Question on Monitor 10B crossover...

heiney9

I had a pair of LSi 9's and have a pair of Mon 5B's with refreshed x-overs and RDO's and like F1 states completely different speaker designs components and theories. In my experience the (2) cannot be compared side by side.

I used the LSi's in my main rig which now have SDA 1C's and I currently use my 5B's for my office/computer rig and they are excellent in that capacity.

Enjoy bot speakers but on an individual basis.

H9

jon s

Well, after breaking in the upgraded crossovers on my Model 10Bs for about 100 hours, I decided to take them out and put back the LSi15s... After listening to the LSi15s, I have come to the conclusion that the LSi15s sound smoother but the soundstage on the Monitor 10Bs are noticeably superior. Better depth and focus. The SL1000s are a tad bright and the bottom end is not as deep as the LSi15. Overall, the LSi15s just sounds a bit flat, no depth and not as focussed. I used all Jantzen crosscaps and the overall improvement from the original caps is noticeable. If the Sonicaps are supposed to be a LOT better, I'd probably be amazed.

heiney9

Jon, it's tough to compare older Polks to newer Polks. I had a pair of LSi 9 and Monitor 5B's with reworked x-overs. They both sounded very good but completely different. In the end the 9's were the superior speaker but they each did some things better than the other.

I have SDA 1C's now in place of the 9's as well as still having the 5B's for my computer/office rig. The 1C's are my choice by far. As good as the LSi's are (and they are excellent) the 1C's just have the magic no other speaker can give.

I was not in any way disappointed in the LSi's just prefer the overall sound of the 1C's for many of the types of music I listen to.

The thing is the LSi's sneak up on you as to how smooth and effortless they are. They have excellent to superb midrange and upper frequencies and Jazz instruments and piano as well as female vocals sound superb on LSi's.

H9

P.s. The 1C's have Sonic caps and RD0's.

jon s

I just picked up a pair of RTA12Cs and am planning to upgrade the caps... I was looking at the Sonicaps but the 4 4.3uF and 12 27uf caps (each speaker has 2 4.4 uf caps and 2 27uf caps on the crossover board. I still need to combine two 27 uf caps to replace the 55uf cap on the main board and two more 27uf caps to replace the woofer caps)plus resistors would set me back about a whopping $500.. I know the Sonicaps are well regarded but at that price the point of diminishing returns really start to hurt... plus I still need to replace the SL2000 with RDOs and they cost $140 total to ship to Hawaii ($48 plus $22 shipping each tweeter).. Polk does not offer free shipping to Hawaii...

Even using the "cheap" Jantzens would set me back $150...

Face

I'm surprised you find the soundstage on the Monitor 10's superior to the LSi's. I haven't heard them back to back, but I thought the opposite.

jon s

After living with the Model 10Bs with the Jantzen caps... I decided to try and go up to the Sonicaps. I just ordered 4 12uf and 2 17uf (Sonicaps do not have a 34uf cap so i have to parallel them) with a pair each of Mills 2.7 ohm 5w resistor and 2.5 ohm 5 watt resistors. Total bill came to $200. I should get them sometime next week.

I am supposed to receive my RDO tweeters today. If all goes well, I am also planning to re-veneer the cabinets afterwards. I am deciding between cherry or walnut. I am also thinking of removing the black vinyl from the baffle and veneering the entire face of the baffle. there is a lip on the edges of the baffle which needs to be planed away.

I am also considering removing the grille posts, drilling them out and replacing them with magets, filling over them and veneering over that. I would then place magnets in the grill holes to match. I am debating on how difficult it would be to cut the venner from the cutouts for the drivers. If successful, I would follow up and recap and re-veneer the RTA-12Cs...

Unfortunately, the external crossover for the RTA-12C leaves me little room for all Sonicaps. i am ordering sonicaps for the tweeter and Jantzens for the bottom end.

McLoki

I will be very interested in your opinions between the two.

Will you at least be able to use some of your Jantzen caps in your 12c's?

Michael

jon s

sorry to say, no... the values are completely different... while the 10Bs only needs 3 caps/speaker... the 12Cs need 10/speaker... a lot more expensive... I can eliminate the 750pf caps so that brings it down to 8/speaker... but five of the eight are large values so they are expensive.

jon s

I just replaced the Polk RDO194 tweeters. The faceplate is about 1/2" taller than the original. How do you swap them out? Did you enlarge the cutout or did you swap the faceplates themselves, altho it looks like the leads on the faceplates of the SL1000 are not swappable.

Secondly, i got a couple of the Mills 5watt resistors. They look like regular cylindrical resistors, not like the box shaped ones on the crossover or like the 10watt Mills. Is that okay?

heiney9

What tweeter do your Monitor 10's have now? If you have the sl1000 or peerless you need to carefully enlarge the opening with a dremel.

heiney9

jon s wrote: »

Secondly, i got a couple of the Mills 5watt resistors. They look like regular cylindrical resistors, not like the box shaped ones on the crossover or like the 10watt Mills. Is that okay?

Yes the square originals are crap compared to the Mills

jon s

heiney9 wrote: »

What tweeter do your Monitor 10's have now? If you have the sl1000 or peerless you need to carefully enlarge the opening with a dremel.

