Help! Humming/Radio Interference - Powered Speaker

Hey guys this is my first DJ set up so I need some help on what to do with my sound. I'm getting a significant loud "humming" noise AND to top it off I hear a loud radio host talking about politics... talk about buzz kill when I'm trying to mix :mad:

DJ Set-up Gear:

1. VCI-100 SE (Traktor Scratch Pro)
2. MBP 13
3. Saffire 6 USB External Audio
4. Technic RP-DJ1200a
5. [ame="http://www.amazon.com/Monster-PRO-800-Color-Coded-Performance/dp/B0002ZO5WC"]Amazon.com: Monster MP PRO 800 with Clean Power Stage 1, Surge Protection, and 8 Color-Coded Outlets High Performance Pro PowerCenter: Electronics@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41BEDVt2bGL.@@AMEPARAM@@41BEDVt2bGL[/ame]
6. Two RCF ART-312As

*Note: All items were purchased new.

Location: On Campus Apartment

Overview:
So first I connected all the power plugs into the Monster Pro 800 (I purchased this after I went to Guitar Center and told them about my problem) Now I connected my VCI-100SE and Saffire 6 USB to my macbook pro via USB. Both are updated to it's most recent versions.
I connected the ART312a powered speakers from it's XLR to the Saffire 6's TRS 1&2 Outputs (the cables are 10 feet long btw) so I assumed the connection would be balanced thus no humming/interference coming from the speakers.

I am obviously wrong.

Now when I brought my gear to Guitar Center and just hooked up one of the speakers with the saffire 6 & mbp the speaker was pretty silent. A slight hum but it was fine.
I tried in different rooms of my apartment and I still get the same radio frequencies coming from the speakers along with the humming. I re-arranged my set up at different angles and made sure all my gear was physically close together but still no luck. Also the volume knob on the speakers have no effect on the loudness/quietness of the humming and radio. I have NO idea what I need to do :confused: and these are the only speakers I have to mix with at home lol.

So ANY "feedback" appreciated! :D

it's your laptop ground. just buy a 3-2 adapter.[ame="http://www.amazon.com/Prong-prong-grounding-converter/dp/B000I96AUM/ref=sr_1_1?ie=UTF8&qid=1298182581&sr=8-1"]Amazon.com: 3 Prong to 2 prong grounding converter: Electronics@@AMEPARAM@@http://ecx.images-amazon.com/images/I/31TabOp5M%2BL.@@AMEPARAM@@31TabOp5M%2BL[/ame]
for one dollar at your local hardware store...

and yes, I know this is getto and it could potentially cause some electrical arcs and such but...don't worry about it.

the other route is getting a ground loop isolator and checking that out.

whats the 3rd prong even for? my laptop charger doesnt have one, so i suppose im ahead of the game.

Third prong is ground. Those adapters are meant to be permanently installed on a plug that doesn't have a third ground hole. You take the screw that the faceplate is screwed onto and mount the adapter to the faceplate with that. the thinking is the electrical box inside will act as a sort of ground since it's attached to the wooden structure of the building. I would recommend looking into a ground loop isolator.

Is there a ground loop isolator product that you can recommend me for an xlr/trs connection?

This is how to solve your problem. 1st thing you need to do is go to guitar centre and bitch slap the person that sold you that monster piece of shit if possible return it. Waste of money. If you make sure your sound card is gounded ie on any conductive surface. The laptop power is not connected in anyway.

The speakers are obv the problem. As nothing you have would be transmitting a radio show. There not a bad pair of speakers. You need to get shielding for the speakers that is where the radio problem is. Ask a local audio store to sort you out

It is the only place it can be. The ppl at guitar center should know that. Im from uk so cant say if they employee morons. But looks like they do. PS dont buy monster it is overpriced rubbish. If you want good cables go to a local supplyier and get them to make you some custom ones will be cheaper and ul get better cabling.

If you still get problems with humming run a bit of wire from the sound card to the ground. Then if you still have problems get some well shielded cables. Then if you still have problems post and ask again

Just spoke to a Man that knows his his stuff about this sort of thing. He rekons ur speakers probs aint the problem. As they are pritty good and the chances are its coming off your sound card. so get a wire and ground it phsically. That monster piece of junk creates a artifical earth. So is pritty useless to be honest.

