RTA-12B Crossover Recap

HoobyHooby Posts: 8
edited May 2013 in DIY, Mods & Tweaks

Just completed my first speaker modification, a full recap of my RTA-12B's. I decided to go with ERSE Pulse X metallized polypropylene caps after reading some favorable reviews on them, and I didn't have an unlimited budget. Total cost was just over $100 with shipping, only took me one night of installing them because I was so excited to get them in. So far, I've only got about 15 hours of power ran through them so I know I have more burn time to go but I can already tell a clarity difference and a stronger, tighter low end sound. I hope it continues to get better, which I'm sure it will.
I've been debating doing other mods, I've read many people dampening the inside of the cabinets, and using dynamat on the driver baskets. I've also heard that getting rid of the fuse will also help with extra clarity in the tweeters. We'll see what happens down the line but for now, I'm very pleased with the sound of these newly capped 12B's! Here's a few pictures of them. Hopefully that link works, if not I guess just copy paste it. Thanks!

Post edited by Hooby on


  • brgmanbrgman Posts: 2,860
    edited May 2013
    Congratulations.I hope it burns it very nicely for you.I have 2 pair and i have been thinking about digging them out and fixing them up.They are great speakers.
    I'M OFFENDED!!!!!

    2 CH-Rogue Audio Zeus w/Factory Special Dark Mods,Joule-Electra 300ME Platinum Preamp,OPPO-105 w/Modwright Tube Mod, Auralic Aries Extreme Server,Polk 2.3TL,3.1TL's,Dreadnought,RTA-15TL's,1C's All Fully Modded,2xRTA-12c's ,Benchmark DAC2 HGC,Synology NAS,VPI Scout w/Dynavector DV-20XH and Rogue Audio Ares Phono Preamp,Sony PCM-R500 DAT,HHB-850 Pro CDR,Tascam CC-222SLMKII Cassette/CDR,MIT S3.3 Shotgun Cables,Shunyata Hyra-8,Shunyata and Triode Labs Power Cords

  • drumminmandrumminman Posts: 3,382
    edited May 2013
    Congrats! I have RTA 12C's that I did the full monty on. Other mods to consider are installing hurricane nuts or Larry's Rings to tightly couple the MW's to the front baffle, and installing a strip of Black Hole 5 on the interior cabinet wall directly opposite the MW's.

    These are all pretty easy to do and make a noticeable improvement in sound quality. Not too expensive either.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
  • starkillerstarkiller Posts: 2,666
    edited May 2013
    Looks pretty cool! Too bad ya gotta solder though...a skill i sure don't have and never did actually:redface:
    Computer room

    Sony PS-X5 Table 681EEE Cartridge
    Hegeman 1 Speakers
    M&K VX-80 sub
    Cambridge Audio CXC Transport
    Rega DAC
    Sutherland KC Vibe Phono Preamp
    PrimaLuna Prologue Four Amp
    Aric Audio Tube Preamp


    Samsung Plasma
    Outlaw 950 pre/pro
    Tannoy Saturn 8's
    Hsu sub
    Emotiva UPA-500 5-channel amp
    Denon DCD-1520 CD player


    Jennings Research Square
    Custom tube preamp
    Crown XLS-1000
    Denon DCD-1500II
    Modded MSB Link DAC
  • HoobyHooby Posts: 8
    edited May 2013
    Haha yea soldering is just a small part of it... I'm definitely not the best, but I can get the job done. The toughest part was probably just fitting the new caps on the board. The new 55 uF cap is a TANK compared to the old one so that was a little tough. Overall I think this is a really good mod to improve the sound, and a pretty quick one as well. Next I'll be looking into the other mods that I mentioned before. Making great speakers sound even better, gotta love it!
  • StantonZStantonZ Posts: 406
    edited May 2013
    I think removing/replacing the polyswitch with a .5 Ohm resistor was a pleasant surprise for me on the high end (I just did my 10B's last weekend). I share your feelings about improvement to the mids/lows; I'm very happy overall!
    Yamaha RX-A2050 AVR (5.0.2)
    (4) Polk Monitor 10B's w/SoniCaps, Mills, and RDO-194 tweets (R/L F/R)
    (2) Polk Monitor 4's w/peerless tweets (Top Middle)
    Polk CS300 center channel
    Analog: B&O TX2 Turntable, Nakamichi Cassette Deck 1
    Digital: Pioneer CLD-99 Elite LD, Panasonic DMP-UB900 UHD Blu-Ray
    LG 65EF9500 4K OLED
  • tmrsttmrst Posts: 10
    does anyone know what the small cap value in mf or uf are?
  • This discussion dates back several years and I hope some are still listening. I want to do this recap, but I have a few questions.
    1. There are additional caps in the low frequency crossover at the input terminals. Has anybody upgraded these? Is it necessary? After removing the LF crossover, there is no slack on the wires to get the circuit board clear of the box.
    2. I have the schematic, but it doesn't note the voltage per cap. I can't read the specs on the original caps. Anybody know the voltage?
  • FaustinFaustin Posts: 968
    On my 12b's the caps on the LF c/o at the input terminals were replaced with Dayton 250v 5% caps. The old caps are going to be at the end of their useful life. Don't remember having any issues pulling things apart. The top c/o was rebuilt with Dayton 250 v on the LF and Clarity ESA on the HP. Member Westmassguy is a good source for c/o info.
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!