Crossover upgrade guide

Crashdot

Greetings,

I've been advised that some of the monitors I've purchased recently are probably in need of replacement capacitors due to their age, and this may be responsible for the unsatisfactory sound I am getting.

I wonder if there is any guide or listing of the parts needed for each model crossover, and recommended brand/source. I am specifically interested in repairing the 5jr+ and 5B units, both of which currently have SL-2000 tweeters, which I can replace with the improved model that doesn't require changing the crossover.

I can manage a soldering iron for basic tasks, but am not extremely knowledgeable with regard to audio electronics.

Thanks!

TennMan

Welcome to the forum. Have you read the great writeup that heiney9 did when he ungraded the 5bs? Probably will answer a lot of your questions.

5b x-over upgrade w/pics [link]

Crashdot

A-ha! I didn't see that since I was searching for "crossover" rather than "x-over". Does anyone know if the 5B and 5jr (ported) have the same crossovers? Thanks for the link!

TennMan

Crashdot wrote: »

Does anyone know if the 5B and 5jr (ported) have the same crossovers?

All the answers to that question are here. Just compare the components in each one.

Rev. Hayes

I don't think they are.

If you want a look at just what is in the speaker you're going to work on check the schematics on this page.

http://www.polkaudio.com/forums/showthread.php?t=38755

Rev. Hayes

oop.

Beat me to the punch there Tennman.

TennMan

Rev. Hayes wrote: »

oop.

Beat me to the punch there Tennman.

Just proves that great minds think alike.

Crashdot

Thanks to everyone for pointing me in the right direction.

Crashdot

I have a few more questions before I can order replacement parts to repair these Monitor 5B, 5jr, and 5jr+ crossovers, and would appreciate the opinions of those of you that are more knowledgeable and experienced that I am.

1. What kind of capacitor is appropriate?

For example, Metallized Polypropylene, Metallized Film, Foil Polypropylene, Precision Audio Capacitor...

2. What are the brands to consider for capacitors (best to worst)?

Some have mentioned Sonicaps, Solen, or Dayton Audio

2. What kind of resistors are appropriate?

For example, Ultra Precision Axial, Audio Power, Ceramic housed, 10W Non-Inductive...

4. What are the brands or vendors to consider for resistors (best to worst)?

Some have mentioned Mills and Dayton Audio

5. Are there recommended vendors?

Some have mentioned Parts Express, Parts Connexion

6. What do I do if the schematic calls for a value that is unavailable? Use the closest, or use a lesser brand?

Thanks for your consideration

TennMan

Lots of good questions that all of us have probably asked at some point since coming here. I'm not really qualified to answer them for you or I would. I can tell you that most of them will be answered if you will do a search for threads where ben62670 participated. He is one of many here who are very knowledgeable on doing the x-over upgrades and the best parts to use for any budget.

What I remember from reading here about doing the upgrades is get the best components you can that fit your budget. Popular capacitors are: Sonicraft, Dayton, and Solen in order of quality. Mills is the resistor of choice and they are not too expensive. I intend to use Dayton and Mills. Popular vendors are Parts Express, Parts Connexion and Madisound. Sorry I can't offer more help.

Joe08867

Honestly if you use the search function you can answer all of these questions.

But here goes some of them.

Like TennMan said Mills is the resistor of choice for most of us.

Sonicraft Polypropylene film Capacitors on average are the choice of most of us here. There is a lot of debate on who makes the best caps and where to use them in the circuit. Some prefer Solens, Daytons and many many others. But if you look around you'll see Sonicraft more than most.

I order Caps through Sonicraft directly. I don't have the number in front of me. Partexpress is also good for most needs and if you want Daytons.

As far as how do you handle values when they don't have what you need. I prefer to split the values. Let me explain. If I need a 60uf and all they have is 55 or 65 I will see if the have 30's and get two and run them parallel. Or I will use a value within 5% like a 57 or 63. Considering the tolerance that Polk used 5% is nothing.

Crashdot

This clarifies a lot of things, but I wonder if it is better to split the values in which of the following ways:

34uF needed; (17uF x2) or (24uF and 10uF) or (33uF and 1uF)?

Also, I'm not sure whether to get 200v, 400v, or 600v models.

I was looking at the Sonicraft site, and noted that they have three series of Soniccaps with different sound characteristics. http://www.soniccraft.com/sonicap.htm

Can anyone suggest which series is best suited to the original Polk Audio sound, or which you chose for your speakers?

To summarize their descriptions of each:

Gen I has a slight advantage on the freq extremes (top and bottom), Neutral, rich in harmonics, warm, without the slightest loss of detail retrieval!

Gen II has a nice Midrange bloom,

Platinums are very fast, but full and rich. The presentation is ultra smooth without loss of detail, focus, or dynamics (but only go up to 4uF and are EXPENSIVE)

I'm really not looking to re-engineer these speakers, I just want them to sound as good as they did when they were new, with the exception of the SL2000 peak.

Thanks!

TennMan

The first thing you should do is decide on a budget and what your objective is when upgrading. Some people go top of the line and others like me just want to replace old caps and resistors to know their speakers sound as good as they can at a reasonable cost.

If you decide Sonicraft is in your budget, they offer custom sizes. You can just order a 34uf and not worry about mixing different sizes in parallel to get what you need. You can also ask them to send matched sets.

If you go with the Daytons and just want to get as good (or better) than the factory caps you can just order the 33uf 5% tolerance, 200v caps from Parts Express and you will be well within the tolerance range of the factory caps. I consider that an upgrade to the factory caps and that is what I'm going to do. I'm sure you will get other opinions.

