RTA12 tweeter question

motorcityguy

Picked up a nice set of RTA12's (originals, not B or C) a while back. I was able to verify the drivers all work, but didn't really get to do any critical listening before purchase.

Previous owner had replaced one of the original Peerless tweeters with a Midwest MT-4115 (8 ohm version). I know Midwest advertises these as drop-in replacement for Peerless, but wondered how it sounds compared to the Peerless. Is it ok as-is? Should I be seeking out a replacement Peerless tweeter so both speakers have same driver?

I won't get a chance to hook them up and listen for myself, for quite a while. I am asking about this now, so I can use the time to start hunting down a replacement before I put them into rotation.

Gardenstater

I'm interested in hearing what people have to say. I just got today a Peerless tweeter used on ebay for $31.98 incl. tax and shipping so that I would have a backup one in case one of mine ever blows in my 7Bs. The seller has one left. You might want to check it out:

https://www.ebay.com/itm/324045578102

motorcityguy

Gardenstater wrote: »

I'm interested in hearing what people have to say. I just got today a Peerless tweeter used on ebay for $31.98 incl. tax and shipping so that I would have a backup one in case one of mine ever blows in my 7Bs. The seller has one left. You might want to check it out:

https://www.ebay.com/itm/324045578102

Thanks! I should have mentioned my Peerless is the early one, marked 7514 and made in Denmark. The fleabay one you mentioned is marked 5514, and is later US version.

Not sure if I would know the difference, but according to Geppy1 (Keith), there is a difference in sound between the two. So I might not be any better off than I am with the Midwest replacement. Let's see if Geppy1 chimes in....

Gardenstater

Oh jeez. You had to tell me that lol? I actually don't know what ones I have, Denmark or US version. For the price though, it will be ok as a backup I guess. My speakers are vintage 1979 and I have never pulled the tweeters out to look but will be doing so soon when I rewire and update the crossovers. I guess I'll find out! At least I only got the one.

@geppy1 what say you? If the US version is not really inferior, but just different, perhaps I should snatch up the 2nd one.

Jazzhead

Get another Peerless. There is universal agreement among those that know more than I (and have compared) that the Peerless is better. They show up on on Ebay. You want the same tweeter in both speakers. By the way, I have a pair of the originals (1980) that are quite impressive in their sound after a full blown series of modifications. It took time, effort and expense, but was well worth it. The most rewarding mods were a DHS Speaker Service (David Shirly) crossover rebuild (Sonicaps/Mills resistors), new Cardas binding posts on aluminum discs, and a David Shirly recommended structural/acoustical mod that overdamped the outer woofers to mimic the crossover frequency roll-off of later versions of the RTA line (dramtically improves imaging/detail). I also replaced the internal wiring with high purity Neotech OCC wire, bypassed the fuses, added more damping material under the crossover module, and did all the other standard upgrades recommended here one the Polk Forum. I can walk you through any/all of these if you desire (relevant threads are on this forum).

Gardenstater

@Jazzhead what gauge of the Neotech OCC wire did you use for the midbass drivers and the tweeters? Did you go lower gauge for the tweeters?

Jazzhead

I used 14 gauge stranded Neotech OCC wire and high silver content solder. I didn't replace the wiring on the crossovers, just all the internal wiring.

Gardenstater

@Jazzhead Oh. Meaning you didn't replace any wires that physically connect to the crossovers? In my 7Bs that's the wiring from the binding posts, fuse, and wires to the midbass and tweeters.

Jazzhead

The crossover module on the original RTA-12 came boxed by itself. Once installed it sits on top of the cabinet and is connected to the internal wiring via that little "pinch" connector at the top of the cabinet. The design idea was to set the tweeter back a bit from the midwoofers for better time alignment (therefore these speakers don't require any tilt or rake angle). If you wanted you could replace all the wiring on the crossovers, to the tweeters, and the wiring to that connector on the top of the cabinet (DHS Speaker Service offered Speakon connectors for this). You have to replace the original female socket on the top of the main cabinet as well etc. My original connectors were in good shape and the original wiring on the crossovers and tweeters is just a few inches in length so we elected to go with the original set-up. I replaced all the wiring inside the cabinet from the binding posts to all the internal drivers, and spliced/soldered together inside at the female crossover connector mentioned above. By the way, compared to the replacement Cardas binding posts, my original posts sounded horrible. I don't think one can really evaluate these speakers until those are replaced. However, my old binding posts may have been worse (oxidized?) than some. Also, my binding posts cups were cracked from age, so I mounted the new posts on some thick aluminum discs I had made at a local machine shop. I think you can get the original style plastic cups as well.

Gardenstater

@motorcityguy Would you happen to have a picture of what your tweeters look like on the inside? I pulled one of mine and no model # and white wire goes to the terminal with a red slash mark which is very odd. I posted my pics in another thread here:

https://forum.polkaudio.com/discussion/189473/pulled-one-of-the-peerless-tweeters-in-my-7bs-and-no-model#latest