Zen Traveler Posted September 3, 2011 Share Posted September 3, 2011 Yeah...I know that it's a ‘lower end’ or a ‘mid-entry level’ Denon AVR from 08's, but, it does offer the 'Bi-Amp' feature, which I'm exploiting since sometimes... Per Denon Specifications it has 'Identical quality and power for all 7 channels, 110W x 7ch (8 ohms, 20Hz - 20kHz)’. If you are running 4 RF-7s on a lower end AVR that really isn't going to help much: http://community.klipsch.com/forums/p/142559/1461527.aspx#1461527 ..You are worng. you can Bi-amp these speakers. It's called "passive bi-amp" where you use 2 amp channels for one speaker. And NO it will not hurt the speaker or amp Channel. True, there is not much advantage to it. I have seen tubes on the HF and SS on the LF. I have seen 3:1 power ratio so you can have more LF at low volume, but a bass knob can do the same thing. If you connect the HF section of the speaker to an amp, the amp will see the 8 Ohms + network load. If the LF section is connected the amp will see a min of 4 Ohms + network....but both will work just fine.... Quote Link to comment Share on other sites More sharing options...
Zen Traveler Posted September 3, 2011 Share Posted September 3, 2011 In 'theory' at 101dB sensitivity (efficiency) of Klipsch RF-7 II, it should produce 121dB SPL @100W RMS @ 3.3 feet distance from speakers and @ 200W RMS it will produce SPL of 124dB. Basically, to increase the 3dB output from 121dB to 124dB, double power (200W RMS) is required from an amplifier. ....The below link/reference should help one to understand what I'm saying. If I have misunderstood, then open for correction! http://www.integratedaudio.com/help/sensitivity.pdf What your article doesn't address is the impedance curve of the speaker in question at different frequencies....Your RF-7s are listed as 101 dB sensitivity and are "8 Ohm Compatible," but that last sentiment can be misleading because it doesn't address that the RF-7s have been reported to dip down to 2.8 Ohms at certain frequencies . Quote Link to comment Share on other sites More sharing options...
Heritage_Head Posted September 3, 2011 Share Posted September 3, 2011 In 'theory' at 101dB sensitivity (efficiency) of Klipsch RF-7 II, it should produce 121dB SPL @100W RMS @ 3.3 feet distance from speakers and @ 200W RMS it will produce SPL of 124dB. Basically, to increase the 3dB output from 121dB to 124dB, double power (200W RMS) is required from an amplifier. ....The below link/reference should help one to understand what I'm saying. If I have misunderstood, then open for correction! http://www.integratedaudio.com/help/sensitivity.pdf What your article doesn't address is the impedance curve of the speaker in question at different frequencies....Your RF-7s are listed as 101 dB sensitivity and are "8 Ohm Compatible," but that last sentiment can be misleading because it doesn't address that the RF-7s have been reported to dip down to 2.8 Ohms at certain frequencies . Keep in mind you double the centers power and the surrounds. My GUESS is if you double the power of 5 channels you will gain around 8-10db (potential mind you). I personally wouldn’t bi amp if you’re just using the avr for power. When you bi amp instead of doing 7.1 your engaging those 6th and 7th channels into the fronts and thus pulling power from all the channels to do it (so you won’t see a 3db increase). I know the manual probably says it’s rated at 7.1 all channels driven but that’s never the case. You have way more power to go around just using 5 channels. Quote Link to comment Share on other sites More sharing options...
pite Posted September 3, 2011 Share Posted September 3, 2011 Well, the article has nothing to do to the dynamic response of the speaker and changing impedance for a given frequency. It's merely showing the a relationship of SPL, Sensitivity, and RMS power required at 8 ohms in 'theory'. To tackle the dynamic response of the speaker that dips up to 2.8 ohms or even lower is 'amplifier' manufacturer's problem. For example, this amplifier went one time in 'safe mode' to prevent amp section from damaging while we were using 'Satellites with Sub-Woofer' in 7.1 configuration. These speakers were 4ohms and I'm pretty sure at some frequencies they were dipping below 2 ohms or even futher when I took it to -10dB. To produce that much of a sound from Klipsch RF-7 II, I don't need to dial more than -45dB. That's the point what I was eluding to with that article, showing the relationship between SPL, Sensitivity, and RMS power. While, NOT claiming that the 2808ci is a hi-end receiver, there might be a incremental benefit to a cost in upgrading to the powerful amplifier, while typically not playing loud at -10dB and beyond. Just like what 'reference_head' said, 'I would look at a sub before an amp. A sub will blow your mind compared to no sub.' But, then who knows, when the upgrade bug hits me! Cheers! Quote Link to comment Share on other sites More sharing options...
