LSIM tweeter issues

jg17512

Loving my 707s until the tweets opened up and gave up,is anyone else having similar problems....Thx in advance John

pitdogg2

what are you using for amplification ?

jg17512

I'm using a Krell ksa 100

jg17512

My speakers are currently out of warranty..

F1nut

Clipped signals.

tonyb

Call Polk and get new ones. Not a common problem but can occur when overdriven as with any speaker.

jg17512

I have went as far as bi amping the 707s,same result.

Clipdat

jg17512

Thanks for ur input,I don't think it's helpful in any way...Grow up

DaveHo

Your clipping the amp. Turn it down. Bi-amping means nothing.

jg17512

I don't think I'm pushing the amp or speakers anywhere close to the point of clipping,it seems like the tweets are just the weak link.

Nightfall

Emlyn

I have noticed the cover plate on the LSiM tweeters can get warm when the speakers are driven too loudly for too long. The distortion is audible sometimes, but not always, before the tweeters are damaged. I have not had a problem with blown drivers on the three sets I use. If the tweeters have blown more than once, it's not a defect in the speakers but a case of overdriving the speakers with a clipped audio signal as F1Nut mentioned above.

The KSA 100 is considered a vintage amp. It is a high current amp design, but has it been serviced at all recently to see if it's still functioning within original specs?

jg17512

I have actually used different amps with the same result,the last amp I used was my aragon 4004 ,it just seems that the tweets just don't hold up.

stangman67

Not sure about the tweets being a weak link. I powered my 703’s with 300wpc and by no means babied them, held up with no issues whatsoever.

jg17512

What's your thoughts,bigger amp.with more headroom?

pitdogg2

well that Aragon should of had plenty. For gets and shiggles what is the most DB in room while you are driving them? 100? 120? .... It sure sounds like they are driven to concert level loudness to me. Are you using any tone controls or an equalizer?

Something is amiss plain and simple

jg17512

I'm running a McIntosh ma6900 as a preamp and I do turn back the high frequencies back on the eq.settings.I'm just to the point where I don't know what to do next..I love the sound of the 707s when they are operational.

WLDock

jg17512 wrote: »

I have went as far as bi amping the 707s,same result.

jg17512 wrote: »

I don't think I'm pushing the amp or speakers anywhere close to the point of clipping,it seems like the tweets are just the weak link.

jg17512 wrote: »

I have actually used different amps with the same result,the last amp I used was my aragon 4004 ,it just seems that the tweets just don't hold up.

Hold up, wait a minute! So you are saying you've blown tweeters more than once? How many have you blown?

For the record one can search the history on this forum, AVSForum, and any other forum, youtube, etc. where folks posts about the LSiM. I don't think you will find posts about tweeter issues. The LSiM improved Ring Radiator tweet is supposed to have higher power handling than the previous Lsi tweeter. Also, given its a 3-way system it has a nice 3000Hz crossover point that should help take some strain off the tweet vs. a typical 2-way system. Also, If one searches back to the LSi line, the SR car audio line that also used Ring tweeters I don't recall reading about tweeter issues. For sure the car audio environment will have higher incidents of distortion and clipped signals. Since the discount and sales started years ago on the LSiM line, there are for sure many home theater guys powering the Front, center, surround LSiM line with the 250 watt a channel Emotiva amps. For sure these systems are played at loud at or near reference theater levels and there are no widespread reports of blown tweeters over on AVSForum given these system have 5-7 tweeters, 5.1, 7.1, etc. IMO, movies can be more dynamic than just music and really tax out a speaker.

So, I will say any massed produced lower cost driver can have a bad one here and there. However, once 2, 3, 4 tweeters are blown in the same system then one has to start considering a problem with the passive crossover or the electronics.

Questions and Suggestions
1) Are you blowing the tweeter in the same speaker or both speakers?
2) If blowing tweeters in the same speaker, there could be a problem with the passive crossover. It should be checked! A bad cap could be the culprit. I've seen this first hand with some older RT series speakers with dried out caps.
3) Is your preamp possibly over-driving your amp?
4) When you were bi-amping could there have been too much gain on the tweeter/mid amp vs. the low/midbass amp?
5) Could there be some issues with the electronics that maybe your ears are not hearing?

Something smells fishy and its not burnt ferrofluid...not in this case, given they are RR tweets!

Inspector 24

Perhaps the crossover suffered damage the first time a tweeter blew?

jg17512

I've lost the tweeters in every configuration so far,whether it's biamping the krells or driving the with the aragons.It's been both sets of 707s as well.I have replaced the high frequency xover to be sure that was a issue as well.I have ran a lot of different speakers and never had a tweeter blow.Klipsch cornwalls,B&W dm16s ...

WLDock

jg17512 wrote: »

I've lost the tweeters in every configuration so far,whether it's biamping the krells or driving the with the aragons.It's been both sets of 707s as well.I have replaced the high frequency xover to be sure that was a issue as well.I have ran a lot of different speakers and never had a tweeter blow.Klipsch cornwalls,B&W dm16s ...

WOW! In all of my car audio and home audio days, I've only blown tweeters a few times. Once, was purely my fault...I literally tried to see what would happen with the volume knob at full tilt. I found out once there was smoke. Next, I stepped away and accidentally let test tones play to some new fullrange drivers at too a loud volume. More smoke...before I could make it back downstairs.
The other cases were a bad crossover and old dried fluid tweets in the Polks. All obvious causes.

The LSiM does not mate well with your gear. Something is amiss.

jg17512

Yea,I was hoping someone else has had similar issues.I love the sound of the 707s and would like to keep them up and running.so far I haven't came up with a solution,the first set was warranty ,after that I have been buying them from Midwest speaker $ 125.per tweeter plus shipping ....

tonyb

How high are you cranking the volume ? Exactly...

CottageChz

I have two sets of lsim, 703 and 705, have run them both with a couple different amp configurations. No problems with blown tweeters. I don't crank them super super loud though. My guess is you have a problem with crossovers or some of your gear. Sorry I can't be of more help, but just wanted to mention I have had no problems with tweeters on two sets of the speakers, also using different equipment to drive them.

jg17512

I do drive them pretty hard ,but never to the point of clipping or distortion,the 707s aren't efficient and they do require a lot of power to make them sound good.

stangman67

They’re 88db, not exactly inefficient either. Me thinks you are driving them way way too hard.

I’m sure they like power, but having power on tap is not the same thing as listening to them at ear and equipment damaging levels.

Clipdat

Why don't you actually list the db that you're listening at instead of continuing to skirt around the question?

F1nut

jg17512 wrote: »

I do drive them pretty hard ,but never to the point of clipping or distortion,the 707s aren't efficient and they do require a lot of power to make them sound good.

Where exactly is the little notch on the volume control knob when you're driving them pretty hard, 9 o'clock, 11 o'clock, 2 o'clock?

At 88dB they are not inefficient loads.

Inspector 24

Maybe he doesn't know and would be surprised they're pumping 110db?

tonyb

jg17512 wrote: »

I do drive them pretty hard ,but never to the point of clipping or distortion,the 707s aren't efficient and they do require a lot of power to make them sound good.

Define "pretty hard"....because my guess is, your overdriving them causing a clipped signal to take out the tweets.

Just because you have an amp on them, doesn't mean you have an unlimited amount of the volume dial to use either.