Monitor 5 Crossover Questions

OutcastColt

Hello all,

I am new to the group and have just been bitten by the vintage bug. I have come across some Polk RT 7 (still looking for another driver) and Monitor 5's that I was able to get my hands on. All being pushed by an HK 330B receiver that I picked up at goodwill.

My question is I planed on rebuilding the crossovers in the monitor 5's, but after pulling it apart the crossover does not resemble any of the ones that I have seen posted.

After reading through several of the threads I see that every one is using 630v caps and the ones in my crossover are 50v ksc's. The values match the schematics so is the voltage something I should be worried about.

My plan is to replace with ClarityCaps and I am looking for suggestions on what to replace for the resistor with. I see that H9 used mills in his crossover rebuild but that is the only one that I have found that specified.

I do have the SL2000's and was planning on changing out the 2ohm resister with a 4.5ohm. I have read that it helps with the +6db spike at 12 or 13K cant remember.

Any and all feedback would be appreciated.

Coy

skrol

The values look correct. The construction looks more modern than my Monitor 5B which used the SL2000 and were made in 1984. Perhaps they are a late run of the 5B or the XO is from a Monitor 5 Series II (1990).

Swap the SL2000 for the RDO194 and you will be very pleased with the highs. Also, get rid of the poly-switch (PS-1).

OutcastColt

Skrol,

Thanks for the reply, I am thinking they are around 1988 or so. From the schematics they are the 5rev and I just replaced the sl2000 for $40. When I go it the sl2000 where damaged, so I will probably hold of on the rdo-194's at least until I recap the hk 330b which will be in about 4 months or less if I can get my self away from listening to system for about a week or two.

Thanks for the info about the poly-switch I will punt that in the rebuild of the crossover.

F1nut

After reading through several of the threads I see that every one is using 630v caps and the ones in my crossover are 50v ksc's. The values match the schematics so is the voltage something I should be worried about.

As long as the voltage is the same or higher, all is good.

Everyone is not using 630V caps. In fact, there's no need for a 630V cap, just makes the size bigger. Try Sonicap instead, comes in 200V, so much easier to fit on the boards and more importantly, sounds great.

For the resistors, Mills 12 watt are an excellent choice, IMO.

I do have the SL2000's and was planning on changing out the 2ohm resister with a 4.5ohm. I have read that it helps with the +6db spike at 12 or 13K cant remember.

That'll kill the spike, it'll kill the all high frequencies too. I read that you just replaced the SL2000's, which is unfortunate as the RD0194-1 is vastly superior. Put those SL2000's back on eBay and grab the RD0's.

westmassguy

F1nut wrote: »

As long as the voltage is the same or higher, all is good.
Everyone is not using 630V caps. In fact, there's no need for a 630V cap, just makes the size bigger. Try Sonicap instead, comes in 200V, so much easier to fit on the boards and more importantly, sounds great.
For the resistors, Mills 12 watt are an excellent choice, IMO.
That'll kill the spike, it'll kill the all high frequencies too. I read that you just replaced the SL2000's, which is unfortunate as the RD0194-1 is vastly superior. Put those SL2000's back on eBay and grab the RD0's.

This^^^^^^^^^
You should also consider the "TL" Modification, which allows use of the RDO-198-1. As good as the 194s are, the 198s are even better. See "schematic_m5b_sl3000mod".

soundfreak1

I used the SA clairity cap (600 VOLT) in my 5jr+'s they sound fantastic.l alsi used the 250 volt esa's in my 12c's ( smaller) also fantastic results.mills resistore work great as well.pull the poly cap and use the rdo 194 and u will be quite surprized.

OutcastColt

All thanks for the responses,

F1nut, thanks for the info on the caps. Whats the cost of the RDO-194's and 198's?

Whats your guys take on solid copper speaker wire to replace what s in the speakers?

Coy

Schurkey

OutcastColt wrote: »

Whats the cost of the RDO-194's and 198's?

About $110 a pair, sales tax included, free shipping for Club Polk members. Call customer service to order.

OutcastColt wrote: »

Whats your guys take on solid copper speaker wire to replace what s in the speakers?

Define "solid copper". Do you mean single-conductor copper wire as opposed to multi-stranded-conductor copper wire? Or do you mean solid copper as opposed to silver-plated copper, or copper-plated aluminum?

"I" would leave it alone, gains will be minimal and expense will be considerable.

skrol

Do the RDO tweeters, capacitor and resistor upgrades and you will be amazed. I used Clarity Cap PX and the difference was incredible.

