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Separate amp useful or not for my setup?


forestelder

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Hello everybody,

 

I am planning to buy a Emotiva XPA 3 gen 2 amplifier to power my fronts RF82's  and RC62II center and let the receiver power my surrounds. At the moment they are powered by a Onkyo TX-NR 3008 receiver. Is it useful to buy the Emotiva or is the Onkyo enough for my setup?

 

I hear alot from other Klipsch users that a Emotiva made a big difference in sound ( more clear, dynamic, open sound  and tight bass ).

 

 

ps. My listen distance is about  9.8 feet and when i watch movies volume is around -20.

 

 

Greetings,

 

 

David

Edited by forestelder
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Now, what I am about to say is only a BASIC rule of thumb.

 

In general, having a separate amp is usually a better way to go.  "IN GENERAL"

Having said that, your 3008 is more than enough to power RF-82 and RC62II.  Tech things to consider:  Just because speakers are rated at 150W RMS handling, does not mean it takes that much to drive them efficiently.  Before my Pioneer Elite SC-91, I was using an Onkyo TX-NR 807.  It was of lesser design that your 3008, and I drove 2 DCM KX12 Series 2 250W huge speakers, an RC 62II, and KLH surrounds.  All but the RC-62II was efficient.  You are driving smaller speakers that are more efficient than my old setup, and my amp in my 807 didn't break a sweat, even during Avengers cranked to very high levels.  

 

Sorry for the round about story.  Case in point.  If you have the money, any purist will tell you go with the separate amp.  And I will tell you that on some level it will sound "better", but not world class changing.  I recently tuned my system using a dirac processor which requires a separate amp from your receiver.  My ears work fine, and the processor I used could barely tell the difference between the Pioneer Elite, and the $4000 Marantz amp I was using to test.  Receivers have come a long way, still not perfect, but yours' is fine for that setup, unless you have microphones for ears and software for a brain.  LOL

 

Hope that is of some help.  Others in this community will help too.  This is a close community.

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I am a huge proponent for quality outboard amplification, much so that I would never go back to just a n AVR in a medium to large room.  With that said, your Onkyo TX-NR3008 is a powerful 54lbs beast that will hold it's own under most situations provided that the room is not overly large and you don't listen at crazy loud volumes.  But if clean dynamics, detail, and punch are important, then amp it.

 

Bill

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Yes for me this is very important, Think i am a bit of a purist. I want to have a immersive movie experience, just like in the the theaters :-)

 

Luckely for me the Emotiva amps are not very expensive, compare to other brands, like Rotel and Parasound.

 

I wander what the experience is of other klipsch users on this forum, who have a similar setup like me.

Edited by forestelder
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I hooked up a XPA-2 to my Yamaha AVR for 2 channel listening, it made a HUGE difference in the sound, for the better. I let the AVR handle the HT duties, the wife and kids do not like the volume like I do.

 

Forestelder, why not get an XPA-5 to handle the whole HT?

 

Oh….welcome.

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Forestelder, if you can afford to do it....amp it. The Emotiva amps are fantastic for the money and going to the Emo amps from two very good Yamaha receivers the amps made a huge improvement. That said, I still have four of the Sherbourn SR-120 receivers in use in my home. These were originally used by custom installers weighing in at 73lbs and providing ample real power across the entire seven channels, unlike the mainstream receivers. The downfall of most receivers is when they are bench tested, now I cannot speak directly to your Onkyo but my FIL has a nice Onkyo receiver and besides it getting extremely hot it becomes a bit distorted at high volume levels. The 140 wpc rating is for two channels driven with a seven channel amp in some high end receivers. When you break it down to seven channels driven it becomes real power numbers around 50 wpc. Still enough to drive most Klipsch speakers but not to reference levels without worry of clipping or slipping into protect modes.

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I am a huge proponent for quality outboard amplification, much so that I would never go back to just a n AVR in a medium to large room.  With that said, your Onkyo TX-NR3008 is a powerful 54lbs beast that will hold it's own under most situations provided that the room is not overly large and you don't listen at crazy loud volumes.  But if clean dynamics, detail, and punch are important, then amp it.

 

Bill

+1

 

I went with the XPA 5 for my Rf 7ii set up and I am very happy with it!  For most movies you'll be watching, you may not notice a difference, but those demo moments when you just want to knock a picture off the wall, the external amp is a great route to go!  Good luck and enjoy!!

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forestelder,

I agree with others sentiment to amplify all channels.

In that way, you will already have the power if you should later decide to upgrade to the same towers for your rear surround.

I run ALL the same speakers for center and surround positions as I lie the effects louder and timbre matching.

