[kevin360]

Dave, if my understanding of the meaningful benefit inherent in a series topology is correct, it's essentially wasted on Maggies as the impedance of their drivers doesn't vary radically with frequency. I suspect 'permitted' may be more appropriate than 'forced', but that's just a guess. Regardless, the 3.7 has a much simpler XO than the 3.6, which I think is good (if one is going to keep the speaker-level, passive, that is).

[rw@cn]

<<snip>>
If I may speak on behalf of the ridiculously expensive for a moment, may I proclaim that I adore build quality? My experience with a wide range of amps confirms Josh's statement about the sonic differences between well-engineered amplifiers – not much. I was shocked at how much the VAC sounds like the Pass, (tube to solid state) but also at how close the two Pass amps are to one another, as well as how similar they sound to an Acurus and a Parasound amp I have. It's a hell of a lot of money for subtle improvements, but the build quality is a different matter – even the Pass amps fall short of the VAC in that metric.

To make a sweeping comment which implies that one must spend huge sums of money for an amplifier to very satisfactorily drive any pair of Maggies is ludicrous, but it may be that the last little bit of refinement does cost pretty dearly. My system has never sounded better than it does right now.

This is not meant to be argumentative, but what do you consider "huge sums of money"? To me both the VAC and Pass amps are huge sums of money. Somewhere around the price of a Pass 350.5 is my ceiling. Somewhere around that price point amplifiers seem to sound much better on my speakers (Logans, 1.7s and 3.7s). This is from a limited sample of 8 or so amplifiers listened to in my home. And no I don't believe I have golden ears.

I agree with you when it comes to build quality and extend this to design quality. It is my belief that a manufacturer that takes the time to build an exquisitely looking product is very likely to take the time to design and implement an exquisitely sounding product. It is often the subtle differences that are important. Being able to hear those little details that are often obscured or missing in some products is important to me. I want to hear as much of the music that can be wrung from the media. Well, as much as I can afford. 

Perhaps this is why you prefer the VAC to the Pass product? 

[medium jim]

I don't think the QR bass-mid would force series crossover use.....or vice versa.  Previous (non-QR) speakers used a series crossover, and current QR (tweeter-only) speakers use a parallel crossover.  However, the series crossover does prevent bi-wiring, passive bi-amping, and other types of fiddling that (maybe) Magnepan was uncomfortable with.

Contrary to popular belief, series crossovers have no inherent "magic" or any other qualities that allow the laws of physics to be breached.  A parallel crossover (configured equally) will create the exact same tonal balance as a series crossover.

Nonetheless, it would still be interesting to take a look at the series schematics.

Cheers,

Dave.

Dave:

Which is more cost effective and or fool proof, Parallel or Series?  I also tend to think that Magnepan was absorbing some warranty costs due to some aftermarket DIY and needed to do something. 

From a marketing standpoint, they potentially could offer them in both configurations to satiate all of their customers. 

Boy what Kevin notes is very true, you can take a path to acheive 99%, but that last 1% can be rather expensive. 

Jim

[Davey]

Well, neither is fool-proof, but parallel crossovers provide a few features that series crossovers don't.  (Independent adjustment of each filter section being the most important.)  There isn't any advantage one way or the other cost-wise unless more components are needed.

Most folks don't think of this but, Maggies by their inherent nature already create a crossover between drivers (a mechanical one) before anything electrical (in the crossover) is even hooked up.  You can easily see this by driving one transducer and monitoring the other with an oscilloscope or suitable meter.  (Obviously I'm not talking about true ribbons here....those are separate transducers.)
This is a form of "built-in" IM distortion.  Maybe a good thing....maybe bad. 

When you start talking costs of support equipment for Maggies, the topic can get extremely nebulous and muddled.  Much subjective evaluation comes into play and that (by definition) renders most opinions meaningless.

Cheers,

Dave.

[rw@cn]

When you start talking costs of support equipment for Maggies, the topic can get extremely nebulous and muddled.  Much subjective evaluation comes into play and that (by definition) renders most opinions meaningless.

