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Discussion Starter #1
Hi all,

New to the DIYMA way of car audio, and in my own setup which I'll describe:

2004 PT cruiser.

Older Pioneer CD deck (line-outs) model escapes me, its a consumer unit.

Old Audiocontrol EQX (original design - only 2 way xover and 13 band EQ)

Nakamichi PA-200 (35Wx2) driving Boston Acoustics S35's in the dash.

Clarion (60Wx2) driving Boston Acoustics SX65's in the stock door location.

Profile 200W driving a 10w3V3 in a 1.2cuft sealed box in the hatch.


I should mention both the door and dash speakers are on the "high" side of the audiocontrol's 90hz crossover point. The sub is on the low side. Also as 90hz is too low for the S35's I've added a high pass cap (it is meant to work at 4 ohms at about 700hz if I recall, It's a very good quality cap too - I wanna say Kimbercap but thats not right, forgive me I might be able to find its value and the brand if I need to.)

Also I have another passive filter on the output of the amp, another good quality cap and a coil meant to act at 150hz 12db slope. I realize this gives me a midbass hole, but thats for tomorrow to fix - my door speakers muddy up if I give em any lower than tha.

****** I get a very annoying "ringing" or harmonic, or some peak that is not in the source material. It happens with high pitched male singers and most female singers, or guitar solo's on the high end. It is very prevalent when the source gets very complicated with a lot of instruments. It only seems to happen at high volume. Its difficult to localize the source it seems to come from everywhere. I would almost say its sorta like low bitrate MP3 sound, but my source is uncompressed (several original CD's)
 

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Disconnect your mids and see if it's coming from the tweeters, then disconnect the tweeters and see if it's coming from the mids. One you figure out which driver it's coming from you can start to fix it.
 

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It sounds like clipping to me. Try to adjust the gains on your tweeters. Clipping will make music sound harsh, especially guitars.
 

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Hmm,

Aren't some capacitors capable of a high pitched whine when powered? My brother has a power supply on his video card that whines with a high pitched tone when he's playing a game that stresses the video card.

If you listen real close at the end of this video you can hear the capacitor whine from a laptop:

YouTube - M1330 Cpu Whine

here is a more direct demo:
YouTube - Acoustically noisy switch mode power supplies

Sometimes the noise can get annoyingly loud.

YouTube - Zalman ZM-1000HP Power Supply High Pitched Squeal With Vsync Off
 

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Discussion Starter #5
Hmmm never occurred to me that it could be the cap itself but you are absolutely right! It only happens under a decent amount of current through the system kinda makes sense too.

Well, in either case I can narrow it down by following gijoes advice - and just trating it like any other troubleshooting problem. At least I could rule out a set of speakers, or if its in all of them - I could blame the old EQ or head unit.

Hmm,

Aren't some capacitors capable of a high pitched whine when powered? My brother has a power supply on his video card that whines with a high pitched tone when he's playing a game that stresses the video card.

If you listen real close at the end of this video you can hear the capacitor whine from a laptop:

YouTube - M1330 Cpu Whine

here is a more direct demo:
YouTube - Acoustically noisy switch mode power supplies

Sometimes the noise can get annoyingly loud.

YouTube - Zalman ZM-1000HP Power Supply High Pitched Squeal With Vsync Off
 

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Discussion Starter #6
Problem found.

Its the design of my system.

I have 2 Boston acoustics sx65's (coaxes) - in the doors, crossed at about 150hz hi-pass.

I also have 2 Boston acoustics s35's (coaxes) - in the dash, crossed at about 600hz hi-pass.

Essentially I have 2 sets of speakers doing the same thing above 600hz. Whats going on is that the 2 sets of tweets are producing some sort of harmonic distortion.

Neither the doors nor the dash speakers were putting it out by themselves.

I had some sort of crackle when midbass was going to the doors - and I quickly traced it to the tweets on the door speakers, which I also found, were removable. Once I pulled the tweeters out of the doors, not only does my setup sound a LOT better, I can turn it up all the way until the deck starts to distort (at about 28/30 on the volume knob) where before 21/30 would give me that ringing.

I chose parts and installed tehm without really knowing what I was doing - I still don't, but I know now to try and keep each speaker doing its own thing by itself, and to recover the best out of my investment I think a 3 way front soundstage is in order.

6.5's handling 60-600, 3.5's 600-2500, and an unknown tweeter in the sail panels or high on the a-pillar to handle 2500+. JL 10w3v3 60 hz and down.

now to find some active xover or to design one that does just that.
 
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