Studio Monitor Noise

D

dave111

New member
Hi everyone,

Trying to solve a problem with noise when I have my studio monitors connected to my computer. How do I fix this?? Better power strip? Better Cables? Ground Loop? Better interface?

I have JBL LSR 305 speakers, Macbook Pro, Caldigit TS3 Plus USB Hub, apogee one (1st gen).

Thanks.
 
What type of noise? Hiss? Hum? Do you hear the noise when you plug headphones into the Apogee?
I suspect it is whatever adapter/cable you are using for the output - I noticed noise when I hooked up my JBLs through the headphone output with a splitter cable when my old Tascam's speaker output died.
Balanced cables from a balanced interface output to the JBLs is the key.
 
It's different sounds. There is a high pitched tone coming through right now. When I turn on my external hard drives, I can hear them spinning up. When I charge my phone on the wireless charging pad, which is plugged into the usb hub, I can hear a weird sound. When my laptop is charging through the usb hub, and not by it's charger, there is a static sound, like a radio that's not tuned into a station.

this is a video sample

Sound Issue – Google Drive

i need to try the headphone port. the apogee one only has one output i think - 1/8 inch idk if that is balanced or not :eek:
 
The headphone port can't be balanced if its a stereo 1/8 jack. For a proper balanced connection, you need a 3 pin connector for each channel, hot, cold and shield. Unbalanced has 2 points, a hot and a cold/shield combined.
 
Sorry, can't listen to your file, it wants me to download something to listen. Post an MP3.

Try headphones
Try doing things without the USB hub

The noise of things like drives spinning up is often picked up by non-balanced cables. My first guess is you need to get a proper interface with balanced outputs.
 
I could watch the movie file. I'm not exactly sure what you unplugged, but it sounded like a really noisy power supply to me.

I run the 305s on my Dell coming out of the 1/8" output on the back into a 1/8" -> RCA adapter, then I made a pair of RCA to XLR cables for the back of the monitors. I've never heard anything like that out of my speakers. Either there's a bad ground somewhere or a bad power supply (perhaps its overloaded).
 
thanks. I live in the USA. Renting an old house with questionable wiring. I ordered a thing to test outlets to makes sure they are grounded and working properly. I will test that out when it gets here.

Seems like i may need a better interface and to use balanced cables to offset what appears to be a questionable power supply. Any chance a DTI box (see link) might solve it if i go from the speakers to DTI box then into the apogee one with the 1/8" headphone cable?

ART DTI 2-channel Hum Eliminator | Sweetwater
 
Before I sunk money into the hum eliminator, That may not fix anything for you. I would try unplugging all the various hubs, ext HDs etc from the system, down to the bare bones. Then add the interface followed by the speakers. If you're clean with that, then you start adding back the various externals until you find the failure. Is there a reason you want to run your Mac from the powered hub rather than the actual PS from Apple?
 
There appear to be some noise issues with the the CalDigit TS3+ when using this dock for certain professional audio devices and also powering the Macbook Pro (MBP). I had this problem too. 2 fixes identified by others in Gearspace et al:
  • Connect the Apple MacBook power supply on the opposite side (in a 4 TB3 port MBP which I have). The TS3+ is no longer charging the MBP. If the noise is still there and your audio device is connected to the TS3+, disconnect the cable and and reconnect the audio interface directly to another MBP port. This fix the noise issue for me.
  • The 2nd fix here that also worked for others. If your TS3+ is still under warranty, call CalDigit and tell them about the noise. Previous feedback indicated that CalDigit advised the owners that the issue was the power supply provided with the TS3+ and replaced it under warranty. The replacement power supply provided by CalDigit was a LITEON PA-1171-72 ac adapter 20V 8.5A 170W. It solved the noise issues for those persons.
Hope that helps..
 
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Another Dave here! Those JBLs are "Class 1" mains powered i.e. they use an earth and so the problem of an earth/ground/hum loop is always a possibility. The Art boxes get a good rep IF you need one but you could try the zero cost, 'shield cutting' dodge. To do this the screen/shield on both plugs from the interface have the cable screen isolated from the sleeve of the plug but connected at the monitor end. N.B. this does not always work and can cause Radio Interference but is worth a try for few minutes work*.

Balanced line working as suggested is always a good idea but it does not ALWAYS fix ground loop problems. Sometimes such problems can be very intractable.

*For jack plugs it is often simpler to just cut of the old ones and make up new. Oh and laptop PSUs can be a bind as well.

Dave.
 
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