Polk Monitor 10 crossover confusion

onwardjames

Hello, everyone!

I have a pair of Monitor 10's, they have the white tweeter, and are from the mid '80s, but don't say anywhere that they are "B" variants. I'm pretty green on this. They also have NO fuse holder (polyfuse, I guess). So I assume they are 10b's.

My question is, I just obtained some Peerless tweeters, and wanted to recap the crossover. Are the Peerless going to play well with the stock crossover, or do I need to obtain some crossovers out of a Peerless pair, because I DO have a line on some.

All help is much appreciated. Thank you, and love the new site.

Tim

westmassguy

You stated they were white, so we figured you meant SL1000s, which had brushed metal plates. The RDO-194 or 198 will fit the recessed openings for the SL2000s perfectly. That's what they were made for. You made an error, just chill a bit, and if the seller won't refund them, re-sell them, and do the 10s properly. They're fine speakers, and once upgraded will amaze you.

westmassguy

onwardjames wrote: »

So the seller refunded all my money, great karma there.
What's the advantage of the RDO-198-1's vs the RDO-194-1's ?

Thanks for the crossover mod link, westmassguy.

Both the 194 and 198 are based on the same technology Polk invested heavily in. The 194s were designed to match the electrical characteristics and overall frequency response of the SL2000, minus the nasty 5db resonance peak at 12-13KHz. The 198s were designed to match the same characteristics of the improved SL2500 and SL3000. They are drop-in replacements for they're respective types. The 198 has more detail than the 194s, but since it's designed as a replacement for the later models, some modifications to the crossover are required if the speaker had SL1000 or SL2000. Bottom line, both are vastly superior to the earlier models, but the 198 edges out the 194 for overall sound quality.

pitdogg2

if you have SL2000 tweeters peerless will be too small for the cut out. If they are SL1000 (which I'm guessing here) they are also not a match for the peerless XO.

mhardy6647

Is the SL1000 the one that kind of looks like the Peerless but has a silver-colored bezel?

(that's the one tweeter from the family that I have very, very little experience with, FWIW)

westmassguy

You'd be better off with new RDO-194s, or do the TL modification and use the RDO-198s. Both are superior to the Peerless in my opinion. You'll have to modify the recessed mounting area regardless of which tweeter you choose.

onwardjames

So, not only have I wasted money buying the peerless, they also won't fit.
Typical of my luck.

mhardy6647

The Peerless are excellent tweeters and nothing so far suggests (to me) that they cannot be adapted to the speakers you have. Whether you want to retrofit the Peerless or "pro-fit" (so to speak) the modern replacements... that's gonna be your call.

onwardjames

Thanks, mhardy. Don't know what I'm going to do.
As usual, I'm in over my head.

dkfreebird

You're in the right place if you think you're in over your head.The people on here will help you in any way they can,they have me!

westmassguy

If the Peerless are in fine shape, you should have no problems selling them. Swapping a crossover from an earlier pair of 10s just to be able to use the Peerless is a step backwards. Polk used different woofers and passive radiators as the 10s progressed. There's a good chance you'll end up with "FrankenPolks" which you don't want.

onwardjames

Okay, I pulled a tweeter. It is SL2000 tweeters. Does this mean the cutout for the SL2000 is TOO LARGE, therefore leaving a hole? Also, the Peerless would need an appropriate crossover (which I have a line on) ??

How does one repair too LARGE a hole?? Any links, old threads??

I apologize for my naivete, but like I said, I'm green on this stuff.

onwardjames

westmassguy, thanks for your help, didn't see your post until after mine.
I'm going to kindly say to hell with this entire ordeal, and either eat the cost of the Peerless if seller won't refund, and be shed of this whole nightmare.
Thanks, fantastic feedback and quick, much appreciated.

gdb

I'd recommend installing the smaller, Peerless tweeter as centered as you can get it, making new screw holes where appropriate and fill in the perimeter gaps with some black caulk if you're concerned about the looks and normally have the grilles off. Enjoy. I love the Peerless sound in my 10A monitors. PS: not sure what would need to be done to Xovers to make your 10s compatible with the Peerless tweeters.

onwardjames

gdb, thank you, I'm seeing if seller will refund 90% of payment. If not, no biggie, may try that. Westmassguy, thanks as well. On down the road, I'd love to upgrade these. With those new tweeters you mention, what mods to the crossover are needed, if you happen to know offhand.
Again, I'm an easily excited person, and yes, I should chill. Drinking Guinness right now in hopes I will do just that.

westmassguy

The RDO-194-1s will drop right in, no modifications needed, and can be done even before the crossovers are rebuilt. If you'd like to use the RDO-198-1s, small modifications to the crossover are required during the recap. The schematic for the mod is here: https://us.v-cdn.net/5021930/uploads/attachments/4/6/7/2/8/18777.attach

onwardjames

So the seller refunded all my money, great karma there.
What's the advantage of the RDO-198-1's vs the RDO-194-1's ?

Thanks for the crossover mod link, westmassguy.

onwardjames

Whoops. Link goes nowhere.

westmassguy

onwardjames wrote: »

Whoops. Link goes nowhere.

Worked fine for me, it should open Adobe Acrobat Reader right in your web browser. If not, got to the Non-SDA Schematics section in the Vintage Forum, and look for the M10 SL3000 Mod

onwardjames

Now THAT's an answer! Thank you so much westmassguy! I'm using a Mac, and it has issues. Will try again later, and probably spring for those 198's and do some modding.

westmassguy

onwardjames wrote: »

Now THAT's an answer! Thank you so much westmassguy! I'm using a Mac, and it has issues. Will try again later, and probably spring for those 198's and do some modding.

