Polk RTA-11TL w/ Infinity EMIT Ribbon Tweet?

[seanengman]

So, I've got a pair of Polk Audio RTA-11TL's and one has a blown SL3000 tweet. The direct replacement is a Polk RD-0198 soft dome tweet. My Dad wants me to throw in a pair Infinity EMIT Ribbon Tweets from his QA speakers.

I would like to know what everyone's thoughts are on this. I know there will be some cutting involved, so there's no going back. Is there anything I should take into consideration?

Thanks,

Sean

 

[SY]

You'll probably have to do a redesign of the crossover. And the polar pattern is likely to be quite different. Do you have good frequency response and impedance measurement capabilities?

 

[seanengman]

I have a multimeter, and an oscilloscope and thats about it. I'm really new to this type of project.

 

[SY]

Well, you're ambitious, so that's a point in your favor. 😀 If you have a sound card in your computer, then with a test mike and some software, you can do the necessary measurements. A useable mike can be gotten for under $100. I have an article in the December issue of AudioXpress showing the basic how-to.

Alternatively, depending on what part of the country you're in, there may be a forum member nearby with test gear whom you can beg for a favor.

 

[seanengman]

Well, I live near Spokane, WA. I'll see about looking up that article. Are there any good beginner projects that will introduce me to the skills I need to build exceptional speakers?

 

[SY]

Many- a forum search will turn them up. It's an amazingly rewarding pursuit, which brings together acoustics, electronics, and woodcraft. Besides ending up with great speakers, you'll also end up learning about all sorts of new and useful aspects of technology.

I would strongly recommend picking up two books to start with: first, Vance Dickason's "Loudspeaker Design Cookbook," and once you've digested that, Joe d'Appolito's "Testing Loudspeakers."

Here's a taste of what you're in for: http://audioxpress.com/files/dappolito2959.pdf

 

[seanengman]

Awesome, I'll add those to my library. Thanks for your time, I appreciate how helpful this site is and everyone here. Mr. Babin has bailed me out of quite a few fixes in my car amp repairs.

 

[SY]

Yeah, Perry is a great guy and a superb resource.

 

[Jim Griffin]

So, I've got a pair of Polk Audio RTA-11TL's and one has a blown SL3000 tweet. The direct replacement is a Polk RD-0198 soft dome tweet. My Dad wants me to throw in a pair Infinity EMIT Ribbon Tweets from his QA speakers.

If you want to preserve the Polk Audio RTA-11TL speakers with the blown tweeter, I would suggest that you replace the bad tweeter with a replacement Polk Audio unit such as shown here:

https://www.midwestspeakerrepair.com/home-audio/tweeters?p=2

This would restore the Polk speakers to operating status with minimal cost and trouble.

The replacement/modification for the Polk speakers with Infinity EMIT tweeters is a bad idea. First, the EMITs are meant to be used in a frequency range of 4000 Hz or above while I suspect that the Polk tweeter crossover is in the 2000 Hz area. Second, a crossover change would be necessary and considerable knowledge and measurement equipment would be necessary to deal with those challenges. Not a good start to your career as as an expert loudspeaker engineer.

To learn about designing a loudspeaker I suggest that you choose a two-way speaker as a first project. You could purchase a kit of parts (see Meniscus Audio or others for possible kits). Otherwise, to roll your own design you would need to transition through driver selection, cabinet construction, crossover assembly, measurement techniques, etc.

Meniscus has parts kits that range from less than $100 to 10 times that amount.

http://meniscusaudio.com/kits-c-133.html

 

[seanengman]

Thanks for the links. I ordered the factory replacements for the Polks.

Hopefully they show up sometime soon.