Modifications to the RTA 15TL

Nice to see some serious effort going in to those Polks

Are those SPIKED yet

I wish I still had my RTA-15TLs. I never got a chance to fully listen to them. I bought them after we sold our house, and so that sat in a storage unit for a while, along with a pair of AR9LSi. I had to sell them because I needed the money, now they never seem to come up for sale around the South Jersey/Philly area. I would buy them back given the chance, I'm buying the ARs back.

I always wondered, what would happen if you "boarded up" the rear facing passive radiator? Maybe with a piece of 3/4" MDF screwed into the same holes as the passive, and will a gasket to stop air leaks. I find that speakers without rear ports (or passives) are easier to place in my room.

Lee.

So i finished the new grills yesterday evening.






So the next question, which emblem/badge should i add to the grills? and where?
I was thinking top center or bottom, not like the original ones (just above the pr).

I finally managed to get another pair of these a few weeks ago. They had one Peerless and one SL-3000 tweeter, which I replaced with RD0198s when I did the crossover mods over the weekend.



Here is a shot of the original crossovers, with a production date of 12/10/90 :



Here they are restored with Solen caps, and Dayton Audio Grade resistors. I went with the Dayton resistors because I wanted to get all the parts from the same source to save on shipping, Parts Express matched the Madisound price on the Solen caps. Some people have used additional boards for the larger caps, but I found with some deft positioning of the components, I was able to get them all on one board, and more importantly to fit back through the hole. I used the original woofer inductor, but used the a Dayton one for the tweeter.





There was an unused solder pad on the board that I was able to use to fit the 0.5R resistor. Those wires might look a bit tight in that area from the 0.5R resistor, the 2.7R, and the 12uF cap, but they are all going down to the same pad anyway.



Here they are going back in. Notice I swapped the tweeter polarity on the board, not at the tweeter. I meant to take pictures of the new RD0198 tweeters, but forgot.





Lee.

leesonic wrote: »

I used Dayton non inductive resistors instead. As I mentioned above, I wanted to get all the parts from one source, as shipping costs start to add up. I don't mind if it's for more expensive parts (like the parts I just ordered for a NAD 2700 power amp), but for just a few caps and resistors? Parts Express was nice enough to match Madisounds price on the Solens. If you hear the difference between Dayton and Mills resistors, you've got better ears than me.

Lee.

In the DIY community, Dayton stuff is used very regularly with spectacular results.

Good Morning All. After spending several years accumulating and restoring Carver Amazings, I have found mayself back dabbling with Polks again. I still think my fully modded SDA 1C are the best speakers I own,

Anyway, I have just acquired a pair 15tl's in great shape from the original owner. I am trying to decide whter to go down this update path. Great work by Decato.

My first question for all of the experts here is are these supposed sealed cabinets like my RTA 12c's and other models with passives. I do not get any movement of the passive cones when I press on the drivers.

You shouldn't press on the driver, you SHOULD press on the passive. A single MW won't displace enough air to significantly move the passive. Think of it like a hydraulic circuit.

Yes. I found a post suggesting to push on both passives at the same time. My enclosures are sealed well. Thanks.

My postings were delayed for some reason. Maybe because it has been so long since I posted. I think the meantime I found d a post somewhere suggesting that both the front and rear passive should be pressed at the same time. The cabinet is indeed sealed. Thanks.

I did the passive radiator modification today, as described on page one of this thread. Basically, this involves removing the SW104 passive radiator with the most weight on it (called "low resonance" by Polk), swapping the SW100 front "high resonance" one to the back, and using an SW105 passive in the front.

Here are some pictures of the passive radiators. The SW105 has a small mass in the center, the SW100 has a larger mass, and the SW104 has two of these masses stacked on top of each other. There is no real difference otherwise in their construction when viewed from the rear.





Here is one of them next to my Dayton/Advent Frankenspeakers.



Regarding my comment above about people complaining over what caps or resistors I used. It wasn't intended to upset or offend anyone. I too have done a lot of crossover work in my time, I've been into this hobby since I was probably around 10 or 11. Other kids used to read comic books, I used to read HiFi magazines. The fact is, pretty much any cap would be an improvement over 30+ year old electrolytics that have dried up. Everyone has their favourite flavour of caps, each to their own. It would be a dull old World if we all liked the same. The other fact is, I'm pushing 50 now, so I probably couldn't hear the difference between Mills and Dayton resistors. The mind is a very strange and peculiar thing, if it's telling us that one cap, inductor, or resistor sounds better than another one, we can't argue with that.

We're all cool, right? Like Sir Richard Starkey AKA Ringo Starr would say : "Peace and love, peace and love".

Lee.