# Help with static/white noise from tweeters, goes along with mid-ranges,



## DigMINN (Jan 5, 2017)

So I just got done doing a large install on my car:

2 NVX Dimple dome tweeters (The re-branded SB Acoustics) on the dash, 2 SI TM65 II in the doors, 4200 NEX, Precision Power 540 4 channel amp and MiniDSP 2x4HD w/ MiniDC power converter. Everything installed pretty easily, turned on and I got sound from all 4 speakers... success!

So I began tuning the DSP yesterday -- have the 6.5s running from 60-2100 w/ a 24db slope, and tweeters from 2100-15000 with the same slopes. I had the amp gain turned almost all the way down, low to mid volume on the deck, everything sounded pretty good, no issues.

I was just driving with my gf, had a song playing in the background at low volume while we were talking, and I began to hear this strange static, almost frog like sound from both tweeters that went along with the song. I first thought, ****, I blew the tweeters out earlier; however, they were not playing loud at all and the amp's gain for the tweeters is almost nothing. So when I got back home I hooked back up to the DSP and muted the tweeters and just let the 6.5's play and I could still hear this sound from the tweeters even when muted, which goes away when both tweeters are un-plugged. If I muted the 6.5s and just let the tweeters play, even at faint volume, I don't hear anything. It seems there's some kind of interference happening, because the static-y sound goes along with what the 6.5 is playing, it's not a constant or randomly played sound.

Since this is my first install, I'm assuming I did something wrong or have a poor connection somewhere, but I'm not savy enough to know. Here is what I was thinking:

1) The tweeters are wired up using quick connect/spade connectors which are not rock-solid connections. I suppose soldering would be better but I don't have a soldering iron and thought this would do. 

2) My ground is bad. I found a grounding post beneath the passenger seat, used a wire brush on my dremel to remove any paint, so I thought this was pretty solid. 

2b) My deck is not grounded to the same post, I just wired it into the black wire off the car's main harness. I realize this should probably be changed, but would that cause this issue only in the tweeters and only when the mid-ranges are playing?

3) The amp is wired improperly/poor connection. Again, I tried to be pretty meticulous about this, but the wiring terminals on the amp are stacked close on top of each-other, and there might be a poor connection here. 

... likely other things I didn't do perfectly that could be affecting this. Hoping someone with more experience can lend me some help! Thanks.


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## gijoe (Mar 25, 2008)

Which tweeters are you using, they make a couple. I probably wouldn't even play the X series tweeters that low. 

I would check all of your connections first and foremost. Make sure that all terminations are solid, and that none of your wires are grounding out on metal.


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## DigMINN (Jan 5, 2017)

gijoe said:


> Which tweeters are you using, they make a couple. I probably wouldn't even play the X series tweeters that low.
> 
> I would check all of your connections first and foremost. Make sure that all terminations are solid, and that none of your wires are grounding out on metal.


These: 

NVX XSPTW 29mm X-Series Soft Dome Tweeters

Yeah, I've thought about bringing them up closer to 2500.


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## DigMINN (Jan 5, 2017)

Update:

So i re-ran the ground from the HU to the same grounding post the amp is on, beneath the seat. The static is still there. 

If I unplug the two RCAs coming off the HU into the DSP, the static still remains -- pretty sure this narrows it down to either the AMP or the DSP. I re-did all of the connections making sure there are no ground-outs or poor connections, so that shouldn't be an issue. 

I'm out of ideas now and curious if anyone has any suggestions of where to look next to further narrow it down? Thanks.


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## GEM592 (Jun 19, 2015)

You said it "goes along with the song" when the 6.5s are on only - do you tend to mainly hear it when the 6.5s are playing lower notes?

If so I would ask if your tweeter rcas are run next to or near your 6.5 speaker wires. More than once I have seen output wires for lower playing drivers induce noise onto rcas for high signals, they are then fed to the amp and heard etc. This can happen even at low levels.

Probably not it is just something to check.


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## GEM592 (Jun 19, 2015)

You can test this pretty easily by first playing a song at a level where you hear the noise clearly, then cross your mids very high for a moment (say 1K on the HP or more) and play the same song at the same level. If it goes away, this could be it.


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## DigMINN (Jan 5, 2017)

So I should cross my 6.5s at 1,000 instead of where they are now (2750)? If it goes away then it's my RCAs? How would I fix that?


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## GEM592 (Jun 19, 2015)

I mean try moving the high pass (lower crossover point of the two) up to 1K or so, so that the low end of the 6.5s is removed. It's a test you can run without messing with your install, cables, etc. 

Steps:

1.) First find a song and level where you hear the noise.

2.) Move the high pass corner on the 6.5s way up (to like 1K). The point is this will cut out the low end of the 6.5s. Yes it will sound wrong but it is a test. 

3.) Listen for noise on same song/level found in step 1.

4.) Put crossover point back to normal.

If the noise went away in 3 above, check if your tweeter RCA cables are being run near the speaker wires connecting the amp to the 6.5s. If so, try rearranging them and see if it helps.


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## DigMINN (Jan 5, 2017)

So that didn't change anything unfortunately

I believe this problem is in my amp -- if I disconnect the RCAs entirely from the DSP, both input from my HU, as well as output to my amp, there is still baseline static in my tweeters. Again, if I hook everything up, play music but mute my tweeters on the DSP, they are not playing a true signal but there is definitely a transmitted signal to my tweeters, on both sides, that sounds like it's trying to play the music my 6.5s are playing, albeit quite faintly and distorted. I had accidentally flipped on the low-pass filter on my AMP channel that's running my tweeters, and there was much less transmitted noise (the tweeters obviously weren't playing anything because their signal coming from the DSP was then muted by the low-pass on the AMP). 

I've re-brushed my grounding post to ensure a good connection, and the problem still remains. I'm not quite sure where to go from here.


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## GEM592 (Jun 19, 2015)

OK, maybe try swapping out the amp to test. If it was recently purchased or under warranty you might try contacting them. It isn't an uncommon problem.


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