Monitor 5b's x-over upgrade w/pics

heiney9 · April 2007

Tin_ear_fool wrote: »

In case anyone is still following this thread, question:

Looking at the Clarity Caps, SAs for the tweets, and PX for the mid-woofer. Would a 30 uF (PX series) work just fine in place of the stock 34s?

That value is pretty far away from the original. It would work but it may change the sound a bit. Why not use a 33uF Solen ?

george daniel · April 2007

heiney9 wrote: »

That value is pretty far away from the original. It would work but it may change the sound a bit. Why not use a 33uF Solen ?

yep, the 33uF solen will work

jakelm · April 2007

heiney9 wrote: »

That value is pretty far away from the original.

LOL...I dont mean to laugh H9, but have you seen Polk's different values for the same drivers in the same crossovers? The values are all over the place. From 4.5 resistors with 34uf caps, to 2.7resitors with 26uf caps. I think Polk was alittle confused at one point. I never understood. Was it trial and error? Who knows.

But back to the subject. Your right,, 33uf Solen.

heiney9 · April 2007

jakelm wrote: »

LOL...I dont mean to laugh H9, but have you seen Polk's different values for the same drivers in the same crossovers? The values are all over the place. From 4.5 resistors with 34uf caps, to 2.7resitors with 26uf caps. I think Polk was alittle confused at one point. I never understood. Was it trial and error? Who knows.

But back to the subject. Your right,, 33uf Solen.

It is kinda of funny but I think it had more to do with all the different types of drivers they used. Several different tweets and mid-bass drivers yeilded a cluster of different value parts in the x-over. The main problem is most of the new parts people will use are 1-5% tolerance so if you are on the high or low end of the value it might make a difference. Most of the original parts were 10-20% tolerance and by now after 20 years or so they are way out there

.

H9

Tin_ear_fool · April 2007

Well, based upon the Dutchman's cap test, I'm intrigued to try out the Clarity Caps. He rated them highly, and they're cheaper than Sonicaps. Besides, he's not the first person who's noted that the Solen's can sound a little forward. The Claritys are supposedly more towards the warm side, so I think they'll match rather nicely with either my NAD 7000 or HK 680i (a tiny tad brighter) receivers.
BTW, I received and installed the RD0194-1 tweeters tonight. As H9 said in an earlier post, I don't hear an appreciable difference yet. A big part of that, I'm sure, is because of the stock crossover parts. I'm itching to get that ear-to-ear grin myself!!:D
So, do you think there's adequate room for a paralleled 30 and a 3.3 or a 4.7 on the board?
Also, for one-stop shopping, e-speakers carries Mundorf MOX non-inductive metal oxides, no Mills. I see some custom speaker manufacturers use these as well. Thoughts?

Okay, so I went ahead and ordered the Claritys and MOXs. Will let you know how it sounds when installed.

Jockos · April 2007

I have the later x-over with the caps mounted vertical on the board. I believe the caps are bi-axial with both leads on one side of the can. Any ideas on mounting the replacements? Thanks Jockos

heiney9 · April 2007

Jockos wrote: »

I have the later x-over with the caps mounted vertical on the board. I believe the caps are bi-axial with both leads on one side of the can. Any ideas on mounting the replacements? Thanks Jockos

Monitor 5b's

. Can you post a pic? Are they Series II with the sl2500 blackish/goldish dome tweeter? I have seen all the innerds of the M5's except the Series II and I can honestly say I've never seen the config you describe. Pics....pics....pics

H9

jakelm · April 2007

I think this is what he is talking about. I think this is series 2

Jockos · April 2007

exactly, also what were the original caps rated at(dc volts)

Thanks,
Jockos

ben62670 · April 2007

http://www.madisound.com/pdf/ClarityCap.pdf
They are cheaper than the solens. I would love to hear how they sound. They are also used in B&W speakers.

heiney9 · April 2007

Jockos wrote: »

exactly, also what were the original caps rated at(dc volts)

Thanks,
Jockos

Check with Ken Swauger at Polk or look at the schematic posted in the troubleshooting forum marked "sl3000 upgrade". That might help, otherwise they are probably the same as the other M5's (voltage rating)

H9

jakelm · April 2007

Jockos wrote: »

exactly, also what were the original caps rated at(dc volts)

Thanks,
Jockos

100dcv

At least thats what all of my caps were rated at.

