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it's was a curiosity as to whether anyone had tried using a center channel to improve the center image focus particularly in wide vehicles (SUVs, trucks, etc.).

I haven't installed my system yet, so this isn't coming from my own observation of something lacking in my situation.
 

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Discussion Starter · #542 ·
it's was a curiosity as to whether anyone had tried using a center channel to improve the center image focus particularly in wide vehicles (SUVs, trucks, etc.).

I haven't installed my system yet, so this isn't coming from my own observation of something lacking in my situation.
trucks…. What is it a Silverado? With a 10’ tall dash line? Lol (I’m kidding)

i know rams and tundras usually have a super solid center…… same with newer tacos with 2” up high ….
 

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I'm getting some weird behavior using the Anu et al method. I love the sound I'm getting from the tune but I want to see if anyone has ideas for how I could resolve this issue. As some of you may remember, I am currently working on integrating my sub into this tuning method.

Here's what happening - if master volume on the miniDSP is loud enough (eg -20dB with the wired remote), when I turn my sub amp's remote gain up to around where it was when I took dirac measurements, I get a popping/distortion sound out of my tweeters when the bass hits. What perplexes me about this is that the sub amp and the amp powering my tweeters are separate amps. Both receive signal from the miniDSP, but they are not connected in any other way (except maybe via remote turn on wire, I can't remember exactly).

Has anyone experienced this? I have solid electrical and did not experience this before the miniDSP. How could adjusting the remote gain on one amp cause distortion in another amp?? I have been working with miniDSP to resolve the issue but they have not been able to pin it down yet. :/
 

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Discussion Starter · #544 ·
I'm getting some weird behavior using the Anu et al method. I love the sound I'm getting from the tune but I want to see if anyone has ideas for how I could resolve this issue. As some of you may remember, I am currently working on integrating my sub into this tuning method.

Here's what happening - if master volume on the miniDSP is loud enough (eg -20dB with the wired remote), when I turn my sub amp's remote gain up to around where it was when I took dirac measurements, I get a popping/distortion sound out of my tweeters when the bass hits. What perplexes me about this is that the sub amp and the amp powering my tweeters are separate amps. Both receive signal from the miniDSP, but they are not connected in any other way (except maybe via remote turn on wire, I can't remember exactly).

Has anyone experienced this? I have solid electrical and did not experience this before the miniDSP. How could adjusting the remote gain on one amp cause distortion in another amp?? I have been working with miniDSP to resolve the issue but they have not been able to pin it down yet. :/

Ahhh , yes , so different amps ? Let me guess , different amp brands…


The fix is use a GLI on the sub amp


The sub amp rca input has different ground path return then the highs amp and is interfering with the highs and your hearing it come though the tweets….


A GLI on sub amp should solve this

I had a Rockford amp with my 3 alpine amps, same issue Rockford was a bass amp

GLI fixed it , as soon as I got the matching alpine bass amp I no longer needed GLI
 

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@oabeieo Yes, two different amps, and different brands. Both get signal from the miniDSP. A 4ch amp powers mids and highs, and a monoblock powers the sub stage.

I will be thrilled if this is the issue!! I have a couple questions though... Does a GLI work for a single channel? My sub amp has mono input. I'm also wondering if the GLI reduces voltage (if yes, I'll want to re-set the gain on the sub amp). Any concerns about coloring sound? And last question, are there good and bad GLIs or will any of them work well?
 

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Discussion Starter · #547 ·
@oabeieo Yes, two different amps, and different brands. Both get signal from the miniDSP. A 4ch amp powers mids and highs, and a monoblock powers the sub stage.

