Possible blown Rt7’s

iwantsomepie

So I just discovered that my parents were former Polk owners themselves at one point. While rummaging through the basement I stumbled upon these babies.

They are Polk Audio RT7 – 17300





Unfortunately they sound like they are blown, the sound they emit is very dull and silent, no bass whatsoever. The little speaker at the top is releasing a tiny bit of sound while the bigger one at the bottom isn’t turning out anything.

I’ve attached a video of the RT7’s playing music; hopefully someone can diagnose the problem from it!

http://www.youtube.com/watch?v=eRogl_cfV4s

The receiver is a HK3480 and the other speakers in the video are my own Polk RTi A1.

I am hoping there is a way to fix these puppies and get them playing again. Any help is appreciated!

iwantsomepie

Well I unscrewed the driver and took a look inside, but I have no clue what I am suppose to be looking for. Personally it all looks fine.

I took some pictures of the connections that are going onto the driver.






I have no idea what is wrong with them, obviously I would like to fix them.
Can anyone help me out, I am a total newb when it comes to speakers and would love some help!

Talweh

Fear not, someone here (with more knowledge than me) will probably be along shortly! Until then I would try to gently push in on the drivers to see if they're stuck or not. For some reason, I am not seeing the pics you posted, but make sure all the wires are connected. That's about all I know

treitz3

Does the cone move in and out on the woofer without any friction whatsoever when you manually push it in?

iwantsomepie

treitz3 wrote: »

Does the cone move in and out on the woofer without any friction whatsoever when you manually push it in?

Yes, I can easily push it in, offers hardly any resistance!

treitz3

Thought so. Check all connections [especially IC's] leading to and from the amp. Also from the amp to the speaker. The speaker sounds fine. You have another issue.

iwantsomepie

treitz3 wrote: »

Thought so. Check all connections [especially IC's] leading to and from the amp. Also from the amp to the speaker. The speaker sounds fine. You have another issue.

Honestly, they are broke. There is no sound coming from the bigger of the two drivers. You might not hear it from the video. The same setup runs my A1's just fine. I am pretty stumped :-/

messiah

Where are you located?

iwantsomepie

messiah wrote: »

Where are you located?

Columbus, Ohio.
I'm even more bummed out now, after doing some more research on these speakers they turn out to be one of Polk's best 'old school' speaker per say.

Would love to get these fixed, anybody have anymore ideas?

vc69

My guess is something in the x-over is shorted/blown but I'm no expert either. Do these have two sets of binding posts to connect to for bi-amp/bi-wiring? Is it possible you are connecting to just the tweeters? If there are two sets of posts, there should be a "bridge" that connects the two sets together.

Kex

Welcome to CP iwantsomepie ... (interesting choice of screen name, Keiko will be pleased to see that his fame has spread far and wide accross the internet). Rest assured, with the excellent c/s Polk still provide for their older speakers, and as long as parts are available, then you will undoubtedly be able to get these speakers working again. If Polk Audio cannot provide the parts new anymore, then it is very likely that other members will be able to help you to find them used.

First things first, though, which means clearly identifying the issue. It is normal for the tweeter to make a light "tin" sounding noise, since the tweeter only handles the higher frequencies. The larger driver, when pushed in should move freely, which apparently, it does. Do NOT push in the center dome of the driver. Like treitz3 suggested, though, you should check and double check all connections (from source player, to the receiver, all the way to the speaker terminals on both ends) to make sure that is not the source of the issue. Also try swapping the speaker connections and see if the problem follows the connection or not.

The h/k 3480 is a very good receiver for two channel, BTW, with excellent power output, and is very well liked by many Polkies.

Good luck!

vc69

vc69 wrote: »

My guess is something in the x-over is shorted/blown but I'm no expert either. Do these have two sets of binding posts to connect to for bi-amp/bi-wiring? Is it possible you are connecting to just the tweeters? If there are two sets of posts, there should be a "bridge" that connects the two sets together.

Should have looked at the pic's a little closer. Doh!

treitz3

Hello again. Try this, take the woofers and hook them directly up to the speaker cables and play at a low volume. You will be bypassing the x-over altogether. Do you hear sound? Does it still have that crackle type sound we hear in the video?

If it doesn't the woofers are fine. Try the same thing I][U][B]AT A LOW VOLUME!!![/B][/U][/I with the tweeters. The same questions with the woofer will apply. Try that and get back to us please.

nguyendot

More than likely the drivers are blown. You will know once you do what treitz3 said about hooking up the drivers directly.