Best 2 Channel Amp Choice?

[gregz]

A discussion from the Testing discussion room meandered into an amplifier selection discussion, so I thought I'd continue it here.

To make a long story short, I'll soon be completing two unpowered 4 ohm subwoofers that will be platforms for my mini-monitor speakers to make pseudo three way mains. The subs are rated for 150W continuous each, and will be operating from 20Hz to 100Hz.

For approximately $300, I have the following tempting power options:

*New Crown XLS 402 pro/DJ amp (easily modified to convection cooling instead of fan)

*Used Carver TFM-35

*Used Adcom 555

Is there a reasonable alternative choice I haven't considered? Which would you choose? The Adcom was quite strong in its day, but the Crown has the advantage of being new with no unknown past abuses.

What would you choose?

 

[WorkerBee]

Gee.....I'm not sure but there is about a 75 page thread about how good crown amps are over at the AVS forum I just read. My sub has an amp built in.

G o o d L u c k and Gregg, your avatar cracks me up seeing it turned sideways

 

[jzac]

http://forums.audioholics.com/forums/showthread.php?t=6780

 

[Mudcat]

Alesis RA-300

Give Alesis at try

http://forums.audioholics.com/forums/showthread.php?t=2380

http://www.alesis.com/

 

[WorkerBee]

When I do graduate to an amp or two the Outlaw monoblocks will be considered and I'll have that Alesis to check out too.....thanks guy's

 

[anamorphic96]

Decisions

Hey Gregz,

The Crown sounds like a good idea. Especially being new with a warranty. The Denon is no slouch and could run everything without breaking a sweat.

However your Denon is tried and true and has worked perfectly for you. So going with the Crown is probably the safest bet. Who knows when the Adcom might decide to toss craps. Warranties are great thing.

So are we gonna get any in progress photos of these subs your constructing. Throw us a bone.

Cheers,
Glenn

 

[gregz]

Thanks, workerbee, but actually I'm perfectly aligned: it's the rest of the world that's sideways

Glenn, you're right. I need to start a thread in the DIY section showing my progress... But progress has been so slow, it's kinda "embarraskin" as Popeye would say. My special order table saw with the 27" rip fence finally came in and got assembled, so now that all my vistors and family are gone I can really get to work again. I've got a whole kitchen renovation waiting for me to finish those speakers...yuck...maybe I should hold off a bit longer?

Mudcat, rumor had it on another thread that you were running some pro-amps, so I've been waiting to hear in from you. Those Alesis have the advantage of no fan by design, so I won't have to tamper at all - and they're comparably priced which is a big plus. Looks like AMS sells them, so I could try them with a no risk return policy.... Hmmmm.... That Alesis RA500 looks like it would do the trick:

250W RMS at 1KHz @ .02% THD should guarantee me at least 188W 20-20KHz; operating at 100W/ch, that gives me close to 3dB of guaranteed headroom plus whatever headroom the amp has by design which is at least +50W...

Not bad, not bad at all!

 

[anamorphic96]

I realized there is an error in my previous message. I meant to say the Adcom is no slouch and could power everything.

Out of curiosity how do plan to brace the cabinet. I have seen all kinds off methods such as radial, and post bracing.

Glenn

 

[furrycute]

Isn't the Crown a pro amp? If so, the Crown amp probably wont have the finesse of a good consume grade amp.

 

[gregz]

Glenn, the cabinet will be bisected by a skeletonized partition for bracing the longest walls, while a combination of cross bracing and internal ribs will take care of the next longest panels.

furrycute, you are correct that Crown is a pro amp. Some of those pro amps are supposed to be pretty darn good, especially when you operate them at home listening levels in their lower distortion range with occasional peaks. They operate at their highest distortion ratings when you're using a sound compressor to output maximum power constantly just beneath clipping as you would for a concert or dance.

Besides, my application is less critical since I'm planning on using a pro amp to power only my subs - which are much less demanding in fidelity than they are in power. I have a very well trusted amp that will continue run my monitors.