Some people here mix and match the components. It is a popular thing to buy the Sonicrafts caps for the highs and and some other brand for the rest. If I had high quality audio components driving my speakers I would consider doing that myself.

Crashdot

For these smaller speakers, the cost to upgrade with better caps is not that great, so I am willing to use either the Sonicraft Gen I or Gen II models. My only objective at this point is to try and improve the tone of these speakers as I have been told the aging factory components may have cause the crossover frequencies to drift.

Thanks

heiney9

Clarity Caps are an excellent lower cost alternative. IMO, for these speakers Sonicaps are overkill. I love Sonicaps and use them in my SDA 1C's, but for a small inexpensive bookshelf it's not necessary.

I used Clarity Cap PX for my 5B's and they sound wonderful. Don't overthink this.

Mills resistor and Clarity Cap PX and be done..........then enjoy.

New RD0194-1 tweeters are a must as well.

H9

heiney9

Also get values that are close.

A 33uF will be fine for the 34uF don't stress over that at all. Voltage is not an issue except the higher the voltage the larger the cap. So if you can get 200 or 250v versions get those instead of the 400 or 600v verisons.

H9

Crashdot

I am less concerned about keeping the cost low (within reason) than about improving the sound and of course, making sure I buy the right parts to begin with.

Thanks!

heiney9

Again, Sonicaps are overkill in this application. But it's your dime so feel free to spend all you want. It's not necessary but what do I know.

Clarity Cap SA are a step up from PX so I guess you could go that route. I think Sonicaps are great, but for 5Jr's and 5B's the extra expense won't net you much if any benefit in sound.

It's like putting the best Pirelli tire on a Chevette.

But in the end it's your decision and your $$$. You haven't even stated what gear you are running or if this is for HT or 2ch.

If this is for HT and you are using entry level to mid tier gear no benefit from Sonicaps either. Perhaps you just want to support a great company.

H9

Crashdot

I currently have a Denon AVR-4306, but may get an AVR-4311 for 4-ohm support if I necessary. At present, I have RTA 12, Monitor 5B, Monitor 5jr+, and Monitor 5jr (ported). I am trying to put these to use as a 5.1 system, but have found the various 5 series to sound as if they are not at all timbre matched. I don't know if this is due to the cabinets or differences in the crossovers. I have a later set of Polk RT55i, CS400, FX/500, and FX/300 speakers that I am very disappointed with compared to the clarity and definition of the vintage models. When I switched with the ones I got out of someone's garage from Craigslist, the first thing my brother said was "I hate to tell you this, but these old speakers sound better than the newer expensive ones".

The problem is that the various 5's that I am trying to use as surround and center speakers sound inexplicably muddy or tinny on their own, so I would like to improve this.

Thanks

heiney9

Don't bother with Sonicaps.

For the older models use Clarity Cap PX series Mills non-inductive resistors and get new RD0xxx tweeters. This will solve the issue of muddy, tinny, etc.

Do these all currently use the sl2000?

F1nut

In case you go with Sonicap's, Gen I are the only type that come in the values you would use. Look at the value specs on their site and you'll see what I'm talking about.

I disagree that they are overkill, especially if you are doing the RTA 12's as well. Keeping them all the same will net better sonic results.

If you have to split the values, go with ones that are as close to each other as possible.

heiney9

I agree with F1 keep the caps the same throughout (whatever you choose) and if you have to split keep the as close as possible.

I still think Sonicaps are overkill for HT and a Denon receiver.

H9

F1nut

I still think Sonicaps are overkill for HT and a Denon receiver.

When you put it that way, yeah probably so if it's just for video. If it's for music, then probably not overkill.

Crashdot

This is also my main listening room for music from CD, HDAD, SACDs, DVD-Audio, and DTS-HD Bluray discs in stereo or multichannel formats. I don't have space for two listening rooms. I use a Denon DVD-2930 disc player connected to the AVR-2930 with Denon Link so I have a digitally delivered signal for SACD (rather than the six analog outputs required when SACD came out). If anyone can suggest a better AV receiver I am open to upgrading, although 4ohm support may be a factor for the RTA 12s.

Joe08867

If you have Sonicaps in the others or are planning to do so then I would go Sonicaps for the M5's. If for no other reason than to keep timbre correct between the RTA's and Monitors.

And like F1 said if you need to split the values keeps the pair as close to the same as possible. If you need a 34uf go with Two 17uf for a 34uf combined, Don't do the 30uf and 4uf combo. You can here a difference.

Crashdot

Correction, I use a Denon DVD-2930CI disc player connected to the AVR-4306 with Denon Link... in that case I need to make a decision about whether to upgrade everything, as I was just thinking of doing the ones that sound muffled to me (5B, 5jr+). Hmmm...

spkrdtr

I have a vintage 1980 Monitor 10a. I've looked thru the schematics list and viewed all of the 'M10' schematics but can't tell which is the 10a. Can anyone help identify the exact one?

StuartB

I can tell you from recent experience that you will want to pull your actual crossovers to verify the components. Apparently there was enough variation in models and actual pieces used that the only way to be sure is to pull your actual crossovers and confirm what you need. I just went through this on a pair of 5Bs. The whole process was very educational, but again, at least from my expereince, there is no absolute 10A schematic that will reflect every speaker's crosover. The flip side of that is that there is an absolute wealth of knowledge on this board. think some of them get a little tired of educating the new comers (like me) but take your time and read....you will be amazed at what you can learn and accomplish.

here is my journey thus far.....
http://www.polkaudio.com/forums/showthread.php?134128-Help-in-refreshing-Monitor-5B-crossover

spkrdtr

Thanks Stuart