Thinking of getting a power amp.

[rufas2000]

I'm debating whether to get a power amp or not. It's basically a cost issue that is making me think about it. Anyway a few questions:

The amp I'm considering is one of those two new Emotiva amps (XPA-2 or XPA-5). Good choice? Can I do better for the price ($799 I believe)? How significant do you think the sound upgrade will be from my Denon AVR-987 (which will be used as the preamp).

Should I get the 5 channel amp if I run a stereo plus sub setup but am thinking about adding centers & rears in the future or will the two channel be fine (and I'll hook up the center & rears to the Denon). I notice the 5 channel amp is the same price as the 2 channel one? I suspect that is because the two channel one delivers a lot more power to the two channels. Any cost-benefit thoughts?

Hookup: I assume I use RCA cables to hook from the amp to the Denon's preouts. Is there any special cable I should buy (type or brand)? I also assume the speakers are connected to the power amp.

Right now I have the speakers (Klipsch's RF-82s) "bi-amped" to the surround back channels (and Front A) of the Denon. Should I just hook the speakers up to the power amp and use the silver connecting bars? Should I use the Denon as well (I'm thinking not).

Thanks for the help.

Edit: I just noticed the LPA1. Its only $500. It obviously won't be as good but would it be sufficient for my needs? Or should I hold out for one of the others? I'm strongly considering it? Seven channels also. Can I bi-amp with the extra channels to the surround back preouts of my Denon?

System info: 11x11 room, Kilpsch RF-82s, rock music but other styles, many GIK panels.

 

[cfrizz]

I'm a big believer & owner of serious wattage! I'm also a believer in doing it right the first time.

If you know for sure that you are going to go with a full surround sound system then get the Emotiva XPA-5 & don't look back. You will notice a huge difference with 200wpc over your Denon.

I started out just like you. I had a Denon receiver, then I got a 2 channel Parasound, then I got an Outlaw Monoblock. If I knew then what I know now I would have gotten what's in my signature now over 2 yrs ago & saved some money from buying power 3 separate times!

You just need 5 RCA's to go from the receiver preouts to the amp & the speakers are hooked up to the amp. The amp will handle all power duties from there & your Denon will just do the processing.

All speakers benefit from more power & 200wpc will drive any speaker to its full potential now & any upgrades done in the future. Especially if you upgrade to 4ohm speakers, they need all the power they can get.

So go for it & enjoy!

 

[Pyrrho]

Your speakers are rated as being 8 ohms, and with a sensitivity of 98dB @ 2.83V / 1m. That means, they are easy to drive and play loud with very little power. (To be precise, they put out 98dB when listening at 1 meter with only 1 watt of power. 98dB is quite loud, and can lead to permanent hearing loss if experienced for long periods of time.) My guess is, at any sane volume, any difference you would "hear" with a new power amp would be nothing more than the placebo effect, and would not be real at all.

 

[rufas2000]

Your speakers are rated as being 8 ohms, and with a sensitivity of 98dB @ 2.83V / 1m. That means, they are easy to drive and play loud with very little power. (To be precise, they put out 98dB when listening at 1 meter with only 1 watt of power. 98dB is quite loud, and can lead to permanent hearing loss if experienced for long periods of time.) My guess is, at any sane volume, any difference you would "hear" with a new power amp would be nothing more than the placebo effect, and would not be real at all.

So I won't hear any difference in quality with a power amp? Loudness isn't a concern but I always want a better sound.

I appreciate the "do it right the first time" philosophy but I really like the price of the LPA-1, the added channels and the idea that I can put my DVD player on top of it (cause the product page says it runs cool). And being impatient, I also like that its available NOW!

Thanks to both of you.

 

[PENG]

IMHO whether you will hear a difference or not depends on many factors. And if you do hear a difference, that difference may or may not seem "huge" to you. Having more power, like the 200WPC suggested, is always a good thing. A good power amp will last many years. Once you get a nice one, you can keep upgrading/changing speakers without having to worry about whether they are hard to drive or not.