More than welcome. You're probably better off just downloading the file from the section I listed. you should also download the M10 Rev schematic as well, so you can see the changes.

On3s&Z3r0s

Don't mean to threadjack, but I was also wondering about modding some 10s and onwardjames might find the answer useful too... Actually, it's two questions... first, if doing the SL3000/198 mod it looks like one of the inductors needs to be changed out for a different value (0.27 mH if I'm my eyes aren't completely shot yet). Is this one from PE what people generally use? Oops, just found another thread on M10 XO's where I saw the recommendation to unwind the stock inductor instead of trying to find a replacement. So, if there is no suitable commercially available part, doesn't measuring inductance require some specialized equipment, or can it be done with a standard multimeter and math?

Second question... all the M10 schematics specify one electrolytic and one mylar capacitor behind the tweeter. I assume you'd use film caps all around now when rebuilding, or was there some magic to that electro/mylar combination? Just wondering cause I hadn't noticed that on other schematics.

westmassguy

On3s&Z3r0s wrote: »

Don't mean to threadjack, but I was also wondering about modding some 10s and onwardjames might find the answer useful too... Actually, it's two questions... first, if doing the SL3000/198 mod it looks like one of the inductors needs to be changed out for a different value (0.27 mH if I'm my eyes aren't completely shot yet). Is this one from PE what people generally use?

Second question... all the M10 schematics specify one electrolytic and one mylar capacitor behind the tweeter. I assume you'd use film caps all around now when rebuilding, or was there some magic to that electro/mylar combination? Just wondering cause I hadn't noticed that on other schematics.

The DCR on that Inductor is too low. You will have to increase the value of the resistor that's in series with it to compensate. Instead of 2.7 ohms, increase the resistor value to 3.0. If you have an LCR Meter, you can also unwind the existing .4mh Inductor.
The only magic that occurred with Mylar and Electrolytic Caps combined, was it made the bean counters happy.
Use quality, Metalized Polypropylenes throughout. Sonicaps or Clarity.

On3s&Z3r0s

Thanks, as always, for the info. I'm very glad I asked since I totally misread that schematic. I thought the 0.5 ohm value meant to change out the resistor next to the inductor rather than being the DCR of the inductor. That would have made a huge mess out of that crossover.

It sounds like the Jantzen inductor plus a 3.0 ohm resistor would be the easier and cheaper modification if that is close enough. I don't have an LCR meter and it seems like the good ones run close to $200. Thanks again for saving my bacon and my prospective XO mods!

westmassguy

More than welcome. Have fun!

onwardjames

One last thing, westmassguy, and whomever can answer....

Since I have the 10b's it seems, should I replace the polyswitch with a fresh one, or go a fuse route? I never get above 10 watts, and that's only a rare occasion. Next, the 194's drop RIGHT IN with no fabbing or box alterations, correct?
Then finally, a full recap of mylar and whatnot with poly caps from Sonicap or Clarity.

Honestly, all this done would be a significant difference, and not too far from the 198 mod? Don't really care to unwind that coil, don't have the tools to measure, etc. And don't wish to get too crazy.

Even stock, these speakers sound very good to me, tho I hear a ringing in the upper register that's present on nearly any song I play. I'm guessing that is the 5k peak I hear about with my SL2000 tweets.

Again, I appreciate the expertise. Been sidetracked with my new to me Dynaco A25's.

westmassguy

onwardjames wrote: »

One last thing, westmassguy, and whomever can answer....

Since I have the 10b's it seems, should I replace the polyswitch with a fresh one, or go a fuse route? I never get above 10 watts, and that's only a rare occasion. Next, the 194's drop RIGHT IN with no fabbing or box alterations, correct?
Then finally, a full recap of mylar and whatnot with poly caps from Sonicap or Clarity.

Honestly, all this done would be a significant difference, and not too far from the 198 mod? Don't really care to unwind that coil, don't have the tools to measure, etc. And don't wish to get too crazy.

Even stock, these speakers sound very good to me, tho I hear a ringing in the upper register that's present on nearly any song I play. I'm guessing that is the 5k peak I hear about with my SL2000 tweets.

Again, I appreciate the expertise. Been sidetracked with my new to me Dynaco A25's.

Replace the Polyswitch with a .5 ohm mills MRA-12 Resistor.
The RDO-194-1 and RDO-198-1 are drop in replacements for the SL2000, SL2500, and SL3000, no alterations are required.
If you do the TL mod, the female spade/quick connect on the ground (white) lead going to the tweeter will have to be changed to a 3/16" female quick connect.
The harshness you're hearing from the SL2000, is a 5db resonance peak around 12-13 KHz.

onwardjames

Expert answer, and thank you very much! I'll be doing the 194's and a recap, and enjoying the heck outta these great speakers. I did try putting some epoxy on the magnets to prevent shift (been told repeatedly) and so far, so good, but I didn't dismantle them. Apparently, a messy pool of glue around the OUTSIDE doesn't do much.
I'll cross that bridge if/when I come to it.

westmassguy

There appears to be a misconception about gluing the magnets. If the woofers are functional, not rubbing, you do not need or would ever want to take them apart. The glue is meant to reinforce the existing glue, and prevent magnet shift. JB Weld, Epoxy are ok, but difficult to work with. I use and recommend Loctite Power Grab, Clear Acrylic Adhesive. Apply a bead on the top and bottom of the ceramic magnet where it meets the front and back plate. Smooth it out with your finger tip, wipe of any excess with a damp sponge, and let it dry for a few hours.