Modifications to the RTA 15TL

boston1450

Hey. Those look fimiliar maybe one day soon i will put em in & see how they sound. Im a slacker

westmassguy

Yeah you think? Rat Bastage, get'em in already..............

boston1450

Ive been painting for 2 days straight & im outside sweating like a pig in heat. Im so backed up between work & the house. If i live to see it all done i will be a happy man

westmassguy

It's Wicked Hawt"....
Try working with a house full of non-English speaking relatives for two weeks.

Fanatic

westmassguy wrote: »

It's Wicked Hawt"....
Try working with a house full of non-English speaking relatives for two weeks.

Try restoring a couple of Polk speakers when you live in Sweden.
Those crossovers look really neat, thats the look i'm aiming for.

westmassguy

There should be some suppliers in the EU for Inductors that match the specs on the Madisounds, Jantzen is in Denmark. Clarity Caps are made in Wales, so there should be a supplier in the UK at least. Vishay/Mills is International, so their Resistors should be available. The Nylon Standoffs I get off eBay, and the riser board is Masonite.

Fanatic

Well, now the speakers are back in action with redone x-overs and new tweeters. The short listeningsession iv'e done is promising!

This is how the X-overs look redone:

westmassguy

Looks great. Did you remember to reverse polarity on the tweeter leads?

Fanatic

westmassguy wrote: »

Looks great. Did you remember to reverse polarity on the tweeter leads?

Of course!

Did also replace all the internal wires, same gauge but new single core wire. Stranded wires tend to give a bit more resistance.

decato

I'm really glad that everyone likes the sound of this modified crossover. I still have the pair that I modified back in late 2006/early 2007. Nearly 10 years later, they still sound good to me.

Fanatic

So the modifications continue.

Now it's time to give the estetics of the speakers an upgrade. It seems to me like the grilles look a bit to much 90's , so i started making new ones. Hopefully they will end up looking a bit more 20-th century. The original design does actually have a design flaw, which is when the fabric covering the frame is mounted, it tends to make the sides of the grille bend towards the center of the speaker (looking like a banan), so i added some extra bracing to the new ones.





The new ones wont be having any angle cut sides/bottoms/tops, just rounded right/left edges and they will be mounted flush with the sides and top of the speaker. This modification won't show any of the veneer when you are standing/sitting right in front.
I'm also thinking about adding a newer badge/emblem, prefferably aluminium colored, or the black/white/red one.

And well, i swapped the 90's looking feet to new black aluminium ones (44x17mm round with a rubber insert)

westmassguy

Nice work!

RandyCroissant

Nice to see some serious effort going in to those Polks

boston1450

+++ Very nice work

boston1450

Are those SPIKED yet

tonyp063

Nicely done. Very pleasing to the eye.
What does the ear say?

F1nut

And well, i swapped the 90's looking feet to new black aluminium ones (44x17mm round with a rubber insert)

Spikes are a much better idea than the amplifier feet.

Fanatic

Needless to say, i like the sound they poduce, else i wouldn't put all this effort in making new grilles!

About the spikes, its not really an option at the moment, since one of the speakers are placed on tiles/wooden floor. If i'll be using spikes it will be when they're placed in another room with "proper" flooring.

At the moment im running a DSPeaker Anti-Mode 2.0 Dual Core in the system, and the Anti-Mode probably produces more wonders than the spikes would have done in my room.

leesonic

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.

Fanatic

leesonic wrote: »

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.

Removing the rear radiator is not a good idea, since it's needed to reproduce lowest frequenceys. You could probably remove both passives and compensate with ports (carefully calculated and tested). But my guess is you'll suffer from distorsion when trying to reproduce the same SPL levels as with the passives.


This is just why i'm using the Anti-Mode,i cant't place any speaker in my room without placing them really close to the wall. The Anti-Mode removes all the boomyness and excessive bass, if i'm not wrong it does also compensate frequenceys with time, so the result is just tight,heavy and articulated bass! Well worth the money if you have limited placement options for your speakers.

Fanatic

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).

boston1450

Excellen work. That shiny top look sweet

leesonic

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.

boston1450

Excellent job. I think youll enjoy the tweeters much better then the way it was. Cant imagine why someone would mismatch tweeters

pitdogg2

Get back to us after they play for about 300hrs. I will be curious as to your thoughts on the Solens in the tweeter section. Can i ask why you didn't use mills or mundorf non inductive resistors?

leesonic

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.

K_M

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.

F1nut

K_M wrote: »

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.

That's only because they haven't used better components to know that Dayton stuff isn't spectacular.

pitdogg2

Yes agree shipping can be a deal breaker at times.

leesonic

I knew there would be people on here that would whine and moan if I didn't use the Solen caps. Usually, I would have used PEX caps from Erse Audio, or Dayton caps. I've done plenty of crossover restorations using these caps, and have had no complaints, both on my own stuff and speakers I've restored for others. You can see my threads over on AudioKarma, same user ID as this one.

Caps are a subject that people have strong but very misguided opinions on. Some people with unlimited funds prefer caps with 24ct gold foil, using the finest snake oil as the electrolyte, soaked in pure silk sheets from free range (not battery) silkworms, and hand-rolled on the thighs of dusky maidens. Me, I've already said what I use. The fact is, a Dayton, Erse, or Solen cap is going to be miles better than a 20 year old electrolytic, so don't lose any sleep over it, just listen to the music.