Cheers,

Dave.

I think "most" and "meaningless" are harsh words here. 

[kevin360]

This is not meant to be argumentative, but what do you consider "huge sums of money"?

Oh, I quite agree with your assessment that the VAC cost a huge sum of money (feel the same way about the Pass). Actually, even used, at less than half of new retail, I think it was a huge sum of money. I can also assure you that it was not necessary to spend that kind of money for the satisfaction I have - I was, after all, just as satisfied before buying the valve amp. I just wanted to give tubes a try and I had some money that I didn't mind spending. It's all part of my mid-life crisis!

I bought a convertible (but its top has to be removed (and left behind )) sports car too. Isn't that what a guy in his 50s is supposed to do?

What might have gotten lost in my previous post is that, without a direct comparison to..., I could be quite satisfied with a number of different reasonably priced amps driving my 3.7s - still could (though, it would take some readjustment).

I tried lots of amps with the 3.6s (only experiment towards that end with the 3.7s was the switch to valves) and several sounded practically indistinguishable. The biggest surprise I got was a Bel Canto - that little ICE amp sounded very good and had plenty of swing. I hadn't heard a high-efficiency design in ages; I thought the last one I heard was awful. My expectations were pretty low. I was wrong. Heck, there are lots of amps with which I could be very happy, but I think I'll keep the one I'm using right now.

[Rclark]

I think "most" and "meaningless" are harsh words here. 

Davey can be a pretty harsh guy.

[rw@cn]

Is he one of the Asylum guys expats? 

[rw@cn]

Oh, I quite agree with your assessment that the VAC cost a huge sum of money (feel the same way about the Pass). Actually, even used, at less than half of new retail, I think it was a huge sum of money. I can also assure you that it was not necessary to spend that kind of money for the satisfaction I have - I was, after all, just as satisfied before buying the valve amp. I just wanted to give tubes a try and I had some money that I didn't mind spending. It's all part of my mid-life crisis!

I bought a convertible (but its top has to be removed (and left behind )) sports car too. Isn't that what a guy in his 50s is supposed to do?

What might have gotten lost in my previous post is that, without a direct comparison to..., I could be quite satisfied with a number of different reasonably priced amps driving my 3.7s - still could (though, it would take some readjustment).

I tried lots of amps with the 3.6s (only experiment towards that end with the 3.7s was the switch to valves) and several sounded practically indistinguishable. The biggest surprise I got was a Bel Canto - that little ICE amp sounded very good and had plenty of swing. I hadn't heard a high-efficiency design in ages; I thought the last one I heard was awful. My expectations were pretty low. I was wrong. Heck, there are lots of amps with which I could be very happy, but I think I'll keep the one I'm using right now.

You know, when I was younger I said many of these same things.  And sometimes I actually meant them. 

In retrospect, I could live with some of the amps that I have listened to. But it would be nice to have my cake and eat it too.

[Davey]

If my opinion is too harsh, you can always ignore it.    I'm not harsh, I just don't tolerate any BS. 

Anyways, I'm not sure why this particular one is too harsh.  Subjective evaluations are (by definition) meaningless to anyone other than the person who did the listening.  A subjective opinion is beyond a basis of general discussion....at least initially.

Over time, folks who have listened to many similar systems (or equipment) can more easily compare opinions (so to speak) and possibly form the baseline where one's opinion might be accepted by the other without a subjective evaluation.....or vice versa.  I can think of a grand total of about three people who's opinion I would accept without first-hand knowledge.  (And none of them are on this forum.) 

But as a general rule, I can't take on faith anyone's opinion on the sound of a system unless I've experienced it myself.

Is that a concept that's too difficult to understand?

Cheers,

Dave.

[medium jim]

Dave:

Howard Cosell would have a hard time with this crowd, so don't fret my friend.   I especially loved the Asylum expat comment. Inference, this is our beach and youi're not welcome, nice!

Jim

[josh358]

I agree about the speakers, but I would add that once you have settled upon your speakers (especially maggies) finding an amp that suits you (and your finances) isn't easy. 

