Speakers popping when adding plugs to same extention

[ukpartydj]

Just got some RCF310a speakers and tried them out for the first time at the weekend and found it odd that when I plugged a light into the same extention lead the speaker popped and again when I unplugged it!
Not a big deal but I seem to remember this happening with some crappy old speakers I used at home!

Is it an issue? :confused:

[JAMdisco]

Answer: plug light in before turning speakers on, unplug light after turning speakers off :D

It can happen and maybe something to do with earthing (either your equipment or venue wiring). Generally if you're plugging in to same extension you will get a 'popping' sound when plugging/unplugging things.

Where possible I always try and run the speakers off a separate loop but in most venues this isn't possible.

I did have a some issues a few years back when I used a smoke machine, every time I pressed the switch to give a burst of smoke, there was a 'pop' from the speakers. Hasten to add I don't use smoke/haze these days as most venues unfortunately won't allow it :(

[DJ Jules]

I get this with my RCF 422a's when I power up/down equipment with noisy power switches and even noisier motors - namely Smoke and Bubble machines. I have to be very careful as I've found both these pieces of equipment can cause USB communication failure if the power cables or the wired remotes for them are too close to the USB cables. I've seen both DMX and MIDI controllers lock up because of this.

Julian

[Djanddisco]

I have a similar issue with a datamoon that goes off when I press the fog

[Vectis]

http://www.amazon.co.uk/Movable-Offset-UF50B-Diameter-Ferrite/dp/B007Q94DMO

Other diameters and sizes are available

[ukpartydj]

http://www.amazon.co.uk/Movable-Offset-UF50B-Diameter-Ferrite/dp/B007Q94DMO

Other diameters and sizes are available

Always wondered why my VGA cables had these on them... are they used for data cables though??

[SamV]

Those ferrite cores are only good for ground hums, they shouldn't work for whats being discussed here. Sounds like dodgy wiring.

[DJ Jules]

Those ferrite cores are only good for ground hums, they shouldn't work for whats being discussed here. Sounds like dodgy wiring.

I think you might be mixing up ferrite cores with ground loop isolators. Ferrite cores remove high frequency noise from cables and prevent the cables from acting as radio antenna - specifically they remove the radio frequency signals associated with the tiny sparks created across switches that gets broadcast as noise.

See http://en.wikipedia.org/wiki/Ferrite_bead for more details.

Julian

P.S. Going to have to get me some of these, none of the USB cables used for my decks or DMX interface have these on at present.

[JAMdisco]

Is it an issue? :confused:

I would say, don't worry about it, just make sure if you plug/unplug anything, make sure you turn the volume all the way down on your speakers or do it before you power them up (i.e. setting up)
Other thing to try is use a different wiring loom to power your speakers (separate from lights etc.) although this is not always physically possible and also difficult to ascertain where the 'other' loop actually is (if at all there is one).

[Solitaire Events Ltd]

I used to use a suppressed switch pack a while back and that stopped all the bangs and pops.

[ukpartydj]

Interesting stuff ... will get some ferrite core things as it seems like a cheap and useful thing to do!

[Excalibur]

I used to use a suppressed switch pack a while back and that stopped all the bangs and pops.


I'm glad you said that. That would have been my suggestion. I stand to be corrected, but I'm not convinced that the ferrite cores will cure the bang as 240 volts arc across the contacts of a switch. The suppression involved is pretty simple.

[ukpartydj]

I used to use a suppressed switch pack a while back and that stopped all the bangs and pops.

Tried the speakers again today for a kids party with smoke and bubble machine and both make the speakers pop.
I've tried to look for these suppressed switch packs but cannot find any??

It is just these RCF310a's which have the problem - my mackies/ all subs are fine.

[spin mobile disco]

Its simply caused by the inrush of power when a device starts as Darren already said.

Ways to suppress are, as already said a mains socket with built in power smoothing or 'suppression' these have a large capacitor in line and allow the fast inrush to be smoothed as it passes through by 'topping up or levelling the current passed through it. Some expensive audio or TV mains adapters have these built in or a large capacity UPS system. Please note the UPS has to be at least 50% higher capacity than the current draw of all items connected to do this.

Or connect your lighting and audio circuit to different mains sockets preferably on a different 'ring' to each other. Most systems have earths and we all know the ground loop hum scenario. However this can also cause the popping as the audio channels also have the same earth pass through them grounding the cables. Balanced cables with good shielding that are not coiled are far more resistant to this. However any mains cable passing close to an audio cable if either is looped will induce a certain amount of current in the cable passing near to it. The more loops the greater the effect.