Look, your present surrounds are probably a lot smaller an a lot less efficient, so they are not going to play early as loud as your mains, even with the SAME wattage pumping through them, and now you are going to handicap them even more by putting more wattage through the more efficient speakers. This is also why I am a big proponent of running a modified tower, same as your other two as your center channel. ;)

I run four big Nakamichi Stereo amplifiers to get 7 channels of amplification. I have 225 watts RMS across the front 3 and 200 watts RMS on the other 4 channels, but I eventually plan on upgrading the second two amps to 225 watts per channel as well.

Roger

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I heard amps can play certain frequencies better then receivers is this true?

NO.  If an avr or amp has sufficient power to handle the dynamic passages, in theory they should perform identical.  Blinded test support this.  A lot of this comes down to personal choice.  I use amps and have stated many times I most likely don't need one with my avr and Klipsch.

Edited by derrickdj1
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Well i have to say my surrounds are also from Klipsch. I have the RS42's who are also very effecient speakers. They rate 93db@2.83V / 1 m. and wattage is 75 W RMS. So i think the onkyo 3008 can handle these well.

forestelder,

Your RF-82s are rated at 98dB efficiency as is your RC-62 II, which is a great match.

The thing that I would explain to you if you did not already know is that 3dB more is twice the physical sound pressure.

The human ear is very inefficient, so it takes 10 dB to seem like it is twice s loud to us, but an additional 3 dB is TWICE the sound pressure.

Therefore; If we take one of your 93 dB efficient RS-42s, it will put out 93 dB at 1 watt RMS, at twice the power or 2 watts, the speaker will put out 96 dB, doubling the power again, gives us 4 watts at 99 dB, so it takes almost 4 times the wattage into your surrounds to play as loud as your front end.

Now, with a high limit of 75 watts RMS on your surrounds, you could only put about 20 watts RMS through your mains for equal output of all speakers.

This is why I find the effects of so many home theatres to be rather non noticeable and ineffective.

You can also get even better sound and louder sound with more articulation by putting your money into more efficient speakers rather than an amp.

As an extreme example, I will use my speakers as an extreme. Mine are 106 dB efficient at 1 watt at 1 meter, or a difference of 8 dB

1 watt is base for you RF-82 t put out 98 dB, so 2 watts would be 101 dB, 4 watts would be 104 dB, 8 watts would be 107 dB, so it would take 8 of your speakers at nearly 100 watts each to play at about the same level as one of my speakers at 100 watts per channel.

I do this to illustrate why I like to match towers for surrounds with the fronts.

I also think that better speakers are almost ALWAYS a better bang for your buck than amplifiers, unless you are getting into really high end speakers with diminishing returns and then it is time to run separate amps for the different drivers of your speakers.

Roger

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Forestelder, if you can afford to do it....amp it. The Emotiva amps are fantastic for the money and going to the Emo amps from two very good Yamaha receivers the amps made a huge improvement. That said, I still have four of the Sherbourn SR-120 receivers in use in my home. These were originally used by custom installers weighing in at 73lbs and providing ample real power across the entire seven channels, unlike the mainstream receivers. The downfall of most receivers is when they are bench tested, now I cannot speak directly to your Onkyo but my FIL has a nice Onkyo receiver and besides it getting extremely hot it becomes a bit distorted at high volume levels. The 140 wpc rating is for two channels driven with a seven channel amp in some high end receivers. When you break it down to seven channels driven it becomes real power numbers around 50 wpc. Still enough to drive most Klipsch speakers but not to reference levels without worry of clipping or slipping into protect modes.

Much respect, here is another perspective.  Just for the sake of the forum.  Teaman makes very good points and please take into account his statements.

 

I agree with what you said, even though I made a counter point within my first post.  That said, the power loss is not that extreme when pushing to reference levels.  Post tuning with the Dirac, obviously using pre-amp out from Pioneer Elite, I was worried about significant power loss.  So I tested at near reference level with my SC-91 with 5 channels driven.  Pioneer managed 128W per channel at near reference level.  In conjunction with my pc and a multimeter, I was able to figure this out by using a tone generator to feed a constant stream of audio to the speakers.  Then, for good measure, I used an action movie (Live Free or Die Hard) during the plane chase sequence.  Never dropped below 125W.  

 

***Note:  Results consistant most likely due to using crossover at around 70Hz.  Does relieve the stress on the 5 channels due to the sub being powered.***

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I never watched a movie at reference levels, its to loud for me hehe. Max is -10 for me. Mostly its around -15 or -20. But maybe now its possible because the amp can produce clean sound without any distortion.

 

 

Thx for the tips and technical input guys.  :)

Edited by forestelder
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