New to me Monitor 5's - tweeter replacement, cross-over recap, what else?

Sosublime · October 5

I am embracing vinyl again and have Sonos throughout the house and do not like way that vinyl sounded through it. I picked up a pari of Monitor 5's with the SL 2000 tweeters. I feel like the highs are a bit veiled and found this forum.

I am considering replacing the tweeters with the RD0194-1 and am looking through old posts to see about recapping the crossovers.

I have these paired with a cheap powered sub so I don't need to worry too much about super low frequencies but would like to tighten up the high end.

As I catch up on all the old threads I wanted to say hi and see if anyone has any other suggestions for me.

Thanks!
Mark

F1nut · October 5

Welcome to Club Polk.

The SL2000 tweeters are anything but veiled, so you have something else going on. Let's start with, what are you using for power?

Unknown · October 5

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F1nut · October 5

Possible, but then there wouldn't be any highs.

Sosublime · October 5

I am using a Wiim Amp Ultra for power with a Clearaudio Basic Plus phono preamp connected to a Fluance RT-85 turntable with an Ortofon 2M Black cartridge. I have a JBL PSW-1000 sub and have the crossover set at 80 Hz on the Wiim. Veiled was probably not the best word to use. I would say they can sound too harsh after listening for awhile.

F1nut · October 5

Ok, thanks for the details, very helpful.

The SL2000 is a nasty sounding tweeter with a 5dB spike around 13kHz. I suggest replacing them the Polk RD0194-1. That's a zero.

If still a bit harsh after that I would look at the Wiim as the ESS Sabre chip to my ears always sounds edgy/harsh. Class D amps can also be edgy/harsh.

Edit: forgot to address your crossover question. Yes, upgrading those will net sonic benefits, but that's not the issue at present. When you do upgrade them avoid Solen, Bennic and Dayton caps. Upgrade the resistors too.

Sosublime · October 5

Thank you! I will order the tweeters. I have just started building this system. What would you recommend in place of the Wiim if the harshness is not relieved with the new tweeters. Thank you!

Sosublime · October 5

I appreciate the responses and feedback F1nut. Are there any brands you recommend currently and do you use parts-express or another online vendor. I will hold off on changing anything else until the tweeters arrive, but supplies seem limited for some things at least in tech these days.

F1nut wrote: »

Ok, thanks for the details, very helpful.

The SL2000 is a nasty sounding tweeter with a 5dB spike around 13kHz. I suggest replacing them the Polk RD0194-1. That's a zero.

If still a bit harsh after that I would look at the Wiim as the ESS Sabre chip to my ears always sounds edgy/harsh. Class D amps can also be edgy/harsh.

Edit: forgot to address your crossover question. Yes, upgrading those will net sonic benefits, but that's not the issue at present. When you do upgrade them avoid Solen, Bennic and Dayton caps. Upgrade the resistors too.

F1nut · October 5

Sosublime wrote: »

Thank you! I will order the tweeters. I have just started building this system. What would you recommend in place of the Wiim if the harshness is not relieved with the new tweeters. Thank you!

Someone else here would be better at addressing that question as I don't have any knowledge of a specific combination streaming device and amplifier.

F1nut · October 5

Sosublime wrote: »

I appreciate the responses and feedback F1nut. Are there any brands you recommend currently and do you use parts-express or another online vendor. I will hold off on changing anything else until the tweeters arrive, but supplies seem limited for some things at least in tech these days.

F1nut wrote: »

Ok, thanks for the details, very helpful.

The SL2000 is a nasty sounding tweeter with a 5dB spike around 13kHz. I suggest replacing them the Polk RD0194-1. That's a zero.

If still a bit harsh after that I would look at the Wiim as the ESS Sabre chip to my ears always sounds edgy/harsh. Class D amps can also be edgy/harsh.

Edit: forgot to address your crossover question. Yes, upgrading those will net sonic benefits, but that's not the issue at present. When you do upgrade them avoid Solen, Bennic and Dayton caps. Upgrade the resistors too.

For crossover components there are a vast number of choices. Forum cap favorites are Clarity CSA or Sonicap Gen I. For resistors Mills-Vishay are good.

Here's some reading for you. I've found his observations to be pretty much spot on.
https://www.humblehomemadehifi.com/Cap.html

heiney9 · October 8

I have a pair of 5B's that met an untimely demise. Well one did anyway, so I'm parting them out. The RD0 tweeters were already sold.

I have a pair of already upgraded x-overs I'm getting ready to sell. If you are interested. Clarity caps for the high pass, Solen for the low pass and all Mills wire wound non-inductive resistors. New wiring. Plug n play, ready to go.

H9

billbillw · October 8

^^^That could save the OP some serious time/effort.

