6503 Gunk - Anyway to clean it?

F1nut · May 2003

I'm talking to the wall.....sigh

VR3 · May 2003

ex-zachery...lol

dorokusai · May 2003

Dashboards crack for a multitude of reasons. I have not seen any scientific data to support the use of Armor All, as a silicon booster. A plastic is already formed in a way that prevents absorption of additives. Yes it does make it shiny, and it works on rubber oriented products very well, but don't expect it to save your 1978 Datsun 280Z dash, even if it existed at that time.

Do I use it on my car? Yea, but I honestly don't know why, I just do. I am a creature of habit.

har_navalta · May 2003

Look how shiny those drivers, thanks to Armor-All. It restores the original looks. Armor all works perfect on both the surround rubber and the cone and also it is safe that doesn't affect the sound or any other means.

Armor all works perfect on the speakers because they are inside without Sun, Rain, Snow or any harsh effect of outside
environment.

I don't know about you, but for me it works perfect.

TonyPTX · May 2003

I always thought the cardboard doughnut was there to protect the rubber surround in case you did a below surface mount of the speaker, (i.e. if you were to mount it under your dash in your car.) It's cheaper in the manufacturing process to make all the speakers the same way rather than having to modify the assembly line for different "versions" of the same driver. Thus, sometimes, you get extra "features" in a product that have no use at all. Much like purchasing a car that has the ability to install extra "options" but you don't purchase them cause you're cheap. Ford ain't gonna change their assembly line cause you don't want power windows. The plugs and wiring are probably there in the door panel, however they give you a hand crank instead of some nice pushbuttons and an electric motor.

As for using Windex, I'd be cautious about it. Seems like you'd be removing oxidized glue from the driver to make it look nice, at the same time, you're compromising the integrity of it.

rskarvan · May 2003

Har,

Very pretty drivers. WOW ! ! !
I am most impressed.
Didn't know you had THE BIG SRS SYSTEM. Again, WOW.

This grills-off photo is the nakey-Polk audio equivalent of a centerfold. I'll leave the crusty socks to Micah though.

Ron

DarqueKnight · May 2003

Originally posted by raife1
We haven't been able to figure out the reason for the cardboard doughnut. I'm guessing that it is there to protect the seam where the rubber surround is bonded to the metal driver frame.

Maybe these are an earlier version of the MW-6503 driver that needed some extra bracing at the surround/driver frame seam.:(

Here's two replys from Polk:

"Hello Raife,

I believe that is a fairly standard cosmetic attachment intended to give a more finished look to the area where the surround is attached to the basket. Some people refer to it as a "beauty ring", or I've even heard the term gasket used. I'll pass your question on to some of the folks in the engineering department for additional comments.

Regards, Ken,
Polk Customer Service"

"Raife,

Cardboard gaskets were originally used to cover the gluing flange
of the surround for several reasons:

* to cover the glue squeeze-out under the surround,
* allow better bonding by allowing more adhesive to be applied
* a means for pressing the glue bond
* a spacer for installation from the rear of a panel surface.

They serve no intentional acoustic purpose. Polk began using an ultr-thin viscosity cyanoacrylate adhesive in ~1980 and was able to bond the surround better and w/o the need of the gasket.

Time marches on.

Thanks,

Stu Lumsden
VP of Engineering, Polk Audio, Inc."

JT,

So, now we know for sure. Although, Stu Lumsden's answer raises another question: If Polk discontinued the use of the cardboad doughnut on the MW6503 driver in 1980 and the SDA SRS went into production in 1985, then, then you may have (old)replacement drivers in one of your SRSs. There should be a date of manufacture on the rear of the drivers. Maybe the original owner blew the first set of drivers and scrounged around and found those old drivers.:mad:

jtconnell · May 2003

It's nice that they're not necessary but all of my 6503s have manufacturing dates of July 1991. How weird is that? This includes the ones with and without the rings.

I think the oxidizing glue theory makes sense. Mildew seems pretty far fetched to me. It's not like anyone puts SDA SRS's in their showers. Even if you had a damp family room, I think it's unlikely that mildew would form there since the speakers themselves should be relatively dry.