 

[BMXTRIX]

While I am not going to make a recommendation I will advise to stay away from Adcom.

In two different companies over 5 years I have seen over 50 different Adcom amplifiers have problems. I don't care how good an amp sounds in a store, if it has the quality of Yugo behind it then it isn't worth purchasing by anyone.

I was never disappointed with the sound of Adcom, but horrendous quality and engineering quality runs rampant from them and unless something drastic has occurred at their facilities, I will never recommend their products to anyone and will do exactly what I am doing now - STAY AWAY FROM ADCOM.

For those who have never had a problem with their Adcom gear, of course I am very happy for you. But, my experience comes from dozens of custom installs and seeing multiple failures repeated from their products. I'm thrilled that some people don't get bomb products from Adcom... but in my experience it simply is not the norm.

I have used and been very happy with both Sonance (bomb proof) and Crown. Crown has zero multi-channel theater type amps though. They seem very, very commerical oriented with 70 volt output on most of their stuff. But, they are also a company building bomb proof amps.

 

[Votrax]

Isn't the Crown a pro amp? If so, the Crown amp probably wont have the finesse of a good consume grade amp.

Crown has amplifiers for many applications. They have amps that exceed the quality of consumer amps easily, but you'll pay a hefty price for them.

 

[WorkerBee]

I'm thinking the Crown's {are} pro amps......a few of those people at avs have been unhappy with the noise associated with the cooling fans. That would be enough to scare me away, but on their website they do make a more expensive "fanless" amps. Two subs? man you must have a real need for some serious woofage

 

[cornelius]

Go for the Crown. Where I work, we have Alesis and Crown, among others, the Crown is much much better sounding than the Alesis. I would also stay away from Adcom. "Studio" and home amps is BS. Good sound is good sound. I've been in homes with Bryston "pro" amps, and major recording studios with old McIntosh power amps.

 

[HowY]

Looked at AudioSource...?

I kinda laughed them off until I needed a small monoblock
for a sub and a plate amp would'nt work (IB SUB)

The amp5.3 is a serious worker and they have now
released a 5 and 7 channel amps and still have
the multi-rack Amp5's

Self sensing on off circuitry and good power.

Just a thought

 

[gregz]

Two subs? man you must have a real need for some serious woofage

LOL! Actually, I run my subs REAL inefficiently in sealed boxes tuned for low, tight response. My boxes also run big for subsonic frequencies, so mechanical excursion would be brutal with just one speaker.

At this point, I'm thinking new is the way to go - especially judging from what I've read about all the Adcom iterations to address design durability issues.

I have the luxury of being able to borrow several different brands of pro amps from a friend, but I suspect that in my strictly woofer application, the audible differences should be negligible. If that's the case, a fanless design wins over a fan design that needs to be adjusted for quiet operation.

I appreciate all the input, I'll keep everyone informed on how it turns out.

 

[gregz]

Ok, this may seem stupid, but I tend to look at weight as an important indication of power handling (transformer), and the Alesis RA500 only weighs 28 lbs, which is the same weight as my 100W/Ch Denon amp. Ditto for the Crown XLS402.

Either my old Denon is massively overbuilt and can double its power output at 4 ohms, or somebody's cooking the books because these are all class A/B amps that should be somewhat in the same ballpark in efficiency.

The QSC RMX1450, in constrast, weighs a hefty 40lbs. That weight gives me warm fuzzies

Am I obsessing one dimensionally, or are my concerns about lighter weighing class A/B amps well founded? I ask because it sure would be convenient to buy the Alesis with no fan...

 

[warnerwh]

An old Parasound hca1200 or 1500 for under about 500 bucks and 200wpc each will do the job nicely.

 

[crashguy]

Go with the Carver, you won't be dissappointed. It will run a stereo 4 ohm load without breaking a sweat. I have owned 2 Carver amps, they rock. They run cool, no need for a fan, they are reliable, and they have high power.

Only bad thing is the meter lights tend to burn out. If you are handy at all, they are fairly easy to replace.