pite Posted September 3, 2011 Share Posted September 3, 2011 Obviously, bi-amping is not double the power to the speakers (i.e. 110W RMS to 220W RMS because I bi-amped), but as the last line from 'Trey Cannon' quote states, the major benefit that I see from passive bi-amping is to help isolating HF and LF sections' load or a dipping for a given frequency. Thus LF and HF amplifier sections have their own dips to tackle for a given frequency and hence potentially a better amp response (again in theory, because I don't know how the amplifier section is designed on 2808ci.). In other words less stress/dipping cycles that amp has to recover when compared to combined LF&HF sections. I totally agree, that very few amps that wouldn't degrade or would handle dipping (dynamic/transient speaker load) without clipping or distorting. So far, with Klipsch RF-7 IIs, we haven't experienced it...Fingers crossed! Quote Link to comment Share on other sites More sharing options...
Zen Traveler Posted September 3, 2011 Share Posted September 3, 2011 Keep in mind you double the centers power and the surrounds. My GUESS is if you double the power of 5 channels you will gain around 8-10db (potential mind you)... That isn't what Trey is saying in the link I provided and doubling the power to a given speaker results in a 3 dB volume increase is the rule-of-thumb: http://www.enjoythemusic.com/magazine/manufacture/0907/ "As audio/video hobbyists, most of us grew up thinking that if we have an amplifier with 50 watts of rated output power into 8-ohm speakers, and that combination produces reasonably clean and loud music, then by doubling the amplifier power to 100 watts per channel, the system would then play twice as loud. Many readers likely still believe that. Not so. Although it's not the easiest thing to comprehend, doubling the amplifier power does not double the loudness. In the above example, the sound from the speakers would not be "twice as loud"; it would only be "a little louder," an increase of 3 decibels." http://www.proavmagazine.com/acoustics/the-price-of-3-db.aspx "The loudness increase is logarithmic — twice the applied power always produces the same 3 dB loudness increase." Quote Link to comment Share on other sites More sharing options...
Heritage_Head Posted September 3, 2011 Share Posted September 3, 2011 Keep in mind you double the centers power and the surrounds. My GUESS is if you double the power of 5 channels you will gain around 8-10db (potential mind you)... That isn't what Trey is saying in the link I provided and doubling the power to a given speaker results in a 3 dB volume increase is the rule-of-thumb: http://www.enjoythemusic.com/magazine/manufacture/0907/ "As audio/video hobbyists, most of us grew up thinking that if we have an amplifier with 50 watts of rated output power into 8-ohm speakers, and that combination produces reasonably clean and loud music, then by doubling the amplifier power to 100 watts per channel, the system would then play twice as loud. Many readers likely still believe that. Not so. Although it's not the easiest thing to comprehend, doubling the amplifier power does not double the loudness. In the above example, the sound from the speakers would not be "twice as loud"; it would only be "a little louder," an increase of 3 decibels." http://www.proavmagazine.com/acoustics/the-price-of-3-db.aspx "The loudness increase is logarithmic — twice the applied power always produces the same 3 dB loudness increase." So with one speaker you gain 3db. But we are doubling the power x5( 5 different times to 5 different speakers). It’s like going from 1 powered sub to 5 right? Quote Link to comment Share on other sites More sharing options...