Jockos · April 2007

Thanks

nerdorama · May 2007

Hi,

I'm new to this forum. My membership was prompted by recent acquisition of some Monitor 5's with the SL2000 tweeters. One of the speakers had a magnet come unglued from the woofer basket, but I've been able to repair that since the voice coil was undamaged.

Have been reading this thread about xover upgrades and have notices several mentions of peaking with this tweeter. Has anyone measured the response and thought of trying a notch filter?

Regards,
John

schwarcw · May 2007

Hi John and welcome to the Club Polk Forums! I can't remember anyone trying a notch filter, but I know it was discussed. A lot of folks have replaced the SL2000 tweeter with a RDO-194 which is available from Polk for $48 each. This replacement tweeter is much smoother than the SL2000 and it doesn't have the spike at 13.5K Hz.

Welcome!

heiney9 · May 2007

If you are going to use them a lot the RD0194-1 silk replacement is the ticket. The difference is very noticeable and pleasant. All Polk speakers that use the sl2000 have a +5dB spike at 13-13.5KHz. It's a characteristic of the tweeter and I'm not sure a notch filter will get the job done accurately. I would also think once Polk was made aware of this (Stereo Review and Stereophile did measurments) they would have used a notch filter of some sort but they didn't; they designed the sl2500 and sl3000 trilaminate tweeters. If you know how to make it work effectively try it and let us know how it works. A notch filter has been mentioned before but I don't think anyone has actually tried it.

H9

nerdorama · May 2007

Hi,

Got the midrange driver back in the box tonight and have been listening for a couple of hours. They seem to have good clarity, maybe a bit forward for my taste and the bass is a bit loose. I'm using a tube amp so that may be some of the bass issue. Midrange is nice and clear.

If can get to it this weekend, I'll make some FR measurements and maybe I can work up a notch filter for the 13kHz peak that's been mentioned. That is if I see it in the results.

John

Sumbrada77 · May 2007

Hey heiney9 this is Sumbrada77. Just re-did the crossover in my 5 today I got from you and did some testing. It's new but I still could hear a difference. Better tighter mids and cleaner highs. I will burn it in and write back in a week with further results. Still a bit bright with the SL2000 but definitely better. I am using it as the center and a little brighter highs do ok with movies. I have not had to do the sheilding as I can use it as is if I keep it low enough under the TV and angle it up. I added a 0.01uf Dayton cap as a bypass with the 12uf cap. I really think it helps. I will add some pics once I transfer them to the PC.
I am also starting my 10A crossovers tonight with the clarity Caps. I will start a new thread with them. Thanks for your help and 5. It really makes a difference with movies.

dorokusai · May 2007

Great project, great results. The silk dome replacement for the SL2000(RD-0194) is the last puzzle piece for you.

Kudos to you for using components that are against the grain.

heiney9 · June 2007

Well it's been well over a month and these 5b's sound fantastic on the "grunt" system in the office rig. The bass is very tight and defined. The mids are where I feel the biggest improvement has come. Everything is so fleshed out and 3 dimensional. These things image just wonderfully; the depth is startling at times. Every layer of a recording can be heard very clearly. The RD0's have smoothed out and tamed the top end nicely; everything is a lot more seamless sounding. I should have taken them to the Chicago PF to get others impressions; next time I will. I would have loved to hear them up against Doug's 10b's.

These are some really great sounding all purpose speakers that do many things well. Many times I listen and type only by the glow of the monitor and they truely disappear in the darkness on the other side of the room. With no perceiveable visual of the speakers one can get lost in the recordings and really hear how good these are now. The best is when I'm on the computer not really paying attention to the music (like I would with the main rig) and the sound takes my attention away from what I'm doing.