When motors first turn on the inrush is greater due to the em surge created by the magnets in the motor so bubble machines that use a high torque motor are notorious for making bangs and pops. Also cheaper lighting with no surge circuit on 250w halogens or discharge lighting. If you start a discharge light on the same circuit as you sound you may hear it 'stiking' through the system like a rhythmic tapping.

http://www.signet-ac.co.uk/manuals/soft6_manual_0.pdf

as example

[Excalibur]

However this can also cause the popping as the audio channels also have the same earth pass through them grounding the cables. Balanced cables with good shielding that are not coiled are far more resistant to this.

A thought occurs. Many amps for passive speakers have a "ground lift" facility, which sometimes alleviates certain problems. Is it possible that the cabs which are unaffected have some form of ground lift applied, and the RCFs don't?

Actually, an answer to the problem springs to mind, but I can't give it just yet. I'll report back later.

[ukpartydj]

A thought occurs. Many amps for passive speakers have a "ground lift" facility, which sometimes alleviates certain problems. Is it possible that the cabs which are unaffected have some form of ground lift applied, and the RCFs don't?

Actually, an answer to the problem springs to mind, but I can't give it just yet. I'll report back later.

No Idea, I been fiddling and my home KRK rokit active speakers make a small pop when the same lights are plugged in / smoke machine used but it's not noticeable ... the RCF's make a loud POP!

Looking forward to this mystery answer!

[spin mobile disco]

The rcf's use a digital power supply to replace the old taroidal transformers they used to use. They are also a bit more prone to power fluctuations as I and others have noticed in the past. I don't think the spekaers have a ground lift but the mixer supplying them may have one.

[Excalibur]

Looking forward to this mystery answer!

Well it's tainted by the possibility of self aggrandisement. :o:o

Put simply, the problem we're facing is caused by 240volts leaping across a pair of contacts, with no suppression. Causes a big click, or bang through a PA. One answer is not to switch 240v, but use a low voltage relay.

OK, I'll come clean. I have in the For Sale section a Transcension Show Director. While I'm fairly sure this would cure your problem, it is indeed the proverbial sledgehammer to crack a nut. I reckon a better answer is to take a switched four or six way mains connector to a tame sparkie, and get some capacitors soldered in. Shouldn't be too expensive.

[ukpartydj]

Well it's tainted by the possibility of self aggrandisement. :o:o

Put simply, the problem we're facing is caused by 240volts leaping across a pair of contacts, with no suppression. Causes a big click, or bang through a PA. One answer is not to switch 240v, but use a low voltage relay.

OK, I'll come clean. I have in the For Sale section a Transcension Show Director. While I'm fairly sure this would cure your problem, it is indeed the proverbial sledgehammer to crack a nut. I reckon a better answer is to take a switched four or six way mains connector to a tame sparkie, and get some capacitors soldered in. Shouldn't be too expensive.

Ahhh I see - I have a friend who repairs electronics and has mentioned capacitors quite regularly, think I'll ask if he can sort it!
Cheers.

[ckpr2]

There are two problems here.
1/ Radiated emissions from the spark when plugging in light.
2/ Conducted emissions.

Radiated emissions are a radio frequency interference into the amp.

Conducted emissions are interference travelling along the mains wiring into the amp.

I always have my audio system on a surge protected mains extension separate from the lights.

[ukpartydj]

I reckon a better answer is to take a switched four or six way mains connector to a tame sparkie, and get some capacitors soldered in. Shouldn't be too expensive.

Asked my friend and he said putting cap's across the mains would work as a bit of a bodge and someone he works with suggested a "special extension lead with supression" :daft: Which kind of sounds like an extension lead with caps already in it!?!


I always have my audio system on a surge protected mains extension separate from the lights.

Is surge protection the same as "supression"? The separate socket idea is great but since I've got these speakers 2/3 gigs there has not been another outlet so I'm thinking It's best to solve this


EDIT -

just found these ... is this what I'm looking for ??? http://www.cybermarket.co.uk/shop/electrical-lighting/uk-plugs-timers-extension-leads/4-way-extension-lead-with-surge-442447.html

[ukpartydj]

forget about that ... I've found a mains conditioning extention lead which seems much more like the thing I need - http://www.ebay.co.uk/itm/Lindy-Mains-Conditioner-Power-Strip-6-Way-/390567537394?pt=UK_Computing_Sound_Vision_Audio_Ca bles_Adapters&hash=item5aefa3aaf2

From what I understand the lead should provide interference free mains power ... which I'm hoping means I can plug lights smoke and speakers all on this strip without the pops

[DJ Jules]

forget about that ... I've found a mains conditioning extention lead which seems much more like the thing I need - http://www.ebay.co.uk/itm/Lindy-Mains-Conditioner-Power-Strip-6-Way-/390567537394?pt=UK_Computing_Sound_Vision_Audio_Ca bles_Adapters&hash=item5aefa3aaf2

From what I understand the lead should provide interference free mains power ... which I'm hoping means I can plug lights smoke and speakers all on this strip without the pops

Looks like that would do the job. In theory though it'd only cut down on conducted noise (e.g. noise being transmitted down the cables) as opposed to radiated noise (e.g. RF noise being broadcast by sparks across contacts). The RCF cabs should be mostly immune to broadcast noise, so it ought to get rid of your issues. I might have to look into one of these as well (as well as Ferrite cores on my USB cables - as these are definitely picking up on broadcast RF noise, not the conducted type).