I would guess Windex would work but I'm skeptical about whether or not it would affect the glue bond.

I suppose we need an expert opinon (Ken Swauger) on that one! Perhaps he could be the final arbiter of the raging Armor All debate as well!

DarqueKnight · May 2003

Originally posted by jtconnell
It's nice that they're not necessary but all of my 6503s have manufacturing dates of July 1991. How weird is that? This includes the ones with and without the rings.

Yeah, that is weird considering the fact that the original SRS was manufactured from 1985 to 1987. The SRS 1.2 was manufactured from 1987 to 1988 and the SRS 1.2TL was manufactured from 1989 to 1991.

jtconnell · May 2003

I heard that. What is also strange is that some of the drivers seem to have more than one mfg. label on them. ie the top label has the July 1991 date on them but there are labels beneath them that don't appear to have dates. If they do, they're unrecognizable. I don't know how someone could remanufacture a driver or why it would be worth doing even if you could.

Ghosts are responsible for this I tell you! They still sound good anyway. As I mentioned in previous posts the cabinet dates are goofy too. One is from 10/86 and the other is from 12/88 which means that it should be a 1.2 cabinet but it has the same dimensions as the one built in 1986. Care to explain that one?

jtconnell · May 2003

The following was the response I received from Ken who had forwarded my inquiry to Stu regarding cleaning the speakers.

""Hello Jason,

The following is a reply from Stu Lumsden, the head of engineering:

"The top treatment on the cone is a nitrocellulose lacquer. It coats only the cone. The dust-cap is permeable - it passes some air. I don't suggest cleaning the cone. The collected dust on the cone will not cause a sonic problem. If there is a white residue on them then it maybe "out-gassing" from the cyanoacrylate [CA] glue used to assemble the driver. This can distribute a white participate during curing and can be cleaned off with a brush. You can use a damp cloth or a cloth with some acetone but don't get it on the cone."
Regards, Ken""

No real verdict on the Armor All except for the recommendation not to clean the cone. Comments?

Jason

har_navalta · May 2003

You can use a damp cloth or a cloth with some acetone but don't get it on the cone."

ACETONE? What the "F"

That is very harsh chemical. I don't agree with. It will riun the part
of your speakers.

NO Thanks... I will not use it.

Armor-all and windex or nothing.

har_navalta · May 2003

Once you applied anything with acetone it will melt that materials.
(eg. paint of your car, nail polish, glue, gums and others like it.)

If you don't agree with me GO ahead try it for your self.

Har

jtconnell · May 2003

Since I don't have a spare pair of 6503 drivers lying around, I have made the executive decision to be happy with what I've got and not screw it up further. I'll probably continue my dry brushing when I get the chance and perhaps use a little Windex on some particularly bad spots.

Putting nail polish remover on anything is bad news as far as I can see.

And to think we all wondered what a good use for the drivers in the attached link would be!

http://clubpolk.polkaudio.com/forum/showthread.php?s=&threadid=9918

DarqueKnight · May 2003

Originally posted by jtconnell
As I mentioned in previous posts the cabinet dates are goofy too. One is from 10/86 and the other is from 12/88 which means that it should be a 1.2 cabinet but it has the same dimensions as the one built in 1986. Care to explain that one?

The cabinet dimensions and weight of the three SRS versions (SRS, SRS 1.2, SRS 1.2TL) are the same. The cabinets of the SRS 1.2 and SRS 1.2TL are identical. The differences between the SRS 1.2 and the SRS 1.2TL are the "TL" version uses upgraded SL3000 tweeters and a completely different crossover.

Although the cabinet dimensions are the same between the SRS and the SRS 1.2/1.2TL, there are some internal and external differences between the two cabinets:

1. The wood caps on the tops and bottoms of the SRS are laminated wood boards with no edge banding. A common problem with the SRS was the development of cracks along the seams of the boards. The end caps of the SRS 1.2/1.2TL used a solid piece of wood with a wood veneer band around the edge of the caps.

