Doing some reading and looking at the components as well as the papers that the crossover is made from for the 3.6r, (I have a pair too and am in the process of trying to find the same sound as you Mikeand1, the Maggies have a4th order L-R Low pass at 280 (not 3rd order at 250) and a first order high pass at 200 which explains a lot reading through the Stereophile review of their measurements. The quality of components is bottom rate. A good passive crossover misses the greatest advantage of all active crossovers, there is no part of worry about over driving the entire amp into distortion and phase problems are not as serious, but these can reach 4.5 db higher than a single amp by ti-amping or even higher when it is just one channel at one side that is over driving a single amplifier. The other is that the amplifiers can be very accurate, articulate without having to spend your life savings.
Problems with ribbons. You must have a high pass filter one them or make sure that no DC can ever enter through the system to your speakers. The best active crossovers died in the mid to late 1990s (they are gold with the exception of Accuphase (Kenwood/Trio Lab group).
I am at 240Hz and 1700. The midrange panel is crossed over at 1200 and not 1700 as the impedance would drop below 2 (tweeter is 3.3 ohms and 4.0-4.2 for the midrange at 1700). If you wanted a two way one would have to calculate a 4th order otherwise, the dip at at 1300-1600 is considerable, the ribbon being a 12db/oct high pass Butterworth.
If you want output, you will have to go solid state and that is not so bad with a good TUBE FRONT END. Don't put a Transistor preamp in front of solid state power amplifiers as it sounds horrible and vice versa. I've had the quicksilver 100w amps with a Threshold preamp and that was terrible. Audio Research in front of a Bristol amp is a no go either.
The Maggie ribbon is surprisingly inefficient but at 1700Hz and above into 4 ohms (add a Dueland while you can of their best resistors of 1 ohm as everyone is cutting budgets and holding companies are buying out the best of what is the rest of reasonably priced audio (B&W really suffered component wise going to China but it is the bean counters that created their new and rotten crossovers).
I am still in search of a good amplifier that doesn't cost 3000 for a class a of 30-50w/ch. Some retro amps are looking real good here (Marantz 7 class A, 24 or Pioneer Series 20 30watt/ch and the latter gets VERY HOT and needs a fan but heats the house in the winter.
Spectral will do nothing to refurbish anything of their products and have little idea of the nanoseconds it takes for over several instruments to start on que in classical music or improvisational jazz for just a few.
A solid 100 watt amp like Benchmark (200 w/ch in 4 ohms) is ideal for the midrange and the low end is your own taste but need. This is where if you want slam, solid state and no passive crossover is needed so all the best the amplifiers can put out is directly to the drivers.
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Hello, Thought I'd throw in my 2 cents as I have a somewhat similar type arrangement. I too run dipole radiating panels and am "multi-amping" my speakers but in a slightly different way. Your 3.6's are great speakers (my first 'hi end' speakers were Maggie MG2B's over 30 yrs ago and afterward I was very happy with MG 3A's for many years). Yours are true 3 ways while my current planars are 2 ways (Apogee Duetta Sigs) which have a separate bass panel and a combined mid/tweeter ribbon. Your crossover scene allows true tri-amping which is very cool. I have what might be deemed "semi-tri-amping" wherein I use an external active crossover (an NHT X-2)to split my main signal at 50hz into a Rel sub, the remaining signal (call it 51hz+) feeds into another active crossover (a fully upgraded Apogee Dax 1) which then splits it into dedicated woofer panel tubed monoblocs (Conrad Johnson Premier 12's) and then to a dedicated amp for the combination mid/tweeter ribbon... This is essentially the equivalent of what you are describing you would like to try. Before I decided to run the mid/tweeter amp I had been using the CJ's and the X2 only, and after the sub relieved the bottom 50hz the CJ's did a great job...(this was utilizing the passive crossovers built into the speakers). Pretty simple, pretty direct...minimum complications and a very very nice sound. BUT, apparently like you, I just couldn't get the upgrade itch out of my mind so when this dedicated external crossover became available I thought I'd take the plunge and pursue the world of TRUE bi-amping...
The story is too long from here so I'll cut to the chase: after a LOT of pondering I knew I wanted tubes (that was never a question) but I also knew I wanted maximum flexibility and of course superb sound. Years ago I ran a pair of VTL MB-125 monos (into Silverline Sonata 2's = awesome combo) and since then became very enamored of the EL-34 tube... simply glorious midrange and a top that can extend as beautifully as the best out there, (especially when driving true ribbon tweeters as both you and I are). I've also appreciated the allure of running them in triode for certain types of music as well as some late night listening sessions but only as an option...full pentode or ultralinear is mandatory of course too. (The VTL allowed switching albeit NOT on the fly) and it was a nice feature.
