HF noise in DEQ2496

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el_ingeniero
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HF noise in DEQ2496

#1 Post by el_ingeniero »

With no input, my DEQ's graph shows noise starting at about 10KHz and increasing with frequency. It's an older model.

See the attached blurry pic.

What's going on here?
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DEQ 2496 HF noise.jpg

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Bill Fitzmaurice
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Re: HF noise in DEQ2496

#2 Post by Bill Fitzmaurice »

Can you hear it? What's the scale on the readout? High frequency noise that's 30dB or more down is usually inaudible.

el_ingeniero
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Re: HF noise in DEQ2496

#3 Post by el_ingeniero »

I believe the scale is going from 0 dB at the top to -60 dB at the bottom.

The hiss is definitely audible when no signal is going into the DEQ and the Xti2000 gain knob is above 50%. I am pretty much deaf above 15KHz, so are most of the people who hear this gear.

As to how it sounds when music is going through it, it varies. I think it lacks sparkle during the quietest passages, but that's maybe my imagination.

I'm more worried that the noise will creep downward in frequency, or that something will go south in a major way.

SirNickity
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Re: HF noise in DEQ2496

#4 Post by SirNickity »

That looks like a typical noise chart for opamps and such, rising toward 20kHz. Not exactly stellar being only -40dB or whatever, though. Whether it's audible depends on the ambient noise, gain factor, and relative signal level of course. I would expect better performance out of a piece of pro-audio gear, even Behringer. But I don't have a DEQ to compare.

wallywally
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Re: HF noise in DEQ2496

#5 Post by wallywally »

I also had a similar phantom signal in my DEQ2496, I re-seated the ribbon cables and now all is good.

Both of my Xti2000's hiss so you may be hearing the amp.
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Bruce Weldy
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Re: HF noise in DEQ2496

#6 Post by Bruce Weldy »

wallywally wrote:
Both of my Xti2000's hiss so you may be hearing the amp.
I only have one xti2000 and it hisses too......none of my xls amps do.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

wallywally
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Re: HF noise in DEQ2496

#7 Post by wallywally »

Bruce Weldy wrote:
wallywally wrote:
Both of my Xti2000's hiss so you may be hearing the amp.
I only have one xti2000 and it hisses too......none of my xls amps do.
From my research this is common on the Xti's and is caused by the DSP. This problem is more noticeable in the piezo array due to higher efficiency. It isn't audible when playing.
Builds:
T-39
DR 280
Wedgehorn 8
Omni 12
SLA
TAT
TLAH experimental

Bruce Weldy
Posts: 8539
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: HF noise in DEQ2496

#8 Post by Bruce Weldy »

wallywally wrote:
Bruce Weldy wrote:
wallywally wrote:
Both of my Xti2000's hiss so you may be hearing the amp.
I only have one xti2000 and it hisses too......none of my xls amps do.
From my research this is common on the Xti's and is caused by the DSP. This problem is more noticeable in the piezo array due to higher efficiency. It isn't audible when playing.
I use it on monitors, which are Yamahas.....I power up the system and the mains are quiet.....but the monitors are hissing like snakes. Nobody seems to notice or care, so it's not a big deal - but it annoys me.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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