 

[Nomo]

So I won't hear any difference in quality with a power amp? Loudness isn't a concern but I always want a better sound.

I appreciate the "do it right the first time" philosophy but I really like the price of the LPA-1, the added channels and the idea that I can put my DVD player on top of it (cause the product page says it runs cool). And being impatient, I also like that its available NOW!

Thanks to both of you.

If we were talking about Polk or Axiom or just about anything besides those Klipsch speakers I would be on board with the "more power the better" approach. But those speakers are so easy to drive that I don't feel that you will here any difference with a power amp.
Don't get me wrong; for the money, Emo is hard to beat. And the blue lights on my LPA-1 are at least a conversation piece. But in your case it's probably not worth the investment for SQ alone.

 

[rufas2000]

If we were talking about Polk or Axiom or just about anything besides those Klipsch speakers I would be on board with the "more power the better" approach. But those speakers are so easy to drive that I don't feel that you will here any difference with a power amp.
Don't get me wrong; for the money, Emo is hard to beat. And the blue lights on my LPA-1 are at least a conversation piece. But in your case it's probably not worth the investment for SQ alone.

Ah, so confusing. I was told in another thread (about speakers) that my specific Klips dipped to 3 ohms at times (despite their nominal 8 ohm rating I suppose) and that a separate power amp would really "make them sing". They did admit that the Denon wouldn't have a problem driving them, just that a separate power amp would show what they could really do.

I appreciate the input though, its just hard to know who to believe. Its hard to have cold, hard facts in such a subjective hobby (what sounds good to one may sound merely OK to another). I guess I'll see what other posters think and perhaps find out for myself (if many of them think it'll be an improvement), if I want to lay out the cash.

Thanks again.

 

[Seth=L]

There could be benefits from adding amplification for those Klipsch RF-82s, and you are correct about that impedance dip. I personally recommend getting a two channel amplifier vs. a 5 channel. Most any 2 channel amplifier rated 100 watts per channel with some dynamic head room should do great with those speakers, the only real concern is stability with low impedance.

I assume you really like the sound of your Klipsch, that's great. I doubt you will have the huge change in SQ like you are looking for by just upgrading your amplifier. Treating your room, adjusting your speakers, or possibly upgrading the speakers would have a much more profound affect on your overall sound quality.

I know what you are thinking, I must be one of those anti-Klipsch guys right? This is not the case at all. I do like that particular pair of Klipsch quite a bit in fact, but that's purely subjective. I would go out and listen to speakers, as many as you can (with your own music). Try to find the most pleasing speaker to your ears for a true upgrade in fidelity (which is subjective in certain crowds). There are some audio gurus that desire the closest to perfect speaker, recreating the the music as it was recorded to it's original state. This is hard to do, and most mass manufactured speakers are incapable of doing this. This is why we must have a wide range of different sounding speakers that we have to chose which sounds best to us. Having a perfect or near perfect speaker is very expensive or time consuming/possibly expensive if you build it yourself. So we must settle in most cases in what we, individually, define as good sound.

Good luck on your audio venture.

Oh, and my amplifier recommendation is this. My personal picks Emotiva XPA-2 for looks and the Behringer EP2500 for performance and bang for buck. Either amplifier will be stable with the recurring 3 ohm load. The Behringer has more raw power, but you may never need it in any case. The Behringer is also considerable less, but may require a modification (replacing stock fan with a quiet fan) and will also require 2 inexpensive 1/4" mono to mono phono adapters.

 

[mtrycrafts]

Ah, so confusing. I was told in another thread (about speakers) that my specific Klips dipped to 3 ohms at times (despite their nominal 8 ohm rating I suppose) and that a separate power amp would really "make them sing". They did admit that the Denon wouldn't have a problem driving them, just that a separate power amp would show what they could really do.

I appreciate the input though, its just hard to know who to believe. Its hard to have cold, hard facts in such a subjective hobby (what sounds good to one may sound merely OK to another). I guess I'll see what other posters think and perhaps find out for myself (if many of them think it'll be an improvement), if I want to lay out the cash.