What I eventually sought out for my application was an amp that could not only meet all of my requirements but in addition, was actually tube-TYPE flexible in case I felt the need to match the 6550's or KT-88's which the CJ's are using driving the bass panels. My answer finally became clear...an amp I had heard about 10 years ago at a dealership; it's a Cary, model SA 280 V12...(mine is an "i"model, F1 edition but that's not the point). It will run EL-34's, 6550's, KT-88's, and a few others as well...all at 100wpc ultralinear OR 50wpc triode as well as varying degrees of 1/3, 2/3 partial triode mix, and all capable of switching on the fly....And it sounds absolutely phenomenal doing dedicated midrange / tweeter duty...I think it would be well worth your while looking into this amp for your application. I will not attest to understanding the math of system/amp synergy in your rig, you will have to do your due-diligence to be sure the specs match up to the rest of your equipment but assuming that all can coincide together, I'm quite confident you will not be disappointed with its virtues...These include but are not limited to its spectacular soundstage, both wide and deep...complete lack of grain, tremendous sense of presence, air and natural timbres... a glorious sounding amp...
I really didn't plan on doing a review here (and I have no association with any brands/dealers/business in the audio field)...I'm just another A'gon addicted Lissnr...
Hope this expands your list of considerations by at least one more...but regardless of this particular amp or not, I would still pursue tubes to handle that tweeter of yours...remember: ribbons (especially midranges and tweeters) + tubes are pure listening bliss.
Good luck and happy Lissn'n |
class 'a'?
Pass xa30.5 clean 30x2 which near triples to almost 100 in a/b, both while nearly doubling into 4 ohms.
I wish I could afford Pass for my panels. I'd do so without even extensive audition and doubt I'd ever look back. |
"There's a Monarchy SM70 listed for $400 (no relation). Wouldn't hurt too much to try."
True, but I didn't much like the sounds of them driving my highly improved Audio Physic Avanti IIIs...very clean but rather uninvolving and a bit thin.
I'd look for smaller solidstate Class-A amps such as the 20-year-old Marantz MA-22 (50 or 75 into 8 or 4) or the more-expensive MA-24 (30 or 60 into 8 or 4). Even older would be a Bedini 25/25 or a Lazurus HA-1A, rated 50 or 100 or 200 into 8 or 4 or 2 Ohms. The Lazurus is hybrid, with a pair of 6DJ8s in the frontend and MOSFETS in Class-A in the output stage. I know of one Lazurus that I owned and a friend does that might be available.
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I don't think the amps are coming close to red-lining; it's the speakers, if anything. I get mylar slap and have to back off the volume long before I get anything like clipping from the amplifiers.
That's why I think it probably doesn't matter that there's twice as many watts for the bass panels.
I'd heard about the power ratings for the ICEPower modules, so I'm aware it's not really comparable to the ratings for something like Pass Labs amps. |
The reason I bring up relative amp power is that for someone like yourself, for which too loud is NEVER loud enough, you theoretically want both amps to redline at the same time. You can always turn the 'louder' amp down, but did you turn it down because it was too loud relative to the other freqs or distorting...ran out of juice? or the panel is at redline? You may end up needing an SPL meter and a calibrated disk, like the one from RIves Audio, which is a match for my RadioShackup analogue meter.
Extreme example. Your kilowatt amp on the lows. coupled with say.....100 watts on the highs. Kilowatt amp doesn't get out of first gear while the 100 watter is off scale. You're looking for the highest peak power without clipping.
Now, something you might NOT know about ASP modules and 'd' in general. They rate power for SHORT TIME PERIODS.
http://www.icepower.bang-olufsen.com/en/solutions/speaker/ASP_SERIES
Go to link an poke around in the data sheets. you'll find the kilowatt amp is that lofty 1000 watts....for 30 seconds. The 500? Time limit is 60 seconds. Both are limited by cooling. Run 'em upside down in some LN2 (liquid nitrogen) and you could get away with it for far longer.
I think that amp amps is sort of a red herring, but may be wrong, if someone can tell me why. It would seem that in order to keep from running the power devices out of the save operating range, you'd have to run that high an amperage at some very low voltage. After all, 40 amps at 50 volts is 2000 watts. My 1.6s have a 4 amp fuse and crossover about 600hz. If thats near the 50:50 point (it's a little high) I'd have to call the entire panel 8 amps MAXIMUM. I'm not going to do the math. My head is killing me from a long day, but you can work out the power. If you don't know off the 'topofyourhead', look up ohms law calculators.
I have measured voltage to my panels using a DVM. This is NOT accurate at all, but I double it and call that 'peak'. Music is much quicker than most meters. If I had access to one, I'd use an O'Scope. Preferably one with 'peak capture'.
Good for you that you've never blown a fuse. In maggie circles, the ribbon is known as a fuse protector. |
Oh, and I've never blown a fuse, so far.
I'll have to pick up a voltmeter to answer your question, I don't have one, and I don't know the answer.
Supposedly, peak output on the 1000ASP modules is > 50 amps (yowsa). Not sure what it is on the Bel Cantos, but it's substantially less -- probably around 20-30A.