2. The SRS 1.2/1.2TL used improved internal bracing for improved resonance control.

3. The SRS used a "blade/blade" SDA interconnect cable whereas the SRS 1.2/SSRS 1.2TL used a "pin/blade" interconnect cable.

The 1988 date on one of your cabinets does not make sense, UNLESS, a previous owner damaged the original cabinet beyond repair an ordered a replacement from Polk. If the 1988 date on the cabinet is authentic, and it really is an SRS 1.2 cabinet, you should see the differences in the wood end caps and the internal bracing.

jtconnell · May 2003

Thanks Raife!

To me, the internals looks the same, I'd need more info on what was done to be sure. Also the wood tops on both cabinets look pretty solid to me but I'll check them out.

Also, I would note that at some point, Polk added the bass brace feature and that required them putting a plug in the cabinets on the 1.2 and 1.2 TLs. My cabinets don't have the plug (or perhaps I don't know where to look for it or what it looks like) but as far as I can see, I don't have it which means the 1988 cabinet is an original SDA SRS cabinet. Weird.

The reason I thought the dimensions were different was becuase the vintage portion of the Polk website claims that they are. When I did the calculations, the 1.2 and 1.2 TL cabinets seemed to have more volume which translated to more bass response. If they're the same, I thought that would have been reflected on the website.

SDA - SRS Size: 63-3/4" H x 21" W x 13" D
SDA - SRS 1.2 & 1.2 TL Size: 63-1/2" H x 21-3/4" W x 13-1/8" D

Perhaps they made an error, just like they did on the price. Moreover, mine seem to be 63-3/4" X 22" W X 13" D. Of course these things are the easiest to measure!

Thoughts?

TonyPTX · May 2003

Originally posted by jtconnell
I heard that. What is also strange is that some of the drivers seem to have more than one mfg. label on them. ie the top label has the July 1991 date on them but there are labels beneath them that don't appear to have dates. If they do, they're unrecognizable. I don't know how someone could remanufacture a driver or why it would be worth doing even if you could.

Ghosts are responsible for this I tell you! They still sound good anyway. As I mentioned in previous posts the cabinet dates are goofy too. One is from 10/86 and the other is from 12/88 which means that it should be a 1.2 cabinet but it has the same dimensions as the one built in 1986. Care to explain that one?

It's fairly common for drivers to be "repaired" on older items that are no longer in production and parts have been discontinued. I've got a pair of old JBL's that I can't buy the tweeters for any more (thus my Vifa tweeter modification project). Harmon put me in contact with an authorized "rebuild" shop, however I was missing one of the orginal tweeters so a rebuild was impossible. Some outfits will take your existing drivers and reuse the basket/magnet and install new surrounds or cones, rewind the coil, etc, back to OEM spec. I've never seen one of these "rebuilt" drivers, but I hope the wouldn't look like that god aweful Ebay auction listed above.

DarqueKnight · May 2003

Yeah, I forgot about the bass brace feature they added to the 1.2/1.2TL. There is a threaded hole on the back 8 inches from the top of the cabinet that the bracing rod screws into. If the bracing rod is not used, a bolt is used instead.

These dimensions come from the SRS and SRS 1.2TL owner's manuals:

SRS: 63-1/2" H x 21-3/4" W x 13" D, weight: 180 pounds

SRS 1.2TL: 63-1/2" H x 21-3/4" W x 13-1/8" D, weight: 180 pounds

When I measured my SRSs and 1.2TLs, I got these dimensions

SRS: 63-1/2" H x 21-3/4" W x 13-1/8" D

SRS 1.2TL: 63-1/2" H x 21-3/4" W x 13-1/8" D

Seems like you have original SRS cabinets. Maybe the person at the factory made a mistake and wrote 1988 instead of 1987.

jtconnell · May 2003

Mine definitely don't have the bass brace. I'll have to check the cabinet dates, but they're computer printed, not written. (It's like a stamped label really). I can also post the serial numbers. The crossover is from early 1987 (January). The other one is from October 1986. Perhaps the cabinet got damaged in a move. Oddly enough both of my speakers were left ones, if you recall from previous postings. Real goofy if you ask me.

At any rate, I'll re-measure. Thanks for the help!:)