Monitor 10b Tweeter and X/O Upgrade

deville

It was suggested that I post this in this section. Sorry for the double.
Hi:
First post. Been lurking and doing a lot of research for a while here, great site and info.
I've owned my Monitor 10b for over 18 years, purchased new and are in excellent shape. I convinced the wife to keep them in the living room for now and had planned to move them into another room later when we get the addition to the house built, but on hold for now.
From what I have gathered for the x/o upgrade, preferences here with the RDO-194 tweeters is the Sonicap 12uF cap for the hi pass filter and Dayton 33uf for the bass filter. The other 12uF cap (original electrolytic) which I have heard referred to as the RC Contour Network, does one prefer a higher quality cap such as the sonicap? Would a Mundorf M-Cap MKP 33uF work for the low pass. I'm in Canada so I'm trying to avoid purchasing from too many different suppliers to cut down on border cost and such.

Also, if upgrading to the RDO-198 tweeter, it seem that only the 0.4mH inductor be changed to a 0.27mH and the 2.0 ohm resistor to a 2.7 ohm. For the inductor, which gauge and what resistance of the inductor to keep the resistance for the tweeter within limits? BTW.... I got this info from the schematic for the Monitor 10-SL3000. I hope its the right one for the 198's.

Still have not totally decided to go with the 194 or with the 198 (opinions welcome). Regardless, depending of the tweeter I choose to go with, the x/o will be upgraded including the resistors, but not the 1.55mH inductor unless absolutely necessary. Sonicaps for the hi pass is for certain.

BTW... the 10b's I have are with the SL2000 tweeters and MW6503.

Thank you for your time. Just want to make sure I am on the right track.

Neil

Boywonder

FWIW, I upgraded my 10B's with the RD0-194's and Solen caps and they sound much nicer than stock, especially the attack/dynamics.

As you have probably already figured out, the -194 tweeters are direct replacements for the SL-2000, and the -198 tweeters are for replacing the SL-3000's.

Replacing the stock electrolytic caps with film caps is the big leap in the upgrade. Depending on your budget, you could use Dayton, Solen, Sonicap, Clarity caps, etc. The Sonicaps on the high pass and Solen/Dayton on the low pass is a good $$/performance compromise. If you've got the budget, you could do Sonicaps all the way.

I would also remove the polyswitches on the tweeters unless you regularly play them LOUD with a lower powered amp/reciever.

I put Sonicaps and the RD0-194 tweeters in my SDA 1C's and they are the nicest sounding speakers that I have owned to date. It's a slippery slope, you start off upgrading your monitor 10's and end up searching the countryside for SDA's to stick Sonicaps and tweeters into......

deville

What are the gains with removing the polyswitches? I haven't had them kick in in years, so probably don't need them.

I ordered all the parts.... sonicaps for the highs and solen fast caps for the low pass, as well as mills resistors.
Have a hang up with purchasing the RDO-194 tweeters though (another thread).

Thanks:
Neil

ShinAce

Just so you know for next time, you can get Solen in Canada. http://www.solen.ca/pub/index.php

Definitely jumper across the polyswitches if you don't trip them. Not to mention they don't always work properly once they're older and have been tripped a few times. It can only help to improve the treble quality.

deville

Thanks ShinAce, I will remove the polyswitches.
Yes, the Solen caps I did order from solen.ca. Had to get the sonicaps from the US, I couldn't find anyone up here that sells them. Parts ConneXion has a lot of brands of caps but I am more confident with the sonicaps because of the info/recommendations from this site.... tried and tested.

Now I just need those damn tweeters!

Neil

Dennis47

I don't think I see any answer to one of the original questinons:

...The other 12uF cap (originally electrolytic) which I have heard referred
to as the RC contour network, does one prefer a higher quality cap such
as a Sonicaps?...

Does anyone know if you can use one 12uF Sonicaps (high pass)
and one 12uF Solens (RC contour network) caps in each of the
Monitor 10B XO upgrade?

Thanks,
Dennis

Boywonder

Dennis47 wrote: »

I don't think I see any answer to one of the original questinons:

...The other 12uF cap (originally electrolytic) which I have heard referred
to as the RC contour network, does one prefer a higher quality cap such
as a Sonicaps?...



Does anyone know if you can use one 12uF Sonicaps (high pass)
and one 12uF Solens (RC contour network) caps in each of the
Monitor 10B XO upgrade?

