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Discussion Starter · #1 ·
For all those who own a pair of the Magnepan 20.7's that's being used for music only and not theater use, can you please answer these questions for me if possible:


1) The dimensions of the listening room including ceiling height and whether the room has windows or not.


2) Space dimensions away from the wall if near a wall or window.


3) What volume levels are you using.


4) If your using a solid state or tubed amp.


5) What amp wattage are you using.


6) What type of music are you listening too.


7) What Ohm level are you using.


8) Are you listening in Stereo or Mono.


9) Amp brand connected to the speakers.



So many different reviews and setups out there on the net it tends to get confusing at times. Magnepan will not tell you what wattage is good for these speakers. They say it depends on your listening style and sound volume your use to. Also room size makes a difference. Also, some people push 10 watts through them and swear by the sound whereas others push over 1000 watts through them and also swear by the sound quality. Some prefer tube amps and others prefer solid state amps. So confusing...!


I'm just curious on what amps and amp wattages are being used for these speakers to help me decide; according to my room dimensions (11.7 feet wide, 19 feet long, 8 foot ceiling, carpeted floor, wood paneling walls, dry-wall ceiling, behind the speakers are windows so speakers will be about 16 inches away from the windows), what I may need.


I personally like to listen to most forms of music like hard and soft rock, heavy metal, classical, techno, Jazz, big band, some rap.



Also was wondering if adding one or two subwoofers will make a difference in some of my music styles.


I'll definitely burn a CD with some of the music I like to listen to and visit the Magnepan Factory to give a proper listen to a stereo, mono and solidstate and tubed sound before making the initial purchase.


But any help from any AVS subscribers in what I may need and your experiences with these speakers is greatly appreciated.


Thanks for your time and if you celebrate it, I hope you have a safe and fulfilling Easter.
 

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Hm, pretty quiet here... I stumbled across this thread.  I don't have 20.7's but I've used a lot of Maggies including 20.1's and their requirements are all pretty similar.

 

Maggies need to breathe.  16" from a back wall or windows is not going to cut it, period, end statement.  I would be shocked if any Maggie lover said anything to the contrary.  I wouldn't try to stick them closer than about 5' to a rear wall.

 

 

Ceiling height is not a big issue... 8' or 9' is fine.  I haven't tried them in anything higher, so I can't comment there, but "normal" heights are all born about equal.

 

 

The other thing that is relevant to Maggie performance in every situation I've ever had my own in and ever seen anyone else's in is the room "breathing".  The sound more open and natural if the room has a significant opening to another room/space, somewhat larger than just a doorway.

 

 

Wood paneling is probably not great, but with enough furniture and other sound traps (purpose-built or not) you should be OK in a room that size.

 

 

I listen to everything, so I'm picky about how set-up and equipment works for everything:  Jazz, pop, rock, classical, organ... whatever.  I like quiet--but not "unbalanced" quiet--in the evenings, and full-blast other times, so that also has to work across the full range of volume levels.

 

 

I probably only listen to stereo...

 

 

Amplification...

 

The best I can describe Maggies' amplification "needs" is that they do best with something that is "relatively high-current" for the amp wattage.  They've been great on 30WPC tube setups, as tube amps can generally really deliver current when required.  However, my favourite electronics for Maggies would be Musical Fidelity or Bryston.  I own an MF kW500 that is currently in-between Maggies as I don't have space where I'm living right now and planned to move to 20.7's anyways.  Anything that doesn't even _tend_ towards otherwise-inaudible soft-clipping (not even something that would be registered as soft-clipping by most) at the power levels you're running it at.
 

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I do not own 20.7's. Take these as general/generic comments.


IIRC Magnepan suggests 3' or so behind the speakers. This is due to their dipole nature; you have to get them far enough away from the back wall to reduce cancellations from their back wave. ESL's have the same issue. Or, treat the wall behind to dampen the back wave. That is what I do in my small'ish room to kill the back wave and allow me to place them closer to the wall behind. It will also improve imaging.


All Maggies act like line sources over most of their range. That means reflections from the floor, ceiling, and side walls are minimal. It also means a little more energy is directed to the listener so the fall-off in SPL with distance is more like 3 dB instead of 6 dB open-space.


