Polk Monitor 70 Tweeters (Help!)

ejperry09

Hi all,
I was on this forum a while back and you guys were incredibly beyond helpful, basically picking out a new system for me consisting of 2 monitor 70's and a harman/kardon 3940. I broke them in for about two weeks. Things sounded great for a while.

Long story short, last Saturday I had a party at my place and things got a tad out of hand and the speakers were cranking pretty loud. Now, I still have a relatively untrained ear but I think I may have damaged the tweeters. I've read everywhere that they're fragile tweeters.

How things sound now is that there's a bit of fuzz over every song that I'm not sure was there before. Granted I'm playing mp3's from an iMac for the most part, but I just don't think things sound quite as crisp. I've run a few tests I found on YouTube, so I'm wondering if there is anything else y'all recommend. Also, if I were to have damaged my tweeters, would they be completely fried (smoking) or do they slowly go out on me? In other words, would it be very easily detectable if I ruined them?

Sorry for the verbosity, but any help would be greatly appreciated! Thanks Polk Community!

ejperry09

Please help!

jayman_1975

don't fret too much about it. Chances are you did smoke a tweeter. Try this. Unhook one speaker at a time. If it's just one that's toast then the other will sound super compared to the blown one. I had this happen to mine. Take it back to where you bought it and have them replace the tweeter. No worries. I had exactly the same thing with mine. Got it fixed and things sounded great again! Good luck.

ejperry09

Thanks. I actually fried both tweeters. Do you think there would damage to any of the other cones? Also, more importantly, could I have done any damage to my receiver? Is there any way of testing the receiver?

jayman_1975 wrote: »

don't fret too much about it. Chances are you did smoke a tweeter. Try this. Unhook one speaker at a time. If it's just one that's toast then the other will sound super compared to the blown one. I had this happen to mine. Take it back to where you bought it and have them replace the tweeter. No worries. I had exactly the same thing with mine. Got it fixed and things sounded great again! Good luck.

jayman_1975

Well it's hard to say. If you figure both tweeters are fried.... possibly it could be the receiver instead. Do you have any other speakers you could hook up to see if they play properly? You described the sound as a bit of fuzz over all the sound. I'm not sure if damage to the receiver could cause this but i know that this pretty much describes a blown tweeter to a tee.

cnh

You can clip most amps and the M-70s can take all the power the HK can deliver and more...so that sounds like what you did.

Call up Polk Customer Service and get some new tweeters if that's what you determine the problem to be, you're still under warranty and that's no prolem.

Clipping and distorted sound...are, of course, no nos.

cnh

jayman_1975

Mine came from the store with a bad tweeter and they were demo's. I had the tweeter replaced and have sent some pretty decent power to them and had zero problems. I'm guess some drunken party goer cranked the volume and blew the tweeters.

Trenchant

You were saying you weren't sure if the sound was there before. How are you connecting your imac to your receiver?

A stereo headphone connection will give off a fuzzy tweeter sound. You will notice a big difference if you switch to an external usb sound card($20-$30) and an optical audio cord($10). Both can be found on ebay dirt cheap.

ejperry09

Thanks guys. I'm currently using a toslink optical audio cord going straight into the iMac. It does make a day and night difference to the headphone connection.

Also, what exactly does "clipping mean"? Is that going to harm the speakers or the receiver? I'm just going to replace the tweeters but I'm concerned I may have done damage to the receiver. Is it possible to damage a receiver by cranking it pretty good?

jax3822

I have a pair if you need them. PM me if you want them.

cnh

ejperry09 wrote: »

Thanks guys. I'm currently using a toslink optical audio cord going straight into the iMac. It does make a day and night difference to the headphone connection.

Also, what exactly does "clipping mean"? Is that going to harm the speakers or the receiver? I'm just going to replace the tweeters but I'm concerned I may have done damage to the receiver. Is it possible to damage a receiver by cranking it pretty good?

Clipping is when you overdrive an amp to the point of producing violent distortions that will damage your speakers and possibly the amp as well. As soon as you hear your speakers sounding less than CLEAN you should BACK OFF THE VOLUME OR ELSE....clipping! This is a simple common sense, not too technical definition, hope it helps?

cnh

nedh84

You should consider getting an amp or two to power your speakers. Powering your speakers on the Receivers power alone can cause clipping if you push the receiver too hard. Basically as you push your receiver the sound waves become jagged and end up damaging your speaker. Tweeters are the first to go. Some clean power from Receiver -> AMPS -> speakers will allow you to turn up those speakers again at your next party. Within limits and reason of course.

I'm new to all this audio stuff so please let me know if I'm right or wrong.

IRLRaceFan

nedh84 wrote: »

You should consider getting an amp or two to power your speakers. Powering your speakers on the Receivers power alone can cause clipping if you push the receiver too hard. Basically as you push your receiver the sound waves become jagged and end up damaging your speaker. Tweeters are the first to go. Some clean power from Receiver -> AMPS -> speakers will allow you to turn up those speakers again at your next party. Within limits and reason of course.

This is what happened to one of my Monitor 70's. I didn't know what my problem was until I called Customer Service and was told pretty much what is mentioned above. Polk hooked me up with a new tweeter (GREAT customer service!!!) and a few days later I bought a set of Emo UPA-1's.
What a difference! I never had a system with external amps before and now I'll never put one together (for myself) without them.

cnh

Although M-70s can handle more power than the HK 3490. You SHOULDN'T be able to clip the HK on M-70s so easily. Amplification does help. But that HK should be sufficient. You can drive LSI bookshelves with that receiver and they are a 4 ohm load. So M-70s should be fine.

cnh

B Run

IRLRaceFan wrote: »

This is what happened to one of my Monitor 70's. I didn't know what my problem was until I called Customer Service and was told pretty much what is mentioned above. Polk hooked me up with a new tweeter (GREAT customer service!!!) and a few days later I bought a set of Emo UPA-1's.
What a difference! I never had a system with external amps before and now I'll never put one together (for myself) without them.

I just replaced a tweeter in my cs1, and i've been looking at the UPA-2 to run my towers, hopefully freeing up some power for my center and rears. Do you think that would help or should I look at a 3-5 channel amp? If i could get away with just the 2ch amp it would be preferred.

ZeroCoolPolks

Distortion will kill a tweeter. I crank my M70's with a Yamaha Z-11, clear & clean power, and they R OK, 4 now anyway