Turns out the fret frames are made of fiberboard, not plastic like my S40s, S45-2s, and CX 50s.

And, both were broken at the vertical midpoint, and both were missing their top pegs.  The screws were there to hold the top half of the fret to the speaker baffle.

WTF?  I mean, dude, think of a better solution than defacing the front of the speaker!

There is serious rust on the screws (and nuts and bolts) mounting the drivers.

As noted above, the cabinets aren't in bad shape.

Here's a side view of one of the new pair.  This is our forum-favorite rosewood/palisander, yes?

Back and right you can see I've mated one of the new pair's frets to the refurbed pair.  Note the broken fret frame.

Here's a proper fret - with some masking tape on the back - on the left refurbished speaker.

Now to decide what to do with this second pair!

Rich:

There is serious rust on the screws (and nuts and bolts) mounting the drivers.

 Must have come from a beach house with a lot of salty air, or maybe they was on a submarine out of San Diego

Was away on business for nearly a week, spent a few days reintroducing myself to the wife and kids, and now it's time to finish this first pair of M70s once and for all.  Step 1:  fix fret (grill) frames of the new donor pair.

The second best thing about B&O passive speakers is how easy old fret cloth peels off the frame.

The right fret frame was literally broke in half.  (The left was just cracked badly.)

A little PVA glue was all it took to fix both frames.  I reinforced the broken areas by gluing pieces of 1/8" dowel into the gaps cut into the fiber board.

The top two pegs on both fret frames were broken off.  Using a pin vise I have in my hobby supplies bin from my days of modelling Warhammer armies, I drilled holes where each peg was misssing.  I superglued short lengths of snipped paper clips into these holes.  Then in turn I superglued 3/4" lengths of 1/8" diameter wooden dowel onto the paper clip.

Worked nicely.

With the fret frames repaired, it was time for new cloth. 

Let's take a moment to discuss the cloth, shall we?  So, the price I have to pay to the wife to allow me to have a two channel system permanently set up in the dinette is this:  she gets to pick out the new fret cloth.  The whole family went out to the sewing store (Joann's) this morning, and my wife picked out something...different.  It's, well, you'll see.

I laid the cloth out good side down on the table, clamped it down with some tension on it, and took the frames outside to spray them with glue.

I gave the front of the frame a thin coat of spray and allowed the glue to set for about a minute before taking it inside and placing it on the cloth.

After placing down on the cloth, I weigh the frame down with some strategically placed coffee mugs topped by books and some old weights from a long-ago discarded universal weight machine.  I believe one should work quickly after allowing the glue to set a minute so I do one at a time at this stage.

After letting both set over an hour (per the spray glue instructions), it's a rather simple matter of cutting/trimming cloth, then gluing to the back.  I used the rather low-tech method of PVA glue spread by the finger to glue the cloth to the fret frame back.  Here's both frets completed.

And what one looks like mounted.

And here's the pair, in what may end up being their permanent home along the long wall of the dinette.  The now complete M70s are hooked up to a Beomaster 1900.  I'll be getting that space next to the BM1900 filled by a turntable shortly.

So, the fret cloth the wife picked out.  I'm not sure whether I like it a lot or think it's hideous.  Not much middle ground available with this cloth.  It's kind of a love it or hate it proposition, yes?

I'm not sure if we should be happy that no women designed speakers at B&O, it sure looks "wifelike"

Wow! just read your posts and admire your skill and patience (sp?)  I must ask about the Makers Mark; how much Mark did it take to finish these projects?????  Also, does your wife imbibe in the bourbon and had she done so prior to picking out the fabric for the frets?

Seriously, I applaud your effort and the results are outstanding. I just found my first pair of speakers and I can see how one could become somewhat obsessed with the Beo world.

Regards,

Carleton, located only a few miles from THE Distillery.

Nice work on the pins and cardboard.
However, I think I will steer clear of the pattern choice discussion and just ask if that is proper speaker cloth
or just a piece of clothing fabric ?
My concern is that if it is not speaker cloth, it will not be sonically transparent and it will eat all treble.
Get someone to hold the grills in front of the speakers on and off and see if you can hear a difference.

Martin

That cloth probably wouldn't have been in my top 10 list of choices, but a man has to do what a man has to do!

I kind of like them, anyway... but I think they would need a bit more (white) space around them to look the best. Time to start looking for the trumpet stands!

Congratulations Rich to your M70 restoration (just a slight criticism about their new fabric  )!
I have used mine during many years and I was very pleased with their natural and linear sound.
Their efficiency is low, less than 90dB/W/m so they need a very powerful amplifier, I think a BM1900 is a little just enough.
I have hooked mine to a Beomaster 8000 with a good Monster M1 MKIII cable and golden banana plugs and in this setup the M70 have revealed all their qualities!
Don't be afraid by the 2x150W RMS of the Beomaster 8000, they hold the power during hours and hours without any problem. Fantastic speakers which have not usurped their qualification of Monitor!

Marc

carleton scully:

Wow! just read your posts and admire your skill and patience (sp?)  I must ask about the Makers Mark; how much Mark did it take to finish these projects?????  Also, does your wife imbibe in the bourbon and had she done so prior to picking out the fabric for the frets?

Seriously, I applaud your effort and the results are outstanding. I just found my first pair of speakers and I can see how one could become somewhat obsessed with the Beo world.

Regards,

Carleton, located only a few miles from THE Distillery.

The Makers Mark was generally reserved for listening sessions, though I'll admit I did have a nip or two while assembling the crossovers!

I have toured the distillery myself and spent many a dollar in the gift shop.  As I type, my coffee mug rests on a red rubber Makers Mark coaster.

Dillen:

Nice work on the pins and cardboard.
However, I think I will steer clear of the pattern choice discussion and just ask if that is proper speaker cloth
or just a piece of clothing fabric ?
My concern is that if it is not speaker cloth, it will not be sonically transparent and it will eat all treble.
Get someone to hold the grills in front of the speakers on and off and see if you can hear a difference.

Martin

 

The material is indeed sonically transparent.  It is a 95% polyester, 5% spandex blend.  I did a crude test of the material prior to construction.  I was fairly confident the material would work (sonically - visually is another matter!) as this synthetic blend is the same blend I have had on my S45-2s for many months (pictured below).

tournedos:

That cloth probably wouldn't have been in my top 10 list of choices, but a man has to do what a man has to do!

I kind of like them, anyway... but I think they would need a bit more (white) space around them to look the best. Time to start looking for the trumpet stands!

I would love a pair of trumpet stands!  Actually, I need two pairs now, don't I!?!?

Let's see, current want list:

Beomaster 4401 (like that's ever going to happen!)

Beovox M70 trumpet stand x 4

Beovox S45-2 stand x 2

1970's era tangential turntable (should be purchased in late May from "JaffBay")

Beomaster 4400 or 4000 to drive the refurbished Beovox M70s (should also be purchased in late May from "JaffBay")

Understanding from a suffering wife (she may never understand!)