Thanks again.

Well, it may or may not dip that low, need to be verified by proper impedance testing, your speaker is still very sensitive. that 98dB is most likely an anechoic condition and in room you can expect another 4 dB spl gain. So, even at 3 ohms, if sensitivity is maintained, or even if reduced, your present receiver should be more than enough for the dynamic peaks the low impedance here and there.

Are you experiencing some sort of deficiency right now?
Better sound comes from better room acoustics, speakers and the recordings, rarely from increased power.

 

[rufas2000]

Thanks to everyone. I'm thinking I'm going to hold off for now.

To answer "Whats wrong with the sound?"; I was getting harshness, and the highs can be unclear (the high frequencies were "competing" with each other). Part of it (a big part) is the small square room and part of it was probably modern heavy metal CDs mastered for volume, boom & sizzle.

I added a sub (found a Klipsvh Sub-12 at BB on sale, easy to return if I decide I don't need one or if I want something better) and replaced the speaker wire (Monster typical with quick lock banana plugs) with Blue Jeans cable (12 gauge, they terminated them). the harshness and unclarity was significantly diminished. I did a poor job on setting up the wire in the first place (uneven lengths, probably didn't have a solid connection with the banana plugs). I just wanted new wire with professional terminations and I think it worked.

I've also treated the room with the GIK acoustic panels. Two 242s behind the speakers, two each on the side of the room, two 244s in the back corners, a monster trap behind the seating position and two tri traps in the front corners. I think I'm set there.

I got some recommendations in a speaker thread to get a power amp with my Klips so I thought I would look into it.

The Klips were a recent purchase and I do like them quite a bit. If they could just tone down on the mid highs a wee bit they would be perfect. But the room might have something to do with it as well. I would change rooms but the only bigger room is right next to my neighbor (duplex) and I don't want to blast her out of her house.

Someday I'll be able to getthe ultimate upgrade, a customized sound room. Until then ...

Thanks again for all the input. You may have saved me $500.

 

[Seth=L]

I will tell you for a fact, the cables made no difference in your sound. I do commend you for going with BlueJeans cables, as they are an inexpensive and quality product. Cables don't determine sound though, and it wouldn't make sense for them to do so. Assume that if a cable is making an audible difference, it is either defective, or is designed in such a way to color your sound (distortion). This should not be the case with the BlueJeans cables.

What toned down your high frequencies would have to be the acoustic treatments you added. Unfortunately I doubt adding amplification will make the harshness or any other sonic signature of the Klipsch go away, only EQing and/or modding the speakers will change their sound. It's possible you might have chosen speakers that just don't quite fit your personal tastes. Don't get me wrong, the RF-82s are some of Klipsch's best speakers available today, but they aren't tailored to any specific person. Don't expect tailored sound from those speakers, or any other mass market speaker system.

I would personally recommend going out and listening to B&W 600/700 series speakers as well as Paradigm's Studio series. They each have a well defined and crisp high end with tight articulate bass in most instances. Of course try every speaker you can, but those sound like they might be a good fit to the sound you could be looking for.

 

[Midcow2]

If you want difference in sound, upgrade speakers

So I won't hear any difference in quality with a power amp? Loudness isn't a concern but I always want a better sound.

I appreciate the "do it right the first time" philosophy but I really like the price of the LPA-1, the added channels and the idea that I can put my DVD player on top of it (cause the product page says it runs cool). And being impatient, I also like that its available NOW!

Thanks to both of you.

The biggest way to upgrade you sound quality is to upgrade your speakers.

The only way increasing your power will help, is if your current AVR is underpowered and you are playing at the high ends and it clips or distorts. You can improve SQ with a cleaner (higher SNR) power Amp or AVR, but the biggest improvement would be seen in upgrading your speakers which in turn might require more power anyway.

Good Luck,

 

[Pyrrho]

So I won't hear any difference in quality with a power amp? Loudness isn't a concern but I always want a better sound.