For example right now I'm listening to Joss Stone's latest and it's like listening to mini SDA's in some spots. I keep hearing all these little things going on in the recording and I'm not even listening critically.

H9

Tin_ear_fool · June 2007

Heiney,
What front end components are you using to drive your 5's?

A few weeks ago, I installed the 194s, the ClarityCaps and Mundorf MOX resistors (had to run jumpers from the board to the huge caps, which I hot glued to the inside bottom), and on either my older NAD or my HK receiver, didn't notice much of a difference. I then put the HK and Monitor 5s in my daughter's room, and haven't really heard them since.

Your latest post has me intrigued; maybe I ought to pull them out and try them with my Arcam integrated, and see how they sound now. If the new parts need a fair amount of current run through them to break in, I can say they'd still need to be. She hasn't run them hard or abused them at all.

Jockos · June 2007

Tin ear,
I actually like the fact that you don't notice a difference. With the solens there is a noticeable difference which I personally don't care for. I have some dayton's on the way. Some reviewers like them and say there're pretty neutral. I would like to get my speakers back to the original sound, but with fresh capacitors.

Jockos

F1nut · June 2007

Jockos, it should be noted that Solens are not the best choice for high frequencies, they tend to be a bit forward and edgy. Maybe try something different there. However, if you want the original veiled sound, get some cheap electrolytics.

As for Tin Ear, maybe you really do have tin ears (no offense) because I don't know how one couldn't notice a difference from jump street. However, new caps do need to burn in, give them at least 100 hours before judging the sound.

heiney9 · June 2007

Jockos, while we all have different hearing and things we like/dislike the Dayton caps probably aren't going to get the job done any better. Now if are just looking for the stock sound, perhaps...........but look at all time, effort and expense just to get them to where they were. I will agree with F1 that Solens aren't the top choice for the highs, but they are much better, by a wide margin, than the originals and much better than many of the budget caps out there.

For this project I wasn't going to drop the coin for the Sonic caps, just didn't make sense financially for an inexpensive book shelf run in a secondary system. However I stand by the huge improvement the Solens made over stock.

As stated earlier the midrange is off the charts, very clean, fleshed out and the depth and layers of information is excellent. The top end is a bit forward, not harsh or shrill just a bit out front. The bass is probably the second biggest improvement. It's very clean, well defined and punchy. The upgrade transformed these speakers from merely average to excellent.

One last thing is these speakers were bought at a flea market by another local Polkie and some drivers including tweets were blown (and replaced by said Polkie) so I suspect these may have been abused. They never sounded all that great from day one, so perhaps there were other issues with mine and when I rebuilt the x-over it made them sound a whole lot better than stock, who knows. I recommend this upgrade w/ Solens w/o reservation.

Tin_Ear, I am running them with a late 80's Yamaha AX-900U integrated 130 per. Computer as a source with the digital signal run thru and AMC DAC-8 digital to analog converter. Std bannana plugs and 12g zip cord for speaker wire. I will also note if you are still using the sl2000 tweeter this upgrade will really make the weakness in that tweeter worse. The RD0 silk dome replacement is the recommended tweeter. There is no way to fix the +5dB peak @13kHZ of the sl2000; it's a real problem made worse by a x-over freshening.

For me burn in is the key for the all parts. These still continue to get better.

As always in this hobby YMMV

H9

heiney9 · June 2007

I might try a little experiment. I have these 2.7 ohm Mills here that are the correct value according to the schematic for this series (w/fuses) so I have to go back into the x-over since I used 2.0 ohm resistors. I want to see if there is a difference.

I'm thinking now of getting a couple of Sonic caps to bypass the Solens on the highs and see if that improves the highs. Since I'm going to be in there again anyways.

Jesse you have a PM

H9

jakelm · June 2007

heiney9 wrote: »

I might try a little experiment. I have these 2.7 ohm Mills here that are the correct value according to the schematic for this series (w/fuses) so I have to go back into the x-over since I used 2.0 ohm resistors. I want to see if there is a difference.

