Monitor 10a and 5b MW Questions, and a Rattle or 2

Van_Isle

A few months ago I acquired a pair of Monitor 5b's (built 1985) and one has recently developed a rattle. I thought it was coming from the PR and had solved it by pulling the driver and rotating it 180 degrees. However the rattle is back and from other posts here it may be the magnet is coming loose on the MW (?). The offending speaker has a MW6502 in it. I also notice the MW in that speaker has far greater excursion than its mate does. Tweeters are SL-2000's.

The fellow I got them from had used picture-hanging wire fished behind the two top screws in the cross-over / terminal cups to hang the speakers ... which probably means they were used for years without a proper sealed enclosure (and probably fell of the darn wall at least once!) ... had I two brain cells to rub together when I bought them I probably should have passed on the sale altogether.

Also I picked up a pair of Monitor 10a's last week. Alas, both MW's in one are frozen. Both speakers have MW6600X's in them (which from what I have read here, weren't used in the 10 series ???). Tweeters are SL-1000's.

Any ideas on further troubeshooting the rattle in the 5b's? Would a poor seal on that one speaker, perhaps as a result of the hanging, be a cause for higher excursion and rattle?

Any chance of using the 2 good MW6600X's in the 5b's, or assuming the rattle is tracked down to a source other than the MW, could the 6502's be used in the 10a's. OR, would it be worth it to obtain replacements for the bad MW6600's and (maybe) the MW6502?

Perhaps one other consideration is that, if I am correct in what I have read, the crossovers in both models are compatible with the SL-2000 and SL-1000's, but since the SL-2000's are physically larger they would make the better "spares" to keep for the 10a's?

Sigh ... so many questions!

Regardless, the enclosures on both the 5b's and the 10a's are fairly rough and I figure I will refinish what ever pair I keep. The 10's I figure would be easier to do (in real wood veneer) as there is no beveled edge to deal with.

The 5b's set me back about $75 (probably too much!) but the 10a's only cost me $5!

skrol

I am not sure what is meant by rattle. Is it a scratchy sound coming from the MW or is it something actually rattling inside. I found a couple sources of rattle in my various speakers. One was the wires inside that come from the XO were rattling against the MW basket. Another was excess pieces of glue rattling inside the cabinet. Might also try swapping the MW in the good speaker with the one that rattles.

Have you done a leak check? Gently press the PR in and hold it. The MW should deflect outward and stay for at least a couple seconds. Many of us have sealed our speakers with a product called Moretite, that you can get from Home Depot or Lowes, with great success. It is a putty like cord that is great for damping vibration and staking down wires too. Keep us posted.
Stan

Van_Isle

It is a rattle with the bass.

skrol

I'd make sure the wires aren't vibrating against anything or that there isn't anything loose inside. Might also check that the screws are tight. Also, make sure they didn't crack the terminal (XO) cup by hanging it.

If you do the leak check and you don't hear any scratchy sounds from the MW, it is likely good. However, I did have one that the spider separated from the basket and buzzed. I was able to re-glue it. This was on an old Polk Audio car speaker (MM6510) of very similar design.

JohnLocke88

Van_Isle wrote: »

A few months ago I acquired a pair of Monitor 5b's (built 1985) and one has recently developed a rattle. I thought it was coming from the PR and had solved it by pulling the driver and rotating it 180 degrees. However the rattle is back and from other posts here it may be the magnet is coming loose on the MW (?). The offending speaker has a MW6502 in it. I also notice the MW in that speaker has far greater excursion than its mate does. Tweeters are SL-2000's.

The fellow I got them from had used picture-hanging wire fished behind the two top screws in the cross-over / terminal cups to hang the speakers ... which probably means they were used for years without a proper sealed enclosure (and probably fell of the darn wall at least once!) ... had I two brain cells to rub together when I bought them I probably should have passed on the sale altogether.

Also I picked up a pair of Monitor 10a's last week. Alas, both MW's in one are frozen. Both speakers have MW6600X's in them (which from what I have read here, weren't used in the 10 series ???). Tweeters are SL-1000's.