Thanks,
Dennis

You can replace the 12uf electrolytic cap with a 12uf Sonicap or Solen (or any film cap for that matter) for an improvement. In general, replacing electrolytic caps with film caps is a great upgrade. Manufacturers use electrolytic caps in higher uf values to save $$; they are way cheaper than film caps. There are differing opinions here about mixing and matching different brands of film caps but replacing an electrolytic cap with a film cap is always an improvement.

The idea behind using Solens/Daytons/etc in the low pass sections an Sonicaps in the high pass section is to maximize bang for the buck. If you can swing the bucks, go Sonicaps everywhere. For value, use Solens or Daytons, etc throughout the xover, it will still be a big improvement over the old stock electrolytics and vanilla film caps installed at the factory.

thsmith

ShinAce wrote: »

Definitely jumper across the polyswitches if you don't trip them. Not to mention they don't always work properly once they're older and have been tripped a few times. It can only help to improve the treble quality.

Shinace, can you explain further. By replacing or removing the polyswitch it can possibly improve the treble quality ?

Thanks,

Face

Yes, it can.

LCruiser122

Hi all...
I recently replaced tweeters (RDOs from Polk) on my 10As.
I now want to do the XO upgrade (due to what I've read)

Could someone give value, quantity, and part #s for these items.
I'm not sure how many or what to order and from where.
It looks like I'll go sonicaps in the highs and prob dayton on others.
Any idea on cost also?

Thanks, I'm just not sure what to order.... specifically.

LCruiser122

Here is a pic of my XO.
What am I replacing?

ben62670

Everything except the coils;)

LCruiser122

So....
the two blu, and 1 yellow.... that's all? What about the item below the one blue cap?

Does anyone know of a thread that specifically lists the parts? Am I replacing the same valued caps or different?
Thanks in advance

Boywonder

You should plan on replacing all three caps (the two blue electrolytics and the yellow mylar) with Sonicaps, Solens, Dayton, etc film caps. For a literally a few more $, replace the sand resistor with a Mills non-inductive resistor or another non-inductive R. The replacement caps need to be the same uf value as the stock ones (they do not see much voltage, but any film cap replacement will far exceed the required voltage, so no problem there) and the replacement resistor needs to be the same ohm value and watt (power) value.

You will be leaving the inductor alone (the coil of wire).

The values that you want to match are on the factory components. They may be a little cryptic, but they should be labeled. If you are confused, post pics of the writing of the component in question with the macro feature of your camera (for a nice, tight close-up shot) and someone here will help you ID.

You can get Solens (or claritycaps) at www.madisound.com or from Michael Percy at www.percyaudio.com

Daytons (and Mills R's. IIRC) at www.partsexpress.com

You can get Sonicaps at http://www.soniccraft.com/sonicaps.htm

The thing below the blue cap is the sand resistor, replace it with a non-inductive wire wound part of the same wattage and R value.

ben62670

I agree with everything BW said except I would not use Solen's on the highs.
Ben

LCruiser122

Thank You Very, very much!

And it IS worth the time, $ and effort...... right?

LCruiser122

If i'm gonna do it , i'll go sonicap on the high cap.(based on what everyone says) I have always found you get what you pay for.
If I don't go sonicap on the bass, I'll prob go Dayton. I've been happy with their products.
Btw... is the yellow one the bass cap?
What about the third cap(blu one?rc contour) Sonicap or Dayton?
I can get the mills resistors from Dayton too. So I only have two places to order from (Dayton & Sonicap)

Boywonder

LCruiser122 wrote: »

Thank You Very, very much!

And it IS worth the time, $ and effort...... right?

It is to the fanatics on this site:D

My monitor 10b's were much improved after the upgrade. As mentioned above, remove the polyswitches and replace with a jumper if you do not listen to them LOUD with a low-powered amp. The polyswitches protect the tweeters from getting blown due to DC from clipping (overdriving) a low powered amp.

They should be either little blue or tan disks with legs, like a small ceramic cap (whatever that looks like). Use left the left over leads from the new cap install (once they are trimmed) for jumper material.

The yellow cap is a small value mylar (film) cap. One of the larger electros (blue ones) is for the low-pass. Search this site for the x-over schematic, it will be clear what everything is once you locate the schem.

LCruiser122

What do you consider low power? I run an early 80s 75 wpc Harman Kardon 680i for LPs and stereo audio or a 85wpc 7.1 Denon for HT use.
However, I am very careful (I've had them since the early 80s) with the 10As as they are VERY special to me.
The risk for removing these polyswitches are worth the upgrade in the highs you think?
The only clipping I would worry about is from dynamic changes from TV and movies...NEVER from my audio listening.

