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Minimus 7 Loudspeakers - Measurements

I guess it's finally time for me to do the Zilch crossover mod for my M7W's. I'm wondering if there are any photos of the crossover as stuffed somewhere in the thread that I've missed? I found the parts list and diagram, but if there's a photo of how it all mounted it would make starting the project a bit easier. My 7W's are (I think) fairly early, made in Japan, Cat no. 40-2039B, what appears to be a serial no. being 0777, followed by 9A9 (anyone know what that all means?). The original crossover must be tired by now and I am quite convinced that the mods will cure exactly what has always slightly irritated me about the 7's and make them the perfect partner in the bedroom for the little Scott 348 receiver. Oooo, sounds sexy.... Scott makes 60 w/ch (1960's w, so say 40 rms or so?) and in that space the slight apparent loss of efficiency won't mean a thing. Thanks to Zilch for all of the great work on this and many other projects.
 
Ha, when this thread started I knew I wanted to do this to a pair of my M7. It took me a year to get around to it but I finally ordered parts and just today applied the mod. The home office space is jammin' to some reggae as I type. Low end provided by an old phase tech passive sub. :music: The only deviation from the spec parts list was with L1. I made use of some 2.5mh I-core inductors I had on hand and just unwound them to get to 1.0mH. I think my DCR on those is a little higher than .17 for the spec part, WT3 showed them to be about .34 ohm. Is that a significant difference? And to what effect?
Thanks to the contributors.
-Buck
 
cubby01 said:
Ha, when this thread started I knew I wanted to do this to a pair of my M7. It took me a year to get around to it but I finally ordered parts and just today applied the mod. The home office space is jammin' to some reggae as I type. Low end provided by an old phase tech passive sub. :music:
Click to expand...

I need to get my Phase Tech PC-50 refoamed. Loved the combination of the PC-50 and the Minimus 7's in my garage system. Did you refoam yours? If so, which kit did you use?
 
cubby01 said:
I think my DCR on those is a little higher than .17 for the spec part, WT3 showed them to be about .34 ohm. Is that a significant difference? And to what effect?
Click to expand...
Hi, Buck,

Not a problem. The woofer's playing a tiny bit softer, is all.... :thmbsp:
 
chicks said:
I need to get my Phase Tech PC-50 refoamed. Loved the combination of the PC-50 and the Minimus 7's in my garage system. Did you refoam yours? If so, which kit did you use?
Click to expand...

Chicks, I did refoam my pc50. No kit just the surround and Aleen's Tacky. I think I used surrounds from Mat Electronics. They are darn cheap but M-E has a minimum dollar order amount. The fit was fine but working with the styrofoam piston is a pain. I think I coated the piston edge at least once and let it dry before I did the real glue on, then went back and looked for air gaps that needed to be resealed. As for the foam like stuff they put on the face of the piston, most of it was gone already so I just brushed as much of that off as I could and left it ugly. I figured it's facing the floor so why stress.
 
cubby01 said:
Chicks, I did refoam my pc50. No kit just the surround and Aleen's Tacky. I think I used surrounds from Mat Electronics. They are darn cheap but M-E has a minimum dollar order amount. The fit was fine but working with the styrofoam piston is a pain. I think I coated the piston edge at least once and let it dry before I did the real glue on, then went back and looked for air gaps that needed to be resealed. As for the foam like stuff they put on the face of the piston, most of it was gone already so I just brushed as much of that off as I could and left it ugly. I figured it's facing the floor so why stress.
Click to expand...

Thanks, I'll have to get around to refoaming this puppy one of these days...
 
Got speaks, got parts, going in!
 

Attachments

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For the Minimus 7 Zilch Lab database!
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Got the hood open!
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Pulled the motor!
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Epay crossover mod bites the dust!
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Zilch says this better work, say it aint so!
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Progress, inhale some lead, twist some wires, layout according to the Zilch. OEM .40mh inductor is epoxied to the connector plate, there it stays. Had to make some mods to the layout plan. This model comes with an extra solder lug. Win some, loose some!
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And thats all for today kids! Gotta go get some mounting harware for Mr. Slegehammer. I will test tomorrow before stuffing everything back under the hood. I am doing one side first so I can do a comparo between the Zilch mod and the Epay mod. :thmbsp: :D
 
HEY, I drew that!

It's a shock seein' my funky-ass layout sketch in your pic.... :tongue:
 
Have one speaker completed and am presently comparing the AK mod spkr to the other spk that has the Epay mod. Quite a positive difference for the AK modded side. Much smoother high frequence performance, not lispy on voices, no harshness on strings or brass. I would imagine after the caps burn in, there will be more improvement. Time to get cracking on the remaining spkr. :banana::banana:
 
1MOR said:
Have one speaker completed and am presently comparing the AK mod spkr to the other spk that has the Epay mod. Quite a positive difference for the AK modded side. Much smoother high frequence performance, not lispy on voices, no harshness on strings or brass.
Click to expand...
Surely, you don't mean to imply that the measurements were right AGAIN...?
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:D​
 
I have had 4 pairs of these that I flipped on ePay. Two pair of 7W (walnut) that were mint. A pair of white ones with black wall brakets. A pair of black ones with no brakets. Bought them all at thrift stores for next to nothing. like 3 to 5 dollars a pair. they all were in fairly good shape the walnut ones were mint no marks on them at all. cloth grills were in great shape. I know the other 7's were metal.
 
Questions about the M7 Measurements project

Zilch, et al,

I have a pair of 7w's (40-2039B) and a white-metal pair (40-2045), both pair MFG'd in Korea. Lucky $5 purchases at thrift stores. Still looking for more, especially the W's.

I've recently read this string and some of the others about the M7's. Kudos to all of you who have done such great work on these mods.

I have a few questions I hope you guys can help me with:

1. Does anyone sell the completed XO mod? If so, please PM me.

2. Was a fix determined for the edge diffraction problems noted in the thread? Some kind of foam or felt was mentioned as a possibility in the thread but I can't find the posts.

3. Is there a consensus opinion on stuffing (material, location(s), amount) the cabinets?

4. I'm looking for a small-footprint used powered-subwoofer to match with these. Is a cutoff of 150 Hz appropriate or would something higher be better?

5. Any plans to look at the Optimus Pro LX5 with the Linaeum tweeter? I've read the Stereophile review and info on the Larry VanWormer mods but replacing the drivers is more than I want to do/spend on thrift store finds.

Thanks.
 
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