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View Full Version : Blowing Focal K2 Power Tweeters..



5150
08-31-2004, 10:07 PM
I am running a JL 450/4. Puts 150RMS to channels 1&2. I am running the focals on the first 2 channels. I have blown 4 tweeters, I think the wiring is wrong some how. Any one got any subjestions?

squeak9798
08-31-2004, 10:11 PM
Where is your gain set, and are you using any EQ'ing (even if it's built into your headunit).

My guess is that either 1) you are simply overpowering them, or 2) you have something set too high (gain or EQ bands) and are clipping the signal.

5150
08-31-2004, 10:30 PM
I got a alpine 9835. I have everything set to stock.

squeak9798
09-01-2004, 01:27 AM
Stock as in flat, or stock as in how it comes straight out of the box (I'm not familiar with the inital settings Alpine gives their decks from the factory, is it flat??). Also, where is your gain set?

5150
09-01-2004, 03:07 AM
The amp stock is set at "flat", the gain is set at, freq is set at 95, abnd imput s.(somthing) is set turned all the way right and a quarter turn back to the left. Im not sure which is the gain.

squeak9798
09-01-2004, 09:53 AM
The amp stock is set at "flat", the gain is set at, freq is set at 95, abnd imput s.(somthing) is set turned all the way right and a quarter turn back to the left. Im not sure which is the gain.

Input S is the Input Sensitivity, or the "gain" as it is commonly referred too. This should not be turned up all the way (turned almost all the way to the right as you said). With the gain this high, you are in all likelyhood clipping the signal which is what is frying your tweeters.

http://jlaudio.com/amps/amp_pdfs.html - Go to the 2nd link from the top, "Interactive Input Sensitivity ("Gain") Setting Tutorial" and follow the steps to properly set your gain, and your problem should be fixed.

5150
09-01-2004, 12:11 PM
Thanks bro I have has 4 blown tweet's, I will yell ya if it makes a diff. What does turning the gain down exactly do?

squeak9798
09-01-2004, 12:16 PM
I'm not good at explaining stuff, so I'll try my best:

The gain matches the inputs to the outputs, basically. It works like an attenuator because with higher voltage RCA inputs (which your headunit has), the amp doesn't need to "amplify" as much of the signal to reach a given power output level. So you turn the gain down with high voltage RCA inputs so that the amp doesn't "over amplify" the signal, which could cause the signal to become clipped and will blow speakers (as you are experiencing :) ).

5150
09-01-2004, 12:24 PM
That worked, thanks man!

5150
09-04-2004, 03:13 AM
turning down the gain works so good, it goes louded and no blown tweets!

squeak9798
09-04-2004, 10:36 AM
:clap: Glad you figured it out

5150
09-05-2004, 01:37 PM
But it seems it is playing a little low notes. i want it only for high's, can i set my amp to do that?

squeak9798
09-05-2004, 02:47 PM
You can use what is called a high pass crossover, which filters out the frequencies below the crossover point. Your amp has one built in, and the headunit you have also has it built. You can use either one. But one thing to make note of is that a high pass crossover is not a "brick wall", it doesn't just kill any frequency below the crossover point. It attenuates the frequencies below the crossover point at a certain rate (i.e. 12db/oct, 18db/oct, etc etc). So even if you have it set to, say 100hz for example, notes that are 80hz or 60hz will still be going through and being played by the speaker, but they will be attenuated. So don't freak out if you set it and your speaker is still playing some of the "lower notes".