problem with berhinger truth 2030A.

[faveladwela]

Ever since i bought these behringer truth active monitors i have had problems when using them with my laptop. I play them through a lexicon alpha soundcard into my laptop for dj set recordings and use with reasons software. I get terrible interference on my recordings. I dont think its the soundcard or my computer processor because both work fine without interference when use with my old speakers and external amplifier.

the laptop processor is Intel core 2duo t5500, used with windows xp

The speakers are fine when used without the laptop but thats not what i bought them for!

maybe my speakers are too powerful for this processor?

any ideas anyone please?

[Stagesound]

Hi there - can you describe the interference please? Sounds like the Behringer's may suffer from an earth loop problem which your previous amp didn't. What was the previous one which worked okay? i doubt that it's a "too powerful" issue.

[saxman]

I did a quick search on Google and there are several complaints about these speakers having poor shielding and picking up radio interference

[EdRyan]

Yeah but if this is the case here, what's generating that much RF?

It shouldn't be the card or the computer. They should only generate trace amounts of rf, and even then they should comply to tolerable levels..

Prime suspects are Mobile phones, radios etc...

[Khazul]

Some questions to help get to the bottom of it:

What make of laptop and does it have a 2 wire or 3 wire power lead to its power supply?
Did it still occur when the laptop is disconnected from the mains and run off battery?
What is the connection to the audio interface - USB2 or firewire?
- If USB2, how if the audio interface power - own power supply or from laptop power over USB?
Do you have everything, including the speakers plugged into the same mains block?
Are you using balanced cables from the audio interface to the speakers?

Its usually a combination of laptop power supply design and audio interface design that is the cause of this. Studio gear has an earthed ground, whereas alot of consumer gear has a floating ground. poor earthing design in audio interface can cause huge problems with connecting laptops to studio gear.

As an example - if I connect the audio from my laptop headphone output to my mixer, then its ground noise hell, but if I use the balance outs from the NI Audio kontrol interface (USB2 and USB powered) into my mixer, then all is quiet as it should be. This behaviour is common to many laptops.

[trbguy]

Have you tried to get your gear someplace else and see if electricity of your studio/home is the cause of interference. Friend of mine had similar problems due to lighting in his bathroom which caused interference everytime somebody used bathroom light. If that is the case one of these might help Samson PowerBrite PB10 Rackmount Power Conditioner at DV247.COM and if your gigging musician those are must for many places you might be playing in.

[pla]

I had a problem with my R6As and and it turned out that my laptop ac adaptor was causing hissing/static because of a ground loop. Pull of the ac adaptor, silence. Solution? Bought a universal adaptor without a earth connection.

[FrankGIK]

Originally Posted by Khazul

Some questions to help get to the bottom of it:

What make of laptop and does it have a 2 wire or 3 wire power lead to its power supply?
Did it still occur when the laptop is disconnected from the mains and run off battery?
What is the connection to the audio interface - USB2 or firewire?
- If USB2, how if the audio interface power - own power supply or from laptop power over USB?
Do you have everything, including the speakers plugged into the same mains block?
Are you using balanced cables from the audio interface to the speakers?

Its usually a combination of laptop power supply design and audio interface design that is the cause of this. Studio gear has an earthed ground, whereas alot of consumer gear has a floating ground. poor earthing design in audio interface can cause huge problems with connecting laptops to studio gear.

As an example - if I connect the audio from my laptop headphone output to my mixer, then its ground noise hell, but if I use the balance outs from the NI Audio kontrol interface (USB2 and USB powered) into my mixer, then all is quiet as it should be. This behaviour is common to many laptops.

I'll bet you *anything* Khazul is right. Laptop power supplies are notorious for generating a ton of hum.

Frank

[trbguy]

Please let us know if something worked for your problem!

[I_Am_Bic_Pentameter]

You would hear the noise before the recordings if it was interference from any of the items you have.

I'm not being funny but it should take you less than a minute to work out who is the culprit (it appears you have)and anything that has a ground loop switch you should flick on and off etc. obviously try balanced cables, try plug points, different ports, standing on one leg reciting Paradise Lost etc. You name it, it is worth a try.

But............

Some things don't work together and I personally get shut of those that don't. Some noise is a real stinker to get rid of and some is the components in the product and cannot be altered by doing all the 'usual' fixes. It's worth bearing that in mind because people do like to insist it can sorted by yourself and sometimes it cannot. There are aids for loops and interference but they do not solve all things.

Laptops are very prone to noise related issues as are soundcards. Once again, some stuff is ok and some is not. The three way connection of Laptop, soundcard and speakers can be a problem sometimes.

It's certainly worth sorting out soon after purchase so goods can be returned/exchanged. There's nothing worse than noise interference.

I hope it's one of the simple things.