Help in refreshing Monitor 5B crossover?

StuartB

heiney9 wrote: »

Did you try them in the openings? Only reason I ask is because in your photo there is about 1/8" gap between the peerless bezel and the cutout and if you are just comparing the tweets physically side by side and not checking to see if they fit in the cutout, then you might be mistaken.

I ask because you say they are not the same size and nothing about them not fitting in the cut out.

It does appear the RD0 is more than 1/8" larger than the Peerless.

H9

I did, there is no way they fit without enlarging the cut-out. Pix on their way.

StuartB

I finished the project today.

I had to go get a Dremel tool to enlarge the tweeter cut out to accept the new RDO tweeters. First time I ever used a Dremel tool...there have been a number of firsts for me as I worked this project.

The cut-outs were not the most elegant work I have done, but it worked.

Here are pictures of the finished product.

I will post a summary of all the work I did, but in the mean time thanks to all of you who gave me input and advice, I really appreciated the help as I had never done this sort of thing before. I know I asked a lot of elementary questions.

I have the Peerless tweeters for sale, but I do not think I have enough posts to actually post in the For Sale section.

StuartB

I have a lot of pix if any one would like to see in more detail
Polk Monitor 5B Upgrade

? Used copper desoldering braid to remove old solder
? Replaced stock 2.7 ohm resistor with Mills 2.7 ohm/12 watt resistor
? Removed foam under new resistors ? left space for cooling
? Replaced stock 12 uF capacitor with Clarity PX 12 uF/250 volt capacitor
? Replaced stock 34 uF capacitor with Solen PB 35 uF/400 volt capacitor
? Used Rosin Flux and WBT silver solder to install new components
? Used hot glue to tag capacitors to circuit board (in addition to existing foam)
? Used JB Weld to glue magnets to speaker frame and pole to magnet
? Replaced stock Peerless tweeters (Danish #7514XXX) with Polk RDO-194-1 tweeters
? Expanded tweeter cut-out to accept new tweeters
? Replaced stock gaskets with Armaflex insulation
? Used Sonic Barrier sound damping to eliminate resonances from mid/woofer and passive radiator frames
? Baked Sonic Barrier and Armaflex adhesive connections in sun
? Used 13/64? drill bit to expand existing screw holes prior to installing hurricane nuts
? Replaced stock wood screws with 8-32 Hurricane nuts and security hex head screws
? Used JB Weld to secure hurricane nuts to MDF
? Stapled Dacron filler to keep from slipping down around passive radiator
? Kept stock wire and binding posts

StuartB

I am currently breaking in the new tweeters and crossovers. They are pretty much new (and different) speakers from where they started from. I know it is too early to make any judgements, but right now they seem to be more refined, maybe a richer sound...less bright, and maybe even less dynamic at this point. None of that is negative. I thought the top end was a little hot on these, even though they had the Peerless tweeters. I think that may have been due to the tweeter and crossover being mismatched (not the right resistors in the tweeter circuit). I will give them at least 100 hours before listening hard....right now just running the Olympics through them all day. Any recommendations on if I should do anything differently to break everything in? Specifically do I need to run higher volumes for any reason?

transmaster

On the Monitor 10B's I replaced the cap's and resistors in my cross overs Soni Cap's Gen 1 for the high side, Axon Tru Caps for the low end. and Mills resistors, as I already documented. In retrospect I should have used the 5 watt resistors instead of the 15watt part, the size was such I had to get creative with the hemostats to bend the leads to fit into the place the polyswitch was mounted, and that was on the bottom of the board. The circuit board lay out was such I could not drill new holes to mount these resistors. As reported I also replaced a pair of burnt out MW6503's, with new ones from Polk. I am about 300 or so hours into the use of these refurbished crossovers and and speakers, right at the +/- 300 hour mark things started to smooth out. I have not noticed a change in the original tweeters but In the MW-6503's I have, at first they where a bit snappish with some zoom bass, and heavy duty percussion. Now things are starting to get luscious. On the soundtrack to the London 2012 Olympic opening ceremony Disc 1, track #4, And I Will Kiss, Underworld, featuring. Dame Evelyn Glennie, and The Pandemonium Drummers. this is the music played during the Industrial revolution segment. This track is worthy to test speakers with, stupendous sound. In my minds eye I see the 10B's represented by Oliver Twist, "Please sir can I have some more". The Onkyo NR709 that is feeding these 10B's in pure music mode,which configures it into a pure integrated stereo amp has surpassed the sound I remember from the Sansui integrated amp's I once had powering these very 10B's.

I am going to purchase a subwoofer. Not so much that I need one but to add another several hundred watts of power to the low end so tracks like "and I will Kiss" will sound like Mjollnir smiting The Earth.

StuartB

I thought I would wrap up this thread with my listening results. I probably have 200 hours on the new crossovers and tweeters. I am extremely pleased with the outcome, and the improvements I hear. The top end is clear and well defined, but not edgy. The bottom octaves are tight and rich, and the midrange is full and sweet. I know these are budget speakers with limited performance, but I am really enjoying them. The overall sound is balanced and cohesive. I would guess that the components I used (Clarity PX caps on tweeter circuit, Solen caps on MW circuit, mills resistors and new RDO tweeters) represent a pretty good mix for this application. I also used Armaflex to make new gaskets all around, hurricane bolts to secure each unit and Sound Barrier to dampen the speaker frames. All in all a fantastic learning experience and a significant improvement in sound. If I can assist anyone is attempting a similar project, please let me know. I am already on the hunt for another project.

heiney9

I feel with this level of upgrades the 5B is a HUGE sleeper and you'd have to spend a lot of money today to better them.

These mods transformed my 5B's a couple three years ago and I enjoy them every single day in my computer/office rig. I think tubes in the mix make them even sweeter.

H9

transmaster

StuartB you did what I did at the advice from this forum, I went with Axon True Caps for the low pass side and Sonicap Gen 1's the the high pass, and the Mills resistors on my Monitor 10B's to say I am pleased is a massive understatement. Below is interesting link. Tony Gee among other speaker design endeavors has an extensive rating page of audio capacitors ones like the Axon, and Solens to caps such as the Duelund CAST which had I used them on my 10B's would have cost me $7,381.02.

http://www.humblehomemadehifi.com/Cap.html