Pro amps vs. consumer for Speakers, not subs?

[Rolyasm]

I tried to find some information on this site about pro amps, but most of the information was concerning subs. I have read a few articles about using pro amps for speakers, and was curious about you opinions. I do have the Behringer 2500 now for my sub, and plan on hooking up some older Polks to see how it sounds. So many of you have pro amps, I was curious if you have done any comparisons? Any reason not to use a pro amp like the Behringer A500 or 2500? I can't see any reason how it could damage my equipment, but thought I had better check.
Roly

[whoaru99]

It will not damage your equipment.

The main drawbacks as I've read are...

1. Fan noise. Most, but not all, pro amps have cooling fans that are fairly noisy.
2. Somewhat more potential for ground loop hum since most (all??) pro amps have a grounded chassis and most consumer stuff is non-grounded.
3. Output level from pre-amp/receiver may not be adequate to drive a pro amp to full output as they (typically) need higher input signal levels for full power out.
4. Adapters necessary to go from RCA to XLR - provided your pre/pro does not have XLR outputs.
5. Cosmetics usually not quite as pleasing unless you like the industrial look.

None of these are insurmountable concerns, and in fact, most are easily dealt with.

Finally, comes the argument about sound quality, which I won't get into because it's largely anecdotal evidence either way. Although I know some here have tried blind tests with them.

Personally, I rented a Crown K2 for a weekend and I think it would not be a problem for me to live with a stack of those driving my HT system. Talk about power and headroom on tap!! :T

[SteveCallas]

Not sure why you started a new thread for this, but if you want further evidence, you may want to look over the monster thread at AVS - "New amp is making me grin from ear to ear". Plenty of people are using pro amps to power their speakers with great results, myself included.

[Snap]

Crown makes some good amps that do not have fans. Just a FYI on that. I am not sure other than price in this day in age, when you can get a good 5 chan amp for a low amount why you would just not get one of those? There are many good companies out there that make amps for HT use that are under a grand for 5 chan!

[whoaru99]

I am not sure other than price in this day in age, when you can get a good 5 chan amp for a low amount why you would just not get one of those? There are many good companies out there that make amps for HT use that are under a grand for 5 chan!

True, but not usually with similar power output and low impedance drive capability - assuming, of course, those items are of importance in any given situation.

Crown, et al., do make some very high priced amps too, but you get TONS of power (as in thousands of watts per channel), computer control and monitoring, built-in electronic crossovers, etc.

[gd]

The main drawbacks as I've read are...

I keep seeing these pro amp threads, and for the life of me, I still can't see what the attraction is... not trying to be contrary, just trying to understand if there's a discernible advantage that justifies all the workarounds... fan noise alone makes it a deal-breaker here.

What is it...
Price?
The opportunity to tinker?
The opportunity to thumb your nose at pricy amp mfr's?

It can't possibly be superior sound quality.

Or can it?... educate me.

[SteveCallas]

Fan noise is typically not a concern, as many put them in dedicated equipment spaces away from the listening position - others just do a fan mod with a resistor. I eliminated audible fan noise on my amps for no more than a couple dollars.

The draw is tons of power for low cost - a large torroidal transformer that is dedicated to only two channels, as opposed to the one or two typically found in 5-7 channel home theater amps. And when it comes down to it, surround speakers really don't need very beefy amplification, so resources can be maximized where it counts, on the front three.

[Audiophiliac]

The guy who got me into audio when I was in high school was a recording engineer on the side. He had some nice Vandersteens, Aerial Acoustics, Magnepans....etc....along with his Tannoy monitors. He always seemed to like his Ashly "pro" studio amps. He biamped his Vandersteens with a couple of them. I thought they were damn fine sounding....but then again, I was in high school.

Anyway. I am not saying one is better than the other. You have to judge that for yourself.

[Rolyasm]

Steve, I guess I started this thread because I did read the thread at AVS but wanted some other opinions. The same people at AVS seemed to love their pro amps, but I hadn't heard much about it from this site, and there are a few people on here whom I think are very smart. I guess it is getting a second opinion.
I see that for the same price of a 100 watt/ channel amp, I can get 200-500 watts. Big lure. Also, adaptability. If I get the stereo amp and it isn't enough, I can just add another amp channel or two, not an entire 7 channel amp. The noise isn't much of a concern. I am putting my amps in the cold storage behind a wall of concrete. The part about my pre not being able to drive the amps to full capacity is a concern. Is there a way to determine if this will be a problem? Also, I see companies, like Crown and Behringer, have a whole bunch of amps to choose from. Is there anything that I should be avoiding with any of these, or is it simply cost vs. power ratios? Can I basically use any pro amp and be okay, or are some types within the same company better at the job than others (Crown K series, vs. XLS vs. CL?)?
Lastly, I have read about the Behringer A500 and the Crown XLS series. Steve, if you or anyone has a list of others I could research, that would be great. I will try to limit my questions about them until I have done some research on each one. I really think the pro amps sound like a great, affordable, upgradable way to go.
Roly

[whoaru99]

I keep seeing these pro amp threads, and for the life of me, I still can't see what the attraction is... not trying to be contrary, just trying to understand if there's a discernible advantage that justifies all the workarounds... fan noise alone makes it a deal-breaker here.

