Modifications to the RTA 15TL
Comments
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Hi been reading and studying this page for almost 2 years and have taken the plunge and ordered the parts. I am a bit of a electronics noob, but I'm now confident I can wire up the crossovers (will probably end up squealing for help right here!).
My RTA's have even starred on these very pages, I bought them off RX7Rotary. Real awesome cabinet job on the sides but he had not performed any mods.
Quick question before I start. I intended on replacing the internal wiring at the same time as doing to xover/tweeters work and started to trace how these had been wired. Mark had obviously rewired as the clip connectors were not present and had been soldered direct to the drives. On tracing it looks like the woofers have been wired in parallel. All + connected and all - connected - with 8ohm drivers a 2ohm load. If I am reading the schematics uploaded for the RTA-15TL's from this site I read it as having the woofers connected in a series/parallel configuration, with 8ohm drivers an 8ohm load. Can anyone advise on the correct wiring?
thanks
Rob. -
The woofers connected in a series/parallel configuration is correct.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Thanks F1nut, that means these have been wired wrong for quite some time! Erk. Be interesting to see how this alters the performance, particularly with amping. Time to pull them apart and start work. Might do this so I can reference what they should be like before modding.
Any tips on which way the factory connected the drivers, i.e. parallel the bottom pair, parallel the top pair and series connect top and bottom, or does it not matter as they are identical drivers?
As well as the xover rebuild, total rewiring, replacing binding posts (they are mistmatched at the mo) and fixing damage to the base of the cabinet so I can fit spikes, I've just noticed that 2 of the woofers have voice coil rubbing. Wish I had noticed that before I placed my order with Helen at polk
. Shipping to NZ can start adding up. I can get them repaired locally by my local electronics shop who are excellent but a little slow, but might see how much new replacements might be. Then I can take time in getting the extras repaired and have some spares. -
robio_d, looking at my schematic, which is probably the same one you found here, it doesn't indicate the driver positions, but they are all the same MW6503 drivers.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Thanks for checking, think I've worked out the wiring order from the LF wiring schematic, translated the loom to speakers and positions. Should be a parallel of the bottom pair and a parallel of the top pair with the two pairs in series. Very handy having the wiring loom schematics to work from.
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Hi, been a bit late with this update but I finished the xover and RTA repair job approx 5 months ago.
Ended up keeping to Brian's exact specs for the build, including xover parts (solens,madisound etc) and damping material, even had a go at adding felt to the baffle. Thought if I'm going to try the mods I would like to try and get a close to the designers specs
Ended up only putting one sheet of extra material behind the woofers and removed some from the radiators for more bass levels, might not be quite as clean but got more volume, with all of the extra damping just felt a little lacking in oompf. I did wrap the cross bracing that is directly behind the 2 woofers tho as it seemed like they would directly reflect those rear firing waves
I originally made up a felt surround for the tweets and I have to say the imaging was awesome, what I did find though was if anyone was sat out of the "perfect zone" the imagine was too precise and you got one speaker or the other so ended up removing it.
HUGE difference with the woofers being wired correctly in amplification needed to drive the polk's - funny that. Dropping the loom back to spec and putting the stack back at 8ohms approx meant that my amps no longer had to struggle to get decent volume 32w can now crank as much as 100-150w did previously.
Hardest bit of all of the process was repairing the base, mainly due to my many failed finishing attempts! Ended up attaching a 20mm piece of MDF to the base, recessed at the side to not detract from the veneer. Actually really happy with the results and means I can now have the speakers on spikes. Also had an added benefit of increasing the mass and rigidity of the speakers.
Ended up building the crossovers from scratch and was actually the easiest bit of the whole process. Mounted them on a mdf plinth with some carpet underlay underneath, thought it might help with vibrations.
After everything was put back together, WOW is all I can say. Immediately everything was better, most notably the warmish nature had been replaced with lush non fatiguing detail and for the first time the soundstage seemed to extend past my ears with one Boards of Canada track leaving me very bemused as the sounds were appearing from just behind my ears
I would say the mods have put these speakers on par to some NZD$4000 speakers I auditioned.
Thanks to all who have posted and helped, and also thanks to VR3 mods for stopping responding to my emails when I was going to purchase a kit, because without that kit I would not have learned so much.