30 W is the same current into the same load whether tube or SS. Tubes delivering high current is counter to my experience (I would have said high voltage but low current with SS being the opposite) but no matter. Maggies present a low'ish 4-ohm load but one that is pretty constant over frequency, no big peaks and valleys or large phase excursions typical with conventional speakers. The impedance does dip lower, to about 3 ohms IIRC, at HF due to the ribbon tweeter but it is still mostly resistive. So, you need an amp that will drive 4 ohms, and enough power to overcome their relatively low sensitivity. Look at something like http://myhometheater.homestead.com/splcalculator.html for an idea of the power you need. Choose "away from walls" and use the sensitivity rating (dB/W) in Magnepan's specs. The way they spec it is non-standard, but has the effect of increasing their rated sensitivity by 3 dB, which IME is a reasonable estimate compensating for their greater directivity than conventional speakers.


FWIWFM - Don
 

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Discussion Starter · #4 ·
Thanks for answering my question. I really don't know which avenue I will be going. I'm still doing research. I'm also looking at the B&W 805 speakers as well. Have a great day.
 

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Discussion Starter · #5 ·
Thanks for your reply. Before diving into these speakers, I'll need to visit their plant and drill the engineers while listening to some of my music generes to make a final decision. I can't seem to find any of the products on display in Pennsylvania near Pittsburgh. I'm sure as I venture out closer to Philly/New York, I'll be able to find them. Have a great day.
 

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The B&W 805's are quite a different beast than the Magnepan's. I assume you mean the latest 805 Diamond? Hopefully you can hear them both to compare. As for Magnepan dealers, there's a list on their website at http://www.magnepan.com/dealer_locations but I'd call the factory for the latest list.
 

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Quote:
Originally Posted by DonH50  /t/1525344/magnepan-20-7s-and-amp-wattages#post_24791393


30 W is the same current into the same load whether tube or SS. Tubes delivering high current is counter to my experience (I would have said high voltage but low current with SS being the opposite) but no matter. Maggies present a low'ish 4-ohm load but one that is pretty constant over frequency, no big peaks and valleys or large phase excursions typical with conventional speakers. The impedance does dip lower, to about 3 ohms IIRC, at HF due to the ribbon tweeter but it is still mostly resistive.
 

That's not exactly true.  If we were dealing with a DC circuit and resistance, not impedance, yes.  However, speakers and amplifiers are reactive.  When the speaker's instantaneous impedance is at a minimum, does a given amplifier continue to deliver more and more current?  This is what Magnepans seem to need:  A "bottomless" (again at the output wattage being asked of the amplifier) Class A or Class A/B amp.

 

Every tube set-up I've seen Magnepans driven with is run through a transformer.  This of course has its own implications as far as the transformers' nonlinear frequency response.  Again, however, tubes don't tend to "choke" on not-very-reactive (low back EMF) speakers like Magnepans.
 

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What? If I measure average power into a load of whatever impedance, then Pavg = Vrms * Irms still applies, at least when I went to school. If you want to expand into reactive power, load factors, and all that jazz, fine, but that is not the way most are used to seeing power reported. Also, when I said "no large phase excursions" that is based on measurements of Magnepan speakers. Their impedance is almost purely resistive except for a little blip at the crossovers, and a slight droop at HF as the ribbon takes over. They do not exhibit the large impedance (magnitude or phase) excursions of most conventional speakers.


Maggies, and panels in general, do have "back EMF" issues despite their mostly real impedance. However, for panels what is probably more a concern is modes in the panels that can cause distortion. Dropping their impedance by using more and/or thick wire might help but that way lies Apogee, a great full-range ribbon design but with obnoxiously low impedance (1 ohm is still an ugly load for most amps, resistive or not!)


I have seen and heard Magnepans (and other speakers) driven by both transformer-coupled tube amps and OTL designs (and a myriad of SS designs). Tube amps generally have fairly high output impedance and a rolled-off top end at full power due to their output transformer, plus the hysteresis and other non-linearity issues you mention. I love the sound of a tube amp on the midrange of my Maggies, but the bass is way better with SS and the highs are also better since the SS amp does a better job with the lower impedance. However, I don't think this is the thread to debate amplifier topology.
 

