Upgrading M40 series II Crossovers...?

Canadianguy55

I just purchased a pair of these and I seen some posts online about upgrading the caps on C1 and C2 on the crossovers. With 8.2UF 1% tollerance. I havent looked inside but is this a easy task?

Thanks

Canadianguy55

I know these are older speakers and maybe not talked about too much!

Any ideas or suggestions would be appreciated....

Thanks

rooftop59

I honestly don’t think it’s worth the effort with those speakers. The mdf is thin, and the woofers and tweeter are super cheap. You might slightly improve the sound quality with better crossover parts, but I doubt the difference will be pronounced given the overall quality of the speakers.

Canadianguy55

Ok thanks! I like the speakers, I was on a budget. Any idea when these came out?

Thanks

pkquat

Based on when reviews started I would guess 2005. The caps should still be "ok". There could be a little improvement with some better caps, although many people still run some the better polk speakers from the 2000's with the original caps. Different caps would not add any value. If you go for it, I would stick to parts express and the like. Some Dayton or Solen metallized polypropylene fast caps would be about as much as I would spend. Others may have some different budget recommendations.

Canadianguy55

I didn't know that were that old. I can get some base out of them, just thinking about the mids and high. There new!

afterburnt

I have 2 pair of M40 series II, I used em for height speakers now I use them for nothing. I did compare them to 60's and they don't stand up. I think they are best for surround duty. The 60's will be employed as such one day.

Canadianguy55

I was thinking of putting whole new crossovers in them, haven't decided though.....I hear what you guys are saying, maybe not worth doing anything to them being lower end.

recoveryone

I use mine in my bedroom HT, work well in smaller room with sub. They do tend to open up as you increase the power.

Canadianguy55

I'm in a tiny one bedroom apt, reason why i picked smaller book shelves, I'm using a Denon AVR 689 to run them, I have biamped them, not sure if soundind any better but it's fine. What size of sub you using?

pkquat

I wasn't aware these had bi-wire capability. If I recall if you bi-wire them without the jumpers you are bypassing the crossovers and using the AVR for the crossover. I would have to see the wiring to be sure. I know some speakers did this, but others still went through the crossover so people would not run full range to the tweeters and then wonder why they blew

Just an FYI. Bi-amping with an AVR does not accomplish much if anything power wise or sonically since everything is powered from one power transformer. Search for bi-amping on here and you will see a number of more detailed posts.

No need to completely rebuild the crossovers if they have inductors (wound wire parts). Those are not affected by age. You might also want to replace any cast resistors with something like mills, vishay-mills, or mundorf.

dromunds

You haven’t mentioned your location. If practicable, I would take the money you are going to put toward the crossovers on these and put it (and the funds from selling the Monitor 40’s) toward acquiring a pair of Peerless Monitor 4’s. If you’re not in a location where that’s a likelihood, there are many other Polk bookies that can be had inexpensively on the used market and then you can eventually rebuild the crossovers as you see fit and when your budget permits. Folks will be happy to provide models if you indicate an interest.

Canadianguy55

pkquat wrote: »

I wasn't aware these had bi-wire capability. If I recall if you bi-wire them without the jumpers you are bypassing the crossovers and using the AVR for the crossover. I would have to see the wiring to be sure. I know some speakers did this, but others still went through the crossover so people would not run full range to the tweeters and then wonder why they blew

Just an FYI. Bi-amping with an AVR does not accomplish much if anything power wise or sonically since everything is powered from one power transformer. Search for bi-amping on here and you will see a number of more detailed posts.

No need to completely rebuild the crossovers if they have inductors (wound wire parts). Those are not affected by age. You might also want to replace any cast resistors with something like mills, vishay-mills, or mundorf.

Hi....I thought what I was doing was biamping without using the jumpers and using 2 discrete amps for each speaker. I'm new to this so pardon my ignorance I didn't know that it bypassed the crossovers inside?

Not sure I like the sound of that, I know I won't blow them, I'm cautious.

The wiring are u talking about inside the speaker or at the back?

I'm in On, Canada:)

Canadianguy55

pkquat wrote: »

I wasn't aware these had bi-wire capability. If I recall if you bi-wire them without the jumpers you are bypassing the crossovers and using the AVR for the crossover. I would have to see the wiring to be sure. I know some speakers did this, but others still went through the crossover so people would not run full range to the tweeters and then wonder why they blew

Just an FYI. Bi-amping with an AVR does not accomplish much if anything power wise or sonically since everything is powered from one power transformer. Search for bi-amping on here and you will see a number of more detailed posts.

No need to completely rebuild the crossovers if they have inductors (wound wire parts). Those are not affected by age. You might also want to replace any cast resistors with something like mills, vishay-mills, or mundorf.

Hi I thought running 2 discrete amps to 1 speaker without jumpers was biamping, I had no idea this was bypassing the crossover? I'm still new to this, i'm cautious still not to over power. Is this the wiring diagram you mean or the back of the speakers?

I'm in On,Canada:)

pitdogg2

you're not bypassing the crossover that I'm aware of, although there is little advantage to what you're doing.

Canadianguy55

Yes I realize this listening to them, they cost me 250 cad, I'm on such a tight budget now..I just noticed for a 100 more I can get the Monitor 60's that have 3 5.25 woofers or would it be better to spend that money on a better made crossover instead for the 40's?

Thanks

dromunds

My comments above were based on what Monitor 40’s and alternatives cost in U.S. (and that you indicated you were looking for smaller bookshelves.) Sounds like Polks are much more costly in Canada. For example, a pair of Monitor 40’s appear to be available for $99 USD on Polk’s Ebay store. I had a pair of the Euro version of the Monitor 60’s a long time ago and I recall I was impressed with them, but they now reside with my cousin. Regardless, if it were me, I would not rebuild the crossovers on Monitor 40’s, for the reasons the other guys mentioned above.

