# Distortion coming from tweeters?



## Rivers (May 11, 2006)

Would appreciate if I could get some advice on this? I run a 2 way setup and had this recently installed in my car recently but realized that the tweeters would distort at high volume.

Here is my setup:
Focal Utopia BE (Tweeters + 6.5" Woofers)
New Rockford PBR300X4 (75watts at 4ohms x 4 channels)
New Helix DSP.2 with tweeters crossed at 3 Khz @ 24 db slope
Stock Volkswagen HU

Rockford amp gain settings;









I had the amp gains initially set to 2-3 since I thought it would probably be better playing music at 70-75% of the HU volume and have the gains set lower on the amp but I realized that there would be noticeable distortion (I hope it is audible in the video).

Raising the gains to 5 on the amp and lowering the HU to under 50% seems to have reduced the distortion, though not completely gone. For curiousity sake, I bumped the gains up to the max and had the HU play at a low volume, but there was too much floor noise so I went back to a gain setting of 5.

Does anyone have any idea what could be causing the distortion on the tweeters? The HU, most likely?


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## toneloc2 (Nov 29, 2015)

what are your cross over settings on the helix,,,,, everything is flat on the hu? amp x overs off? little more info on settings,,,,, i run the utopias as well all amps bridged 200w to the tweets 300w to the mids clear as a bell all the way up...


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## Rivers (May 11, 2006)

Have the both Woofers and Tweeters crossed at 3 Khz @ 24 db. I muted the woofers in the video though.

Everything is flat on the HU, Amp crossovers are turned on.


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## toneloc2 (Nov 29, 2015)

should be running the cross overs with the helix shut the amp ones off...


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## Rivers (May 11, 2006)

Sorry, I meant the crossovers on the amp are turned off; They are set to All Pass. Crossovers are all set on the Helix DSP.


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## BlueSQ (Mar 22, 2007)

Hook the wires going to the tweeters up to different speakers. Start diagnosing from the drives back to the source.

Also I think 75w rms is too low for that front stage.


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## Rivers (May 11, 2006)

I think 75 watts would be OK based on the technical sheet? Nominal power is at 15 watts with Max power at 200 watts.

I doubt both drivers have an issue right? I need to find someone who has a spare set of tweets


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## DC/Hertz (Nov 27, 2011)

75 is plenty. But that 15 is full range RMS. 
I'd as said and hook up different speakers on that channel.


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## BlueSQ (Mar 22, 2007)

Rivers said:


> I think 75 watts would be OK based on the technical sheet? Nominal power is at 15 watts with Max power at 200 watts.
> 
> I doubt both drivers have an issue right? I need to find someone who has a spare set of tweets


You don't need spare raw drivers, just a single speaker. You're looking for distortion from the channel. Since you're only sending high frequencies, any speaker that has a tweeter should do. If you use a higher OHM speaker you might have to up the gain a bit just to test.

Ultimately, the point is to find out of your tweeters are the issue or your signal. If the spare test speaker sounds clean, you'll want to pull the tweeters and test them outside of your system to see what's up. If you end up doing that, be sure to use caution with your crossovers.

Did you buy those BE tweeters used?


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## Rivers (May 11, 2006)

Thanks. I am guessing the stock 6.5" speaker from the car would not work then?

I bought them off a friend probably like 10 years ago and they seemed to have work fine in the other cars, though I might have only recently realized this issue.


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## BlueSQ (Mar 22, 2007)

Rivers said:


> Thanks. I am guessing the stock 6.5" speaker from the car would not work then?


You need one that will handle at least 15 watts RMS and is designed to play 3khz and up. A home bookshelf speaker would be a good place to start since it has it's own built in passive x-over and a tweeter. The idea here is process of elimination. 








Rivers said:


> I bought them off a friend probably like 10 years ago and they seemed to have work fine in the other cars, though I might have only recently realized this issue.


It's very noticeable in your video.


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## Elgrosso (Jun 15, 2013)

They seem to play much below 3k here, or is it a youtube effect?


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## Babs (Jul 6, 2007)

Also consider the DSP.2 now has a clip indicator light.. That can help determine if the signal feeding it is clipping at the DSP input. Consult the manual on it. I recently tested gains from my head unit to my Pro-2 and found it was pretty consistent with my DD-1 tester with a 1khz and 40hz signal.. Test with speakers disconnected of course.


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## BlueSQ (Mar 22, 2007)

Babs said:


> That can help determine if the signal feeding it is clipping at the DSP input.



Can you elaborate on this? I wasn't aware a signal can clip at the DSP input from a low level source.


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## DC/Hertz (Nov 27, 2011)

Any source can clip. Very few do not.


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## Babs (Jul 6, 2007)

BlueSQ said:


> Can you elaborate on this? I wasn't aware a signal can clip at the DSP input from a low level source.


Sure.. An analog DSP input is not unlike an amplifier input.. If the source signal is too hot for the gain settings it will clip, just like an amplifier.. Helix's have internal gain potentiometers.. Your DSP.2 looks like it has one on the external, which you should see some documentation on that in the manual. It might be for high-level, or for both RCA and high-level inputs. Don't know. But the clip-indicator is a new thing on these version 2 DSP's (DSP.2, DSP Pro-2) and best I can tell, it's fairly accurate when I tested mine.. Easy enough to test if you disconnect speakers just to protect them, then lay a 1khz tone through the system into the DSP, or possibly do a fresh all-pass 0db no-EQ tune (never let that be saved because that would be bad bad bad on tweeters and mids).. But then run the 1khz tone through it to look for clipping.. You'll likely find a point on the head unit where clip is detected momentarily.. That might be clipping "at" the head unit, or at the DSP input from the head unit overpowering it at the particular gain setting.

Sorry.. Couldn't come up with a better more concise explanation. Hope that helps. And I could likely be wrong as all get out.  Hence "Consult thy manual".


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## DC/Hertz (Nov 27, 2011)

I think the Bit software has been doing input clip for a while. It worked good for them. But the Bit has De-EQ also


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