Sosublime · October 8

F1nut wrote: »

Sosublime wrote: »

I appreciate the responses and feedback F1nut. Are there any brands you recommend currently and do you use parts-express or another online vendor. I will hold off on changing anything else until the tweeters arrive, but supplies seem limited for some things at least in tech these days.

F1nut wrote: »

Ok, thanks for the details, very helpful.

The SL2000 is a nasty sounding tweeter with a 5dB spike around 13kHz. I suggest replacing them the Polk RD0194-1. That's a zero.

If still a bit harsh after that I would look at the Wiim as the ESS Sabre chip to my ears always sounds edgy/harsh. Class D amps can also be edgy/harsh.

Edit: forgot to address your crossover question. Yes, upgrading those will net sonic benefits, but that's not the issue at present. When you do upgrade them avoid Solen, Bennic and Dayton caps. Upgrade the resistors too.

For crossover components there are a vast number of choices. Forum cap favorites are Clarity CSA or Sonicap Gen I. For resistors Mills-Vishay are good.

Here's some reading for you. I've found his observations to be pretty much spot on.
https://www.humblehomemadehifi.com/Cap.html

Thank you for the offer; however, the tweeters and parts to upgrade the crossover have already shipped out.

heiney9 · October 8

Yeah, I saw the original post, but it didn't dawn on me at the time to make the offer. I have (4) passive radiators too. If you find yours aren't performing 100%

I'll eventually post in the FS section.

H9

Sosublime · October 9

Thanks for the offer H9. As I work on the tweeter, crossover, and other upgrades I will let you know if I see any issues with the passive radiators.

Sosublime · October 12

Later on this week I am going to be taking these apart (one at a time) to reseal the cabinet, epoxy the magnets and dynamat the speaker baskets. After these are resealed, what is the best way to determine if the passive radiators are working as expected? If they go bad does it results in pressure leaks?

Gardenstater · October 12

What you can do is push in on the PR and hold it there. You should see the midwoofer move outward as you push the PR in, and while you are holding it in you should see the MW slowly recede over the next 3 secs or so and stop. Then when you release the PR the MW will swiftly recede the rest of the way to the original position before you pushed the PR.

Gardenstater · October 12

Just realized you were asking how to check function of the PRs. What you can do is play some low tones and watch and feel for the movement of the PR diaphragm. Actually the most movement should be around 60 Hz because that is the tuned resonance frequency. At 60 Hz, the PR should have lots of movement and the MW very little because it is acoustically coupled and in phase with the PR and at that point almost all of it's energy is going into moving the PR.

But what I gave you above is a way to check for any leaks whether they be a torn surround on a PR or MW or cabinet joint leaks or gasket leaks or whatever may be.

Sosublime · October 13

Thanks for the additional information George. Yesterday I sealed the cabinet, epoxied the MW magnet and applied dynamat to one of the speakers. The pressure test improved on that speaker. My plan is to do the other speaker today and once both are done I will look for a test with 60 Hz. Thanks!

Gardenstater · October 14

I meant to say something else and just remembered. You were talking about your plans to put a subwoofer in and how that would tighten up the bass, which it probably will. But I have the same set up with my 7B and in my case I am not using the internal crossover in the sub and just letting it add on the low end sPL in my somewhat small room but which is open to other rooms. Anyway, what I meant to tell you is that you will still be able to tighten up the bass further by bracing the baffle on your M5s, which, even though it is narrower than my 7Bs and is less prone to flexing, will still get you tighter bass. I used @xschop steel semi-rings epoxied into my baffle and still haven't gotten around to adding additional bracing, but the slam I got from that mod was impressive. There is probably still some improvement to be made even though it is hard to imagine.

Sosublime · October 14

George, I appreciate the information. I have completed the magnet epoxy, dynamat, and sealed the cabinet on both speakers now. I am trying to do incremental work so I can determine the difference; however, over the weekend I picked up a pair of Sunfire Architect's Choice Series II amps for a great price so they have been introduced into the mix to see how they sound in my room. I already have a JBL PSW-1000 that I have been playing with on and off. The room is very challenging acoustically (large rectangular room that is half dining room (no furniture) and half sitting room which is open to the second floor. I have been playing with placement and orientation of the speakers as well as sub in this awkward space.

I have been swapping out other equipment along the way. I replaced the Wiim Amp Ultra with an Emotiva TA1 that is being used as a preamp and Wiim Pro for streaming.

For the bracing, would you recommend wood or threaded rod and just one brace between MW and PR? I am looking into getting some hurricane nuts as well. Is parts-express the easiest place to source them?

Thanks again for all of the feedback and assistance.

Gardenstater · October 14

It can be challenging to get control over null spots with bass in a small room and the large openings help to suck out the bass pressure/slam you want. I've had great luck with rolling up thick polyurethane foam and positioning it in the corners between ceiling and walls. Not WAF or GAF friendly but it really worked great.