I have tried a number of amps at home and can attest that they sound different. Not as different as various speakers, but different enough to warrant careful selection. These maggies (while not a difficult load as the old Logan CLS) can make an unsuitable amp sound pretty bad when stressed. Also there are a number of amps that just don't like the 4 ohm load.

No question that Maggies are sensitive to amplification because while they're a largely non-reactive load, they're inefficient, revealing, and needs lots of current. To make things difficult, needs vary tremendously. 1000 watts is only twice as loud as 100 watts, and so there are endless debates about how big an amp you need. The key word there is *you*!

To confuse matters more, people are always being mislead by those Radio Shack meters, which are average rather than peak meters. Watching the output of an amp with an oscilloscope will tell you whether it's clipping or not. With a Radio Shack meter, you have to guess (add 10 dB to the reading is usually a pretty good one).

Then too, RMS specs don't tell you what you really need to know, how the amp does on the peaks, which are much higher than the RMS level. Amps vary in this regard. They vary in recovery when they do clip. And tube amps can be pushed a lot harder before clipping becomes offensive.

So, lots of arguments . . . and that's just power.

I don't think I've ever heard two amps that sounded the same to me, either. They all have their character and quirks. I do think you can find good amplification that fits your needs if you shop carefully and look for "bang for the buck" stuff or buy used. I think Satie's approach is a great one and I'll likely end up doing something similar. You can get a big pro amp for practically nothing and it's going to do great on the bass. Then get something smaller and sweeter for the highs.

Some day, it will get bass duty, but for now, I'm just going to use my XPA-2 full range while I experiment with placement. Have I heard better amps? Sure. Is it so good that I'd be happy using it forever? Yes. (Of course, I'm not Tonepub, I've never had $10,000 amps on my Maggies. I've always found that once I get used to something, I miss it on some level when it's gone, e.g., I've enjoyed my MMG's immensely, but they're never going to replace my old Tympanis.)

[josh358]

Maybe you could ask Wendell, but do you know what the Magnepan policy is for making schematics available to the public?  It would be interesting to take a look at the new schematics for the 1.7, 3.7, etc.  I haven't seen anything anywhere.

Sure, I'll ask him. I'd be curious to see them as well. There is a schematic of the 1.7 on the Magnestand site, it's hand-drawn and a bit hard to follow but it does seem plausible, it looks like a single pole series crossover with the supertweeter segment .5-wayed. Didn't we discuss it back on the Asylum?

I have no idea what's in the 3.7 but it looks like its electrically still a three-way, at least, I tried to count wires in the picture, it was pretty fuzzy so I may have counted wrong. It also seems to be .5-wayed, but this time between the woofer and midrange and done acoustically, via the tuning buttons -- as in the Tympanis, but on one panel rather than two. And I've read that the electrical crossovers are also 6 dB/octave, though I'm not sure if that's true throughout -- I read that in one of the reviews and you know how inaccurate those can be.

[SteveFord]

Johsh,
I don't know if you'd get the same holographic effect with a powerhouse pro amp/tube combo as you'd get with just big tube amps alone.
Not pro gear but SteveK went from biamping with 4 VTLs to Class D amps (I believe) and gained with lower costs and noise floor but lost ground with the 3D sound.  That's paraphrasing from memory so perhaps he'll chime in.
The alarm still goes off at 5:30 AM so enjoy your evening.

[josh358]

Dave, if my understanding of the meaningful benefit inherent in a series topology is correct, it's essentially wasted on Maggies as the impedance of their drivers don't vary radically with frequency. I suspect 'permitted' may be more appropriate than 'forced', but that's just a guess. Regardless, the 3.7 has a much simpler XO than the 3.6, which I think is good (if one is going to keep the speaker-level, passive, that is).

This is my pet theory on why they chose the series XO for the 1.7 -- the impedance does vary because the supertweeter segment is much shorter than the tweeter+supertweeter together. And a single pole series XO will maintain constant amplitude response. Otherwise, you'd need a Zoebel network, and that would be expensive plus you'd have to fit it in.