Thanks again.

Boywonder

Keep in mind that the film caps that you are going to be installing are WAY bigger than the electrolytics that you are removing, so you will need to get a little creative with shoe-horning them in there. Solder them up, then hot melt glue them down. You can piggyback the new Caps on top of each other if needed.

You may also want to consider upgrading the binding posts while you are in there, it's a slippery slope.

Boywonder

LCruiser122 wrote: »

What do you consider low power? I run an early 80s 75 wpc Harman Kardon 680i for LPs and stereo audio or a 85wpc 7.1 Denon for HT use.
However, I am very careful (I've had them since the early 80s) with the 10As as they are VERY special to me.
The risk for removing these polyswitches are worth the upgrade in the highs you think?
The only clipping I would worry about is from dynamic changes from TV and movies...NEVER from my audio listening.

Thanks again.

Most folks here would consider a receiver to be fairly low power, the risk to your tweets depends on your listening habits.

You can leave them in if you are worried about it, and you may be able to call Polk support (parts dept) for a free new pair. They don't age well. In fact, my neighbor gave me a 42" Fujitsu plasma TV a few years ago because it kept turning off after being on for more than a hour or so, and it was out of warranty. The problem ended up being a 50 cent polyswitch.

LCruiser122

Thanks again. I'll follow those directions.

I can't seem to locate the polyswitches. Where do you think they are located? Do I have them since I have the fuse on the back?

I've attached photos. Two blue caps are 12 uF and 34uF, under the 12uF cap are two (resistors); 1 each 2.7 and 2.5. The yellow film cap has TI , E0012-1 , 12J100V on it...not sure what to get.

What kind of posts would you recommend?
I'm not affraid of mods if I have direction/advice.

Thanks

ben62670

You don't have them if you have the fuses. Vampire makes great solid posts.
You will need 4 12uf caps, 2 33-36uf caps, and the resistors. The yellow cap is a 12uf;)
Ben

LCruiser122

I'm looking at them online.
So you are saying, in effect, the 12uF and the yellow one can both be replaced by the SAME cap...12uF? As far as between 33-36 uf, I can get any in that range? (i'm having trouble locating a 34uF)

And the "most important one" (Sonicap) is the blue 12uF or the blue 34uF?
Also, the 2.5 & 2.7 resistors... is both replaced at 2.5 ok? (I would need 4..2 per speaker)
Dayton has different "types" of film caps... any recommendation as to which one?

Thanks, I REALLY appreciate the advice.

Boywonder

LCruiser122 wrote: »

I'm looking at them online.
So you are saying, in effect, the 12uF and the yellow one can both be replaced by the SAME cap...12uF? As far as between 33-36 uf, I can get any in that range? (i'm having trouble locating a 34uF)

And the "most important one" (Sonicap) is the blue 12uF or the blue 34uF?
Also, the 2.5 & 2.7 resistors... is both replaced at 2.5 ok? (I would need 4..2 per speaker)
Dayton has different "types" of film caps... any recommendation as to which one?

Thanks, I REALLY appreciate the advice.

The schematics are is located right above the first active post on this page, they are the last sticky. If you have the original monitor 10's, check out that schematic.

It looks like you've got 2 12 uf caps and two resistors in the tweeter circuit, a 2.5 ohm 5w and a 2.7 ohm 5w. The 34 uf is on the midwoofer circuit.

You can wire caps together in parallel to add the uf values. So a 32 uf wired in parallel with a 2 uf gives 34uf. Another feature of adding a parallel "bypass" cap is that you can use a small value (like 2uf above) film to bypass a large electrolytic (or film) cap. Search this forum for "bypass cap" Some folks swear by bypass caps, others swear at them. In general, smaller caps are "faster" than large ones, giving better transients, etc, although this can be a topic of much debate whether or not they make speakers sound better.

ben62670

LCruiser122 wrote: »

I'm looking at them online.
So you are saying, in effect, the 12uF and the yellow one can both be replaced by the SAME cap...12uF? As far as between 33-36 uf, I can get any in that range? (i'm having trouble locating a 34uF)

And the "most important one" (Sonicap) is the blue 12uF or the blue 34uF?
Also, the 2.5 & 2.7 resistors... is both replaced at 2.5 ok? (I would need 4..2 per speaker)
Dayton has different "types" of film caps... any recommendation as to which one?

