Help in refreshing Monitor 5B crossover?

StuartB

I just picked up a nice pair of 5B speakers. They appear to be all stock with Peerless tweeters. The sound is a little boxy or boomy in lower mids. I was thinking that I may try to upgrade the crossovers to improve the sound. Anyone willing to advise me on doing this? Totally a newby in this area. Would need to start with pulling the crossovers and selecting the right components to replace

Thanks in advance for thenassistance.

Stuart

Mystery

Welcome to the club Stuart!
If you use search function, you can see 100's of threads on crossover upgrade.
Here is one for you: http://www.polkaudio.com/forums/showthread.php?89117-Monitor-5-x-over-upgrade

soundfreak1

Migjt be able to resuce tje bopm by dynamating the drivers. It did wonders to my 5jr+ and i used the Clarity SA's in the cap mod and tjey did wonderful things for them. But start woth the dynamat amd go from there.

skrol

Boxy and boomy are terms I usually don't associate with the Monitor 5's. My 5A's tend to be a little lacking in bass while my 5B's are nice and tight. I wonder if the Daycron batting may have slipped down out of place. It should be positioned behind the mid-woofers and, typically, not behind the passive radiators.

Another thing you might try is different placement. While I don't know how you have them placed, try moving them out from the back and side walls if possible.

GlennDog

skrol wrote: »

I wonder if the Daycron batting may have slipped down out of place. It should be positioned behind the mid-woofers and, typically, not behind the passive radiators.

Would the positioning of the Daycron apply to all Polks with PRs ? The Daycron extends upward behind the Tweets, too . . . right?

Thanks,

G

heiney9

Boxy and boomy are NOT descriptors I would ever use to describe Monitor 5B's. A crossover refresh with modern poly caps and Mills resistors will do wonders, but I have to ask about placement and gear choices. What are you using and how are they set-up?

I use a 30wpc push/pull tube integrated in a smaller room and they are as open and natural as can be as well as having the ability to rattle the handles on a couple cabinet drawers and vibrate a sliding closet door. All with zero tone controls so I know they are capable of pretty solid bass too.

H9

drumminman

GlennDog wrote: »

Would the positioning of the Daycron apply to all Polks with PRs ? The Daycron extends upward behind the Tweets, too . . . right?

Thanks,

G

Polyester batting should be placed from the tweeters down to the lowest MW, no lower. Definitely not at the level of the PR.

StuartB

Placement did make a difference. When I first auditioned them the setting was less than ideal. Once I got them some space and up on 20" stands the sound got much better. Still thinking about upgrading the crossovers since it seems relatively simple. And will try the dynamat. Two questions, what brand of capacitors and resistors do you like for this modest speaker and where do I find the dynamat? Also planning to seal the speakers with Mortite.....I assume I use the Mortite on all three drivers and maybe even the rear box with speak connections?

skrol

drumminman wrote: »

Polyester batting should be placed from the tweeters down to the lowest MW, no lower. Definitely not at the level of the PR.

This is generally true. However, my factory original Monitor 5A's both have it going from top to bottom including behind the PR's. I have wondered if this is why they are weaker in the bass department but I didn't want to deviate from the original design.
Stan

Mystery

skrol wrote: »

Boxy and boomy are terms I usually don't associate with the Monitor 5's. My 5A's tend to be a little lacking in bass while my 5B's are nice and tight. I wonder if the Daycron batting may have slipped down out of place. It should be positioned behind the mid-woofers and, typically, not behind the passive radiators.

I think OP has 5A's since he mentioned the tweeters are peerless unless 5B's came with peerless.

skrol

Clarity Cap PX are a nice affordable capacitor. A step up would be the Clarity Cap SA. SoniCraft runs some good deals on their SoniCaps from time to time.

Mils or Mundorf resistors are good.

heiney9

Here is my adventure, documented.

http://www.polkaudio.com/forums/showthread.php?51420-Monitor-5b-s-x-over-upgrade-w-pics&highlight=upgrade

In the beginning I started with Solen caps and then towards the end I swapped the high pass caps for Clarity PX's which were much better, as documented.

H9

StuartB

Mystery wrote: »

I think OP has 5A's since he mentioned the tweeters are peerless unless 5B's came with peerless.