TAKE IT BACK IF YOU STILL CAN

your soundcard aint cheap so shouldnt be shielding but could be. Also maybe as said before invest in some new cables

a ground loop isolator doesnt solve the problem, ground loops are usually caused by faulty laptop power packs

If your laptop's power cord is causing a ground loop you can find out by unplugging your adapter and running on battery. I had the same problem and have had the adapter on my laptop for 2-3 years now.

@tombruton69: Lol it's a little late to return it but its alright. It actually did dumb down the humming a little bit but the radio interference is louder than ever.

When you mentioned shielding for the powered speakers, do you mean I need a certain type of cable for it?

This is what I use to connect from my ART312as to the Saffire 6.
[ame="http://www.amazon.com/gp/product/B0013MLBFM"]Amazon.com: CBI Ultimate Series Male XLR to 1/4 Inch TRS Cable - 10 Foot: Musical Instruments@@AMEPARAM@@http://ecx.images-amazon.com/images/I/417c0oFBzCL.@@AMEPARAM@@417c0oFBzCL[/ame] Are these cables not shielded?

@Conall & @djpbe: Either/or, I still have the same level of interference whether I have my MBP power plugged in or not. Which is very strange cause I've been searching through the internet and majority of people that's having this problem mention that the hum/interference goes away when they unplug their laptop's power cord.

*So my guess is that it must be the cable that's connecting my powered speakers to the audio interface... Hm...

**I spoke to the guitar center worker after I told him the Monster Pro Surge Protector did jack squat. He was so sure that it would fix the problem. His excuse was that since I'm living at college on campus, there must be a radio tower that's giving strong signals... :eek:

Btw I appreciate everyone's input! Please keep em coming :D

Quote:

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Originally Posted by tombruton69

Just spoke to a Man that knows his his stuff about this sort of thing. He rekons ur speakers probs aint the problem. As they are pritty good and the chances are its coming off your sound card. so get a wire and ground it phsically. That monster piece of junk creates a artifical earth. So is pritty useless to be honest.

TAKE IT BACK IF YOU STILL CAN

your soundcard aint cheap so shouldnt be shielding but could be. Also maybe as said before invest in some new cables

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I would trade in that MONSTERthingy too!

Hey my second post is probs more correct. Create a real ground on the sound card by some wire and your floor. I actually mean you can get sheilding to put around speakers to stop signals coming in. you could also put this on your sound card.

As to your shielded cables talk. All cables have some sort of sheilding even if its just plastic unless there bare wire. I dont think using well sheilded cables are going to solve the problem but they certainly wont do any harm. Honest just ground your sound card it should solve it. if you have any mates who dj get them to bring there soundcard round and see if theres has the same problem

if it is RFI.. you need to get some extra ferrite beads to snap onto your cables..

here is a link to some from radio shack http://www.radioshack.com/product/in...ductId=3012599


and some reading material about how they work
[ame="http://en.wikipedia.org/wiki/Ferrite_bead"]Ferrite bead - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Cable_end.JPG" class="image"><img alt="" src="http://upload.wikimedia.org/wikipedia/en/thumb/7/73/Cable_end.JPG/220px-Cable_end.JPG"@@AMEPARAM@@en/thumb/7/73/Cable_end.JPG/220px-Cable_end.JPG[/ame]

edit: there was this story on the blog a while ago too.. have a read over this as well. http://www.djtechtools.com/2009/03/0...-pesky-cables/

After reading the links you sent me it seems like I attach the ferrite beads to the USB cable for the VCI-100 and the Saffire 6 USB correct?

@tombruton69: Hey so I tried your method and the humming and radio I/F did go down a little! But it is still unbearable argh. Maybe the guy at Guitar Center was right about the radio tower near my school is sending out "too much radio frequency" lol...

how close is it. Maybe you are going to need a shit load of shielding everywhere from your sound card to your speakers. So shielding on round the card. Top quality cables and shielding for the speakers.

Will speak to my mate that does the festivals again. I know they get alot of interferance on outdoor rigs as there is shits loads of equipment and about 100k of speaker power

just spoke to my mate make sure everything is grounded.