Any ideas on further troubeshooting the rattle in the 5b's? Would a poor seal on that one speaker, perhaps as a result of the hanging, be a cause for higher excursion and rattle?

Any chance of using the 2 good MW6600X's in the 5b's, or assuming the rattle is tracked down to a source other than the MW, could the 6502's be used in the 10a's. OR, would it be worth it to obtain replacements for the bad MW6600's and (maybe) the MW6502?

Perhaps one other consideration is that, if I am correct in what I have read, the crossovers in both models are compatible with the SL-2000 and SL-1000's, but since the SL-2000's are physically larger they would make the better "spares" to keep for the 10a's?

Sigh ... so many questions!

Regardless, the enclosures on both the 5b's and the 10a's are fairly rough and I figure I will refinish what ever pair I keep. The 10's I figure would be easier to do (in real wood veneer) as there is no beveled edge to deal with.

The 5b's set me back about $75 (probably too much!) but the 10a's only cost me $5!

1. Swap the "good" MW into the "bad" speaker. This will tell you if the problem lies with the cabinet, or with the MW.

2. If it's the cabinet, do the things everyone else has talked about.
If it's the MW, go buy a replacement. Purists will say get the exact same MW that came with the speakers, but I believe either a MW6501, 6502 or 6503 will work in the Monitor 5. (To those more knowledgeable than myself, please correct if this is wrong)

For the 10As, To the best of my knowledge the MW6600X was a replacement driver. And, if you're running the SL1000 tweeters, MW6501 or MW6503 (the spec driver) will work. 6501s can be had relatively cheaply. I just picked up a few on ebay for a DIY project I've been meaning to start for some time.

3. Post your results.

Van_Isle

JohnLocke88 wrote: »

I believe either a MW6501, 6502 or 6503 will work in the Monitor 5. (To those more knowledgeable than myself, please correct if this is wrong)

I think the 6501 and 6503 are 8-ohm while the 6502 is a 4-ohm driver (see http://www.audiokarma.org/forums/showpost.php?p=638325&postcount=13), so if this info is correct, it wouldn't be a good replacement for the 5b's.

HOWEVER, with my 2 brain cells obviously no longer intact (and perhaps influenced by my previous "rattle" experience) I think I have nailed down the source of this new rattle - it isn't the driver or the cabinet at all. It is something in the glass shelving unit in the bar area right next to the speaker ... I think the mirror tiles glued to the wall (we just moved and I set up the system in the rec-room of the new house). So ... another reason to get rid of that awful early 80's bar set-up. Sorry folks! I guess my ears are about as good as my brain cells!

So, hopefully, on to the Monitor 10's .... there are a number of references on this site, etc. to 6600x's showing up in Monitor 10A's and 10B's, RTA11's, perhaps others ... but also references to this being one of the "rarest" of Polk MW's (just my bleeding luck!).

Does anyone have specs for the 6600X's, similar to the link I provided above?

lukewayne

glad you solved your problems so quickly welcome to club polk.

on the issue of which to keep, keep both pairs i also recently picked up a set of m10b' and m5b's off craigslist, i paid more for my 10's than 5s but a similar situation, i had one bad tweeter, and one bad mw overall, i've got the 10's set up as front and the 5s setup as rear with a cs350ls center i picked up on cl also and i am happier with my surround setup than i have ever been, so don't ditch one pair they are both good speakers.

Van_Isle

This may turn out ultimately to be a space issue .... Monitor 5b's, 10a's, Advent/1's, Paradigm 3Se Minis, 2 pairs of Paradigm Titans, a pair of Pro-Linears about the same size as the 10's plus the full HT setup ... hmmm.

JohnLocke88

Van_Isle wrote: »

This may turn out ultimately to be a space issue .... Monitor 5b's, 10a's, Advent/1's, Paradigm 3Se Minis, 2 pairs of Paradigm Titans, a pair of Pro-Linears about the same size as the 10's plus the full HT setup ... hmmm.

I know... you definitely have a 'space issue' Fill in the gaps with with more speakers