Pass Amps do quite well into 4 ohms--, I am using an Aleph 5 into Totem mani-2s
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It takes a monumental experience in audio for me to be impressed with an amplifier. I use 4ohm speakers that dip to a solid 2ohm in the bass. The BRYSTON 4bsst is just amazing. Neutral to your source component but wait a minute.... I have re-read your post. 60x20 room. Not a problem get the 7bsst mono amps and don't look back. Seriously, I never thought of ever owning/listening too etc. a Brytson amp. Mty dealer lent me a 4bsst as a stand by amp- but after a month I want to buy one. Been doing this for a LONG time. These SST amps are extremely musical.
Brace yourself or skip over reading my post if you are only looking for "nice words". I would rather "tell it like it is" and let you sort things out for yourself. At least with this approach, you know what you're dealing with and what to expect.
First of all, you're going to have problems with your speakers in terms of trying to place them and achieve relatively flat response in the bass / mid-bass region. The overall design, in specific, the placement of their woofer, is far from optimal. You can't mount a single woofer up that high and have it work properly.
Secondly, you should do some research of your own on the subject pertaining to what amps do well into lower impedances. Some of the amps mentioned here really don't do well into lower impedances. This has been covered in these forums and a magazine review also.
Thirdly, when looking at power ratings of an amp, look at what the amp clips at into various impedances, not what it is rated at. This will give you a better idea of how sturdy the entire amp ( both the power supply and the output stage ) really is.
Fourth and lastly, that is a BIG room. If you expect to generate high spl's there, your speakers will be eating power from an amp like a stranded survivor on an island would eat a bag of M&M's that drifted ashore. Take that into consideration. Not only will the sound be cleaner, but you'll have less chance of driving the amp into clipping and / or damaging the speakers from the associated distortion. Sean
Audes Blue in a 60'X20' room is a BAD idea! This speaker is more suited to a 14'X24' type of room at the most. You probably cannot generate enough SPL to "fill" your room. To do so, you'll probably be playing with very loud volumes, the excursions on the woofer are going to be very large & in a short time (a month I guess, if you are lucky) you will need new tweeters as you probably will be running close to max. power into them! The specs say max. long-term power=130W & max short-term power=200W - using the short-term power #, this will generate 104 SPL @ 3m & using the long-term power, this will generate 107dB SPL @ 3m. Doubling the distance (to 6m) drops the SPL by 6dB. This speaker is only 47" tall & goes down to ONLY 45Hz (+/- 2dB) with one small-med 8" woofer.
At any rate, another amp that does well into 4 Ohms is the Clayton M100 but it is only 100W/ch. The bigger amps S2000 or M2000 are much more powerful - 600W/ch into 4 Ohms & 1000W/ch into 4 Ohms. However, they are expensive (but damn good)!!
I think you need to get much bigger speakers (for eg. PBN Montana XP, KAS or WAS, one of the larger Dunlavys or JM Lab Utopia or the GR Research Alpha LS)if you want to fill the room. A better idea might be to section off the room so that you can create a much smaller space into which the Audes Blue can play. This will make you *much* happier!
I tried to use Maggie 3.6's in a 60' X 28' room and partitioned it down to 45 X 28 for better results.
I've been using a pair of Cary V12i Monoblocks with the 3.6's, having tried various SS amps such as McIntosh and Belles. The Mac ran out of steam at modest levels (200 watts into 8 and 4 ohm) and the Belles sounded too bright for my tastes.
The Cary's are good, great in fact for smaller scale music, but I fealt that the stage width/depth was somewhat smaller than it could be.
A few day's ago one of the Cary's blew a fuse, leaving me potentially musicless through the holiday. I went to my local dealer and picked up a 20 year old Perreaux 2150B that he had collecting dust. My thoughts were that any sound is better than no sound.
When I hooked up the Perreaux......what a revelation!
The speakers just dissapear and the stage width is incredible. Dynamic contrasts such as those playing Big Band music are incredible...the bottom end control is excellent also.
Anyway, I'm now looking around for a more modern Perreaux and may eventually try a Marchand x-over with the SS on the bottom end and the Cary's on the treble. Or I may just ditch the Cary's and use a Perreaux 3150 or something newer from their range.
Incidentally, I've found very little on the Perreaux amps here at AG, some comments from Sean who was/is using them to drive subs, but no detailed comparisons between different models in the range or comparisons with other amps capable of delivering high current into difficult loads. I can't find any feedback on the more modern Perreaux's either, just a couple of threads on the 3150B
Anyway, right now I would highly recommend that you check out a Perreaux amp for your 4 ohm speakers.
Any Perreaux owners out there?
Have owned a Perreaux PMF1850 (180 watts-8 ohms, 330 watts-4 ohms)since 1985. It's driven Acoustat 2+2's with no problems and is currently driving my Martin-Logan Aerius i's. It's an awesome piece of equpiment and if you can find any of the Perreaux's of that vintage used, snap it up. Like they say, takes a lickin' and keeps on tickin'.
Rooze: Glad you're "temporary fix" worked out as well as it did for you. Nothing like a pleasant surprise, huh? : )
As you noticed, i have a couple of Perreaux's that i use for subwoofer duty. Both are 3150's and run in the same system driving eight NHT 1259's ( two per channel ). I've had other Perreaux's, but these two seemed to work best for what i wanted out of them. In comparison to the 2150's, the sound is much smoother and warmer with far greater authority on the bottom end. Even though these amps look the same externally and even quite similar internally, there are some very noticeable design revisions that differentiate one from the other ( other than power output ).
Tvad: The earlier Perreaux's didn't have any type of protection circuit other than fuses on the mains and in the rails i.e. no speaker protection due to signal degradation. I think that after Peter Perreaux sold the company, there were other designers involved and the products changed markedly. As such, i wouldn't expect the same sonics or performance from later Perreaux models as what was delivered from earlier models. I do know some folks that had some of the newer models and from what they told me, the bass performance still seemed to be intact.
From what i've gathered here, everyone that seems to be reasonably happy with this product line are using the original models that Peter designed i.e. the 1150, 1850, 2150, 3150, 5150, etc... Having said that, even amongst these amps, sonics do differ.
El: While i stopped following the thread, the test results that John Curl posted on the Carver Pro ( no relation to Bob Carver or Sunfire ) amps leads me to believe that they are far less "potent" than what the spec's would lead one to believe. If memory serves me right, these amps were going into oscillation at 180 wpc @ 8 ohms. Even if their power supplies were up to the task, that would only equate to 360 wpc @ 4 ohms under ideal conditions. Given the lower impedance and the fact that most amps become less stable as impedance is dropped, even that figure may be somewhat optimistic.
JHoriwitz: All of the speakers that you've mentioned are known for being "tough loads". The fact that the "little" Perreaux has been able to drive them to your satisfaction is quite a statement.
As a side note of similar nature, there was someone on Agon that used to run two 2150's in bridged mode to drive Acoustat's. Given that Acoustat's drop below 1 ohm and a bridged amp sees half of the speaker impedance ( 1/2 an ohm ), i think that says a LOT about the ruggedness and reliability of the older Perreaux's in general.
As far as the comments made regarding Pass designed amps, my experience is that they sound better at low impedances than they do at higher impedances. If you can find one that has a suitable power rating, that would seem to make these amps a good candidate for what you are looking for. Sean
I was under the impression that Nelson Pass recommended his 3 stage Alephs for loads below 4 Ohms but not his 2 stage Alephs. As for me, I must be the odd bird here who prefers the sound of the X series (which with out regard to power requirements shouldn't challanged by the 4 Ohm impedance) to the Alephs. I haven't heard the newer XA series yet.