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Discussion Starter · #10 ·
Now I'm getting really confused. Now I don't know if I should concentrate on Solid State Amps or Tubed Mono Block amps.
LOL!
 

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Quote:
Originally Posted by DonH50  /t/1525344/magnepan-20-7s-and-amp-wattages#post_24792442


What? If I measure average power into a load of whatever impedance, then Pavg = Vrms * Irms still applies, at least when I went to school. If you want to expand into reactive power, load factors, and all that jazz, fine, but that is not the way most are used to seeing power reported.
 

Right, except the core of what we're talking about is how they sound given specific electronics.  So Pavg is... irrelevant.  We care about the net result of the reactance of the speakers+electronics, and of the amp's behaviour (not reactance) across varying instantaneous impedance, as far as it relates to what you hear.

 

 

 

John:  As much as tubes can sound nice with Maggies IME and IMO they're more of a hassle to get configured in a way that's ideal for Magnepans.  As I mentioned Bryston or MF amps are basically a free pass to "my Maggies sound awesome!"  The MF kW500 I purchased was purchased with the sole intent of using it for Magnepans, and IMO it does its intended job flawlessly.
 

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@phox: I think we are talking in circles. My core question was why you thought 30 W meant different current from different amplifiers and I think I understand where you are coming from. Any other discussion is just going to confuse the OP.


@Cigarjohn47: "phox" and I agree a SS amp would do the best job driving those 20's (or the 805's) if you are getting one amp and do not want the fuss and hassle of dealing with tubes. I have a soft spot for tubes but they can be a pain. IME a good tube amp will provide a gorgeous midrange but you will miss a lot of bass and the highs might not be as good. I use inexpensive Emotive amps with my Maggies but appreciate Bryston's performance and build quality if not their price. Magnepan used to demo with ARC equipment (Audio Research Corporation -- tube gear -- and ARC used to have Maggies set up in their factory showroom) but lately Magnepan has been demo'ing with Bryston.
 

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Discussion Starter · #14 ·
Then I guess the best way for me to go is to get both. Use SS for my rock music and Tubed for maybe classical and jazz (Swing).
 

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Classical can be very demanding, at least much of what I listen to (and play). Large dynamic range, and kettle drums and such take a lot of power. I love jazz, big band and small group, and again I prefer solid state for more realistic drums and bass. If you have the funds, Bryston is a great choice. If not, Emotiva and Outlaw are popular consumer choices, and for most bang for the buck I would personally get a Crown XTi series pro amp.


For context, I ran an old ARC D-79 tube amp for years, alternating and sometimes supplemented with various SS amps (using a crossover before the amps so the tube was on top, SS for the bass panel). I was a college kid for some of this time but worked in a boutique audio store plus as a tech and asst. installer at a couple of others. ARC (tube and SS), Bryston, Conrad Johnson, Krell, ML, PL, Threshold, Perraux, Hafler, Crown (pro amp), and various other amps rotated through my system; some I owned, some just for fun. I stayed with a hybrid ARC D-79/Counterpoint SA-220 system (using several different crossovers) for many years. The Counterpoint (tube front end, MOSFET outputs) did not match the bass of some of the other pure-SS amps but provided the best blend with my D-79. I eventually went SS full-range and am quite happy with the sound. Frankly, my advice would be to get a decent SS amp and enjoy.


The 805's and 20.7's are very different in every way. You really need to hear them both and then talk about amplification.
 

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I'll also chip in here:  Part of the reason for the kW500 I own is that it's a tube pre (in front of a big, ballsy A/B dual mono amp...) so I get pretty close to the best of both worlds.  Highly recommended (or the newer kW550) for Magnepans...
 

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I have a pair of 1.6q in a room about 2/3 the size of yours. The speakers are about 2 feet from the rear wall and about 18" from the side walls. The speakers are slightly toed in. After much experimentation, this configuration yielded the best bass reenforcement and imagery


I use a hk 75/ch stereo receiver. I have had excellent results with previous hk receivers and this one is no different. HK has a history of making high current fast amps with a wide frequency response. In fact they pioneered much of this long before it became trendy.


