New-to-me RT16s

concealer404

Hi All,

Picked up a pair of RT16s (and a CS350) on Sunday. After realizing that the tweeter on the left side one as set up wasn't working because it was missing the biamp jumpers, i "fixed" that with some loose wire and then sat down to listen for a couple hours.

Came away pretty conflicted. The impact and bass range is pretty impressive. However, there's a pretty small window in which they actually "come alive" and image well and generally smooth out the freq curve....

That window seems to be about 2 clicks on the preamp, between "Sounds not awesome" and "BLOW THE WALLS DOWN AND MAKE YOUR EARS BLEED."

Driving them with a Parasound HCA-1000A, B&K Ref 5 SII preamp.

Mainly so far i think the tweeters are my least favorite part of them.

The speakers in general are in good working order, but slightly cosmetically challenged. I have almost nothing into them, so i'm willing to take on a little bit of a project for fun. I blew $28 on some Dayton speaker spikes, and now i'm looking at refinishing them, removing the remaining grill posts and shaving them flush, and maybe "upgrading" the tweeters if there's documentation out there.

So i'm looking for two or three things, if you all wouldn't mind giving me a hand:

1) If one was too lazy to make their own speaker jumper wires, what pair (left/right) of < $40 jumpers do we like? There's a dizzying array of options on Ebay ranging from $10-$1000, in various configurations. I doubt there's a huge science behind this, so.... "Works" and "looks kinda cool" are my criteria. If i have to make my own, i will. I've been considering making some custom (short) length RCAs for my Schiit Uber Stack anyways.

2) Is there any documentation concerning swapping out tweeters in these old relics? I haven't found much in my hour or so digging. I did find that the woofers are no longer being produced by Polk so i'm either hitting used market or finding the people making the "pretty damn close" reproductions if one of mine fails, but no real info on tweeters. I'm guessing they aren't part of the SL2000 "family" and upgrade path.

3) Any real benefit to rebuilding/upgrading the crossovers in these things? I'm somewhat handy with a soldering station and well... these are pretty low risk.


Thanks in advance, will be interesting to see if i can get these to displace my Paradigm Legend V.3s (I still think i prefer them after some A/B comparisons last night).

Rich502

If you want to greatly expand the window where they come alive you may require a beefier amplifier. These things can take some serious power with two 7.5" drivers in each tower. I've consistently run them on 250 per side without any strain on the RT-16's. The only downside to that is, with the tri-laminate tweeters things can get pretty bright pretty quickly in absence of any room treatments and or carpeting.

As far as jumpers, give bi-wiring a try with whatever speaker wire you have laying around. The one other thing with the RT-16's is that they also benefit from being placed further away from the back of the wall to reduce boominess. The last recommendation that I received from Ken S, from what I recall, was to have them at least 36" from the front of the speaker cabinet to the rear wall, if possible.

concealer404

Hrmmm.... so if i like this sound, i need to look at an HCA-1500, then. Bummer. The Paradigms like power too, but apparently don't "need" as much as these?

Room has carpet, but no treatments otherwise. The layout (and that it's a rental) prevents any real effort being made to treat it.

Bi-wiring won't easily be done with my cables and i'm not sure i want to bother rummaging around in hopes i have enough wire to do 2 runs each speaker of the same kind of wire. (I'm sure i don't have that to be honest.)

36" away from the wall...... hrm. I also don't have that kind of space.

The tweets are honestly my biggest complaint. The bass, while it has a little bit of a hump right now, isn't obnoxious. They're still pretty musical and they're certainly "fun." But due to the tweeters, i can actually run the Paradigms (3x 6.5" drivers per speaker) louder without it being fatiguing. I wouldn't think the power requirements would be THAT different between the two speakers, but i also haven't really bothered to look at the efficiency measurement of the two.

Appreciate the info! I will move them out from the wall and see if that drastically changes anything for the better. If so... i may just throw them in a closet until I move.

Rich502

Sensitivity on the Polk speaker is 90db and the recommended power range is 30-250.

codycatalist

Replacement tweeters are SL6508 apparently, at least that's what Polk "Recommends". The originals were SL6501, on another thread I read that they advise to contact Polk to make sure the SL6508 will drop in as their could be slight differences in the dimensions but mechanically they work similarly. I don't know the upgrade path for that tweeter model but at least you know the model number now. = ]

dromunds

Don't the RT-7's and others use the same tweeter? Maybe you could find a rough pair (or single) of those cheap on the used market and cob the tweeter(s) out of them.

concealer404

The tweeters are working, i just don't like them. Never liked the Polk trilams much.