I believe they are 5Bs. The tag on the rear says 5B but I am guessing they are early production the SNs are 1733 and 1750.

heiney9

If they have peerless tweets (from the factory) and fuses they are 5's or could be 5A's. 5B's have the sl2000 tweets and early 5B's have a tweeter fuse, later 5B's have a polyswitch in the x-over.

H9

StuartB

Well they say 5B on the back on the tag with the SN, they have fuses and they have the Peerless tweeter....black fabric with a small hole in the center of the dome.

The components on the cross over include 12 and 34 capacitors and a 2.7 resistor.

Kind of an odd mix of models it sounds.....but it sure appears to be all stock.

heiney9

If they have both fuses chances are they are 5A's, but we all know Polk used all different kinds of parts across the transitional models.

H9

heiney9

It is possible if you aren't the original owner that someone put peerless tweets in them. Always check the x-over and driver parts numbers, never assume your's is exactly the same as a posted schematic.

H9

StuartB

heiney9 wrote: »

It is possible if you aren't the original owner that someone put peerless tweets in them. Always check the x-over and driver parts numbers, never assume your's is exactly the same as a posted schematic.

H9

I have opened up both speakers and they have the same crossover components...and I believe they are the same values as the early schematic....now I need to figure out which parts to buy and then start bugging you to guide me through the process!

skrol

Do they have a year stamped on the mid-woofer? My 5A's w/ Peerless are from 1983 and my 5B's w/ SL-2000 are from 1984. Both my 5A's and 5B's have fuses on the tweeter only.

The first pic is the Monitor 5A and the second is the 5B.

drumminman

skrol wrote: »

This is generally true. However, my factory original Monitor 5A's both have it going from top to bottom including behind the PR's. I have wondered if this is why they are weaker in the bass department but I didn't want to deviate from the original design.
Stan

The batting should definitely not be behind the PR - it kills the output. Position it properly and listen - I bet your bass will be more pronounced and tighter - better quality. If you don't like it it's easy to put it back the way it was.

When I got inside myMy RTA 12C's (which I purchased new in 1984) to perform some mods the batting had fallen down to the bottom of the cabinet. I put in a strip of Black Hole 5 and repositioned the batting - bass output much improved!

StuartB

So would the consensus be that I use Clarity caps on the high pass (12 uF) and Solen on the low pass (34 uF) and then Mills or Mundorf on the resistor (2.7 or greater). I am thinking I might go higher than2.7 on the resistor to take a little of the edge off the tweeter.

StuartB

skrol wrote: »

Do they have a year stamped on the mid-woofer? My 5A's w/ Peerless are from 1983 and my 5B's w/ SL-2000 are from 1984. Both my 5A's and 5B's have fuses on the tweeter only.

The first pic is the Monitor 5A and the second is the 5B.

They did but I forget the year! I bought some Armaflex and will track down some Dynamat. When I pull the speakers to treat them I will post the assembly date.

skrol

For low pass, Jentzen is also good.

StuartB

Anyone care to advise on the impacts that "Larry's Rings" would have on these speakers as I consider rebuilding the crossovers, adding Dynamat and Armaflex ..etc. will I start to exceed the cost/benefit threshold. Right now I have about $80 in the stock speakers with Peerless drivers.

heiney9

StuartB wrote: »

Anyone care to advise on the impacts that "Larry's Rings" would have on these speakers as I consider rebuilding the crossovers, adding Dynamat and Armaflex ..etc. will I start to exceed the cost/benefit threshold. Right now I have about $80 in the stock speakers with Peerless drivers.

Did you read the link I provided? It says in there what impact the rings have as well as a tutorial for installing them. I would also leave the resistor values alone. You have the peerless tweets? If not, get the RD0's.

H9

StuartB

I am about ready to order the parts to upgrade the crossover and speaker. Based on the recommendations on this board, I am thinking I will use a Clarity PX 12uf for the tweeter and a Solen 35uf for the woofer. They can be purchased from Madisound for $9.35 and $12.75 respectively. The only other option would be to use Dayton caps from Parts-Express (12uf for $8.87 and 33uf for $10.14). Any final recommendations on caps between those options? Also, the original woofer cap is 34uf. Am I OK using either 33 or 35uf?