I appreciate the "do it right the first time" philosophy but I really like the price of the LPA-1, the added channels and the idea that I can put my DVD player on top of it (cause the product page says it runs cool). And being impatient, I also like that its available NOW!

Thanks to both of you.

If you want better sound, almost always the answer is either better speakers, or dealing with room acoustics (which includes the positioning of speakers). There is a psychological tendency, however, for people to imagine an improvement when they expect an improvement, and therefore people doing silly things (I will not presently list them, to avoid taking us off topic about the merits of some useless "tweak") often gets people believing they actually work. Indeed, when people are told that there is a change that they think will make the sound better, but no change has actually been made, they often believe that the sound has improved!

In the case of a replacement amplifier, you would need to level match it with the internal amplifier of your receiver, and then listen "blind" (i.e., not knowing what you are listening to), in order to determine if it made an audible difference. Typically, people do their listening sighted (so bias has full opportunity to influence one's opinion) and without level matching. Without level matching means that one might be very slightly louder than the other, and in that case, subjectively, the slightly louder one will seem to be more detailed (it is louder, so of course you can hear more detail!) and with more bass and treble. The seemingly more bass and treble has to do with the fact that human hearing is not linear, and as you turn down the volume, the bass and treble appear to diminish more rapidly than the midrange. This, by the way, is why "loudness compensation" switches have been on a lot of two channel receivers, to take care of this when listening at low levels of sound. So, without level matching, one might subjectively sound better simply due to a slight difference in volume. But the other one may very well be able to sound the same, if one only turns up the volume control.

In other words, the "experience" of most people on such things is completely useless, because they have failed to perform a proper listening test at all. A poorly conducted listening test is often worse than nothing, as one may be misled to believe that one knows something that one does not know at all. And then, when someone points out this fact, as I am doing here, the person is often apt to become offended, because I have accused them of being human and not some superhuman being that has calibrated hearing that works better than measuring devices.

The above, by the way, is very well documented, and I suggest you search and verify the information on your own.

 

[Pyrrho]

Ah, so confusing. I was told in another thread (about speakers) that my specific Klips dipped to 3 ohms at times (despite their nominal 8 ohm rating I suppose) and that a separate power amp would really "make them sing". They did admit that the Denon wouldn't have a problem driving them, just that a separate power amp would show what they could really do.

I appreciate the input though, its just hard to know who to believe. Its hard to have cold, hard facts in such a subjective hobby (what sounds good to one may sound merely OK to another). I guess I'll see what other posters think and perhaps find out for myself (if many of them think it'll be an improvement), if I want to lay out the cash.

Thanks again.

It would be better to contact Klipsch about the impedance than to trust a post on line. But if what you say is correct, then Klipsch is a worse company than I thought. It is ridiculous to rate a speaker as 8 ohms that dips to 3 ohms at times. In my opinion, such things should be regarded as fraud. It is certainly not what one would normally expect with an "8 ohm" speaker. Still, you are probably fine with your receiver, unless Klipsch lied about the sensitivity as well.

 

[rufas2000]

Cables don't determine sound though, and it wouldn't make sense for them to do so. Assume that if a cable is making an audible difference, it is either defective, or is designed in such a way to color your sound (distortion). This should not be the case with the BlueJeans cables.

I suspect my lack of DIY fu may have caused the cables to be a little "defective". I'm still glad I replaced the old Monster ones with Blue Jeans cable. Now I know I got rock solid cables and a solid connection, improved sound or not. They look sharp as well.

It would be better to contact Klipsch about the impedance than to trust a post on line.

I was paying more attention to the "power amp can help part" than the reason why.I figured the person had experienced improved sound from a dedicated power amp. I wanted to experience it too. But at least I looked for more opinions first.

BTW: as far as Klipsch as a company: on the speakers one of the magnetic grills didn't have a magnet that worked so it would stick but not quite snug. I emailed Klipsch and they told me that the retailer (Best Buy / Magnolia) would order the replacement grill. I emailed Best Buy and they said they couldn't order parts. I sent another email to Klipsch with a copy of Best Buy's response and they sent me the grill. So I like Klipsch as a company (and not Best Buy so much).