OutcastColt

Define "solid copper". Do you mean single-conductor copper wire as opposed to multi-stranded-conductor copper wire? Or do you mean solid copper as opposed to silver-plated copper, or copper-plated aluminum?

"I" would leave it alone, gains will be minimal and expense will be considerable.

Schurkey,
Single-conductor copper wire, I was gong to use strands of Category 6 network cable which I have plenty of. It is typically 23awg and solid copper core. With my 330b I am only pushing about 25 watts so I dont see the 23awg as huge deal, but again I am no expert.

I guess with all the sugestions I am going to have to bite the bullet and by the rdo's, should I do the 194 or 198's?

TennMan

OutcastColt wrote: »

Schurkey,
Single-conductor copper wire, I was gong to use strands of Category 6 network cable which I have plenty of. It is typically 23awg and solid copper core. With my 330b I am only pushing about 25 watts so I dont see the 23awg as huge deal, but again I am no expert.

If that is your only choices I think you would be better off sticking with the factory wiring.

F1nut

westmassguy makes an excellent suggestion, TL your speakers and use the RD0198-1 tweeter.

As for the cabinet wire, why would you replace 16 gauge with 23 gauge?

OutcastColt

F1nut, I figured that the solid copper core would be better then the factory wire, but wasn't sure. From past experience I know that solid copper core although smaller typically would have a lower resistance then stranded cable (if true copper), but again with the wattage probably would be minimal.

I am new to audio so trying to absorb as much as I can. I have dealt with electronics, air traffic control radars, communications networks, but I am a noob in audio but I am fascinated by it. So please disregard my ignorance, but I prefer to ask questions when I am not sure about something or do not have the data to back it up. I do search but tend t o have a habit of seeing squirrels and tend to loose my train of thought (SLAMMING MY HEAD ON THE DESK)......LOL $hit squirrel, vodka gotta go need a refill.......

But all thanks for all the suggestions

pitdogg2

OutcastColt wrote: »

Schurkey,
Single-conductor copper wire, I was gong to use strands of Category 6 network cable which I have plenty of. It is typically 23awg and solid copper core. With my 330b I am only pushing about 25 watts so I dont see the 23awg as huge deal, but again I am no expert.

Cat 6 data wire can degrade the sound as some of it has a higher capacitance and can roll off highs or lows....been there done that. Stick with wire that is in there.

OutcastColt

pitdogg2,

Thanks for the info I will stay with the wire that is in there.

Coy

Weber

I would look for a older set of crossovers and rebuild them.That pcb seams to crowed for any bigger caps.Use some mill spec 18 awg silver plated ofc wire to re-wire them.They will be so open and airy you will think they disappeared.

Zentish

F1nut wrote: »

westmassguy makes an excellent suggestion, TL your speakers and use the RD0198-1 tweeter.

What does "TL your speaker" mean?

StantonZ

I'm another happy customer with the RDO-194 replacement; I also used SoniCaps and Mills resistor on the XO upgrade (I second F1's comment about NOT doing that resistor change). However, DO replace the PolySwitch with a 0.5 Ohm resistor (or so): those PS wreck your high-end.

TennMan

Zentish wrote: »

What does "TL your speaker" mean?

TLing your speakers refers to modifying your crossover to make them compatible with the Polk RDO-198 Tri-Laminate tweeters. In some cases, as with my SDA 2B and CRS+, it only requires adding an additional capacitor to the crossover.

mikemokr

TennMan wrote: »

TLing your speakers refers to modifying your crossover to make them compatible with the Polk RDO-198 Tri-Laminate tweeters. In some cases, as with my SDA 2B and CRS+, it only requires adding an additional capacitor to the crossover.

I've searched and deduced some of the answer to this but what in a nutshell are the requirements for a speaker to be TL'able? SL2000 tweeter? SL1000? I assume not the Monitor 4 with SL1500 because no upgrade path for that tweeter. Assuming a tweeter that can be swapped out for the 198, are only certain stock xo's compatible for some reason?

I'm interested in this mainly for vintage Monitors. Currently I specifically am wondering if I could TL my Monitor 5JRs, circa 1988 with SL2000. Actually the latest iteration of my thinking could involve a TL mod for just one of the 5JRs, for use as a center with CRS+ 4.1TL and something else TL'd in the rear.

TennMan

mikemokr wrote: »

I've searched and deduced some of the answer to this but what in a nutshell are the requirements for a speaker to be TL'able? SL2000 tweeter? SL1000? I assume not the Monitor 4 with SL1500 because no upgrade path for that tweeter. Assuming a tweeter that can be swapped out for the 198, are only certain stock xo's compatible for some reason?

