bootman
Emo VIPs
Typing useless posts on internet forums....
Posts: 9,358
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Post by bootman on May 26, 2018 16:32:53 GMT -5
What exactly are you trying to gain in your current setup before going down the road of dumping more amps into a speaker? Whoa, didn't realize this thread is > 4 years old.
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Post by leonski on Jun 4, 2018 12:46:02 GMT -5
I know this is WAY out of date, the thread starting in '14, but I bought some Used Magnepan MG-1 panels in the early 80s. My amp at that time was a Kenwood Integrated, the KA-7100 of 60x2@8 and 80x2@4. I think the MG-1 panels were 5 ohm, nearly resistive. This worked well for a long time until I was able to 'up amp' to a Carver Cube of 200x2@8 and maybe 250x2@4. Amp and speakers ran out of 'ooomph' at the same time.
I hope Jackfish still has his Magnestands. I've heard 'em at a friends house and they are quite good, a definite step 'up' from the MMG.
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Post by leonski on Jul 11, 2018 18:22:08 GMT -5
Has anyone considered adding to more amp cards in the XPA2 Gen 3 and biamp in the same chassis? I have 3.7R's and wondered if this would be worth doing? I've spoken to Emotiva sales several times and several of the guys have said the XPA2 is THE amp for the 3.7's and that was about all they could recommend... I don't think that ANY of the Magnepan X.7 speakers can be biamped. The 1.7 has a series crossover. The .7 probably the same The 20.7 and 3.7i might be different, but from my readings on Audio Asylum (planar group) that is NOT the case. Sorry. Just buy enough amp.
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Post by donh50 on Jul 11, 2018 19:03:36 GMT -5
I drove my older MG-IIIa's to ear-bleeding levels with an XPA-3 and then later an XPA-2. Sounded fine to me.
3.7's are not bi-ampable IIRC; they removed that option. I am not a proponent, though bi-amped mine for years (active, not this "passive" bi-amp stuff popular today). If you need more power, you are much better off getting a bigger amplifier.
FWIWFM - Don
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Post by mgbpuff on Jul 11, 2018 19:56:25 GMT -5
Has anyone considered adding to more amp cards in the XPA2 Gen 3 and biamp in the same chassis? I have 3.7R's and wondered if this would be worth doing? I've spoken to Emotiva sales several times and several of the guys have said the XPA2 is THE amp for the 3.7's and that was about all they could recommend... The 3.7R's have a weird series crossover design that is impossible to split apart and bi-amp. I wouldn't mess with that if I were you.
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Post by leonski on Jul 11, 2018 21:06:36 GMT -5
According to 'sources', Magnepan made a decision to go with the Series Crossover. Some audible benefits, but a few downsides, as well. To go with a REAL BIAMP systme, you'll need to FIRST gut the crossover and go to line level crossover with something like MiNiDSP to make it right. That's gonna be a LOT of work.
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Post by vcautokid on Jul 12, 2018 2:56:17 GMT -5
Sure. The XPA-2 has the current swing the Maggies want. I drove MMGs with my XPA-2 no problem, as the impedance on maggies maybe reactive especially up high in frequency range. They tend to drop fairly low in impedance, so the XPA-2s current delivery is great. You would have to spend allot more to beat the XPA-2 performance. IMHO.
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Post by donh50 on Jul 12, 2018 9:09:51 GMT -5
The impedance does not really get more reactive at HF but does drop in magnitude especially with a true ribbon tweeter. At least up until the x.7 series; I have not seen curves for the latest models (and don;t have one to measure).
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Post by leonski on Jul 12, 2018 12:33:54 GMT -5
The impedance does not really get more reactive at HF but does drop in magnitude especially with a true ribbon tweeter. At least up until the x.7 series; I have not seen curves for the latest models (and don;t have one to measure). Maggies generally are a fairly benign load. Low sensitivity? Yes. Low but not wacky impedance? Yes. But not a very reactive load, at least if they are, it is not at some impedance minima where the problem would be magnified. Or perhaps at frequencies demanding a lot of power. www.stereophile.com/content/magnepan-magneplanar-mg36r-loudspeaker-measurementsStereophile review of 3.6 with true ribbon. Flip to the measurments page for details. I don't see much reason for the new panels to measure much different than than the old. Stereophile measured the 1.6 and 3.6 to good effect.
