. To me, this leaves a simple solution, you need 4 to 5 times the RMS wattage of where you get the listening level you enjoy listening at. I have four 200 watt RMS per channel stereo amplifiers for 7 channel surround sound, and my Klipsc TSCM speakers are 106 dB or 108 dB efficient at 1 meter, depending on which piece of Klipsch advertising spec sheet you reference. An amplifier needs propper head room, as well as good quality sound reproduction, and with speakers at the level of the RF-7, you should be looking at seperates that you can afford most definately. Even multi channel amps are a comprimise over multiple amplifiers.

Roger

[laager]

Just because the amplifier in a receiver is rated at 95 watts per channel, and plays from 20 to 20,000 Htz, does not mean it will make 95 watts all the way from 20 to 20,000 Htz.

Yup. Although there is one particular manufacturer that rates their amps according to how much they will deliver (at minimum) at any frequency from 20 to 20,000Hz, at (or below) rated distortion. NAD.

[usmcsoldriver]

What about AMC. The AMC 2100 In perticular. I am thinking about gett 1 then later on getting another and running them bridged.

http://www.amchome.com/content/amc-2100-stereo-power-amplifiers-100w-x-2

they are about $250 new but I found one for less than 150$ on Ebay.

If I buy them when I find them at under 200$, I could get 3. 1 for 2 channel - High Pass, 2 for Mono - Low Pass. That will give the Tweeter 100 watts and the Woofers 200 watts with a supposed 500 watt dynamic power Total cost 600$, or get something like that B&K that was linked earlier for ~ 500$

But first I have to tackle the big road block. I never thought to check the Receiver for Pre Outs. Wasnt thinking about getting sperates at the time and I got a descent deal on it. So yea, how can I hook up Seperate Amps when my Damn Receiver doesnt have Pre Outs?!?! I got a solution, anyone wanna buy a Sony STR-DH700 7.1 Receiver, 230$,Retails for 300$! (he says this knowing its not going to happen.)