Anatomy of a Polk RT3

[Guiria]

When it rains it pours. I had plans for dual subs, plasma, etc then right before I commit I lose my job...sheesh. Needless to say I'm on a pretty tight budget now. To top it off my right main channel (Polk RT3) is now blown. There is very audible noise like flapping / fuzziness coming from this speaker in the lower audible range of the driver (currently crossed over at 80 Hz at the receiver).

I thought I'd open it up and take some pics. The cabinet is actually not bad with a 1" mdf front baffle and 3/4 mdf throughout.

I'm looking to replace the driver in the right only, or replace all sets of drivers in both speakers to have essentially a new pair of speakers in an old cabinet.

Any one with experience in this arena? I'm unsure how to go about looking for new drivers given the box design. Two ports with different lengths? How do you go about computing what frequency those ports are tuned to?

I'd be willing to make some cabinet modifications (internally) to make the cabinet work for a different set of speakers if necessary.

One more thing, these speakers are 10 years old

These are specs pulled off the Polk Audio Website regarding the RT3

--------------------------------------------------------------------------------

Driver Complement
Mid/Woofer 1 - 5-1/4" Diameter (13.34cm)
Dynamic Balance® driver
Tweeter 1 - 1" Diameter (2.54cm)
Dynamic Balance® polymer dome tweeter

Electrical
Overall Frequency Response 50Hz - 25kHz
Lower -3dB Limit 63Hz
Upper -3dB Limit 23kHz
Nominal Impedance 8 ohms
Recommended Amplifier Power 20 - 100 w/channel
Efficiency 89 dB

Dimensions
Cabinet Size 12-1/2" H x 7-1/4" W x 8-1/2" D
(31.75cm H x 18.41cm W x 21.59cm D)
Enclosure Type Vented, dual port


Any help would be appreciated.

http://www.racecyclesonline.com/RT3

 

[croseiv]

I'd email Polk Audio's customer service with the info. You can probably get the exact driver from them.

 

[mazersteven]

My first thoughts as well. I would get the drivers that are designed to go with that enclosure, and crossover.

Thanks for the pictures.

 

[Guiria]

I talked to Polk this morning and they want $70.00 + shipping for a single driver.

If I join club Polk I can get the driver for 56 shipped because of a 20% discount but still...

It seems to me that running a pair of speakers one with a new driver and one with a 10 year old driver would not be ideal. I guess I'm not in an ideal situation anyways

 

[Ron Temple]

One of the nice things about Polk is that they still support products over 20 years old. The replacement driver might sound a bit tight out of the box, but will soon sound exactly the same as the old one...might sound exactly the same out of the box. Join CP, replace it and get back to listening.

 

[ParadigmDawg]

Sorry about the job loss. Keep your head held high as you will work again and probably will find something better. I lost what I thought was my dream-job last year and felt hopeless for some time but in the end, I got a better, higher paying one.

 

[mazersteven]

It seems to me that running a pair of speakers one with a new driver and one with a 10 year old driver would not be ideal. I guess I'm not in an ideal situation anyways

As long as there is no damage to the 10 year old driver, you shouldn't be able to hear a difference.

If you install a different driver then the original Polk. You will change the sound of the speaker.

 

[Guiria]

Sorry about the job loss. Keep your head held high as you will work again and probably will find something better. I lost what I thought was my dream-job last year and felt hopeless for some time but in the end, I got a better, higher paying one.

Thanks for the encouragement. I am actually getting involved with a couple of startups that are atleast paying me something, not as much as I used to get but it's putting food on the table. Obviously with a few startups on my plate the earnings potential is significant if we can continue to grow the business.

 

[Guiria]

If you install a different driver then the original Polk. You will change the sound of the speaker.

Which isn't necessarily a bad thing if I could swap the driver in both speakers. I've had these for 10 years, I could explore a different sound.

 

[ParadigmDawg]

Well good, sounds like you will be ok. My "hard times" could have been worse last year. With my severence package and working on the side, I was making more than my old income but still felt bad and depressed about losing my job.

Now get those PAs fixed so you can enjoy your music!

Thanks for the encouragement. I am actually getting involved with a couple of startups that are atleast paying me something, not as much as I used to get but it's putting food on the table. Obviously with a few startups on my plate the earnings potential is significant if we can continue to grow the business.

 

[ParadigmDawg]

Oh and here is a pair of your tweeters for 40 bucks.
http://www.mavin.com/index.php/products/polk-audio-sl5501-tweeter--pair--soft-dome-high-performance

 

[ParadigmDawg]

Opps...you dont need a tweeter, you need a driver....

 

[j_garcia]

Polk doesn't make their drivers, so there has to be a second source for them.

I found a thread on club polk that had this to say about that midbass:

Hello,
The original driver for that speaker is the MW5806, which we have a substitute MW5808 which is currently in stock. Be sure to mention your Club Polk membership when you telephone at 1-800-377-7655 to place an order.
Regards, Ken

(it is from 2004 though).

 

[croseiv]

Polk doesn't make their drivers, so there has to be a second source for them.

Really? I always thought that was the one thing they did make. I know I read that they at least design their drivers
I know the tri-laminate dome tweeter was designed by Polk (at least twelve years ago though).

 

[j_garcia]

I do think they design them for certain but probably don't make them in house any longer, or at least not all of them for sure. The ring radiator tweeter on the LSis, for example, is a Vifa tweeter made to their spec.

 

[ParadigmDawg]

Dont we have a Polk Rep on this forum?

 

[croseiv]

Dont we have a Polk Rep on this forum?

Yes we do. Surely he can set us straight!

 

[mazersteven]

The ring radiator tweeter on the LSis, for example, is a Vifa tweeter made to their spec.

And what a great tweeter it is.

 

[mazersteven]

Dont we have a Polk Rep on this forum?

dorokusai
http://forums.audioholics.com/forums/member.php?find=lastposter&t=47071

 

[ParadigmDawg]

That's him, we should be able to get a free driver out of this deal!

dorokusai
http://forums.audioholics.com/forums/member.php?find=lastposter&t=47071