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Minimus 77/Audiosource LS-TWO/A refoam

HTHMAN

Super Member
I have long owned several pair of the Minimus 7 family of speakers. I currently have 2 pair of the original 7's that were made in Japan that I bought new when they first came out, one pair of Optimus Pro 7AV's, and 2 pair of Optimus Pro 7X speakers. I never owned a pair of the Minimus 77's. Recently. I acquired a pair of Audiosource LS-Two/A speakers at a great price--FREE. They appear to be exactly like the 77's with no port. They were in good shape except for the rotted foam around the woofers. I intended to either replace the speakers or repair the foam. Neither seemed to be a good option. It is hard to find a speaker that will fit and all the foams I found were $20 a pair. I found a link on this forum for some cheap surrounds and ordered them. EBay item # 360313218816
I documented my work and thought others might find it helpful.

Here is the speaker with the damaged surround. As you can see, it is identical to the Realistic speaker.
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First, remove the damaged speakers
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Remove the old surround by scraping it off the back of the speaker cone. I mostly used my fingers. There is a gasket that covers the outside edge of the surround. remove it carefully to avoid damaging it Here is speaker with surround removed.
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Surrounds: Note, the rolled bulge goes in, not out like the originals.
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The surrounds fit perfectly on top of the cone and could probably be installed to the inside, but the originals were on the outside. Also, as you can see, if you install on the inside, the surround rides a little above the speaker frame.
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To install outside the cone, spread a little glue on the top of the tapered edge. I recommend Aleene's Tacky glue.

Spread the glue to the edge ridge of the surround. This will aid you in centering the surround
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Work the surround under the cone by stretching very slightly. Center the cone in the white ring. Press and pinch around the cone to attach the surround to the cone. Make sure it is centered and let dry until glue turns clear.
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Once dry, glue the edge of the surround to the frame by lifting the edge and supplying glue to the frame. Make sure the speaker stays centered. Check that the speaker does not rub by pushing the cone in and out a few times. The suspension is stiff and should not need to be shimmed.
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Next, glue the gasket back in place on top of the surround.
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Press the gasket down around the edge. Turn speakers over and place on waxed paper. Let dry for a couple hours or more.
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Here we have the finished product.
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I tried these out and they sound great. I did an A/B comparison to my Minimus 7's. The larger pair do have a little more bass and a little fuller sound. The highs sound pretty much the same. The 7's sound a little crisper, but that may be due to there being a little less low end or a different crossover. Anyhow for $4.50 for the surrounds and $1.50 for a bottle of glue, you cant beat the sound of a $6.00 speaker.
 
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Upside down?

Are you sure you didn't install the surrounds upside down?

No, the bulge goes in, not out on that pair of surrounds. If you flip them, the edge does not match up with the cone angle. Looks a little strange, but the sound should not be affected by that.
 
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They were installed originally with the terminals at the bottom, but there was a slit in the baffling for the wires. It was a stretch to put the wires on the bottom and it pulled the baffling down to the bottom on the enclosure. I could not see any reason that the speaker orientation would make and difference. If I am wrong, let me know and I will flip it.

Nah, that shouldn't make a difference, although it can sometimes cure a voicecoil rub.

I meant where you state that the surround roll goes in, rather than out on the original. Are you sure they're meant to roll in, and that you didn't have upside down at that point.
 
Edited post

Nah, that shouldn't make a difference, although it can sometimes cure a voicecoil rub.

I meant where you state that the surround roll goes in, rather than out on the original. Are you sure they're meant to roll in, and that you didn't have upside down at that point.

I misread your post, so I edited my response. I figured some sharp eyed reader would notice that I flipped the woofer so that is what I was thinking. Yep, the rolls go in on that set. I have no idea why they would have done that, but they work perfectly.
 
I glued the inside ring ON TOP of the woofer, and it seems to work just fine. Wish I'd done it like you did. Didn't notice until too late.
 
Foam finally blew on my trusty Optimus '77's a couple weeks ago. Had never re-foamed b4, so this seemed like a good place to start. Did 'em last night, following the excellent tutorial above. Seemed to work just fine. Only hard part was waiting for the glue to dry :D

I use the '77's for gear demos when selling on CL, 'cause they're so rugged, just throw 'em in the back of the CR/V, no sharp corners to dent or veneer to scratch.

Thanks for the excellent tutorial, I may go back and get those Baby Advents @ the GW, if I can find cheap foam for them. The ebay seller sent these ones real quick, and they were real cheap.
 
Just finished my Optimus Pro 77s. Little harder then the ones above, the trim ring was destroyed when I removed it. Reglueing the outside edge require more attention.

They sound great, thanks for the thread and info.
 
For their size they are an amzing little speaker- I have the walnut versions that I double stack for really nic effect.
Great work done here! You are quite skilled- you might also consider a poy recap.
DC
 
I bought a XO update on Ebay a few years back and they made a world of difference. Cleans em right up since they don't have much of one stock. Curious where you got the surrounds. The few I've bought recently come close but don't fit right.
 
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Search for eBay seller bootapest2 in the advanced search. If not listed, contact him. I had to do that once and he said he had accidentally left the item off and promptly listed it. It was listed as a 4 1/2 to 4 3/4" foam. Just ask him for it.

I just looked. Here it is.
http://www.ebay.com/itm/a-pair-of-F...90?pt=Speakers_Subwoofers&hash=item3a74ce542e

Thanks for the info, for some reason, this Ebay listing is blocked for me since I am located in Canada... I can't even see the ad! I will try to contact the seller directly hoping that he is willing to ship across the border.
 
I just refoamed my 77s and the tutorial was most helpful. Very astute point about installing the new foam under the woofer. This works as it should...if installed above, the voice coil resting point will no longer be centred in the gap, but will be slightly lower than it was originally. This could result in the coil form bottoming and the voice coil leaving the gap with high level bass notes. Not good for distortion.

I used pliobond glue...let it become tacky and keep pressing and smoothing the surround until all ripples are gone and good contact has been made.

I had also previously installed Zilch's and Pete B's Minimus 7 crossover...works wonderfully in the Minimus 77. Any irritating brightness/harshness is gone and the overall sound is clean, smooth, detailed and well balanced top to bottom.
 
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Since I goofed and refoamed to the front of the woofer, I'm wondering if over time, the VC doesn't simply start to recenter the woofer.
?

They play fine, and don't complain, even far up the volume scale.

Considering ordering those nice pre-built crossovers off that site. Apparently the guy has early Parkinsons, might not always be available.
 
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