Welcome! Need support, you got it. Or share your ideas and experiences.
Return to Planar Speaker Asylum
24.16.162.179
In Reply to: RE: New Clues in the 3.7 Crossover Mystery posted by sparky62 on February 04, 2015 at 19:12:42
The question(s) is......why would anyone want to be buy these crossovers? What use would they be to anyone? Cut 'em up for parts to build something else? Possibly frankenstein them into a 3.6 system?
And, why would the seller want to sell them? If the speakers are ultimately sold, they'll be worth more if the "original" crossovers go with them.
Obviously the seller's objective here is to make a few bucks on the "mystery" (which isn't really much of a mystery) of the new Magnepan 3.7 series crossover. :)
This is actually just about as irritating as Magnepan's zipped-lipped comments regarding the new crossovers.
Dave.
Follow Ups:
"And, why would the seller want to sell them? If the speakers are ultimately sold, they'll be worth more if the "original" crossovers go with them."
Perhaps the speakers were severely damaged plus being too costly for Magnepan for repair/restore them. So the seller is salvaging parts and trying to sell them off to minimize his/her loss. I think it's unlikely that he/she knows anything about any 'mystery' and wouldn't give a care if they did.
It's unlikely the speakers are damaged. The statement "These were replaced with external custom built crossovers" in the Ebay ad seems to indicate they're probably working fine.
But who knows??? :)
Dave.
I was wrong in my assumption and humbly apologize. You are absolutely correct, it was an oversight on my part having forgotten: "These were replaced with external custom built crossovers" ....
(Sorry, yet another one of my 'senior moments'.)
I think I have seniority on you. :)
Regardless, if I were the owner, I'd hang on to them.
Dave.
He now has a pair of external XOs which must deliver better SQ because:
a) they are mounted off the panel, and
b) use better-quality parts (parts that Magnepan couldn't afford to use bcoz doing so would price the 3.7s out of being an economic buy).
So selling them will recoup something to put against the cost of the new external XOs.
But I sure would like to know what that schematic looks like. :-)) I wonder if it was anyone here who bought those XOs?
Andy
The reserve was not met and the highest bid was $1.50. What does that say to you? :)
Dave.
These factory X-overs are now listed on Canuck Audio Mart.
http://www.canuckaudiomart.com/details/649177076-magnepan-37-oem-passive-crossover-network-pair-with-schematic-crossover-frequencies-amp-roll-off-rat/
There seems be be a rather large discrepancy between what the seller is asking and what the market is willing to pay, at least based on the E-Bay offers.
He's essentially selling the design I guess. I'm not sure why it took "a considerable amount of time to measure the response to each of the elements." That's about a five minute job for me once my laptop is setup next to the exposed crossover on a speaker.
I still don't understand what a prospective buyer would have in mind for these other than possibly transplanting into a 3.6.
Oh well.
Dave.
"This is actually just about as irritating as Magnepan's zipped-lipped comments regarding the new crossovers."
Greater than their zipped-lippedness as to how a 3.7 is turned into a 3.7i?
I had exactly the same thoughts.
In any case, it looks like the crossover is just a standard 3-way 1st order series. It would be nice to know the impedances of the drivers. (I suspect the standard 3, 3.3, 4.0 for the tweeter, mid and woofer) and the inductance of the coils. Perhaps someone with a 3.7 would be willing to measure the resistance across the mid and woofer --no surgery needed other than opening the access panel.
Edits: 02/06/15
You can't measure the midrange driver without a wire disconnection or two since the large inductor shunts it. The woofer can be measured pretty much directly via the positive and negative terminals. (One inductor in series which can be subtracted.)
Regardless, without the L value of the inductors, it's difficult to determine the exact alignment.
Did you determine the capacitor values by sleuthing that photograph?Dave.
Edits: 02/06/15
I think the mids are about 6 ohms. The foil is 0.001" x 0.1" and about 48 feet long.
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: