Loud "pop" sound on startup only with XLR

[Klaim]

I recently changed how I setup my Helix Floor in my "studio", now I have USB going to the PC, S/PDIF going into my audio interface and I hear the Helix by default directly on my audio monitors.

However, I remarked that when I turn on the Helix while the monitors are on, I got an scary "pop" sound immediately when igniting power (yes I know it's not the best order to turn on devices but it's more practical for me at the moment to have the speakers on most of the time and turn on the helix when I need to use it).
I did some experiments:

• helix ==S/PDIF and any numeric signal from USB==> audio interface ==RCA==> monitors : no signal on helix boot
• helix ==Jack L&R ==> monitors : no signal on helix boot
• helix ==XLR==> monitors: scary "pop" on helix boot
• previous setup: helix ==XLR (not sure if it was the same cables)==> audio interface ==Jack-to-XLR==> monitors : no signal on helix boot (did that for years now)

 

I can continue to just use the jack output, but I was wondering if that's normal or if I should be aware of some potential issues?

[datacommando]

31 minutes ago, Klaim said:

helix ==XLR==> monitors: scary "pop" on helix boot

Hi,

 

This is not something that I have encountered with a similar setup. 
 

I have Helix USB in/out to Mac, Helix XLR out to XLR in on Tannoy Reveal monitors.

 

The monitors are usually already on line when the Helix fires up and I’m not aware of a scary “pop” - The Helix starts up so quickly that I can be noodling around on the guitar as the Mac is still booting up.

 

Does this “pop” occur if you have the volume down on the Helix until it is fully booted up - maybe a volume surge?

 

I hope this helps/makes sense.

 

EDIT:

If you are sending audio to the PC over USB what is the function of the S/PDIF connection?

Edited October 19, 2021 by datacommando
Question

[Klaim]

4 minutes ago, datacommando said:

Does this “pop” occur if you have the volume down on the Helix until it is fully booted up - maybe a volume surge?

 

 

Yes, I experimented with turning every volume knob to 0 and it still did the pop. I think it's more electric than anything but it's weird that it only happen with that output + cables.

Could it be a cable issue? I assume not but just to be sure...

[Klaim]

By the way, the sound also happen when I turn the Helix off while the monitors are on. It's even louder when turning off.

I also just tried:

• having the audio interface turned off does not change a thing
• removing all input source didn't change a thing

 

Another info: the monitors and the Helix are on the same power strip, not sure if it plays a role or not but it would still be weird that it would only affect XLR

[datacommando]

13 minutes ago, Klaim said:

Could it be a cable issue? I assume not but just to be sure...

Hmm… also not sure. I know mine are all good and I always have cable tester on hand to check any suspect cables.

 

You possibly need to verify they are  functioning correctly using something like this.

 

https://www.studiospares.com/studiospares-ultimate-cable-tester_458260.htm?gclid=CjwKCAjw2bmLBhBREiwAZ6ugow_nTTuzC8NXQHs65xa101tHGKYRxXH8PP1NjOdN4BDss28VVEqYjBoC1P4QAvD_BwE&gclsrc=aw.ds

 

Not sure what else to suggest right now - it almost midnight here - time to sleep, and think some more later.

 

[spaceatl]

The rule of thumb of in ALL professional audio studios and live audio production companies is preamps power on first, power amps power on last....power down is reverse...amps first then preamps...It may be that something in your chain does not have a safety relay(s) or the relay(s)...I am not sure if Helix has them, but I think they do..

 

But I would suggest you follow this age old rule with your audio gear...Get power sequencer...losing RCF drivers on a pro audio system that is 4x overpowered is a very real and extremely expensive risk. Every time a speaker pops (amp clip), it is hit with a little DC and nothing wears a voice coil faster...

 

Here's a thought...not sure but this can cause pops with lots of gear

If you are running very low or incorrect output levels (xlrs mic level and speaker at line level)...then you over crank the input to the monitor and it pops when both start at the same time....that is because the input on the amp is too sensitive....check for that...mismatched levels is really common with Line 6

 

This was very common on the HD modelers because the XLRs were fixed at mic level and lots of folks plugged into line level monitors and basically running everything full tilt just to get a decent stage volume...That will pop like a mf...

[Klaim]

9 minutes ago, datacommando said:

Hmm… also not sure. I know mine are all good and I always have cable tester on hand to check any suspect cables.
 

You possibly need to verify they are  functioning correctly using something like this.

 

You just reminded me that I do have one of these, will try to check them ASAP.

I also noticed that the Jacks TRS seem to generate a very low background noise in the speakers (Presonus Eris 5) even when the Helix is turned off, so I would prefer to use the XLR as there is no noticeable background noise with these.
 

12 minutes ago, datacommando said:

Not sure what else to suggest right now - it almost midnight here - time to sleep, and think some more later.

 

Same, it's past midnight here.

[Klaim]

3 minutes ago, spaceatl said:

The rule of thumb of in ALL professional audio studios and live audio production companies is preamps power on first, power amps power on last....power down is reverse...amps first then preamps...It may be that something in your chain does not have a safety relay(s) or the relay(s)...I am not sure if Helix has them, but I think they do..

 

But I would suggest you follow this age old rule with your audio gear...Get power sequencer...losing RCF drivers on a pro audio system that is 4x overpowered is a very real and extremely expensive risk. Every time a speaker pops (amp clip), it is hit with a little DC and nothing wears a voice coil faster...

It's not that easy in my setup to do so, but I will try a way to be able to easily turn on and off the speakers, so that I can do that before and after turning the helix on/off.
I note the power sequencer idea as a potential future investment.

 

 

5 minutes ago, spaceatl said:

If you are running very low or incorrect output levels (xlrs mic level and speaker at line level)...then you over crank the input to the monitor and it pops when both start at the same time....that is because the input on the amp is too sensitive....check for that...mismatched levels is really common with Line 6

 

I don't think that's the issue as the pop happens exactly when I switch on/off the Helix, that is when switching it on it is heard exactly when the screens turn on, before the Helix even really started to boot on the screen.
I also tried with an empty preset just to be sure but it doesn't change a thing, as expected.
Also my XLR output are at Line level (all the output are).

 

[theElevators]

Is it every single preset/snapshot, or something in particular?  Try to see if it's a particular preset with a volume pedal in the beginning.  I have heard the infamous pop on such presets/snapshots. 

[Klaim]

10 hours ago, theElevators said:

Is it every single preset/snapshot, or something in particular?  Try to see if it's a particular preset with a volume pedal in the beginning.  I have heard the infamous pop on such presets/snapshots. 

 

It is not related to presets but startup, before presets are loaded. I tried with empty presets with no difference.

[Klaim]

It took me a while but I finally found the time to use my cable tester to check the XLR cables: there is no apparent issue, no variation in the signal at all.

So the issue seems to come from the Helix, but it's not clear why the XLR output only are affected.

Meanwhile I started changing my setup to be able to easilly switch on/off my monitors so that I can switch them off before turning the helix on. That helps but it's annoying compared to when I was sending the audio directly in the audio interface, there was no such noise.
Is it possible that the issue comes from the speakers XLR input?

[usedbyanr]

I have a Pod Go connected to Eris E5 XT monitors with XLR cables (XLR on the speaker end, TRS on Pod Go because that's all it has). I get the exact same pop when I turn the Pod Go on. I think there is a minor pop when turning the Pod Go off. I just assumed it was normal and changed the sequence that I use for powering up. I don't care to hear that and I was unsure if it was doing anything to the monitors. It seems like it may be a Presonus monitor thing rather than the Helix/Pod Go. 

[datacommando]

5 hours ago, Klaim said:

I finally found the time to use my cable tester to check the XLR cables: there is no apparent issue, no variation in the signal at all.

Hmm… I was expecting that you might have found that the issue was a bad connection on the XLR.  

 

That’s usually the source of speakers “popping”. 
 

Don’t know what else to suggest now.

 

File under “mystery”.

[Klaim]

I did a last test: plugging the XLR cable into the monitors while both are powered, both powered minutes before.
I was expecting a noise at plug, but nope, no noise.

So for now the only source plausible is "signal coming from the XLR output of the Helix". Meh.

Yeah @datacommando I think I will stop here for the weird search and just use the new (less simple) setup I have to avoid doing the noise.
 

[Klaim]

22 hours ago, usedbyanr said:

I have a Pod Go connected to Eris E5 XT monitors with XLR cables (XLR on the speaker end, TRS on Pod Go because that's all it has). I get the exact same pop when I turn the Pod Go on. I think there is a minor pop when turning the Pod Go off. I just assumed it was normal and changed the sequence that I use for powering up. I don't care to hear that and I was unsure if it was doing anything to the monitors. It seems like it may be a Presonus monitor thing rather than the Helix/Pod Go. 

 

I totally missed your post, thanks for the info.

[coachz]

On 10/19/2021 at 6:41 PM, Klaim said:

By the way, the sound also happen when I turn the Helix off while the monitors are on. It's even louder when turning off.

I also just tried:

• having the audio interface turned off does not change a thing
• removing all input source didn't change a thing

 

Another info: the monitors and the Helix are on the same power strip, not sure if it plays a role or not but it would still be weird that it would only affect XLR

Turn helix on first, then speakers.  When  turning off, speakers first.

[Klaim]

18 hours ago, coachz said:

Turn helix on first, then speakers.  When  turning off, speakers first.

I know, I already said (multiple times) I change setup to do that easilly (I couldnt before). But that doesnt clarify if the issue is with the Helix, it's just a general good practice/workaround.

BTW I did a few more tests and can reproduce the issue (but far less loud) with a Zoom G3X, so I suppose the issue is with the speaker or interraction between speaker and Helix. The message from usedbyanr also goes in that direction. What I didn't try is to do the same with different speakers.

Anyway ok.

[HonestOpinion]

On 10/26/2021 at 1:18 PM, Klaim said:

I know, I already said (multiple times) I change setup to do that easilly (I couldnt before). But that doesnt clarify if the issue is with the Helix, it's just a general good practice/workaround.

BTW I did a few more tests and can reproduce the issue (but far less loud) with a Zoom G3X, so I suppose the issue is with the speaker or interraction between speaker and Helix. The message from usedbyanr also goes in that direction. What I didn't try is to do the same with different speakers.

Anyway ok.

 

Yes to all of your suppositions. Certain powered speakers are inherently more prone to this "interaction" than others. I use to have some old JBL powered monitors that loved to pop - loudly - if you failed to turn them either on/off in the correct order. I had JBL subs that literally made a prolonged shutdown sound like an alien ray gun if you got the shutdown order incorrect. Other powered speakers I have owned were less prone to popping. Might just have been the way their amplification sections operated or were set. I hate to belabor the turning off/on order thing as it has already been mentioned a couple of times, but really that is the way to go if you want to minimize the risk of damaging your speakers and have a silent shutdown. Shutdown order is proper procedure, not a workaround. 

 

I understand being concerned that it could be a problem with your Helix and only testing with multiple powered speakers, cables, varying the speaker's settings, and trying different Helix presets, can definitively answer that question. For me that would be a lot of work to do just to figure out if my Helix made a sound when an incorrect startup/shutdown procedure was executed. I find it unlikely that this is a hardware issue with the Helix but anything is possible.

 

Btw, do you have the Helix's output set to line level? Looks like your Presonus Eris 5's expect that. If you put a volume block at the end of a preset, set your expression/volume pedal to global, and have it all the way heel-down when you turn on the Helix, do you still get the pop? How about on a New/empty preset? Just a couple of variables that might help eliminate the preset or global settings as the culprit.  

 

Lastly, and certainly not limited to Line 6,  you would think by 2021 the industry would have figured out an inexpensive and standard/required piece of included circuitry to stop pops from occurring between different speakers and devices, regardless of startup/shutdown procedure. I will say it does seem to be less of a problem now due to changes to the equipment that is commonly used than it used to be where your Crown power amps could blow out your PA speakers in a hurry.

[Klaim]

2 hours ago, HonestOpinion said:

Shutdown order is proper procedure, not a workaround. 

 

In process of becoming an habit (until I get some automatic thing someday).

 

2 hours ago, HonestOpinion said:

I find it unlikely that this is a hardware issue with the Helix but anything is possible.

 

I am now convinced it is not but the fact that it was only happening with the Helix and only with XLR in/out was disturbing enough for me to be sure, because if need to repair the Helix it will probably not be cheap (I think I passed the 2y guarantee). So far I've been lucky but I guess I'm a bit anxious.
 

2 hours ago, HonestOpinion said:

Btw, do you have the Helix's output set to line level? Looks like your Presonus Eris 5's expect that.

 

Yes it's line level. Also I don't think it's related to sounds produced by the Helix anyway as it appears when the screens get powered, before the firmware screens even appears.
Though I might be wrong. A power related thing is probably the source.

 

2 hours ago, HonestOpinion said:

If you put a volume block at the end of a preset, set your expression/volume pedal to global, and have it all the way heel-down when you turn on the Helix, do you still get the pop? How about on a New/empty preset?

I tried before with an empty preset, no change in behavior (it's one of the clues that it's not related to generated sound).

 

2 hours ago, HonestOpinion said:

Just a couple of variables that might help eliminate the preset or global settings as the culprit.  

As a variation of all my other attempts, I also tried this just now: Global EQ activated with level -60dB
Result: still the pop at both startup and shutdown.

 

2 hours ago, HonestOpinion said:

Lastly, and certainly not limited to Line 6,  you would think by 2021 the industry would have figured out an inexpensive and standard/required piece of included circuitry to stop pops from occurring between different speakers and devices, regardless of startup/shutdown procedure. I will say it does seem to be less of a problem now than it used to be where your Crown power amps could blow out your PA speakers in a hurry.

 

Yeah it appeared weird to me mainly because
- I started music+guitar late so most hardware I used so far is very modern (and definitely not old school in any way - and I avoid real amps because they are too expensive, big and fragile XD) so I probably dodged this kind of issues involuntarily;
- Since I got my Helix I never experienced this until I decided to plug the XLR output of the Helix directly in the speakers instead of passing through the input of the audio interface.
I guess I was just not exposed to this kind of issue until now.

Lesson learned.