Julian

[SoundONE]

I have to be very careful as I've found both these pieces of equipment can cause USB communication failure if the power cables or the wired remotes for them are too close to the USB cables. I've seen both DMX and MIDI controllers lock up because of this.

Julian

I too have had this Julian, I swapped all my usb cables for very high quality cables with ferite beads, but it made no difference. Believe it or not the simple solution for me was to remove the external corded mouse, I now use one with a tiny little dongle and have never had this problem since even with cheap usb cables without ferite, seemed it was the external mouse that was letting the spikes into the usb circuit.

[DJ Jules]

I too have had this Julian, I swapped all my usb cables for very high quality cables with ferite beads, but it made no difference. Believe it or not the simple solution for me was to remove the external corded mouse, I now use one with a tiny little dongle and have never had this problem since even with cheap usb cables without ferite, seemed it was the external mouse that was letting the spikes into the usb circuit.

Ironically I've been avoiding using a wireless mouse because of concerns with interference with the other kit :D

Might to have to give that a go...

Julian

[ukpartydj]

I have no idea if this is connected but oddly enough since I started using the RCF speakers my AUDIO6 traktor interface has started playing up, it occasionally does it at startup so never put the 2 together however all this talk of USB cable interfereance is making me wonder if that there is possibly a connection... a few tests are due I think!

Meanwhile I've purchased the extension lead and will update with any progress in the speaker popping area.

[ukpartydj]

UPDATE //

Unless I've done this wrong - having the speakers come off the mains conditioning extention lead does not help.
The speakers still pop loudly.
However I tried it on my home speakers which make a very small pop (hardly noticeable) and it does eliminate that.


Will probably ask my friend to open up the speakers and test the insides as it's obviously an issue with the speakers/amps themselves.

[Excalibur]

UPDATE //

Unless I've done this wrong - having the speakers come off the mains conditioning extention lead does not help.


I think you have done it wrong. You're trying to quieten the arc across the auxiliaries, not the speakers. Plug the RCF's into a normal cable, and everything else into the conditioning one, see if that helps. Worth a try.

[ukpartydj]

I think you have done it wrong. You're trying to quieten the arc across the auxiliaries, not the speakers. Plug the RCF's into a normal cable, and everything else into the conditioning one, see if that helps. Worth a try.

Will give a go at the weekend, cheers.

[katman]

Do the speakers still pop if you unplug the input leads and turn the volume down ?

If so, then it is the speakers picking it up, if not, then it is something further up the audio chain such as your signal leads, mixer or even the playout itself.

You say you get a pop on your home speakers as well which indicated to me that it is being picked up by leads or mixer etc. The reason it is so much more pronounced on your disco speakers is probably down to the fact that they are much louder speakers therefore more noticeable.

You need to prove exactly where the interference is being picked up. Nothing you do at the speakers will stop it if they are being fed the pop in the first place !

[Excalibur]

Nothing you do at the speakers will stop it if they are being fed the pop in the first place !

Correct. My worry is that with active speakers, you have longer signal cables, and in close proximity to power cables. Short signal cable runs are preferable in many ways. One reason why I distrust actives.

[ukpartydj]

Do the speakers still pop if you unplug the input leads and turn the volume down ?

If so, then it is the speakers picking it up, if not, then it is something further up the audio chain such as your signal leads, mixer or even the playout itself.

You say you get a pop on your home speakers as well which indicated to me that it is being picked up by leads or mixer etc. The reason it is so much more pronounced on your disco speakers is probably down to the fact that they are much louder speakers therefore more noticeable.

You need to prove exactly where the interference is being picked up. Nothing you do at the speakers will stop it if they are being fed the pop in the first place !

I'm assuming if one set of speakers don't have an issue, but another one does, then it is the speaker that is at fault or the speaker does a bad job of eliminating the bursts compared to other speakers. I will try putting the mains conditioning extension into the plug instead of just feeding the speakers as mentioned and fiddling a bit with XLR's on Friday to see if anything changes otherwise I'll be looking inside the speaker for answers.

Just had a thought, I have no idea if it's just one of the speakers or both... that's a pretty quick way to make a good guess at if it's the speaker that is at fault.

[ukpartydj]

Right, the mains conditioning extention doesn't help. Only one of the speakers has the issue. Think That speaker needs looking at.

- - - Updated - - -

Right, the mains conditioning extention doesn't help. Only one of the speakers has the issue. Think That speaker needs looking at.