I'm thinking now of getting a couple of Sonic caps to bypass the Solens on the highs and see if that improves the highs. Since I'm going to be in there again anyways.

Jesse you have a PM

H9

It wil work to replace the 2.0 resistors, but you might want a higher value than 2.7. I would recommend 3.5ohm. My 7's use a 4.5ohm, but I find they are too laid back. 3.5ohm should be perfect.

Jockos · June 2007

This is a great thread, as many people are interested in redoing they're crossovers.

Thanks Heiney

Tin_ear_fool · June 2007

During the whole RDO tweeter/Sonicap/Mundorf resistor upgrade for my Monitor 5s, the speakers were "down" a week or two, and I didn't take any "before" notes with particular music selections for a before and after review. Furthermore, I didn't do an A/B comparison with one modded and one not, and since my aural memory is fairly hazy (along with most homo sapiens...well documented) , I wasn't immediately wowed by any improvement, except for a slightly smoother top end, IIRC.

I do my best to not let the "I paid alot for it, so therefore, it must sound better" rationale compromise my judgment.
I will admit to having a bit of an "instant gratification" flaw, and that's why I fairly quickly moved them into my daughter's room.

Again, though, I will drag them out and try again, as well as compare their sound to my Vandersteen 1Bs and Shahinian Arcs.

More to follow...

heiney9 · June 2007

Tin_ear_fool wrote: »

During the whole RDO tweeter/Sonicap/Mundorf resistor upgrade for my Monitor 5s, the speakers were "down" a week or two, and I didn't take any "before" notes with particular music selections for a before and after review. Furthermore, I didn't do an A/B comparison with one modded and one not, and since my aural memory is fairly hazy (along with most homo sapiens...well documented) , I wasn't immediately wowed by any improvement, except for a slightly smoother top end, IIRC.

I do my best to not let the "I paid alot for it, so therefore, it must sound better" rationale compromise my judgment.
I will admit to having a bit of an "instant gratification" flaw, and that's why I fairly quickly moved them into my daughter's room.

Again, though, I will drag them out and try again, as well as compare their sound to my Vandersteen 1Bs and Shahinian Arcs.

More to follow...

I've been around this hobby a long time and the whole "instant gratification and leaps and bounds difference" just isn't going to happen. I've come to expect and notice subtle changes with gear upgrades, etc. YThis takes patience and listening time. In my case however for whatever reason the 5b's were transformed into a much better speaker.

Keep chipping away at it but if you never really took "mental" notes before the change there maybe an improvement, but you could be completely oblivious to it

. I guess just judge them on how they sound now.

comfortablycurt · March 2009

First off, sorry to resurrect a thread that's going on two years old.:)

I'm considering doing some XO upgrades to my Peerless Monitor 7A's sometime later this year, and I have some newb questions.:o

I opened them up a little bit ago, as I couldn't seem to get any clear information on what resistors were used in the Peerless 7's. I kept seeing conflicting information, I read in a few places that they used a different resistor. I read in other places that they used multiple resistors. Mine have two.

Mine are the (earlier?) ones that are fused on the back for the tweeter protection, before they used the poly switches. I opened them up, and this is what I found.

12uf cap
34uf cap
2.7 ohm 5 watt resistor
4.5 ohm 5 watt resistor

Should I replace them with the same values I assume? I've read about people using different values and getting better results. Would I be better off to try a different value?

Also, should I replace the coils(inductors?)? I haven't found much about replacing those...are there any benefits to be had with different ones? All of the schematics I've seen show these as having two coils...Mine(also Brocks according to the pictures) only have one coil. Is there another one somewhere separate from the XO?

I was also planning on upgrading the internal wiring with some 12 or 14 awg, as well as using some Mortite on all of the drivers.

Any help would be appreciated.

Thanks for the excellent write up Brock.:)

Monitor 5b's x-over upgrade w/pics

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