I also seem to maybe have a driver on the fritz. Rotated it last night and initial impressions seem to point to it being "fixed," but i need to spend more time with it and some quality source material to get a better sense.

Should also think about tracking down a good spare (or four).

These do a pretty good "wall of sound," though. I'm warming up to them, just wish the tweets were a bit less harsh.

I'm keeping my eye out for a cheap pair of RT-7s regardless to store in a closet until we move and have space for an HT, then i'll slam all this together with a B&K processor and some random 5 channel amp and call it soup.

codycatalist

Not sure if something like this is plausible for you but maybe this...

forum.polkaudio.com/discussion/comment/2317067#Comment_2317067

mantis

Man I have always wanted to pick up a pair of RT16's. One day I'll go on a hunt for a mint pair.
The RT series back then where always very bright depending on what you mated them with.
I'd find a B&K Reference amp like a 200.2 and that should smooth them out a little and give you awesome dynamics and punch. I like Parasound amps but not really my cup of tea.
Upgrading the Tweeters might also require a crossover change to blend them in better. I'm sure there are plenty of people on here who have been down this path.
I love those speakers.

concealer404

codycatalist wrote: »

Not sure if something like this is plausible for you but maybe this...

forum.polkaudio.com/discussion/comment/2317067#Comment_2317067

That's probably a bit outside my wheelhouse at the moment. I may just go through and generally freshen up everything and see what that does, but if there's not a fairly easy upgrade path a la SL series tweeter, i'll probably not bother going any farther. Seems like a lot of effort expended in a quest to equal the tweets of a pair of speakers i already also own.

concealer404

mantis wrote: »

Man I have always wanted to pick up a pair of RT16's. One day I'll go on a hunt for a mint pair.
The RT series back then where always very bright depending on what you mated them with.
I'd find a B&K Reference amp like a 200.2 and that should smooth them out a little and give you awesome dynamics and punch. I like Parasound amps but not really my cup of tea.
Upgrading the Tweeters might also require a crossover change to blend them in better. I'm sure there are plenty of people on here who have been down this path.
I love those speakers.

I'll see about tracking down a 200.2 regardless. I was looking for them when my old cyclops died but they were all unreasonably priced at the time, and i got a pretty nice deal on this Parasound which i actually like a lot. But hey, if the B&K is better, it's better.

I don't know that i'd call the speakers "bright," there's just a real definite point where all of a sudden the tweets get pretty shriek-y. They're a little brighter than the Paradigms but i liked the Paradigms on this setup because it was a very warm-bordering-on-downright-dark sound, which is my preference to avoid fatigue.

Either way, these RT16s are FUN if kept under control. Watched The Fifth Wave last night (terrible movie) and the "slam" and dynamics these things will put out without a sub is pretty amusing. One point in their favor: They ARE handling movie voices in a 2 channel setting better than the Paradigms do.

xschop

Try a set of SL5000 tweeters if the RT16s are crossed over @2.5-3khz
From goog images someone has already done this.

concealer404

Hrm interesting. I will see if i can figure out what the xover is. Thanks!

concealer404

I can't find the xover numbers or schematics for these things.

I did find a few pairs of cheap SL5000s on ebay. Maybe i should just try it and see what happens?

xschop

What ohms do the factory tweeters show?
The RT16 and S4-S10 (which have the SL5000s)
are very similar in the crossover tweet network.

concealer404

I'd have to check. Speakers overall are 8ohm supposedly, which seemed a little strange to me.

xschop

I looked over both schematics here and if it were me, I would copy the S10 crossovers. Use an air-core 0.50mH inductor on MWs and a 4.7uF cap on the sl5000.
From info I found on RT16 MWs they are 8 ohm but in parallel so the crossover point will match the S10's as their MWs are 4ohm.
I've modded two sets of S4,6 crossovers to have just the 4.7uF cap and it is the sweet spot for the Sl5000's

concealer404

Hey thanks for the info.

Got caught up in life again, and actually picked up a pair of Paradigm 11se MKiii on Saturday so they're currently in the rig. Absolutely ridiculous speakers, i'm loving them.

But now this means i'm more likely to tear into the RT16s since they're not really doing much at the moment.

So it looks like i just replace the 4.4uf cap with a 4.7uf, then drop in the SL5000s and let it rip? I may consider just rebuilding the xovers entirely, was planning on re-doing the foam/deadening inside as well anyways.

xschop

No. My suggestion is remove the 4.4 and the 10uf. Then drop in a 4.7uf where the 10uf once resided.

concealer404

Oh, i got it now. I didn't look long enough to see the 10uf the first time, my mistake.

Thanks!