I'm interested in this mainly for vintage Monitors. Currently I specifically am wondering if I could TL my Monitor 5JRs, circa 1988 with SL2000. Actually the latest iteration of my thinking could involve a TL mod for just one of the 5JRs, for use as a center with CRS+ 4.1TL and something else TL'd in the rear.

I'm not the best person to answer your question about which speakers have crossovers that can be TLed. My experience with vintage Polks is limited to the ones that I have owned. SDA 2B, CRS+ and monitor 10B. In general, I believe the speakers that would have factory installed crossovers that are compatible with the RDO-198 tweeter are the ones that came from the factory with the SL3000 (and maybe the SL2500). For specific models that can be TLed I'm sure someone with more knowledge than me will chime in.

mikemokr

To clarify, I'm looking for characteristics that allow a model to be TL'd, whether simply via a drop-in 198 (like from an SL3000) or with xo mods plus the 198. For one specific question, is anything with an SL2000 TL'able with xo mod or is that not possible in some cases for some reason? Don't mean to hijack the thread but I don't think this strays too far off topic.

westmassguy

mikemokr wrote: »

I've searched and deduced some of the answer to this but what in a nutshell are the requirements for a speaker to be TL'able? SL2000 tweeter? SL1000? I assume not the Monitor 4 with SL1500 because no upgrade path for that tweeter. Assuming a tweeter that can be swapped out for the 198, are only certain stock xo's compatible for some reason?

I'm interested in this mainly for vintage Monitors. Currently I specifically am wondering if I could TL my Monitor 5JRs, circa 1988 with SL2000. Actually the latest iteration of my thinking could involve a TL mod for just one of the 5JRs, for use as a center with CRS+ 4.1TL and something else TL'd in the rear.

You'll need to identify exactly which 5Jr you have, as there were several versions. Check the component values of your crossover against one of the schematics here: http://www.polkaudio.com/forums/showthread.php?38755-POLK-AUDIO-Speaker-Wiring-Schematics-amp-More-ALL-MODELS-except-SDA
Sanctioned TL Mods are usually denoted as SL3000 or TL. That doesn't mean your Monitors can't be modified. Some TL mods are simple, where a New Shunt Capacitor is added, while others require changing Capacitor values and Shunt Inductors.

mikemokr

I will do that WMG but I am wondering if there are any general rules of thumb. Am I right to surmise from your reply that having an SL2000 doesn't in and of itself make a Monitor eligible for a TL mod, whether sanctioned or not? Are there any automatic show-stoppers in the crossovers?

My questions are geared in part to potential future purchases, especially since numerous Monitor models with SL2000s seem to be fairly common. But I'm also thinking of my Monitor 7s (1987, SL2000) as when the time comes to mod those I'd like to TL them if I can.

westmassguy

There is no general rule. Each must be investigated individually. Your Monitor 7s with SL2000 tweeters should have a crossover nearly identical to the 5B. So, while there's no Monitor 7 SL3000 Mod, the 5B SL3000 Mod will work. The Revision 2 schematics were the last versions of the Monitors and came with SL2500 Tweeters. Many of the Cap and Inductors values are different. I would not use those as a guide.

Hawnfi

Aloha all!
I'm just an old carpenter that loves good sound. I'm new to the Polk world and see a pair of M5s on Craig's List asking $150. I'm not about to attempt a recap so is there someplace (or someone) who I could send the CO to bring them up to standard?
I'm setting them in a typically small condo room with a lot of glass walls and feeding them through a Luxman 40 wpc. Mostly classical listening.
Any advice?

Jimbo18

The post above you is from westmassguy, who is one of the people on here that will do the recapping.

Prices in Hawaii are probably different, but $150 seems a bit high for M5s, unless they are scarce there and in fantastic shape. Also, be aware there are a bunch of different versions of M5's.

boston1450

+1 on the above. Depending on what you have for 5's & tweeters - you could change out the tweeter for a better "Drop In" replacement from Polk. Then do the crossover upgrade because those 20+ year old Xovers are tired. WMG does outstanding work. I also have the 5a's & plan on doing those. They are a fine speaker. Welcome to the forum

gdphoto

How do you determine exactly which Monitor 5's you have? Mine only states Monitor 5 on the back with SN's. I noticed 1986 on the XO's.

gdphoto

Also, If I just do a basic XO mod, can I still upgrade to RDO 194'S?

skrol

Based on the year, I'd say Monitor 5B. The 5A ended with 1983 and the Monitor 5 Series 2 started around 1989. Post a pic and we can tell for sure.

The tweeter choice would depend on the XO mod. If you simply upgrade XO components then go with the RDO194. If you do the TL mod then go with the RDO198.