Thanks, I REALLY appreciate the advice.

Yes the 2 12uf caps can be replaced by the same style caps.
On the highs
http://www.soniccraft.com/sonicaps.htm
or
http://www.parts-express.com/pe/pshowdetl.cfm?PartNumber=027-430
On the lows
http://www.parts-express.com/pe/pshowdetl.cfm?PartNumber=027-944&DID=7
For the resitors these would be fine. They are 1% and the stock one are 5% IIRC
http://www.parts-express.com/pe/pshowdetl.cfm?Partnumber=005-2.5

ShinAce

thsmith wrote: »

Shinace, can you explain further. By replacing or removing the polyswitch it can possibly improve the treble quality ?

Thanks,

There's an entire thread on it:
http://www.polkaudio.com/forums/showthread.php?t=73470

My viewpoint is that a breaker or polyswhitch is a non-linear device. Which means it has different specs at different power levels/frequencies. When there's a transient, or a hit of treble, say, some good classical music crashes, the switch absorbs more juice than listening at low levels. Since classical is so dynamic, you want lots of headroom. The switch compresses your headroom. It also has an equivalent series resistance(depending on power), and a stray capacitance.

This kind of makes me a hypocrit, since I've built a pair of bookshelves with audio breakers. I chose to put the breaker on the entire speaker because of my sister's setup. Small receiver, but big enough to blow the speakers. If there's too much bass(read: too much power), the breaker will trip before it distorts badly and kills the tweeter.

With that said, there's nothing wrong with the Polk approach. The reason I did it was because the speaker is for a family member. I want it to be as reliable and user-friendly as possible. My other designs are more sonically goal oriented. I'm not saying the switches destroy the sound. I'm just saying they are designed for protection, not just sound. That's what they have to do.

LCruiser122

ShinAce wrote: »

There's an entire thread on it:
http://www.polkaudio.com/forums/showthread.php?t=73470

My viewpoint is that a breaker or polyswhitch is a non-linear device. Which means it has different specs at different power levels/frequencies. When there's a transient, or a hit of treble, say, some good classical music crashes, the switch absorbs more juice than listening at low levels. Since classical is so dynamic, you want lots of headroom. The switch compresses your headroom. It also has an equivalent series resistance(depending on power), and a stray capacitance.

This kind of makes me a hypocrit, since I've built a pair of bookshelves with audio breakers. I chose to put the breaker on the entire speaker because of my sister's setup. Small receiver, but big enough to blow the speakers. If there's too much bass(read: too much power), the breaker will trip before it distorts badly and kills the tweeter.

With that said, there's nothing wrong with the Polk approach. The reason I did it was because the speaker is for a family member. I want it to be as reliable and user-friendly as possible. My other designs are more sonically goal oriented. I'm not saying the switches destroy the sound. I'm just saying they are designed for protection, not just sound. That's what they have to do.

Are you saying my fuse set-up is better ? (from a sonic perspective)

ben62670

Yes, but the fuse holders in those tend to oxidize pretty bad. I typically bypass the fuse on the board. If you don't blow the fuses then you may want to bypass it also.
Ben

Russ_L

Neil is lucky; my two pairs of Montor 10s have two fuses each. There is a one amp fast blow on the tweeter leg, and a two and a half amp fast blow on the mid-woofer leg. Ben is right about the fuse holders oxidizing.

I only have the speakers for a few days now. I pulled the fuses out two nights ago. They were oxidized to the point that I could not read their values. Using a cloth, I cleaned the fuses to where I could read the values. That left the fuse holders, which were badly oxidized.

While speaking to Ken at Polk customer support about bypassing the fuses he recommended Flitz polishing paste http://www.flitz.com/p-16-flitz-polish-paste.aspx to clean the fuse holders (or any other electrical parts). My order should be arriving today from Flitz. I’ll be cleaning the fuse holders tonight and installing new fuses at the same time. Funny thing, the speakers sound very nice without any cleaning.

Ken told me in general that he advises customers against removing the fuses. In my case, since I have the Peerless tweeters (very hard to come by) he is recommending that I leave the fuses in. OK; does someone have the link to those audiophile fuses I’ve seen advertised in the past?

Hmmm; when does this ever end?:D

thsmith

ShinAce wrote: »

There's an entire thread on it:
http://www.polkaudio.com/forums/showthread.php?t=73470

.

Thanks ! Not sure I need to do anything with the polys but maybe something to do next time I open the cabinet. At least jumper it just to see how it sounds.

Thanks again