RT 16 tweeter replacement

12andrew23

I can't access most of the threads here. My RT 16 tweeter is out (second time) and support informed me the stock SL6501 has been replaced by the SL6508. Are these two matched close enough to just replace the one or should I replace the pair?
Thanks

F1nut

You should be able to access all threads except the Flea Market.

Second time......perhaps over driving your AVR?

I don't know the specs of either tweeter, but I would say since they are different models you should replace the pair.

12andrew23

Nor can I respond to private messages yet, even though I want to. I need 25 posts for some threads and 10 for PMs. Guess I could spam the board but that's no fun. Regardless, I am interested in discusssing the PM from this morning, if I can get a direct contact.

Overdrive - who me???

F1nut

Really dude!?!

12andrew23

Whatever - I had an offer I couldn't not respond to. Blame the rules.

rooftop59

I PM'ed him. We are adults here, I'm a big boy and can take care of myself, and just trying to take care of a fellow polkie. I don't need "forum rules" to protect me, I have a brain, common sense, and autonomy. Some of these rules are ridiculous.

12andrew23

Can't say I understand, but if I get another dozen or so posts I can follow the thread on the SL6501 and the SL 6508.
Cheers

[Deleted User]

Hello,
If Polk's CS department recommended the SL6508 as a suitable replacement then you should consider that. Before they make any kind of substitution they consult with the engineering department, specifically the transducer engineer, to make sure the parameters are a match.
Sometimes the tweeter's color or physical shape might be different, but mechanically and electrically it will work.
You might want to describe the associated equipment, listening preferences, room size and volume levels you enjoy and we can, maybe, make some suggestions to prevent a repeat problem.
Regards, Ken

12andrew23

Thanks Ken
I understand you to say that a single SL6508 would work alright paired with the SL6501? IE, I could just buy the one and be more or less ok?

Specs:

Powered through at Harmon Kardon 3485 2.1, spec'd output at 120 W at 8 ohm, 150 W at 4 ohm.
Last setup: "A" channel to 4 ohm Quart One; "B" channel to Polk RT16 8(?) ohm, often played at the same time - ie channels A and B at the same time.
Input is either from desktop PC "out" to receiver "in," or (more often)
Pro-Ject Debut Carbon LP player (nice)
which has an aggressive output.
Speakers at the 11 ft wide end of a 12 ft long enclosed room, two carpeted exterior walls, two interior walls 50% covered with books or LPs, one door (insulated) - its also a practice room.

Polk RT16 became secondary after purchase of used MB Quart One.The Q1s are now in need of at least one woofer and two tweeters. They are 4 ohm with a 6 ohm tweeter - I think.

Thanks for asking!

12andrew23

Oh, and volume level - I've found the sweet spot in the room, and there is really no such thing as too loud. Sitting in a solid wooden chair on pier-and-beam you should feel the bass in your rib cage. Sort of like the Memorex tape ad...

F1nut

Last setup: "A" channel to 4 ohm Quart One; "B" channel to Polk RT16 8(?) ohm, often played at the same time - ie channels A and B at the same time.

There's a good part of your problem.

and there is really no such thing as too loud.

And there's the rest of it.

It's a wonder the HK is still working.

12andrew23

Well it is slowing down a bit. I figured A and B were independent and just kept polarity down the lines, but also never considered ohmage. I guess the Polk are 8ohm? and if so, would the Q1 cabs retrofitted with new crossovers, woofers and tweeters to an 8 ohm 100W system, say for a mid three-figure amount be worth pursuing? I'm thinking not.
(is the 6 inch really a woofer or should it be midrange or full range?)
And then there's that volume knob...

[Deleted User]

Hello,
You should be fine with just a single replacement tweeter it will sound the same as the original.
When you operate A+B speakers from the receiver's point of view the impedance is their product divided by their sum. That is a 6 ohm plus a 4 ohm speaker load would be 24 divided by 10 would mean 2.4 ohms which is pretty low. However since you are using two different speaker systems which will have different impedance curves the minimum impedance might not be quite that low at power demand frequencies (low bass).
Your audio system will tell you when the receiver is clipping or producing distortion, you'll hear two things primarily. One will be a harshening of high frequencies transients, a stridency or brittle quality, think of the letter group "TS" becoming "TZ" instead. In fact a friend of mine always called it "tizziness".
The second clue is a little harder to spot. It will be a feeling of the sound being compressed or clamped, as if the music were constipated. This is caused by an over-stressed power supply beginning to sag and fail in meeting the demands. Simply make sure you have all the tone controls set "flat" or bypassed, especially any bass boost and reduce the playing volume when you hear any of those symptoms.
Cheers, Ken

F1nut

Ken, there's a third clue. The tweeters keep cooking.

rooftop59

What he needs is actually a tweeter for an RTi6, not an RT16.

deafbykhorns

What he needs is a bigger amp that doesnt clip. Those chip amps in receivers dont have much headroom

Msabot1

Actually needs?? How about a little common sense regarding basic ohms law and it's practical effects on equipment?? No offense intended.....

12andrew23

Well my bad. The RT i6 calls for an RD0690-1 that is OEM and my concerns re: having to buy two are no irrelevant. It's on the way.

I do appreciate the education on channels. Low resistance means increased amps which means increased chance of blowing something? I don't crank A and B, but will crank A on occasion. If I rebuild the Q1s they'll probably become 8 ohm so that would be a 4 ohm combined load (8x8/16) as opposed to a 2.7 ohm combined load (8x4/12). I can see how the reduced load would change the outputs on the amp rated 120 W at 8 ohm, 150 W at 4 ohm, and I can only guess at the 2.7 load - maybe 190 or so?.

This from someone that literally (as in really) smoked a 15 inch guitar amp speaker back in the day.

deafbykhorns

Msabot1 wrote: »

Actually needs?? How about a little common sense regarding basic ohms law and it's practical effects on equipment?? No offense intended.....

None taken, just have a little experience with amps, I'm fully aware of ohms law.
Clipping kills speakers most the time unless he's running these for pro sound or long parties. Most speakers will take some time to self destruct if the amp is not clipping. Example, My 100wpc Khorns could take 450wpc driven just under clipping for 10 minutes(hence my moniker), after that I didn't have the gonads to drive them any longer. Nothing wrong with cranking them up for short periods of time.

12andrew23

Just installed my new tweeter, put on a Hoodoo Gurus LP and moved to the sweet spot. -15 good, -10 nice!, -5 awesome, but, dropped the bass/treble a bit and it sounded safer; -20 fills the room nicely. Still have the bass thump so all is good. Awaiting word on the Q1 rebuild, but that's another forum.

F1nut

You should have bought at least 10 tweeters for future use.