Magnepan 3.7: I give up

[sdolezalek]

About the logo (I hadn't thought about that). As to the AC nature of the current I, of course, also agree; but I'm as puzzled as you as to why there would be an audible difference. In one way, the differences sounded almost like having the polarity reversed on the speakers (which is another whole Maggie topic of its own as to polarity of the tweeter vs md vs bass). So I'll join you in the curious as to whether anyone has a scientific explanation wait...

 

[Part-Time Audiophile]

Why Dueland? And not Mundorf or Caddock? Just curious.

 

[barrows]

I am of the opinion that Duelund makes the best speaker crossover components. The capacitors are extremely expensive, but the resistors are at least affordable, and the tweeter padding resistor is in direct series with the signal, so a critical component.

You could compare sonics with Mundorf, and others, once everything is broken in and stable. I would not roll resistors until your are settled in on cables either.

 

[Part-Time Audiophile]

But they don't fit. Those lovely wound silver conductor wires don't extend far enough to fit the posts. The resistor 5.5" long! I'm going to need to somehow extend the wires to fit. Suggestions welcomed before I start smashing this undoubtedly excellent $100 "investment".

 

[curbfeeler]

UniCrystal TM OCC SILVER Hookup Wire

http://www.vhaudio.com/wire.html

Wrap a spiral of this silver wire around the lead of the resistor to provide an extension. Or would that be too inductive? ;>)

 

[4est]

I warned you before about this in an earlier posting on this thread...

 

About the only thing to do is solder ends to them or return them and get some other non inductive resistors. Previously I recommended Mills brand as a very good start, but the Mundorf will do just fine at 3x the price of the Mills. I'll be happy to solder something for you btw. PM me if you are interested...

 

Moreover, the quality of those resistors far out weighs the rest of the components in the crossover. Also, the sound (or lack thereof) of resistors has a far smaller effect than the sound of capacitors or inductors. Put another way, $100 towards capacitors or inductors will reap much more benefit than $100 in resistors. Resistors intrinsically have less adverse effects on the sound unless they are particularly bad.

 

[4est]

At least use wire nut!

 

[Part-Time Audiophile]

As my daughter would say: [insert raspberry here].

 

I called PartsConnexion and they went through the bins and found me 4 2R0 10w resistors that have the longest (touching) leads. Those will be fine. They're swapping them out for me.

 

As for the quality of the resistors, Forrest, you're undoubtedly right. It's totally overkill. The Mills would have not only been fine, it would have been excellent. But I'm a bit compulsive. Yeah, it's a problem.

 

Anyway, while I'd love to rip the crossover out and redo it externally, that's not an option with the new 3.7. It's all integrated into the panel and there's no (simple) way to bypass it. I suppose you could order it that way, but I didn't. Whoops. Alternatively, you could put the panel on the bench and DIY your way to a better crossover but that seems a bit extreme to me.

 

If that fails, I'll get some wire from the link curbfeeler put out (thanks, btw!).

 

Also, there's no nut per se. There's a post, a hole really, with a screw that you can use to tighten down on the hole to create better contact. Banana plugs fit perfectly into the hole.

 

[barrows]

Nothing wrong with being compulsive when it comes to audio, as the compulsion usually does lead to better sound!

While I mostly agree with 4est as to the overall crossover quality, there is one thing to consider: in most cases, a high pass filter to a tweeter will consist of capacitor(s) in series, and perhaps, an inductor(s) and resistor(s) in parallel to the positive lead. Normally the only resistor in series will be a resistor which is used to set the level of the tweeter in relation to the other drivers (to pad it down). The resistor you are replacing is in series, so unlike a resistor in parallel, it will have a significant impact on sonics. I have found that anywhere the signal passes through a series resistor, is a worthwhile spot to have the best resistor one can use.

Of course, rebuilding the entire crossover, and using really great capacitors for the series caps could reap even greater benefits, but that is something for another day...

 

[4est]

Of course Barrows is correct in his assessment of a series resistor, but my point was that the series capacitor has a much greater sonic impact.

 

[barrows]

4est, totally agreed! When the R is so easy to upgrade, it is irresitable to use a good one.

When I have $ again I am going to re-build my crossovers with really good caps (I have no series resistors in mine). I think I'll do one speaker at a time, and then listen test to each speaker in mono. Should be interesting...

 

[curbfeeler]

One of you go first. I'll be interested to read what you learn, especially with respect to disassembly and space available within the panel to accomodate parts.

My pair of MG 3.7 are settling in nicely. Drums and string bass are very convincing. With padding resistor installed at both mids and highs the balance is very good. I'm taking a set of ICs and speaker cabling by Transparent from a local dealer for a spin this weekend, stuff that is roughly similar in price to Nordost Frey. I have a loom of Frey en route to hear after the Transparent trial.

 

[barrows]

always implement an external crossover if more room is needed. Isolating the crossover from speaker resonances can be a benefit as well...

Beware with the Frey cabling, long break in is necessary to hear what it can really do. The mid/low bass did not come around in my Frey cables 'til around the 400 hour mark, or perhaps even a little longer. Before that it sounded amazing, but a little lean.