I lkie the Klipsch's, I just can't give them what they really need, a bigger room for them to shine in. The bad part is that I'll probably be in a position to buy different speakers before I'm in a position to find a new place to live.

I guess the next step is to determine whether I'll keep the Klipsch Synergy Sub-12 or bring it back and exchange it for something else. Now I know that a sub will improve the sound because the low bass isn't bouncing off the walls so much due to speaker/wall proximity of a smaller room. Besides if I want home theater eventually I'll need a sub.

Thanks again.

 

[jcPanny]

Emotiva amps

I have the LPA-1 driving my 4 ohm onix speakers that are about 10 dB less efficient than your Klipsch. Your current receiver is probably adequate for the Klipsch, but the LPA-1 or other amp will have more power and headroom.

If you want the LPA-1 act fast because this model is being discountinued and the replacement 7 channel version will be more expensive.

If you want to experiment with an amp, you can pick up a Behringer A500 for about $180 shipped.

 

[Nuglets]

I'm just going to repeat what many others have said but...if you feel you are missing something in the sound of your speakers then I suggest auditioning some speaker's other than Klipsch. I personally have only heard one set of klipsch speakers that sounded decent to me and they are very old and would never have been found anywhere near Best Buy. I'm not trying to knock you or your speakers, I just strongly recommend not buying audio equipment from Best Buy because I have never heard a speaker I enjoyed from there and like I said...I haven't heard more than one set Klipsch speakers I have enjoyed. So, if you want to try an amplifier and see what happens feel free to do so but I personally don't think it will give you what you are looking for. However, a new set of speakers that you have auditioned against many other speakers and taken your time to compare and find what you like and dislike about each one will likely give you exactly what you want with or without an extra amplifier.

 

[darien87]

It would be better to contact Klipsch about the impedance than to trust a post on line. But if what you say is correct, then Klipsch is a worse company than I thought. It is ridiculous to rate a speaker as 8 ohms that dips to 3 ohms at times. In my opinion, such things should be regarded as fraud. It is certainly not what one would normally expect with an "8 ohm" speaker. Still, you are probably fine with your receiver, unless Klipsch lied about the sensitivity as well.

I was told by a stereo repair guy that most speaker companies actually do this. They list the "nominal" impedance, because impedance changes with frequency. I don't know if it's even possible to design a speaker that stays at exactly 8 ohms throughout the range of 20Hz - 20,000Hz.

 

[mtrycrafts]

Thanks to everyone. I'm thinking I'm going to hold off for now.

To answer "Whats wrong with the sound?"; I was getting harshness, and the highs can be unclear (the high frequencies were "competing" with each other). Part of it (a big part) is the small square room and part of it was probably modern heavy metal CDs mastered for volume, boom & sizzle.

.

Well, there is the issue, room acoustics but in this case your recording has a whole lot to do with the sound. Break down and get a nice classical to test your setup. Also, your speaker's frequency balance has a lot to do with your issue too. Amp is not up there.

 

[PENG]

Impedance of a speaker is typically not constant. It most likely varies with frequency and some will have more fluctuation (including dips) than other and that is one of the reasons why they use the word "nominal". Such as the following found on the Klipsch site:

RF-82 Specifications
frequency response 33Hz-23kHz +/-3dB
power handling 150W RMS / 600W Peak
sensitivity 98dB @ 2.83V / 1m
nominal impedance 8 ohms compatible

If Klipsch specifies the speaker's nominal impedance as compatible with 8 ohms they mean you can power with the speaker with an amplifier that is suitable for use with 8 ohm speakers regardless of the fluctuation. If the speaker needs amps that are suitable for use with 4 ohm nominal speakers then they would have said nominal impedance 4 ohms compatible. If you amp cannot handle impedance fluctuation such as dipping to 3 ohms and/or rising to say 12 ohms at times, then you should consider replacing it.