Help with polk monitor 10a

TennMan

DDAN6815 wrote: »

Well it appears they're frozen, I can actually live with the sound of these speakers as long as I have my sub, but knowing I'm not getting the full range,I've disconnected them. I'm trying to decide if I should purchase 4 new drivers, or is it with the investment. The cabinets are in great condition. I really like the sound of these speakers, the highs are great and very natural sounding for the type music I listen to. I have several other sets of speakers, such as My favorites The Apogees, Celestion UL6, Paradigm phatoms, and Klipsch kg3.2. So it's not like I really need another pair, but it's something special about these speakers.

DDAN6815 wrote: »

How do you fix air leaks in the cabinet? ... should all drivers have some type gasket around them.

If you can live with the sound of speakers that have frozen MWs and MWs that are disconnected why would you be concerned with air leaks in the cabinet?

DDAN6815

I only made that statement to give an example of the type sound I'm getting from the frozen mw. I don't think anyone that has any kind of appreciation for music, or appreciation for speakers would be satisfied with speakers that are not up to par. I can only speak for myself. My plan is to either sell the speakers as is, considering the cabinets are in great condition, or replace all MW with new ones from Polk, abs have the crossovers rebuilt and upgraded.

F1nut

^This^

ghud

I know this thread is a little old, but I have three question regarding the MW, peerless tweeter and binding posts in my 10A's

I pulled the MW and they are marked 6KU 132 then underneath that 557744. They test out at 3.4 Ohms.

So are these original 6502 or replacements? The magnets are on there really good, however I will do the JB weld reinforcement, it's the prudent thing to do from all that I have read..

Secondly, the peerless tweeter is stuck in there pretty good, I guess the Moretite, if that's correct, is holding strong... Should I gently heat it with my heat gun or pry it or both?

Finally, my 10A's have two fuses and I plan to keep them, but I want to replace/upgrade the binding posts, what's the best option for the posts?

Thanks for all of help here, I do love my 10A's. I'm going to rebuild the XO's. And make a new cabinet out of 3/4" Mahogany plywood as the original cab is in bad shape.

ghud

I have to change the Ohms reading on my MW, I initally read them while attached to the XO, they read 6.7 and 6.8 now that they are removed from the XO, also there's stamp on the inside of the cone it reads ST5111. I should have removed them first..

F1nut

To the best of my knowledge, those are not Polk drivers.

Pop it out from the back.

Cardas binding posts.

If you make them out of plywood, you will change the tonal qualities of the speaker. Not a good idea.

pkquat

Those are Polk drivers from what I have gathered by searching the 6KU 132 number. I am not sure about the following 6 digits. There is are two old ebay listings in this post that reference MW6500. FYI, the MW6500 is no longer made. There are replacements, but they are not identical and change the sound a little in the early models. The used marked is the only place for the MW6500.

http://forum.polkaudio.com/discussion/154227/polk-mw6500-driver-early-version-1979-80ish

And this old FS ad. http://www.worthpoint.com/worthopedia/polk-audio-model-10-1-woofer-speaker-92767412

A vintage expert may chime in who knows more specifics. From what I gather those are the MW 6500's and correct for the M10's with the peerless tweeter based on this post.

http://forum.polkaudio.com/discussion/168538/hello-newbie-here-can-you-tell-me-exactly-what-i-have

As for the cabinets, @F1nut is 100% correct, for this type of speaker and enclosure it should be a particle board cabinet with veneer. The particle board helps dampen reflected sound inside the cabinet, and is how the original cabinets were designed. Changing the cabinet material would be a complete redesign of the cabinet.

The following thread may be helpful. @willwilly made veneer cabinets for the later version of the 10's that did not use the peerless tweeter. Plywood was discussed there too. He wound up using MDF I think. IMO MDF is still too solid and dense of a material, but it is still better than plywood in this application.

http://forum.polkaudio.com/discussion/172032/building-a-pair-of-polk-monitor-10s

notified

In regards to removing your tweeters. I have a set of mini monitors that time had bonded to the cab. Even after removing the mf to push up from underneath didn't help,
What eventually worked for me was to get a thin automotive feeler gauge that would slide in partially under the flange with some slight force and repeat this action around the tweeter flange to loosen the bond somewhat,
Then with the feeler blade wedged under the flange take a thin blade flat screwdriver [or similar] and with it wedged slightly under the flange while on top of the feeler gauge gently attempt to rock it left to right [using a sight force being careful not to bend the flange] while carefully pushing in slightly,
Carefully doing this around the flange should break the bond and by carefully lifting it up partially you may be able to remove the gasket intact by giving it a slight even pressured tug to remove it from the flange

ghud

Thanks for the comments fellas,

F1Nut, I hope you mean Formula 1, if so I hope this season is different from last, like to see a bit more from the Scuderia and the best would be Hass..

I digress, which post from Cardas?

I can do the veener, but one thing, MDF is very different from particle board from which Polk built the original cabinet, does the Monitor 10 need that less dense material, particle board? Is it a degree of sonic preference? Or design parameters?

Pkquat, where did you see that info regarding the 6KU 132 and which version of the 6500 did that correspond to?

notified, I used my heat gun at 260oF and ran it around the outside of the Peerless for 45-1min then pushed it out from the back, no problems.