I will be thrilled if this is the issue!! I have a couple questions though... Does a GLI work for a single channel? My sub amp has mono input. I'm also wondering if the GLI reduces voltage (if yes, I'll want to re-set the gain on the sub amp). Any concerns about coloring sound? And last question, are there good and bad GLIs or will any of them work well?
contrary to popular believe, a GLI does absolutely nothing to the signal….

it’s an isolation transformer that’s only used on the return path the outer shield… (at least quality ones are that way)

even the cheap $35 PAC is a decent quality

If both of the amps had even somewhat similar resistance to ground from outer shield there would be no noise…. Some of them are high impedance some of them are low some of them are isolated and some of them aren’t

150-2000 ohms is pretty common ( but it can go as high as 10 K) it’s a simple ground loop

it will work… i’m certain of it
 

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I'm happy to report this issue is resolved! When I swapped out the old RCA for the GLI, it eliminated the distortion in the tweeters. What's interesting, is I also swapped the old RCA for another standard RCA (not a GLI), and that ALSO eliminated the problem. So the GLI was not needed, but the RCA needed to be changed out for sure.

Side note: I did not measure voltage, but I think I perceived more bass with the non-GLI RCA vs the GLI, so maybe voltage is lost through the GLI.

It could have been a long time until I thought about messing with the RCAs, so massive thanks to @oabeieo for the direction on this fix! I was pretty puzzled by this one! And I'm SO HAPPY to have my bass back to it's full potential 🔈🔈🔈
 

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Did you place it on the input RCAs into the DSP or the output side RCA to the amplifier?
 
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Discussion Starter · #551 ·
I'm happy to report this issue is resolved! When I swapped out the old RCA for the GLI, it eliminated the distortion in the tweeters. What's interesting, is I also swapped the old RCA for another standard RCA (not a GLI), and that ALSO eliminated the problem. So the GLI was not needed, but the RCA needed to be changed out for sure.

Side note: I did not measure voltage, but I think I perceived more bass with the non-GLI RCA vs the GLI, so maybe voltage is lost through the GLI.

It could have been a long time until I thought about messing with the RCAs, so massive thanks to @oabeieo for the direction on this fix! I was pretty puzzled by this one! And I'm SO HAPPY to have my bass back to it's full potential 🔈🔈🔈
so a cable…. A ha !

it shouldn’t have messed with bass at all

otoh , it’s another amp on the return I’ve heard of weird stuff before… that one is new to me.

glad it’s workin now… 😋🥳😎
 

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This was the RCA from the DSP output to the sub amp's input.
Do you by chance have amps with balanced inputs and others with unbalanced inputs in your system?
 

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Discussion Starter · #555 ·
All my amp inputs are RCA, so unbalanced.
i Wonder if he meant pseudo balanced (like JL)

minidsp uses isolated pseudo balanced outputs

It uses common mode rejection on its input side iirc…..I asked a few years ago when it didn’t work on a tru line8 and that was why
 

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Amp models are ESX QE1200.4 and Wolfram O-8000.1

I don't think either have fancy inputs.

But just so we are all on the same page here, the issue was resolved by swapping out the bad RCA cable. I've had bumpin enjoyment for almost a week now.
 

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All my amp inputs are RCA, so unbalanced.
Like JL Audio, they can run balanced on RCA inputs.
I ask because I run 2 JL XD 400/4's and 2 Wolfram 3000.1's and I had noise until I switched the Wolfram's to twisted pair cables, Stinger 4000 series.
 

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Like JL Audio, they can run balanced on RCA inputs.
I ask because I run 2 JL XD 400/4's and 2 Wolfram 3000.1's and I had noise until I switched the Wolfram's to twisted pair cables, Stinger 4000 series.
Interesting! Wonder if Wolfram is the common element here. Is that the W-3000.1? That's a half-bridge, whereas my O-8000 is full. That may not make a difference though. I also own the W-3000.1 btw, I like that amp a lot.
 

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Interesting! Wonder if Wolfram is the common element here. Is that the W-3000.1? That's a half-bridge, whereas my O-8000 is full. That may not make a difference though. I also own the W-3000.1 btw, I like that amp a lot.
I think the problem was "balanced" and unbalanced rca's hooked up to the MiniDSP, not necessarily a brand problem.
Yes, I bought 2 of the W-3000.1's, and I like them too, but they are huge.
 
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