To insulate them you can wrap ur speakers in tin foil. Also unplug everything and run ur speakers with the gain turned up and tell us if you hear anything

I'm so glad I found this thread. I bought the Saffire USB 6 a couple of weeks ago and I've got exactly the same problem. It's not like radio interference, it's just hum. So here are some things about my setup:

-The hum occurs on my desktop and laptop
-I've tried unplugging the power on my laptop, and I still get the problem (although in some cases it was a lot better without the power plugged in
-The internal cards in my desktop, my laptop, and my mac don't hum
-All my testing was done by plugging headphones in to the lineout at the back (but the problem is the same with my stereo)
-I remember a little bit of hum with my old M-Audio card, but nothing like this.
-I also tried wrapping the cable with that ferrite stuff. Made no difference.

I'm ready to take this thing back to the store. People here have mentioned grounding the card by attaching a cable from the device to the floor. Huh? My floor is wooden (non-conductive). How would that help? Anyway the saffire is already sitting on the floor.

try plugging in the speakers into a different outlet i the room. (one that is NOT connected to the sound "source" ie computer)

I had the same problem until i moved my set up around and now it doesn't hum.

I'm just using headphones.

But, how would you get sound from a sound source without connecting it. Sorry, very confused about the post above.

Quote:

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Originally Posted by Syncretia

I'm just using headphones.

But, how would you get sound from a sound source without connecting it. Sorry, very confused about the post above.

---

SORRY...
I was replying to the original post.

Will somebody please help me for the love of god!!!!!

OK. I ended up taking the damn thing to the store, swapped it for a new one and I've got the same problem. Perhaps slightly less... Not sure.

So I have tried this on three freaking computers now. Mac Minit, PC Laptop, PC Dekstop - the same problem in all of them. And the same problem at the store with professional balanced monitors.

I'm at the point now where I don't believe it's anything other than a design flaw of the interface. What else could it possibly be?

Quote:

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Originally Posted by Conall

a ground loop isolator doesnt solve the problem, ground loops are usually caused by faulty laptop power packs

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Not true... Group loop isolators work in lots of cases especially when the load on the mains ring is heavy from things like the Bar/clubs fridges.
I have first hand experience of this and my power bricks are fine.

Also:
Where are you DJing..?

Do you have Energy Saving bulbs in your lamp/lights..?

Do you have them on a dimmer switch..?

Energy saving bulbs cannot always be dimmed and when they are dimmer they cause terrible mains hum.

Quote:

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Where are you DJing..?

---

This problem occurs at home and it also occured at the store where I bought the interface. It also happens in many rooms in my house (laundry for example). It also occurs when I unplug the power sometimes. However, since I exchanged the box, I can't recreate the noise when I unplug the power altogether.

Quote:

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Do you have Energy Saving bulbs in your lamp/lights..?

Do you have them on a dimmer switch..?

---

No, and No.

I have tried turning everything in the house off (fridges, other computers, lights, TV, etc.). The problem still occurs.

I have tried this on three separate computers. The only time I don't get the hum at the moment is when I plug it in to my laptop and there is no power connected. But, remember that with the older box (before I swapped it), it used to hum even when there was no power plugged in.

This is what DI boxes are for. The real cheap ones (good enough for home use) go for about 40 euro's here, US being cheaper with most tech, I guess you can pick one up at Guitar Centre for a few bucks.

Be sure to ask for a stereo DI box. TRS from the soundcard goes in, turn on ground-lift and plug the XLR in its output and in the powered speaker.

Buh?

Call me ignorant but what does a DI box have to do with this?

I'm not recording from an external source. This is not on the recording side.

Basically, when I turn my saffire on and hook it up to my stereo or earplugs, it hums like a $2 hooker.

How would a DI box solve this?

Quote:

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Originally Posted by Syncretia

Buh?

Call me ignorant but what does a DI box have to do with this?

I'm not recording from an external source. This is not on the recording side.

Basically, when I turn my saffire on and hook it up to my stereo or earplugs, it hums like a $2 hooker.

How would a DI box solve this?

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He's assuming it's a 50cycle (60cycle in the US?) hum from a ground loop. A DI with a ground-lift is likely to sort that kind of problem right out.

I'm considering buying a ground lifter just to finally put to rest the idea that this could be caused by a ground looping problem but before I do, I have tried this:

-Laptop connected to power
-Saffire connected to laptop
-Earplugs connected to saffire

The problem still occurs.

Doesn't a ground loop only occur when 2 or more power sources are connected?