Canadianguy55

i bought the M40's from Amazon.ca, The 60's I seen today at Best Buy.ca for $300/pair thats with the sale that ends March 7th....it says you save 210, so actually they usually go for 500/pair lol

pkquat

As mentioned that schematic shows Bi-Wiring is going through each crossover and not bypassing it.

The easy way to think of bi-amping / bi-wiring, especially with an AVR, is connect a fire hose to your average outdoor house spigot. The fire hose has very little resistance. You can only get up to a certain flow out of the nozzle at the end. Now split the flow from the spigot into another fire hose with the same nozzle. You will not get any more flow. Similarly, do the same with a small water pump that has just enough to barely pressurize one hose at max flow rate. Again, when you split it, there will be little to no gain. True bi-amping involves 2 power supplies and amps, i.e. two pumps drawing from two suction hoses in a very large pond. Now you have twice the amount of water. Another way to think of true bi-amping is to have a speaker and powered sub woofer setup. One amp / power supply is powering the high end, and one amp / power supply is powering the low end. The crossover is happening before the amps (in many cases), and the crossover is adjustable. Bi-amping only really becomes an advantage when you want to tailor the crossover setting and the type of amp used for the high and low ends.

I would keep an eye out in the used market for some polks. Some deals even in CA do show up. The peerless tweeters are ideal in either the M4 or M5's. The M5's of that era can have cracking on the PR surrounds or the rubber gets stiff and will crack.

The M4's with the "triforce" tweeters are also nice, or M5JR's. Of the smaller speakers the M5jr+ with the 6.5" PR is a sweet spot. When bargan shopping though, sometimes you can find some M5's or even large M7's for the price of the 5jr+.

The 5Jr's have the least expensive crossover to upgrade as well.

Canadianguy55

I just looked inside of these and they have one big piece of white baton inside, just sitting in the middle. Not up against the sides or top or bottom.

Could this be improved buy putting some more or better dampening, insulation inside or is this should stay as is?

Thanks

dromunds

I noticed a pair of what appear to be Peerless Monitor 4 on the Toronto Craigslist although they say they are Monitor 3. Lol.

pkquat

Canadianguy55 wrote: »

I just looked inside of these and they have one big piece of white baton inside, just sitting in the middle. Not up against the sides or top or bottom.

Could this be improved buy putting some more or better dampening, insulation inside or is this should stay as is?

Thanks

The middle is where it should be, and I would recommend leaving it as is. It is just filler to make the cabinet appear bigger to the speaker. Some of the more densely packed can have some sonic effects and affect air flow for speakers with ports or PR's. Generally the material is placed behind the tweeter and/or midwoofer. Since these do not have ports or a PR, the location is fine. You may find adding some more makes them sound more rich, or it may muffle the highs or midrange. You can always experiment.

dromunds wrote: »

I noticed a pair of what appear to be Peerless Monitor 4 on the Toronto Craigslist although they say they are Monitor 3. Lol.

If these are near you. Get them!!

Canadianguy55

When i looked inside, everything is so well put together and in it's place. I doubt I'm going to do a thing to them, I 'll keep them the way they are!



Greg

dromunds wrote: »

I noticed a pair of what appear to be Peerless Monitor 4 on the Toronto Craigslist although they say they are Monitor 3. Lol.

Are they for a 100 dollars, they have 6.50" woofers? What's the difference? I'm new to the Polk products.

dromunds

It appears there are two separate ads for the speakers on Toronto Cragislist. They appear to be the same seller. One ad is for Polk Audio VINTAGE bookshelf speakers. $100. They call them "Polk Audio Model 3". Lol The other ad says Speakers SPEAKERS Spkrs and has several other speaker brands listed in addition to what appear to be the Peerless Monitor 4, which are described as "Vintage Perfect." Somebody else could maybe confirm that those are Peerless Monitor 4's - as I can't cut and paste the ad - but assuming they are Peerless Monitor 4's in "perfect" condition as advertised they are a find for $100 that I would personally snap up.

pkquat

Canadianguy55 wrote: »

When i looked inside, everything is so well put together and in it's place. I doubt I'm going to do a thing to them, I 'll keep them the way they are!



Greg

dromunds wrote: »

I noticed a pair of what appear to be Peerless Monitor 4 on the Toronto Craigslist although they say they are Monitor 3. Lol.

Are they for a 100 dollars, they have 6.50" woofers? What's the difference? I'm new to the Polk products.

Yes they are.
https://toronto.craigslist.org/tor/ele/d/scarborough-polk-audio-vintage/6807077135.html

Considering its $100CAD, that is a really good price. The peerless is a preferred tweeter. It is very smooth sounding, and blends very well with the midrange driver. The imaging is great as well. The crossovers on these will likely need to be rebuilt, but they should still sound pretty good. The 6.5"MW has the signature polk midrange sound that reproduces vocals, strings, guitar, well pretty much everything with great detail and clarity. These will also have more bass that what you currently have. Some here may cringe at tone control, but I had a nice ~ 50Hz tone control on a pre-amp that picked up as these rolled off. At low to moderate volumes they sounded like a much bigger speaker.

The resale value on these is much higher. These are sought after. I wish I had a pair my self. I have the later version that does not have the peerless tweeter.

dromunds

That's $75 US dollars! I am shocked these are still available. Might be because the seller has described them as Monitor 3. Lol. I have a pair of these Peerless Monitor and they're not going anywhere. These are supposedly "mint perfect." If it were me, and assuming they are even close to as advertised after an audition, I'd run not walk to get these, then I'd sell those Monitor 40's.