But mainly huge thanks to Brian/Decato for kindly putting this info up for use. You have improved my system overall by a huge measure
Because I had so much fun doing this I am thinking about making another set of xovers using "premium" bits (clarity caps esa/mundorf supremes/solen perfect lays). I know that the improvement will be nowhere near the first, but am I curious to see how higher cost parts will perform. As I will make new boards I can swap both xovers in and out for testing. The new xovers won't be cheap, but still way cheaper than normal cable or rare NOS tube upgrades, so worth a shot -
But mainly huge thanks to Brian/Decato for kindly putting this info up for use. You have improved my system overall by a huge measure
Because I had so much fun doing this I am thinking about making another set of xovers using "premium" bits (clarity caps esa/mundorf supremes/solen perfect lays). I know that the improvement will be nowhere near the first, but am I curious to see how higher cost parts will perform. As I will make new boards I can swap both xovers in and out for testing. The new xovers won't be cheap, but still way cheaper than normal cable or rare NOS tube upgrades, so worth a shot
Excellent! I am so glad to hear that the mods worked out well for you. If you do go through with purchasing "premium" components, please post your results. I still have my RTA 15TLs and use them all the time, but I never bothered to install higher-end components. I did use Clarity Cap SAs in my 1.2 TLs, but I can tell you they did not measure as well as the Solens. The Clarity Caps I received had higher ESR and looser tolerances (12.23 uf vs Solens 12.00 uf). -
If I do I will certainly post the bits used and impressions. The difference between the solen's/madisounds and other costliers caps/parts is one part hoping to get a wee bit more out of the polks, but also to test if more $'s does in fact = better, and I'm willing to find out that they might just not!
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My compliments to you for this excellent thread. I'm new to this but recently purchased an RTA 15T (not TL). This comes with SL3000. Here is what I have for you :-
I have decided to upgrade based on your recommendations. I have already ordered RD0198 from polk. I opened my Xover and noticed that It is slightly different from what you have shown. Please see attached sketch (circuit diagram). Everything looks same except there is one more small capacitor on the tweeter side of the circuit. The capacitor does not have a value but it says -090 910S.
So should I continue with the same suggestion that you have made ?? -
Welcome to the upgrade fever Leosangeet. The "extra capacitor" you are seeing on the tweeter side is the polyswitch that was used to help keep people from damaging the tweeters. You are fine to proceed without if you are using sufficient amplification and don't abuse the volume knob. It is not a value. You can search the forums and find some suitable polyswitches if you choose.
There really is not a "15T" model...the fact that it has the SL3000 it is a "TL" model and you can continue without issues. The T vs TL on the 15 model can be discussed somewhere in a thread here. Have fun! -
cincycat13 wrote: »Welcome to the upgrade fever Leosangeet. The "extra capacitor" you are seeing on the tweeter side is the polyswitch that was used to help keep people from damaging the tweeters. You are fine to proceed without if you are using sufficient amplification and don't abuse the volume knob. It is not a value. You can search the forums and find some suitable polyswitches if you choose.
There really is not a "15T" model...the fact that it has the SL3000 it is a "TL" model and you can continue without issues. The T vs TL on the 15 model can be discussed somewhere in a thread here. Have fun!
Thanks for your quick response. I have ordered all the parts.
Yes I know what you are saying about difference between T and TL. This is discussed earlier on this thread. I also had the argument with the Polk lady earlier today. I know this is 15TL but my speaker tag and the sticker on the X-over says 15T. Please see attached. -
cincycat13 wrote: »Welcome to the upgrade fever Leosangeet. The "extra capacitor" you are seeing on the tweeter side is the polyswitch that was used to help keep people from damaging the tweeters. You are fine to proceed without if you are using sufficient amplification and don't abuse the volume knob. It is not a value. You can search the forums and find some suitable polyswitches if you choose.
There really is not a "15T" model...the fact that it has the SL3000 it is a "TL" model and you can continue without issues. The T vs TL on the 15 model can be discussed somewhere in a thread here. Have fun!
Upgrade done. Speaker sounding much better. Thanks again.... -
Leosangeet wrote: »Upgrade done. Speaker sounding much better. Thanks again....
Excellent! I'm happy to hear that you are pleased with the modifications. -
After reading this thread for the last few days I'm ordering some components from parts express and going to bring these puppies back to life. bought them off craigslist with fried inductors, shorted caps, blown tweeters, etc... poor speakers already ordered the new tweeters... my SRT's will have to hold me over till the new parts arrive
once i get the 15TL's up and running I'll post my SRT's for sale assuming i can get my post count up. on a side note, any reason why the post count must be so high for someone to post a for-sale ad? I emailed the admin but never got a response, kinda disappointing. -
After reading this thread for the last few days I'm ordering some components from parts express and going to bring these puppies back to life. bought them off craigslist with fried inductors, shorted caps, blown tweeters, etc... poor speakers already ordered the new tweeters... my SRT's will have to hold me over till the new parts arrive once i get the 15TL's up and running I'll post my SRT's for sale assuming i can get my post count up. on a side note, any reason why the post count must be so high for someone to post a for-sale ad? I emailed the admin but never got a response, kinda disappointing.
