View Full Version : Polk Monitor 10 Crossover Recap Photos


rushfan
05-31-2010, 09:50 PM
Hi all,

I recapped my Series 2 Monitor 10's yesterday and I thought that a couple of you might be interested in a few photos of the crossovers. I bought a kit online from a seller who seems to know his stuff. His instructions were clear as day and the whole job took me about one hour. Experienced DIY'ers could do it in less, I'm sure.

What you can't see in the photos is that the single 27 mfd capacitor on the left side in the first photo has been replaced by a 12 mfd and a 15 mfd capacitor wired in parallel. The 12 is soldered to the 15's leads and hidden underneath the PCB. This kind of reverses the situation where the OEM 12 mfd and 4 mfd parts were replaced by a single 16 mfd capacitor, seen at the top in the last photo. I hot glued the new parts to keep everything from moving around.

I wish that I could tell you how the upgraded speakers sound, but I really don't know at the moment! The speakers reside in my living room which is Grand Central in my house. I only gave them a quick listen at low volume to ensure that I put everything back together properly. I'm hoping to give them a real audition in another day or two. I can tell you this for sure - the bass response is noticeably improved. Even at low volume I could tell right away.

I'm not expecting miracles - the speakers sounded great before the recap - but I am looking for a bit more finesse from them. Recapping crossovers is such a cheap and easy upgrade. My Pioneer HPM-100's were an order of magnitude better after recapping their crossovers.

I'll report back in a couple of days when I have given the Polk's a proper audition. In the meantime, if it's not against the rules, PM me and I will reply with a link to the seller's listings. He has kits for all of the different Monitor 10 versions.

Thanks for looking!

johnda
05-31-2010, 10:00 PM
Cool! Let us know how you like how it turned out.

EPI-Center
05-31-2010, 10:10 PM
which tweeters are on those?

rushfan
05-31-2010, 10:20 PM
which tweeters are on those?

SL2500. Not the Peerless, but decent nonetheless. The tweeters are quite nice sounding - lots of air and no sizzle.

rushfan
06-01-2010, 08:47 PM
Well, I gave the speakers a good workout tonight and the verdict is: they sound great!

I tested them with a variety of recordings and they did well with everything that I threw at them. I played Steely Dan, Thievery Corporation, St. Germain, Dire Straits and some Dave Matthews Band on them. The thing that I noticed the most was the improved midrange. Before the recap I found the speakers a bit shouty when pushed. Now the midrange is silky smooth with nice detail and tone. I found the bass somewhat exaggerated at first, as I hinted at in an earlier post, but after about 15 minutes that just went away. The speakers seemed to be searching for equilibrium for the first 30 minutes or so but they really seemed to settle down after that. I can hardly wait to hear what another couple hundred hours of playback will do for them.

The bottom line for me is that the overall tone of these Polk monitors has improved since the recap, and they were pretty good to start with. I think that they deserve a better room than I have them in at the moment, and proper stands too. I've got drawings of the factory stands to build from so that's my next project.

I'd like to hear from other Polk monitor owners out there, especially those of you who have upgraded your crossovers. Are there any other tweaks for these speakers that you know of? Please share!

jheu02
06-01-2010, 09:45 PM
Just curious why you went with the BP 'lytic vs film caps for the 27uF since you were splitting them up anyway?

John

rushfan
06-01-2010, 10:12 PM
Just curious why you went with the BP 'lytic vs film caps for the 27uF since you were splitting them up anyway?

John

Hi John,

Great question, but one I cannot directly answer. The parts were provided in a kit so I just went with what was supplied. The designer says that he tried out many combinations before settling on the version that you see in the photos. I lifted the following from his description:

"A 12dB/octave low-pass filter consists of a inductor in series and a capacitor in parallel with the dual 6-1/2" bass-midrange units. It's function is to send the low frequencies to these units. Non-polar electrolytic capacitors can perform very well in parallel to any driver and in this application, with these loudspeakers they produce superior results to that of polypropylene film capacitors. However, as with all capacitor types, significant audible differences exist between brands and models. The non-polar electrolytic capacitors supplied with this upgrade kit are of the highest quality and are responsible for much of what you will hear."

I hope that this answers your question. The bass isn't quite as tubby as it was before the upgrade but to tell the truth, I was grooving to the improved midrange a little too much to zone in on the bass response. I'm going to have to move the Polks into a better room to get the full effect.

Thanks for your question!

elnaldo
06-01-2010, 10:26 PM
Non-polar electrolytic capacitors can perform very well in parallel to any driver and in this application, with these loudspeakers they produce superior results to that of polypropylene film capacitors
--- Very interesting ...

rushfan
06-05-2010, 12:59 PM
I have spent a few more hours listening to these Polks and they are indeed better sounding than before. They are especially impressive when heard from across the room. I know that this is largely a function of the accoustics of the listening space but even this aspect of their performance has improved. They make me want to stop doing what I am doing and go sit down and listen to them.

That's the very definition of captivating, isn't it? :D

jhoyt
06-05-2010, 03:10 PM
Hmmm, interesting. I have a pair of the original Monitor 10's just languishing after they were ousted by DCM's. Where did you get this upgrade kit? Ebay? Seems like I've seen it before. About the electrolytic vs. film cap, the cap in question is parallel to the signal path, not in series with it. You definitely want film caps in series, but I guess not so much in parallel. The job of that cap is to "suck" the high frequency information out of the signal that passes on to the woofers, and shunt it to ground.

terra1
06-05-2010, 03:21 PM
rushfan was kind enough to respond in a PM to me, but you can probably search eBay for this Polk monitor upgrade. The seller also has different versions for series II.

bluesky
06-05-2010, 04:24 PM
Very clean looking crossovers.

rushfan
06-05-2010, 08:13 PM
Hmmm, interesting. I have a pair of the original Monitor 10's just languishing after they were ousted by DCM's. Where did you get this upgrade kit? Ebay? Seems like I've seen it before. About the electrolytic vs. film cap, the cap in question is parallel to the signal path, not in series with it. You definitely want film caps in series, but I guess not so much in parallel. The job of that cap is to "suck" the high frequency information out of the signal that passes on to the woofers, and shunt it to ground.

That's correct - I found it on Ebay. There wasn't a kit for the Series 2 monitor when I first checked but the seller was putting the finishing touches on one when I contacted him. My understanding of electronics is very elementary so I have to leave the theory up to others, but the seller had excellent ratings and a number of interesting upgrade kits. I found out about him from a satisfied customer in another forum.

I guess that he must be onto something with the electrolytic capacitor. The bass has tightened up noticeably and remains satisfyingly deep. I was listening to some electronic music today (Phutureprimitive) and the bass was positively cavernous. You'd think that I'd be used to this by now (my best speakers feature dual 6.5" woofers too) but I cannot get over how low those small drivers go.

Very clean looking crossovers.

Thanks. I guess that it was a good idea to snap a picture before I went nuts with the hot glue, eh? :D