So I've got both speakers broken down and have ordered parts for the XO rebuild. I've mocked up a stacked XO on a 4" diameter 1/8" MDF circle, it measures 5 3/4" tall from the back side of the retainning cup for the posts. My question now is if I build this configuration it leaves only 3 1/4" from the top of the 0.4mH coil on the XO to the back of the magnet on the MW 6500. Is this too close to the MW, will I have problems associated with this design? Should I enclose the XO in a similar fashion as a mid range driver enclosure in other designs? I guess shield the XO from the MW. I can slightly change the CuFt of the cabinet to make up for that enclosure if its necessary to maintain the correct CuFt of the original design.

Let me know what you guys think, Thanks Greg

pkquat

ghud wrote: »

I can do the veener, but one thing, MDF is very different from particle board from which Polk built the original cabinet, does the Monitor 10 need that less dense material, particle board? Is it a degree of sonic preference? Or design parameters?

The particle board is more about design parameters. As @F1Nut mentioned a different material will change the tone of the speaker. The cabinet material is a factor in the overall design. Particle board also has some natural dampening characteristics. It helps reduce reflections inside the cabinet which can add unwanted noise. It also lends itself to a simple box design. A harder surface such as MDF or plywood is more prone to reflections. Speakers that use these materials often use horns or have a separate enclosure for mids and tweeters. The rest of the cabinet is designed to minimize unwanted reflections.

ghud wrote: »

Pkquat, where did you see that info regarding the 6KU 132

The links, sections in blue, is the information I found. The first is a polk forum post. It contains links to two old ebay ads that reference the 6KU 132 and MW6500. The worthpoint link is an old ad that says some 6KU 132's were pulled from Monitor 10's. The last polk forum link mentions 6KU 132's and also says MW6500's were used in Monitor 10's with the peerless tweeters. I had never heard of 6KU 132 before your post. I assume that is what is underneath the Polk label with the MW65XX number stamped on it. Sometimes the labels fall of, but I don't know whether the 6KU 132 is in reference to the speaker or the magnet assembly.

ghud wrote: »

and which version of the 6500 did that correspond to?

While I am not an expert on the 10's the MW6500's are the correct era for peerless tweeter. I don't think there are versions of the MW6500, at least that I am aware of. If it is a different MW number such as a MW6501, MW6503, MW6510, MW6511, etc. these are different speakers with different Ohm ratings and specifications / characteristics.

On a side note, since you are looking at building cabinets, I'll toss out an idea. You might be able to build Monitor 7's vs 10's. What I do not know is if the PR's are the same between the two models. They are the same diameter, but may have different specifications. The 7's used a single MW inline with the tweeter and PR, vs the side by side setup of he 10's. The 7's have better stereo imaging since everything is in a vertical line. The side by side set up of the 10's tends to blur the imaging some. On the other hand the 10's have more bass, although some people feel they are a little boomy. People consider the 10's better for rocking out, and the 7's better for critical listening (not to say they don't rock).

Hopefully someone will chime in on the crossovers. I know people have rebuilt them with larger caps. Sonicaps and Mills resistors are the preferred components around here for rebuilding the crossovers, although there are some other high quality options.

ghud

Thanks Pkquat,

I'm not opposed to going vertical, I've just completed a rebuild on a 4412 and placed them in a vertical array. I'm pleased with the result. I've got a lot of woodworking stuff as my job requires finish cabinetry, so to build a 7 from a 10 is no prblem. Is there a schematic of the 7's XO somewhere?

I could also offset the Peerless and both MW6500's, place them in a vertical array on either side of the PR and mirrior image the cabinets. I would correct the interior CuFt/CuIns so it would be the same as the original design. Just a thought..

My mocked up rebuild XO on the 10 has the updated1.55mH coil mounted to the bottom of the 4" disc. I raised the XO off the binding post mounting bracket 1/2" standoff with the addition of an1 1/2" standoff to total 2" so the coil will clear. From there the two cap are on either side of the 0.4mH coil on top with the two 2.7Ohm resistors flanked on each side.

I was hoping someone can help me with the spacing between the top of the 0.4 mH coil and the back of the MW6500's magnet, it's around 2 7/8" clearance. Is this a functional problem, with it affect the performance of the XO or MW?

My thought is if it's a problem I could build an enclosure to shield the XO from the back of the magnets. A tube wrapped in shielding material, I guess...

I could always mount the XO to the back panel if necessary.

Could someone please recommend which Cardas binding post will fit into the 10's?

The Ply vs particle board

I guess I can't burn up a sheet of 3/4" Mahogany plywood as the customer changed their mind and wanted Oak instead, don't really want to return it, I've dealt with my supplier for such along time, I'll just stick it in the rack. On a good note this means I can do just about any species I want as they have lots of veeners.

Thanks so much Greg

willwilly

Love it!

MDF vs partial board...
MDF M10's are different than the originals. My MDF boxes, laminated with walnut and oak, 1 " MDF front and rear, upgraded cross overs, vintage drivers, PR'S and 194 tweeters.
They are massive, Dampened as close to original as I could achieve. I have learned a great deal with my first semi diy speaker project and one is don't mess with the cabinet material. These speakers are nice but lacking in the one thing I loved about the 10's, boomy. These are clear and tight, too tight. I'm running a Polk woofer between them to make up for my bass habit.
If I ever chose to make another pair, it would be partial board and a vinyl skin. Or, just fix up a pair vintage 10's. I'm finishing my 7's now and hope the influence of MDF isn't as drastic. Good thing they're pretty.

PR'S
I have a pair of 10's PR'S and a pair off 7's PR's. My research, (This forum, so it must be true) shows the same part number for both... All my PR'S have the same hand written part number. And since I bought them off EBay, they have to be authentic...

Vertical Drivers.

I considered making a vertical DTD,PR using the same cubic inches as a ten and use Polk parts. Still worth a try in my mind.