The only place I have found the Mills resistors is Partsconnexion. The 2.7ohm 12 watt resistor is $5.50. Is there any one place to get all these components and not have mess with multiple orders? Partsconnexion does not carry the PX Clarity caps, and their cost for Solen caps is somewhat higher than Madisound.

Finally, since I am going to take everything apart, I am planning on getting a set of "Larrys Rings" and then add Armaflex and Dynamat to the speakers. BY that time I will have done just about everything I think you can do to a set of 5B Peerless speakers. I will probably end up spending more on the tweaks and upgrades than I did on the speakers themselves. I hope I am not going way beyond that cost/diminishing returns threshold. but this will certainly be a learning experience.

Thanks for all the help and assistance thus far.

drumminman

StuartB wrote: »

I am about ready to order the parts to upgrade the crossover and speaker. Based on the recommendations on this board, I am thinking I will use a Clarity PX 12uf for the tweeter and a Solen 35uf for the woofer. They can be purchased from Madisound for $9.35 and $12.75 respectively. The only other option would be to use Dayton caps from Parts-Express (12uf for $8.87 and 33uf for $10.14). Any final recommendations on caps between those options? Also, the original woofer cap is 34uf. Am I OK using either 33 or 35uf?

The only place I have found the Mills resistors is Partsconnexion. The 2.7ohm 12 watt resistor is $5.50. Is there any one place to get all these components and not have mess with multiple orders? Partsconnexion does not carry the PX Clarity caps, and their cost for Solen caps is somewhat higher than Madisound.

Finally, since I am going to take everything apart, I am planning on getting a set of "Larrys Rings" and then add Armaflex and Dynamat to the speakers. BY that time I will have done just about everything I think you can do to a set of 5B Peerless speakers. I will probably end up spending more on the tweaks and upgrades than I did on the speakers themselves. I hope I am not going way beyond that cost/diminishing returns threshold. but this will certainly be a learning experience.

Thanks for all the help and assistance thus far.

I haven't modded 5B's, but I've done two other sets of vintage Polks. I found the improvement to be substantial. I'd be shocked :eek: if, after the caps and resistors burned in, you didn't hear a large improvement in smoothness, clarity, bass response, imaging.

I haven't spent time with the 5B's either, but many here at CP seem to think that those and the 7's are the best of the Polk monitor series. Of course I'd put the RTA 12C's up above those. . . .:cheesygrin:

soundfreak1

+1 drumminman, i was schocked with the 5jr+ they went up in all catogorys with the mods
A truly supperior bookshelf speaker. Bit i really dont include the rta in the monitor series, i lnow "tech" they are according to polk but my 12c's are a diff. Animal. And the 7's & 5's i feel are in a class by themself.

drumminman

soundfreak1 wrote: »

+1 drumminman, i was schocked with the 5jr+ they went up in all catogorys with the mods
A truly supperior bookshelf speaker. Bit i really dont include the rta in the monitor series, i lnow "tech" they are according to polk but my 12c's are a diff. Animal. And the 7's & 5's i feel are in a class by themself.

Hey SF1, have you done other mods besides those listed in your signature? If so, which ones?

The RTA 12C's really fly under the radar - an amazing speaker with a little TLC.

StuartB

Based on your input I have ordered 12uf Clarity PX caps,Solen 35uf caps and 2.7 ohm Mills resistors. Should be here early next week. I also have picked up some Armaflex. The only open questions are whether I use Larry's Rings or Hurricane bolts and whether I use Dynamat or something less pricey from Parts Express. Also wondering if I ought to replace the binding posts while I have everything apart.

Once I get everything apart I will post some pictures and the date on the mid/woofer. The tags say 5b, I have Peerless tweeters that are fused, and the Polk tab is on the bottom if the cabinet, not the grill.

I will be looking to get a lot of input from you as I start this project....any input or advice beyond what has already been offered would be much appreciated.

jmwest1970

I've been silently following this thread because I have a pair of Monitor 5 speakers that I'd like to upgrade as well. If you can please post pics of the process as I've never done anything like this myself.

Thanks!