Regarding the post count, the Flea Market is for the Community members to buy and sell things at prices that are lower than they tend to sell elsewhere. Its also a protected marketplace that we only want contributing members to use.
So no drive by sales.
Once you've hit 100 posts we tend to have a feel for you as a person, you've become an "involved" member, etc.
My sig line says it all"....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963) -
my SRT's will have to hold me over till the new parts arrive once i get the 15TL's up and running I'll post my SRT's for sale
I'm curious, why would you replace the SRTs with RTA 15TLs? -
didn't buy the RTA's to replace the SRT's, just kinda stumbled across them on craigslist and decided to fix them properly. If i sell the SRT's i'll use the RTA's and put the $3k in the bank to be that much closer to retirement. I figured i'd chime into the polk forums to offer them to fellow polkies but it seems one has to go thru a background check to get any love on here lol. it's okay, i work with the FBI and do investigations for a living, so maybe i'll fit in
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Mark , you in the Austin area? ...Ive seen a ad for some srt's here not to long ago on CL ...they must sound awesome ....
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If i sell the SRT's i'll use the RTA's and put the $3k in the bank to be that much closer to retirement.
No problem. Good luck with the mods and best wishes for a long, happy retirement. -
yes, southwest austin.
decato, disregard the PM. -
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no sweat, I just replied back I wanted to pick your brain a few days ago about the inductor in the tweeter circuit but i already placed my order. my fingers are crossed.
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crossovers are in, sound good thus far, however one tweeter is starting to fail. sadly the infamous intro to Yes - Owner of a lonley heart sounded compressed in one channel. swapped tweeters and located the culprit. rdo198's should be here on tuesday. oddly enough, i noticed the printing on the oem crossover circuit boards was incorrect. I think it was C2 and C3 that were swapped. the schematic is correct tho.
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new crossovers, new tweets, and new grill cloth. project is done, another fine polk speaker restored and off to craigslist along with my SRT's. I can't keep buying speakers, I guess we could have worse addictions
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new crossovers, new tweets, and new grill cloth. project is done, another fine polk speaker restored and off to craigslist along with my SRT's. I can't keep buying speakers, I guess we could have worse addictions
reported -
Nice work on the restoration!
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reported
why am i reported? I must say this is the most unwelcome audio forum around. I've got 3000-8000 posts on other forums, so i'm no stranger to the web. I feel like i'm spinning my wheels here trying to increase my post count to 100 so that I can post my SRT's and other polk gear for-sale. Where else to sell polk gear but to offer it to other polkies first but I guess in the end no one really cares. -
why am i reported? I must say this is the most unwelcome audio forum around. I've got 3000-8000 posts on other forums, so i'm no stranger to the web. I feel like i'm spinning my wheels here trying to increase my post count to 100 so that I can post my SRT's and other polk gear for-sale. Where else to sell polk gear but to offer it to other polkies first but I guess in the end no one really cares.
And yet after posting in different threads YOU KEEP alluding to all your gear you have for sale. Several members told you to stop but yet you keep tossing it in another thread...Good Grief man I'm sure you're not that dense. Trust me we watch out for the kind of stuff you're doing.
Take a look at j1mmy would you like that same banner......your call
If you have a good deal on you stuff weather it be eBay or Craigslist we all scour those and we will post it here for those who are looking and or interested.
Just contribute its that simple. -
Never have I seen such disrespect to a fellow forum member. And needing 100 posts to list something for sale? just plain hideous... Again, I was just trying to CONTRIBUTE to the forum by offering my rare polk audio gear to "fellow polkies" first. For me, Audio is a hobby, not a lifestyle. It's in our blood or else we wouldn't be here - from the beginner home theater guy to the serious audiophile enthusiasts. either way, it's supposed to be a form of entertainment i.e. FUN, but this forum and it's divergent motions eliminate any possibility of such. (you know what they say about the few bad apples.) So picking on the new guy is just not happening on my watch. I'll take my audio quests elsewhere and will make my final contribution by not logging into this forum any longer. Enjoy.
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Never have I seen such disrespect to a fellow forum member. And needing 100 posts to list something for sale? just plain hideous... Again, I was just trying to CONTRIBUTE to the forum by offering my rare polk audio gear to "fellow polkies" first. For me, Audio is a hobby, not a lifestyle. It's in our blood or else we wouldn't be here - from the beginner home theater guy to the serious audiophile enthusiasts. either way, it's supposed to be a form of entertainment i.e. FUN, but this forum and it's divergent motions eliminate any possibility of such. (you know what they say about the few bad apples.) So picking on the new guy is just not happening on my watch. I'll take my audio quests elsewhere and will make my final contribution by not logging into this forum any longer. Enjoy.
Buh bye now...