Re what's left of my ears: I have to play it loud to drown out the tinnitus! |
What difference does it make how many watts I have on the bass panel relative to the mid/ribbon?
Keep in mind, with the DEQX unit as my pre-amp and crossover, I can set the volume level of each independently. So as long as I've got a sufficient number of watts for each, why should it matter that I've got 1000 watts on one, and 500 on the other? I can still get a flat frequency response just by matching the volume levels. |
Yes, I believe in the biamp setup, that the 500 is underpowered relative to the 1kw, with the crossover at 200hz.
For 'average' music, the 50:50 point is about 350hz. So, with an even lower crossover it may be 45:55 or perhaps worse.
I'd start by using same amps on the 2 sections....
Now, I'd also measure power output to the panels, even as crude as a DVM. I think the power rails in those amps is what.....80 or 85 volts?
Have you popped a fuse.....yet?
The noise you hear is mylar slap, basically the panel 'bottoming out'. Not recommended, as a general rule.
I don't know that 20.1s play much/any louder. Just move more air and so can couple to a larger room. The NEW 3.7s may have better frequency balance or sound better to whats left of your ears.
If you got the loot to just toss out that you may 'need to upgrade to the 20.1s.....' I'd suggest taking the cash and up-amping to a brace of Pass amps. Don't get me wrong, I, too, have a 'd' amp. And while I'd love to have the pass INT-150, I'm sticking where I'm at and will do room tuning before turning to the bottomless pit of bi/tri amping with the thousands of adjustments.
Keep us posted on your progress. |
There's a Monarchy SM70 listed for $400 (no relation). Wouldn't hurt too much to try.
Frankly, wrong speakers for the application if you want "farting" level SPL's. Staying dipole/planar, there's Genesis and VMPS (RM60/sub, Supertowers) for that and you can still use the correction of the DEQX and parts of the active crossover (up to 120 Hz high pass for Genesis). |
Well it's not that I don't like my current setup, just trying to improve on it. I thought there was a big improvement when I moved to a bi-amp setup, and I'm thinking tri-amping would be another step up.
It's my general impression that tube amps are known for their sweet highs.
I totally get the point about less power being necessary for the higher frequencies. I was thinking I wouldn't need anything near 125 watts, even with the crossover at 1.7khz.
And do you really think I'm underpowered with 500w per channel on the mids/ribbons right now? I'm surprised to hear that.
BTW, re the "farting" -- if you turn up the volume loud enough, peaks in bass will cause the panels to "rattle" or emit an unpleasant "thwapping" sound. At that point, I know I have to back off, and that's as loud as I can go.
I'm about to move into a bigger room. Wonder if I'm going to need to upgrade to the 20.1's... |
I was just floating the idea that power needed is related to the crossover frequency. 10k was an extreme example and used to illustrate how little power is needed above very high crossover frequencies.
If you had the perfect amount of power per 'way', they'd all redline about the same loudness.
I'd generally stick to the stock crossover points. The folks in WhiteBear Lake spend a bunch of time getting that part right.
You say you like 'd'amps. I have one, too. So, I've got to ask, what do you NOT like about your current setup? Why do you think tubes are the 'cure'?
Several higher power tube amps may do. ARC would be on the short list, since many panel owners use and like them. |
Gahh... typos.
"factor setup" -> "factory setup", meaning Magnepan's own crossover point is 1.7khz between the ribbon and mid panel. |
PS - I just figured out your name isn't Bill... |
Bill,
Thanks for the advice. Until recently, I had the crossover closer to 300hz. But I experimented with it a great deal, and putting it at 200hz seems to make for a much tighter and faster bass. (That's also the crossover freq used by Magnepan.)
I'm amazed to hear you suggest the ribbons should be crossed at 10khz. I was thinking something around 1.7khz, which again is what the factor setup uses.
Have you tried this?
BTW, I really like the Class D technology, and would be reluctant to move to Pass amps. I think Class D sounds great with Maggies, and I like the lower power bills, less heat, smaller size, etc. |
Given the low crossover of 200hz, I'd say the upper freqs are under powered, especially for someone who like to crank 'em until just short of farting....however loud THAT is!
The 50:50 power point is around 350hz for 'average' music. Right now, I'd suggest your REF500s are running into the wall sooner than the 1000s.
It's not that the ribbons are more sensitive and not needing 'much' power, but that the music above the crossover contains less and less energy, meaning you don't need mondo amps to run it, just electrical compatibility.
Another ICE amp would work for tri-amping....just keep the power to frequency spread within reason for the crossover. IOW, if you cross to the ribbon at 10khz, you may only need the 125 watt module. At that point, the 500 for the mids would drop back into line.
If I had your level of bad habit, I'd think seriously about with Pass amps. If you insist on sticking with the bi-amp setup, a selection of 'a' amps would work fine.
Happy Electric Bill. |