What is it...
Price?
The opportunity to tinker?
The opportunity to thumb your nose at pricy amp mfr's?

It can't possibly be superior sound quality.

Or can it?... educate me.

Tinkering is some of it, but when you think about it, what is the desire of many stereo reproductions? To sound like live, yes?

What do most use for live reproduction? Mark Levinson, Krell, Classe, Halcro? No, they use Crown, QSC, Crest, etc.

Take for instance the K2 I rented. It cost me $30 to have for a weekend a 500wpc@8 Ohms amplifier. It is a "digital" amp and there is no fan noise because there is not a fan. My AVM 20 has XLR outs, so that was not a problem. Perhaps because I have dedicated outlets, I had no hum problems. This Crown was literally plug and play for me. The power and dynamic punch of this amp was incredible and I own several fairly powerful and well respected amps of the consumer sort. The K2 could have smoked my speakers (and almost did - never heard the woofers bottom before) and the clipping light didn't even flicker.

Nothing I say can convince you so I'm not really sure why I even responded. You can only try for yourself to see the results. I hope that preconceived notions do not limit your objectivity.

[Rolyasm]

Okay, I appreciate everyone's thoughts, but please, please, lets not let this get out of hand. I read one thread on this site about amps sounding different and it was a firing squad.
I like the idea of the upgradability and versatility, so I am almost positive I'll go the pro amp way unless something drastic changes my mind. So far my list to research is Crown, Blue Ice, Behringer and Crest. I really don't want to spend more than $2,000 for my seven channels of amplification, so if you have suggestions, please keep that in mind. Thanks so much.
Roly

[Martyn]

Roly, take a look at musiciansfriend.com and similar sites. You can look up all the major brands and models, and usually read owners' reviews. Bear in mind that lots of owners are using pro gear for pro purposes and thus might have different priorities, but you can read between the lines.

[SteveCallas]

The part about my pre not being able to drive the amps to full capacity is a concern. Is there a way to determine if this will be a problem?

Just avoid any of the amps that have an input sensitivity above ~1.2V and you shouldn't have any problem feeding them with home audio gear. It's the amps that have a sensitivity of 1.4V (which is common) that create some problems.

Also, I see companies, like Crown and Behringer, have a whole bunch of amps to choose from. Is there anything that I should be avoiding with any of these, or is it simply cost vs. power ratios? Can I basically use any pro amp and be okay, or are some types within the same company better at the job than others (Crown K series, vs. XLS vs. CL?)?

Some have better internals and more features than others, power aside. But as you move up into the lines, you'll find the 1.4V sensitivity basically becomes a standard.

Lastly, I have read about the Behringer A500 and the Crown XLS series. Steve, if you or anyone has a list of others I could research, that would be great

I use the Carvin HD1800 - sensitivity of 1V and very quiet fans. Other lines commonly used are QSC RMX and Behringer EP.

[---k---]

See if you can get ThomasW to comment on the Crown XLS amps. In the past, I beleive I have seen him comment that he isn't impressed by them, that Crown is trying to hit a certain price point. This may be for subs though more than mains. Mark Seaton has also told me to avoid the XLS for sub duty, so again does this apply to mains? I don't know. AVS loves the XLS though for its price.

I think if you are new to the hobby and don't have a golden ear that you probably won't hear the differance. That there are probably better areas to spend you're dollars that will make a bigger impact than an Audiophile amp.

But, once you have the best speakers, a treated room, and decent cd player, then maybe it makes since to start to look at amps fancier than the pro-amps.

I've look at Thomas's profile and a few others, and notice that they aren't using pro-amps for thier mains. This indicates a lot to me. But, I also know what all other gear that they have in the chain.

You have to go for the things that make the biggest impact first.

Try a pro amp, if you don't like it sell it.

[gd]

Nothing I say can convince you so I'm not really sure why I even responded. You can only try for yourself to see the results. I hope that preconceived notions do not limit your objectivity.

Nope, not at all... I was only asking, and trying to get a more practical perspective than what I've read in other forums... some of them can get overly fervent.

Like everything else, it can only be truly proven in one's own listening room.

Thanks for the replies, guys.

[Rolyasm]

---k---,
I was hoping Thomas would chime in because I am sure he has many experiences with these amps. I know this is a controversial, or opinionated subject, which makes it even more difficult to make a decision. I don't see a bunch of people all taking one side. Both sides seem to have pretty strong arguements and opinions.
Steve, thanks for the input voltage rating. That will help to guide me.
Roly

[---k---]

Yeah, it is tough. I think Steve is probably the only one to have done a side-by-side test and dared to discuss it on the differnt forums. It seems like the people who have the money for the expensive audiophile-style amps look down on the pro-amps, and vice-versa.