[medium jim]

Steve:

My experiences support what you have noted, tubes produce a holographic 3 Dimensional Soundstage better than SS.  Again, this is what I have experienced and other may have different experiences.

Bass is typically better with SS and supports the camp that bi-amps.  As noted earlier, I employ a pair of subs that reinforces the bottom 2 octaves.  The amps for the subs are class a/b SS and integrate very well with my Maggie's. Effectively, I'm bi-amping by proxy.

Jim

[josh358]

Johsh,
I don't know if you'd get the same holographic effect with a powerhouse pro amp/tube combo as you'd get with just big tube amps alone.
Not pro gear but SteveK went from biamping with 4 VTLs to Class D amps (I believe) and gained with lower costs and noise floor but lost ground with the 3D sound.  That's paraphrasing from memory so perhaps he'll chime in.
The alarm still goes off at 5:30 AM so enjoy your evening.

That's an interesting question. Satie may be better able to answer it than I can. I've heard lots of explanations for that tube 3D effect, even come up with some hypotheses myself, but on this I'm like Dave with subjective listening opinions -- I don't know whose explanation to trust. And since I don't have an explanation, I'm not sure if it affects the entire frequency range or not. I do know that the obvious flaws I hear in bipolar and D amps tend to be in the upper mids and highs, particularly in cheap or poorly-designed amps, many would say large ones as well. So that was what I had in mind when I spoke of best of both worlds.

Off to sleep myself pretty soon . . .

[josh358]

Most folks don't think of this but, Maggies by their inherent nature already create a crossover between drivers (a mechanical one) before anything electrical (in the crossover) is even hooked up.  You can easily see this by driving one transducer and monitoring the other with an oscilloscope or suitable meter.  (Obviously I'm not talking about true ribbons here....those are separate transducers.)
This is a form of "built-in" IM distortion.  Maybe a good thing....maybe bad. 

I think the 3.7 is particularly impressive in that regard, have you seen that picture of the diaphragm? With the new row of tuning dots, I picture the acoustical center of the driver literally sliding over to the tweeter strip side as frequency increases, so that the width of the active part of the driver is always < lamda and you minimize crossover region lobing between the bass and midrange segments. That has to do great things for the power response. As you point out, that's harder to pull off with discrete drivers, though you can still do a .5-way, dual tuned panels as in the Tympanis, or tune or .5-way a separate woofer panel or midrange as in the 20.x. I've thought idly of doing that to a segment of my IVa's midwoofer panel, to cover that troublesome range from 100 to 300 Hz where it's a bit opaque . . . but Wendell's right, don't mess with success.

[medium jim]

Josh:

Wasn't it you that posted a link to an interview with Wendell Diller wherein he noted that Magnepan does extensive R&D and have tried just about all the published DIY mods.  My point is that they're acutely aware of what is and what isn't. 

The 3.7 has received glowing reviews and to date the 20.7 has from TAS. This tells me that while Magnepan is rather conservative, they still deliver some mighty fine speakers right off the shelf at a price point that puts them in reach of the average guy. Better is the fact that they are made in the USA.  This is what this thread is about.  Nevertheless, I feel that this has fleshed out some interesting points of view and has been educational on many levels.

Nothing can replace each of our personal 1st hand experiences that lead each of us to different paths to achieve what we each consider to be the ultimate listening pleasure. While money is definitely a factor, it is more than that and "that" sometimes is too hard to quantify in mere monetary terms.

Jim

[Æ]

if my understanding of the meaningful benefit inherent in a series topology is correct, it's essentially wasted on Maggies as the impedance of their drivers don't vary radically with frequency.

If anything, just the opposite of that.
Any passive crossover, regardless of the toplogy is easier to implement when the impedance is constant (flat). A highly reactive impedance can be compensated for, but when the impedance is flat (not reactive) then the engineers work is so much easier. A flat impedance allows the transfer function to look and perform just like it does in textbook formulas.