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Post by donh50 on Jul 12, 2018 13:25:15 GMT -5
I've posted "endlessly" here and elsewhere on their impedance; since I responded earlier in this thread wasn't going to repeat again (and yet...) Since a lot of people are making the same points hopefully the OP gets the idea.
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Post by leonski on Jul 12, 2018 14:12:38 GMT -5
Agreed, but some persons, myself included, can make useful sense of the Stereophile measured data.
end:
One of my goofier bosses had a posting in his Cubbie.
'In God We Trust, All Others Bring Data'.
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Post by pedrocols on Jul 12, 2018 14:29:28 GMT -5
Wouldn't be easier and a lot more fun to just listen and throw the data out tue window?🤔 I am sure God likes it better when you listen...😁
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Post by leonski on Jul 12, 2018 15:29:46 GMT -5
Engineering folks do NOT trust anything but data. I was a wonderful guesser and relied upon in some cases when data failed and came up with nutty solutions and experiments. Sometimes, it even WORKED! Sometimes, NOT. But in the long run, using data to manage a production facility is the Only method that works. Relieably and consistently, at least.
QC is not the way to run it, however. I've gone on enough about 30+ years of observations and learning.
It's all about being compartmentalized. Data / Measurments have a place. But buying what someone MAY call a system using that method is almost assured to be a failure.
I consider stereo selection to be equal parts Science and Art, with a dose of guesswork and experience tossed in for good measure. Good or bad measures is certainly no guarantee of good or bad results.
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Post by donh50 on Jul 12, 2018 19:07:26 GMT -5
I'm an analog designer so am used to a mixture of art and science in engineering, including the premise that data is not always complete, accurate, or precise. Completely trusting SPICE is one road to ruin... But I do tend to quiver when Marketing tries to violate fundamental physics.
Among the problems with audio stuff are that the tests that would show the differences are rarely reported, understanding the test results is rarely obvious to non-techies, expectation bias is rampant, and on the other side techies are sometimes to quick to dismiss listener's impressions that may lead to greater understanding of real problems (or not). Throw in a healthy dose of marketing based upon wild claims, inapplicable test results and pseudo-scientific babbling, and insane prices, and you have a recipe for a lot of shouting. I usually try to avoid such threads as there is usually no chance of changing anyone's mind. In the end what matters is what the listener wants to hear.
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Post by leonski on Jul 12, 2018 21:17:14 GMT -5
That about sums it up, now doesn't it!
Can't disagree 'cause I've seen all or most of the above at one time or another. But again, knowledge of how some specs actually apply can help you thru the fog.
For example? I'm a fan of the 'power cube' measurement system. Results are indiciitive of the ability to drive highly reactive loads. FEW care or can interpret thsee results and NO consensus exists among amp manufacturers to actually apply such testing. Good results don't guarantee good sound while poor results and a demanding speaker CAN spell trouble. Case Closed.
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Post by donh50 on Jul 12, 2018 21:32:26 GMT -5
Yah, the PowerCube is a really neat idea: www.audiograph.se/ They have a version now to work directly with AP analyzers. I'd like to think it will be used more but it's an expensive option, may not show amplifiers in a good light, and as you said most folk won't really understand it anyway.
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Post by leonski on Jul 13, 2018 0:47:20 GMT -5
Wanna confuse the B-Jeepers out of everyone but a real Techno Nerd? Show 'em a Smith Chart which covers impedance, reactance and frequrency with ONE curly-cue line on what I think is a log / log chart. I've been round and round about 3 laps with the folks emo about The Power Cube device / measure and get no traction. And I get their reasons. Few understand it. Fewer stilll would actually publish results and I don't see ANY American Publication nut up to actually take such data. Not to forget that a 'good' result would still be NO guarantee of 'good sound'.
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Post by donh50 on Jul 13, 2018 8:20:17 GMT -5
My world has been mostly RF/mW so no problems with a Smith Chart. But yeah, "Techno Nerd" probably fits...
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