Everybody gets their hurricane nuts from Parts Express afaik.

With the 7B you definitely want two braces but with the 5B you may be able to just do a single one (@xschop ?). I would probably use a 1 in. round hardwood dowel if I did one but I would probably do 2 (maybe slightly smaller dia. if you go with 2 would be OK) because overkill always works 🤣

SCompRacer · October 15

I used two 1" wood dowels in 7c's. Possibly 3/4" could be sufficient in the smaller cabinet? I used a Kreg pocket hole jig to drill holes on each end for glued and screwed joints. Screws are optional.

They were cut to exact length of ID and had to be rolled into place through the PR hole. I wouldn't call it a press fit but they were snug.

I used a piece of cardboard as a template to mark both ends for placement. You have to flip template around for opposite sides/ends. Once in place, roll to side and apply glue to both sides, roll back into place. Use your finger to apply a fillet of glue around joints. Wear a surgical glove if you don't like wood glue on your finger.

Sosublime · October 19

For folks following along, the upgraded caps and resistors made a huge difference. It sound like a blanket has been removed from in-front of the speakers. Everything was more crisp, nuances came through more, and overall clarity increased.

I have been back about taking pictures documenting every step in the progress, but take some the next time they are apart.

Upgraded completed so far:

Epoxy applied to MW magnet
Dynamat applied to speaker baskets of MW and PR
Speaker box sealed
Crossover upgraded with ClarityCap CSA and Mills resistors, poly switch removed and 0.5 Ohms added to original resistor value of 2.0 (2.5 Ohms resistor used

Upgrades pending

Install 1" wooden dowel braces x2 each side of box between MW and PR
Install hurricane nuts
Install 1.25" sonic barrier
Replace crossover wires

Projects after I am done upgrading these speakers

Replace meter lamps on 2x Sunfire Signature Amps I picked up a few weeks ago that sound great
Keep an eye out for a pair of Monitor 7 or 10's for some additional lower end
Move JBL sub around to see if I can find a better place to tighten up the bass

Sosublime · October 21

Thanks everyone for the encouragement, feedback and advice. I think I have tackled the most common suggestions for upgrading these speakers with the exception of the phase plugs which I need to spend some time reading up on. I didn't get too much time to listen to them last night after I finished everything.

Here is the completed list:

Sealed cabinet with Locktite Power Grab
Used JB Weld epoxy on MW magnets and put dynamat on cage
Dynamat on passive radiator cage
Hurricane nuts and 2x 1" wooden dowels for internal bracing
Crossover upgraded, it was challenging getting the larger caps on the board and secured with some hot glue and zip ties
Sonic barrier behind MW

Sosublime · October 21

I tried doing some listening today and noticed something was off. Isolated it to stuck voice coil in one of the 6502 MW that has already had the magnet epoxied with JB Weld. Not sure what happened during the last disassembly/reassembly, but the the speaker no longer moves freely when pushed. It sounds like it is rubbing on the voice coil. Since the magnets have already had epoxy applied and they did not move, is my best course of action to source a used 6502?

It measured 3.6 ohms. Pictures for reference. Spider looks good.

Gardenstater · October 21

That's a bummer. Must've been on the verge of rubbing and the adhesive had already let go. I think they used a steel filled epoxy instead of an acrylic. Ferrite and low carbon steel have different thermal expansion rates and also the plating on the front plate probably doesn't help adhesion much.

Ohms and spider do look good. Sometimes there can be a crack in the spider but that probably would only present problems when playing music with lots of lows and you can feel the rubbing just manually.

I've advocated using Gorilla Max Strength Clear for just this reason. It is tenacious but it isn't impossible to remove. I think you'd have to use a dremel with an appropriate pointy bit to get that epoxy off. I had my OEM MW6500s start to rub after I had glued them and I was able to get them apart by cutting the adhesive out with an Xacto knife. I wouldn't try that with the epoxy.

Sorry you experienced this temporary setback.

xschop · October 21

You can heat the JBweld with a torch around perimeter and then chip off. You just need to clean the pole-piece to magnet area anyways.

Make a jig per instructions here from PVC pipe and re-align it.

Sosublime · October 21

Thanks xschop, will review the thread and give it a try.

xschop · October 21

You can also soak it overnight in acetone in a shallow dish, just don't submerge enough to remove the base plate to magnet epoxy. JAT

Sosublime · October 22

I have it in some acetone and will soak it overnight. If that does not work, I will try to file off what I can of the JB Weld before taking a torch to it. This weekend I will pickup what looks like a 3" PVC fitting from the repair thread and a hose clamp for the jig.

New to me Monitor 5's - tweeter replacement, cross-over recap, what else?

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