Zen Traveler Posted September 3, 2011 Share Posted September 3, 2011 While, NOT claiming that the 2808ci is a hi-end receiver, there might be a incremental benefit to a cost in upgrading to the powerful amplifier,... A sub will blow your mind compared to no sub.' Cheers! Cheers Pite, and I wasn't ditsing your Denon AVR. I have the Denon AVR 3805 and AVR 3803 driving my other 2 less demanding Klipsch Home Theaters and love them! When I had to drive the HT listed in my sig with the AVR 3805 for a few months, I had to switch out my side surround towers for Bookshelf speakers and then had to listen between 4 and 6 dB lower because of distortion at the higher levels I had been accustomed with my 48XX series AVR. Quote Link to comment Share on other sites More sharing options...
Heritage_Head Posted September 3, 2011 Share Posted September 3, 2011 I know it wouldn’t give you 3db x5 = 15db because as you add more that number stars to scale down so that’s where my 8-10db guess came from. I have seen a chart just can’t remember what it was. Quote Link to comment Share on other sites More sharing options...
Zen Traveler Posted September 3, 2011 Share Posted September 3, 2011 So with one speaker you gain 3db. But we are doubling the power x5( 5 different times to 5 different speakers). It’s like going from 1 powered sub to 5 right? No. We are talking about the SPL at a given spot and in one of the links it explains how the logarithm works. Quote Link to comment Share on other sites More sharing options...
pite Posted September 3, 2011 Share Posted September 3, 2011 While, NOT claiming that the 2808ci is a hi-end receiver, there might be a incremental benefit to a cost in upgrading to the powerful amplifier,... A sub will blow your mind compared to no sub.' Cheers! Cheers Pite, and I wasn't ditsing your Denon AVR. I have the Denon AVR 3805 and AVR 3803 driving my other 2 less demanding Klipsch Home Theaters and love them! When I had to drive the HT listed in my sig with the AVR 3805 for a few months, I had to switch out my side surround towers for Bookshelf speakers and then had to listen between 4 and 6 dB lower because of distortion at the higher levels I had been accustomed with my 48XX series AVR. np...All, I could say that either we are lucky having one of the nice Denon piece or may be because hearing loud for shorter duration doesn't tax the receiver. Fingers crossed! Quote Link to comment Share on other sites More sharing options...
A1UC Posted September 3, 2011 Share Posted September 3, 2011 HSU VTF-15 H [Y] Quote Link to comment Share on other sites More sharing options...
pite Posted September 3, 2011 Share Posted September 3, 2011 HSU VTF-15 H OMG, you have two of them! Cool! [H][Y] Quote Link to comment Share on other sites More sharing options...
JasonJCarney Posted September 3, 2011 Share Posted September 3, 2011 This thread was started by Blubitrates.... today we got word he gave them to his parents. [] Sorry bud... hopefully everything works out with your health.[Y] Quote Link to comment Share on other sites More sharing options...
BluBitRates Posted September 4, 2011 Author Share Posted September 4, 2011 A speaker given to the parents is not a speaker lost. There room is a lot bigger than where i had them so that is a plus. Quote Link to comment Share on other sites More sharing options...
Moderators Youthman Posted September 4, 2011 Moderators Share Posted September 4, 2011 Absolutely. You get to keep them in the family and still be able to enjoy them from time to time. Quote Link to comment Share on other sites More sharing options...
JasonJCarney Posted September 4, 2011 Share Posted September 4, 2011 A speaker given to the parents is not a speaker lost. There room is a lot bigger than where i had them so that is a plus. Very true. Still have your 3400 available? Quote Link to comment Share on other sites More sharing options...
BluBitRates Posted September 4, 2011 Author Share Posted September 4, 2011 pm sent jason. Guys can anyone recommend a good tv stand for the rc-64ii? My parents want to get a new tv stand now. Quote Link to comment Share on other sites More sharing options...
Zen Traveler Posted September 4, 2011 Share Posted September 4, 2011 pm sent jason. Guys can anyone recommend a good tv stand for the rc-64ii? My parents want to get a new tv stand now. Isn't that just like parents...Give them one thing and then they want something else. [] Quote Link to comment Share on other sites More sharing options...
Heritage_Head Posted September 5, 2011 Share Posted September 5, 2011 Awesome pic!! [] Quote Link to comment Share on other sites More sharing options...
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