I tend to really agree with Steve. But, I also think that as you start perfecting things that the very very minor differances that weren't audiable at one point may start to be audiable. I think (and this is mainly my opinion based on prue pragmatisim) that very few of us get the speakers, position and room correct enough to hear the differance in amps, and those that claim they can are fooling themselves. But, there are a few that can hear a differance, and if that differance is worth the extra money to them, more power to them.

So far, I'm not spending the money on a fancy amp, but do keep getting tempted by something like Outlaw because it is a reasonable price and a small form factor for 5 channels.

[kgveteran]

The guy who got me into audio when I was in high school was a recording engineer on the side. He had some nice Vandersteens, Aerial Acoustics, Magnepans....etc....along with his Tannoy monitors. He always seemed to like his Ashly "pro" studio amps. He biamped his Vandersteens with a couple of them. I thought they were damn fine sounding....but then again, I was in high school.

Anyway. I am not saying one is better than the other. You have to judge that for yourself.

I'm starting a winter project.I'll be putting three Ashly Fet-200 in one chassis.They will be bridged and the big drawback for now will be that they share a dedicated 20a line.Ashly asured me no problem running 4ohm monitors if the bass is rolled of at 100hz.Why, I'm not sure.Actually I looked into some Mos-fet kits and they are real pricey.I could do little upgrades to the Ashly's for much less. I always like the sound of the Fet-200.It puts out about 385watts into an 8ohm load bridged.

I've asked about the Behringer 500a, but not too many reviews on it.I would like to do three of them for a six channel amp system.At about 159.00 each, thats a hell of a power house.

[Rolyasm]

Behringer Vs. Denon, my results

Okay, okay. Now before you all jump down my throat and tell me all the things I did wrong for this comparison, please realize that I DON'T review equipment for a living, I probably DON'T have the proper equipment and/or time to do this test the right way, and I DON'T offer this as advice or arguement. It is what it is.
Scenario: My Behringer looking at me from the confines of it's sub setup with 4 -15" drivers. It wanted to try driving my Polks and since I am considering some pro amps for my HT, why not. Out came the Behringer to its spot next to my Denon 3801. Did I mention this amp is heavy? Just so I can seem kind of scientific, here are the specs for my POLK RT800i: Freq. 42Hz-25kHz
-3dB, 8 ohm, 90dB efficiency. Recommended Amplification 20-250 watts.
I set up my mains only and listened first with my receiver. Using an SPL I set all my listening volumes to 90dB, which is louder than I normally listen to. I have a test CD I use that has pipe organs, heavy rap, Dido, Damien Rice, Black Eyed Peas, Ava Maria, and even though I really don't listen to her much, Brittany Spear's "Toxic" really has a good range.
I listened to about 1 minute or so of each song from the beginning, always keeping an eye on the SPL. I have to say I really like my Polk's. I would say they are rich, not bright, but not exeptionally detailed as I have recently noticed after hearing some THX systems like M&K, or even RBH T1. Anyway, on to the Behringer.
Wow, a complete difference. It was night and day. hehe, just kidding. I listened to the same songs, same SPL and was surprised there wasn't a huge difference. But there was a difference. To me the Behringer was more laid back, wasn't as harsh, or is it called sibilance? With the Denon, there were a few times when I thought I heard the speakers struggling. The bass got a little sloppier perhaps. It sounded like distortion. With the Behringer, I didn't notice that. The harsher songs were still a little harsh, but the songs that really shone to me were the more acoustical songs, like Damien Rice's "Blower's Daugher" and Dido's song.
Now it got more interesting. I invited my wife down. She knows less about this than I do. I know, scary. Anyway, I had the Behringer hooked up so I had her listen to it first. The lights were covered so she didn't know which one was playing. Same process. Listened to a few selected songs, then switched to the Denon while she went in the other room. I had some ear covers on by this time and just focused on the tracks and SPL. After both auditions, I asked her opinion. I could tell she wanted to please me and choose the amp, but she got it backwards. She apologized and said she liked the first scenario the best, which was the Behringer, but she thought was the Denon. Her thoughts were very similar to mine. She actually said she liked the bass better with the Denon on one song because it sounded "looser" or "fuller" and not as tight. She described it as the speakers sounding like they were going to shake out of the cabinet. She really liked the same songs for the same reasons and thought Brittany did a great job. With the Denon she said she heard more background noise. She said esses were essier and the harsh songs seemed harsher. I noticed on the Denon she actually covered her ears once or twice with the same SPL. After my disapproving look reminded her this was for science, she quickly removed her fingers.
Tomorrow we repeat the test. I will be very curious to see if we get the same results. Of course I know which is which. That is why I had her help. I will laugh if she determines the exact oposite in the morning, but I'll let you know.
Roly

[SteveCallas]

Now when you say you set listening levels to 90db, do you mean you used test tones to set each option at a master volume level of 90db, or with actual music playing, you averaged ~90db? If calibrated to 90db from the seat with test tones, and played at that level, I can definitely see the amp section of a receiver starting to have a few hiccups with dynamic peaks and bass.

[Rolyasm]

With actual music listening my SPL was reading 90dB. The only thing I adjusted was the volume level on the pre or receiver, both being the same.