 

[curbfeeler]

My local dealer will toast the Frey speaker cables and ICs, hopefully shortening the duration of their conditioning.

 

[Part-Time Audiophile]

But will they butter?

 

[Jim Smith]

This is anecdotal and is not presented as incontrovertible fact.

 

I've had better results with burning in cables with music and or a similarly balanced changing signal like ocean surf.

 

For CES one year I put all of my new show cables on a cable cooker before leaving for Vegas.

 

Still don't know if maybe I simply overcooked them (ran them too long).

 

But they were a sonic mess when I arrived. Fortunately we had almost three days before showtime. George Cardas' helpful suggestions & Charlie Hanson's Ayre IBE disc were instrumental in helping us to get the sound to where it needed to be.

 

Tried one more time with a cable cooker with similar results.

 

Burned in cables with music ever since.

 

Hey, I said it was anecdotal!

 

[curbfeeler]

OK, Jim, dish ;>) Which cable cooker was used with disastrous results?

 

[audiozorro]

I heard the same advice from several folks who will only use music to burn in their cables.

 

The Savant Audio website has several interesting white papers on cables.

 

http://www.savantaudio.com/savant12.html

 

 

[Jim Smith]

It's gotten favorable write ups. It's the most famous one. I consider the company owner a friend.

 

So I cannot say.

 

It was an anecdote that SHOULD have said - try a cable cooker with some cables before you automatically assume it'll be better.

 

Furthermore, I may overcooked the cables. IME, a lot of dealers put it on automatic, then get busy/distracted, and can do a similar thing.

 

But music is simple to use and we don't have to buy anything or pay anyone.

 

[esldude]

Well, I have used square waves, 60 hz from a wall socket for speaker cables (loaded with a suitable capacitor), pink noise (or FM interstation hiss), some burn in tracks of various sorts, and of course music. Also have done things like rig up a way to feed higher voltage from a power amp through low voltage interconnects.

 

Not sure I found the best method. Seemed to vary with the cable somewhat actually with some seeming more effected than others.

 

In the end, mostly just leave it playing with some music.

 

[4est]

I just use music. It seems counter effective to use a signal that is different than the one the cable will see in use. Furthermore, IME moving the cable appreciably negates some of the effects of burning in as well.

 

My .02, and that is about all it's worth.

 

[Jim Smith]

I just use music. It seems counter effective to use a signal that is different than the one the cable will see in use.

 

Agreed.

 

Furthermore, IME moving the cable appreciably negates some of the effects of burning in as well.

 

Agreed, although some cables seem to be more immune to this aspect than others. For example, some Cardas cables - such as GR - used to suffer from moving them around. At shows, the order of the day was to get the system set-up and try to minimize moving the cables as much as possible.

 

My .02, and that is about all it's worth.

 

Not agreed.

 

[Part-Time Audiophile]

I've overcooked cables before. 4 days on the Cable Cooker and the Stereolab Reference cables came out sounding like Cardas Golden Reference.

 

If that reference doesn't mean anything to you, it goes like this. Take a cable known for great frequency extension and over the course of four days of benign neglect turn that cable into one that sounds more like an SET amp than a solid-state amp -- it's all mid range with heavy frequency roll off on both extremes.

 

If ever I doubted that cables can sound different, or that cable break-in really mattered, that experiment cured me.

 

[Jim Smith]

You should overcook Cardas Golden Reference as I once did.

 

Talk about dead, dead, dead...

 

The only thing that restored them was continual playing of music.

 

We don't have to agree on whether or not they were the best cables - but we can definitely agree on the effects of overcooking!

 

[curbfeeler]

I tried a loom of Transparent cabling in the signal path of my system over the long weekend. The complement included balanced 2m & 1m Super ICs, a single-ended 1m Ultra IC and a 10-foot pair of Music Wave Ultra speaker cables. The speaker cable was placed on XTerminators to adapt the spade lugs to the Maggies’ banana receptacles. These cables had been in use at the dealership, so they had some time to burn in. They had not been on a cable cooker. All contacts were cleaned with 99 percent isopropyl alcohol and treated with Caig DeOxit Gold.

The Transparent did many things well. Bass was well defined and weighty. The midrange was well articulated. Balance across the frequency spectrum was good. Sibilance was not coarsened.

Where they fell down was:

High frequency extension, or air.

Pulse. Dynamic swing was somewhat diminished.

Coherency. Continuousness. Things seemed less of a whole, slightly confused spatially and harmonically.

The dealer had said the noise floor would be lowered and hence ultimate resolution enhanced. That did not happen. That may be due to the measures that were already put in place to minimize noise in my system.

The samples were chosen to be comparable in price to Nordost Frey. I would conjecture that the networks used on the Transparent cabling were limiting performance, as there are all sorts of points in the design and construction of these cables for mischief: the layout of parts, circuit boards, soldered connections, parts quality, connectors chosen, dielectric and sheathing, housings. Needlessly complex, perhaps.