Anyway, please explain how I could solve this problem with a DI box. Remember, this is the setup:

PC-(USB)>Saffire-(RCA)>Analog Receiver-(Speaker Cable)>Speakers

Where would I put the DI box in this chain?

Oh my #@$@ing god!!!

For @#$@'s sake!

I have a gig on Friday night. I set all my shit up with my laptop and it is humming like a mother@#$#er! Jesus! WTF?

This thing is humming so #$@ing bad, it's going to embaress the $@#$ out of me.

@#$# Focusrite!

I solved the problem. The answer as a DI Box (Behringer HD400 ).

This is the setup

PC (USB)->
Saffire USB 6 (Balanced Out) ->
DI Box (Unbalanced Out RCA) ->
Stereo/Headphones

But, I'm pretty convinced that this was not a ground looping problem. I'm convinced that this was because of a lack of grounding. I'm still sure that the interface itself is faulty because 3 internal sound cards don't have this problem, the M-Audio FTP doesn't have this problem, and the NI Audio 2 doesn't have this problem either.

BTW: I recommend getting a different card for DJ'ing etc. I bought the NI Audio 2 last night and it's perfect without the DI box. Any sound card that needs a DI box is shit.

I have an Audio 2 DJ and have this problem. Only when my laptop power is plugged in though. Does that mean I just have a faulty power adapter? My ground loop isolator doesn't solve the problem.

DJTT users, please advise.

Quote:

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Originally Posted by Edwin Smallhans

Hey guys this is my first DJ set up so I need some help on what to do with my sound. I'm getting a significant loud "humming" noise AND to top it off I hear a loud radio host talking about politics... talk about buzz kill when I'm trying to mix :mad:

DJ Set-up Gear:

1. VCI-100 SE (Traktor Scratch Pro)
2. MBP 13
3. Saffire 6 USB External Audio
4. Technic RP-DJ1200a
5. [ame="http://www.amazon.com/Monster-PRO-800-Color-Coded-Performance/dp/B0002ZO5WC"]Amazon.com: Monster MP PRO 800 with Clean Power Stage 1, Surge Protection, and 8 Color-Coded Outlets High Performance Pro PowerCenter: Electronics@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41BEDVt2bGL.@@AMEPARAM@@41BEDVt2bGL[/ame]
6. Two RCF ART-312As

*Note: All items were purchased new.

Location: On Campus Apartment

Overview:
So first I connected all the power plugs into the Monster Pro 800 (I purchased this after I went to Guitar Center and told them about my problem) Now I connected my VCI-100SE and Saffire 6 USB to my macbook pro via USB. Both are updated to it's most recent versions.
I connected the ART312a powered speakers from it's XLR to the Saffire 6's TRS 1&2 Outputs (the cables are 10 feet long btw) so I assumed the connection would be balanced thus no humming/interference coming from the speakers.

I am obviously wrong.

Now when I brought my gear to Guitar Center and just hooked up one of the speakers with the saffire 6 & mbp the speaker was pretty silent. A slight hum but it was fine.
I tried in different rooms of my apartment and I still get the same radio frequencies coming from the speakers along with the humming. I re-arranged my set up at different angles and made sure all my gear was physically close together but still no luck. Also the volume knob on the speakers have no effect on the loudness/quietness of the humming and radio. I have NO idea what I need to do :confused: and these are the only speakers I have to mix with at home lol.

So ANY "feedback" appreciated! :D

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Here's what's happening:
You are located near an AM radio transmitter, and the wiring in your setup is acting as an antenna. The radio signal is "loud" enough to overdrive the input stage(s) of your equipment, causing them to act as AM detectors. You were probably out of this field at the Guitar Center, which is why there was no problem there.

In short, your speakers have inadequate RF filtering, like a lot of other equipment. I wonder if your microphones, etc. are also picking up the station. Maybe, you could listen to the output of your mixer with earphones, with the mic gains up all the way, to see if they are also picking up the station.

The "fix" should be simple and cheap: You need to install or have installed one or two resistors and capacitors to make a low-pass filter, which attenuates the incoming AM signal below the point where the input stages act as detectors. These filters need to be installed inside the amplified speakers. A simple RC filter with a cutoff of ~50 KHz should help a lot. Pls. reply if you would like details on installing such filter(s). I will need to ask you some questions.