I have SL1000s in the speakers now... shoot... now I gotta buy a dremel tool... how do you make the cut straight?

Face

It doesn't have to be perfectly straight, just don't get overzealous.

dcmeigs

jon s wrote: »

I have SL1000s in the speakers now... shoot... now I gotta buy a dremel tool... how do you make the cut straight?

I tried using a router but I did'nt have enough clearance around the plastic fasteners that hold the grill in place to do the whole job. I finished up with a utility knife and a sharp chisel. I don't se why a guy couldn't do the entire job that way if he clamped a straightedge in place to keep the knife cut even. Think through the hole placements, because the old ones are so close to the desired locations of the new ones as to be a PITA.

jon s

Okay, I replaced the SL1000 tweeters with the RDO194s. I bought a RotoZip with a fence and a router bit to increase the size of the cutout. I just enlarged to top of the original big enough to drop in the RDO194 tweeter. Had to remove the mid-woofers so I could get some clearance for the fence. I was surprised to see that the bass passive radiator and the mid-woofers are not sunken into the baffle. Makes me really think about veneering the entire front baffle.

Went to Woodcraft and they only had walnut so I picked that up. But I do not have enough to do the front lip (if I decide to just replace the vinyl walnut "veneer"). I have to order 2"x25' edge veneer.

If this comes out, I will refinsih the RTA-12C but the top of the cabinet will be difficult with the two bolts, the crossover junction as well as the rubber padding that the tweeter assembly sits on.

Getting back to the Monitor 10B, I can safely say that the RDO upgrade was worth it. The imaging is slightly better, the harsh high end is subdued. My Sonicaps for the 10B just arrived and I will work on them on Sunday, replacing the Janzten caps I put in there last month. The caps are HUGE>... there is no way to put those on the RTA-12C.

Odd, the stuff I ordered from Parts Express two weeks ago has not arrived yet. will have to check on it on Monday...

jon s

HOLY SMOKES!!! I just removed all the Jantzen caps from the crossover and replaced them with Sonicaps. The difference was not subtle. with the Sonicaps, there was an immediate sense of "air" or ambience to the music. The high frequencies opened up without feeling harsh. The was a definite improvement in depth and the sound was better focused. complex ensembles was revealing in its clarity. Upgrading the Model 10Bs to the RDO194s and Sonicaps is a definite upgrade anyone and everyone should consider.

Next up... the RTA-12Cs....

McLoki

jon s wrote: »

HOLY SMOKES!!! I just removed all the Jantzen caps from the crossover and replaced them with Sonicaps. The difference was not subtle. with the Sonicaps, there was an immediate sense of "air" or ambience to the music. The high frequencies opened up without feeling harsh. The was a definite improvement in depth and the sound was better focused. complex ensembles was revealing in its clarity. Upgrading the Model 10Bs to the RDO194s and Sonicaps is a definite upgrade anyone and everyone should consider.

Next up... the RTA-12Cs....

Thanks for posting - My order will go in tomorrow...

Big Dawg

Has anyone ever tried these kits sold on eBay?

http://cgi.ebay.com/Polk-Audio-Monitor-10-RTA-11-Upgrade-Kit_W0QQitemZ260416319059QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3ca205ae53&_trksid=p3286.c0.m14&_trkparms=65%3A1%7C66%3A4%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A200

For $25, is it worthwhile? I haven't held a soldering iron since I was in Jr High, and never did get that damn radio to work!!!

Interested in comments - want to try upgrading 10Bs with SL1000 and 7Bs with peerless to RDO194s with updated crossovers.

NJPOLKER

Big Dawg
Forget about it!!!!!!!!!
Do a forum search here and you'll find a lot of great info on where to buy capacitors and resistors. You'll also find excellent direction on doing the modifications. pictures too.

Big Dawg

NJPOLKER wrote: »

Big Dawg
Forget about it!!!!!!!!!
Do a forum search here and you'll find a lot of great info on where to buy capacitors and resistors. You'll also find excellent direction on doing the modifications. pictures too.

That's what I figured - I've been reading tons, this is a great forum.

Where in NJ are you? I live in East Brunswick.

Dennis47

F1nut wrote: »

That is the correct part list.

(4) 12uf Sonicaps
(2) 34uf Sonicaps
(2) 2.5 ohm resistors
(2) 2.7 ohm resistors



Yes, but you want to upgrade to film/foil caps.

You can find a nice selection of caps and resistors here,

http://www.soniccraft.com/products/capacitors/film.htm

http://www.soniccraft.com/mills_resistors.htm

This is an old thread about Monitor 10Bs, but I need a verification....
I downloaded the schematic and it shows 10Bs with polyswitch as
using a 2.0 ohm 5 watt resistor and a 2.7 ohm 5 watt resistor.

F1nut states above that the 10B use a 2.5 ohm 5 watt resistor and
a 2.7 ohm 5 watt resistor.

Which is correct for 10Bs that have a polyswitch?

Thanks...

F1nut

That was the correct parts list for his speakers. Your 10B's might be the newer version, so I strongly suggest that you open one up to verify the values. They will be printed on the caps and resistors. I would also suggest going with the 12 watt Mills instead of the 5 watt.