I listen to mostly disco with some reggae, classical, jazz, and lounge music in the mix. Sometimes loud but not earth shaking.
 

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CigarJohn47, I am glad you asked this and noticed that the thread was empty for some time with no responses. I listened to both the 20.7 and 3.7i's at the dealer and was wondering if I put the cart before the horse as I purchased a tube amplifier with a rating of 150 WPC via KT120 output tubes recently. Now I've been on a search for speakers and ultimately have settled on panel speakers due to their endearing sound quality. I now wonder if I should have purchased a different amp being of SS variety instead, or maybe should have purchased the speakers first.


Those that have better knowledge than I on this subject have commented and I was hoping they could shed some light for me too and I hope that I didn't hijack your thread as it is within the same vein/topic.


My listening habits are 90db peaks, but sometimes go to near 100db peaks. I can place the speakers maximum 5 feet out from front wall, side walls are 16 feet apart and it is an open concept dedicated listening area where the speakers see lots of cubic feet.


Do I have enough amplifier to drive preferably the 20.7? Or would the 3.7i be a better match? ... or trade the amp in for a SS unit?


Thanks
 

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Quote:
Originally Posted by moonw5  /t/1525344/magnepan-20-7s-and-amp-wattages#post_24794744


CigarJohn47, I am glad you asked this and noticed that the thread was empty for some time with no responses. I listened to both the 20.7 and 3.7i's at the dealer and was wondering if I put the cart before the horse as I purchased a tube amplifier with a rating of 150 WPC via KT120 output tubes recently. Now I've been on a search for speakers and ultimately have settled on panel speakers due to their endearing sound quality. I now wonder if I should have purchased a different amp being of SS variety instead, or maybe should have purchased the speakers first.


Those that have better knowledge than I on this subject have commented and I was hoping they could shed some light for me too and I hope that I didn't hijack your thread as it is within the same vein/topic.


My listening habits are 90db peaks, but sometimes go to near 100db peaks. I can place the speakers maximum 5 feet out from front wall, side walls are 16 feet apart and it is an open concept dedicated listening area where the speakers see lots of cubic feet.


Do I have enough amplifier to drive preferably the 20.7? Or would the 3.7i be a better match? ... or trade the amp in for a SS unit?


Thanks

That amp is no good, send it to me and I'll deal with it whilst you get a decent SS amp.



You'll probably be fine. It is a big enough amp to provide enough power and low enough output impedance to provide good bass. (No, probably not as good as a big SS amp, but I am not sure if you would notice a big difference, especially if you add a sub -- see below.) Check out this advice from my earlier post (#3): Look at something like http://myhometheater.homestead.com/splcalculator.html for an idea of the power you need. Choose "away from walls" and use the sensitivity rating (dB/W) in Magnepan's specs. The way they spec it is non-standard, but has the effect of increasing their rated sensitivity by 3 dB, which IME is a reasonable estimate compensating for their greater directivity than conventional speakers.


Here's where I depart from some others based upon my experience and my measurements: While the 20's claim 25 Hz (and probably do it) I have always found Maggies, and planer speakers in general (dynamic or ESL), fare poorly with LF content. Due to the way our hearing works most of the power goes to the LF's, eating up dynamic range/headroom in the amplifiers and the panels, and distortion gets very high. Due to limited excursion, at LF the awesomely low distortion planers (any type) offer in the midrange quickly degrades with large LF signals applied. You can also place the subs for best overall room response since that is often different than where the L/R speakers are placed. For those reason I have always preferred to add a good sub or two to handle the bottom octave or two. I have not heard the 20.7's, but I previously found that to be true for the 20 and 20.1 and have no reason to believe the 20.7's are different. It has to do with planer designs. I determined ages ago I preferred servo designs to best match panels and my current subs are Rythmik.


In your case, subs would also help fill such a large, open space and allow your 20's or 3's to take full advantage of your tube amp.


YMMV - Don


p.s. I never cared for vintage Mac SS amps, purely personal opinion. I just felt other amps at similar and lower price points offered much better sound/performance. The output autoformer seems like a good idea but IME causes problems by interacting with many speakers due to its load-sensitivity. Less an issue with Maggies, but... Boy they look nice, though!
 
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