Will my Krell drive a 2 ohm load?

Too stressful for that amp! Get a pair of active subs instead of the DWM panels. Cone woofers in a well-designed enclosure have superior bass over any planar!

Really too stressful? I would guess that if any amp can take it Kell would be a good choice.  However Subs would be ideal.

Not all Krell’s have the same capabilities. 

thanks for your opinions!  I have 2 REL subs in this system already. The DWMs are supposed to augment higher frequencies than the subs.

After doing a bit of research, it's hard to say what the answer is.

One clue is that the specs show a power rating for bridged mode only for 8 ohms, and not for 4 ohms. In bridged mode the amp would "see" a 4 ohm load as a 2 ohm load. So that is not encouraging.

Also, these measurements of the three-channel version of the amp, which is specified identically to the two-channel version in terms of power capability per channel, indicate that the amp falls somewhat short of doubling max power into 4 ohms (498.7 watts) compared to 8 ohms (294.8 watts), based on the 1% distortion numbers. That is also not encouraging.

On the other hand, though, the specified 8 ohm power rating for bridged mode is 4x the rating in stereo mode, which suggests that the amp has robust power supply and current capabilities. Also, I suspect that the impedance of the bass panels is much higher than 4 ohms at frequencies above the bass region. (You might want to ask Magnepan about that). So those factors are encouraging.

Regards,
-- Al

P.S:  I'm not sure what the reference in your initial post to an "active biamp setup" means.  That would seem to imply that there are two sterero amps.  Is that the case?

Regards,
-- Al

P.P.S: Ok, I see in your other thread that the Krell amp is only powering the bass panels of the Maggies, with a Classe amp handling the mids and highs, and with an active crossover ahead of the two amps. So that would seem to be another encouraging factor, since the Krell amp would only be handling a small part of the spectrum, albeit a part that often requires more power than higher frequencies.

Regards,
-- Al

jji666

Your Krell while good, isn't the typically pictured brute Krell that can drive a locomotive, or maybe a 2ohm load properly with conviction. 
I would say no to it driving that combined load well. The KSA150 type  Krell's would be better.

Cheers George

Thanks to all for the input.  I'm looking for a second one to drive the DWMs.  

Too much for the that particular  Krell.  A McIntosh MC-2300, 2500, or 2600 can drive a two ohm load as they are rated safely to .5 (half ohm).

I know, I had the 2300.  There wasn’t anything it couldn’t drive.

N

KSA or one of the Class A Krell Amps are what you are looking for....they will be a higher price point than one of the KAV amps which are part of their HT amps and processors series back in the day.

I have a classic KSA-80B driving my Apogee Scintilla One Ohm speakers.  That amp was made to do that, and does so superbly.  That said, I have recently ordered a pair of Vandersteen Model 3 Subwoofers to get the bottom octave and relieve the top end of the lower frequency power requirement.  I like the way the Sub 3's integrate with the main speakers.  When I get them installed I will be able to speak how they work.  Not sure about the KAV Krells.  Call the factory, they will be honest with you.  The KSA-100 or 150 would be good also.  I saw a pair of KSA-200's on audiogon and got me thinking.  Went with the Vndersteens instead.

Listen to George's reply above.  He has never steered me wrong.

You might want to try an Anthem P2 (stereo) or P5 (5 channel) they can drive anything down to 0 ohms (shorting) and do it all day.

You might want to try an Anthem P2 (stereo) or P5 (5 channel) they can drive anything down to 0 ohms (shorting) and do it all day.

Can you post a link to where it says that?

Cheers George

Panel bass is the best by far. Much lower distortion than a dynamic driver with better bass detail.  Unless you are playing a lot of rap or hip hop dont ditch your bass panels. I would grab a beefier Krell to do the job. Cone subwoofers sound like mid fi. 

Yes I’m interested in seeing what improvements might occur with the bass panels from the 20 series technology supplementing my 3 series Magnepans. I am not presently starved for bass. I love the sound of the bi-amped maggies and REL subs. But I am wondering if there is additional mid-high bass detail I could add without bloating the system. What I’d really like to do is run all 4 channels of the 2 DWM bass panels (probably at a very low volume per each panel), which causes me to consider doing this through a multi-channel amp rather than in parallel.

But of course that begs the question about how to get each bass signal from the active crossover multiplied by 3 to each amp input, and to be able to manage the gain for each input. It’s gonna look like someone’s pro-audio desk.

I didn’t realize the rabbit hole I’d jumped into when I bought those DWMs...

I also have a Classe CA-200.  I think that will handle a 2 ohm load but again not sure how well.  That would put the Krell running the mid/tweeter with the Classe on the woofers.  

Georgehifi,If you go to the anthem website and look at the specs section and look under power output at the bottom of the chart it states, Statement P2 and P5 amplifiers are stable into any impedance down to a short circuit at full output. You can also read the reviews where some reviewer placed a fork across the terminals and the fork got hot and vibrated until it fell off but the amp never shut down but just kept playing.

Yes it's not that they can drive big current down to a short, it has protection circuits that either switch the amp off during a shorted output or severely current limit it's output, not a great thing it's said for sound quality.
As you'll find amps like Agostino, Gryphon, Krell, ect ect don't use these types of circuits as they are said to be detrimental to the sound, but then they can also blow up if shorted.

Cheers George  

hook it up and find out 
 what's wrong with you? 
   Don't take that the wrong way big dog     

I did hook it up.  

Well, actually, I swapped out the bass and mid/treble in the biamping setup first, so that my Classe CA-200 was on the bass and the Krell KAV 250a was on mid/treble duty. The Classe is rated down to 2 ohms although it doesn't double into it. 

Without the DWM's resistors, it sounded horrible.  The Classe lost all control of the bass and it was just one big boom, no matter the level set on the crossover.  

Add the resistors and it is an entirely different story.  Much of the clarity of the bass is restored and the speakers just sound a little "thicker" and weightier.  The bass panels are not screaming, just adding a little oomph. Still needs work, some tweaking, perhaps separate amplification and full range input (bypass the active crossover) for the DWMs, but I can see that this has some potential for an improvement in the Maggie experience.

The Classe has been playing for an hour now and isn't hot...

Update:  been playing at low volumes for many hours now. Classe is still not hot (cooler than the Krell, actually) and my ears are adjusting to the slightly stronger bass.  

This needs to be better integrated and dialed in.  There's work to do.  But it appears that adding the DWMs is a worthy endeavor.  At least as a fun test.