KVR Audio

wazun · Post by **wazun** » Wed Apr 25, 2007 7:02 pm

Hi!

I got my new monitors today, Tannoy System 600a. I connected them to my Fireface 400 and when no music is playing I can clearly hear hissing and some other noise when my hard drive spins or when I move the mouse.
In my fireface dsp mixer I had to pull the outputfader down to around -30db, otherwise it would be too loud.
Is this normal? Would this change if I would insert a passive volume controller like the sm audio pro nano patch and push the output gain in my dsp mixer up to 0db and then adjust the volume on the passive volume controller?

BertKoor · Post by **BertKoor** » Thu Apr 26, 2007 8:00 am

First you have to set the gains properly:

* Start with setting the monitor's input level switch at the back to the "+4" setting. (alas there's no proper volume control there) instead of "-10". Then you've attennuated 14dB already.

* Then adjust the volume with the mixer software of the fireface.

These monitors are rather loud indeed (SPL of 107dB while 85dB is the recommended monitoring level) so you might be helped with a simple mixer or passive attenuating device (some resistors or trim pots, DIY can do)

where02190 · Post by **where02190** » Thu Apr 26, 2007 4:00 pm

BertKoor wrote:First you have to set the gains properly:

* Start with setting the monitor's input level switch at the back to the "+4" setting. (alas there's no proper volume control there) instead of "-10". Then you've attennuated 14dB already.

* Then adjust the volume with the mixer software of the fireface.

These monitors are rather loud indeed (SPL of 107dB while 85dB is the recommended monitoring level) so you might be helped with a simple mixer or passive attenuating device (some resistors or trim pots, DIY can do)

First off the difference between +4dbu and -10dbV is 11.2db, not 14.

Are you using bnalanced cables? If not, that will help.

Does your interface have a monitor/control room volume control? Where is it when you hear this noise?

85db is very loud, and the upper level of where you should nominally be monitoring65-75dbA is more suited for long term listening. Use your interfaces monitor/CR room level to contol this, or get an external monitor controller, such as the Samson C-Control.

stoolz · Post by **stoolz** » Sun Apr 29, 2007 4:05 pm

this may sound odd but do you have your latest graphics drivers installed?, i have had similar problems with ati cards mainly. if you dont use the card for 3d gaming try uninstalling the control panel leaving just the drivers for instance. it coudl also be a dodgy psu, laptops have similar problems when charging.

WOK · Post by **WOK** » Sun Apr 29, 2007 5:07 pm

Insert a DI-Box with ground-lift.

where02190 · Post by **where02190** » Sun Apr 29, 2007 8:37 pm

WOK wrote:Insert a DI-Box with ground-lift.

Absolutely the wrong answer. DI boxes convert instrument level unbalanced signals to mic level balanced signals. Neither your DA output or your monitor inputs are either of these. DO NOT listen to this ignorant advise.

stoolz · Post by **stoolz** » Mon Apr 30, 2007 7:13 pm

also make sure all your other drivers are up to date, usb etc. turn windows sounds off also.

WOK · Post by **WOK** » Sat May 05, 2007 10:22 am

where02190 wrote:
WOK wrote:Insert a DI-Box with ground-lift.
Absolutely the wrong answer.

Absolutely not. I bought a (used) Edirol USB-Interface, and after connecting to my notebook, the digital noise was awful - I could hear every HD access. I thought it came from the bus-power, so I soldered a stable power supply to it - useless. At the end I had the idea with the DI-box (for the ground-lift) and - everything clear without any hiss. The hiss came from the ground / shield of the computer (don't know why) and so was transfered to the audio-cable via the shielding.

BertKoor · Post by **BertKoor** » Sat May 05, 2007 11:36 am

Especially with notebook setups lifting the ground at some point in the chain is THE solution to get rid of annoying interference.

Panda · Post by **Panda** » Sat May 05, 2007 6:01 pm

Actually i've had the same problem with a Fireface800. Connecting it to a different firewire port solved the problem for me.
I'm blaming the computer actually, because i had the same problem with the soundcard i had before, an m-audio 1010LT (PCI).
I tried using balanced cables, putting the monitors in a different mains socket than the computer etc. Didn't help, because it wasn't (and i think the OP's problem isn't) a ground loop.
Btw, 85 dB SPL is about the same as 70 dBA i think no?

where02190 · Post by **where02190** » Sun May 06, 2007 9:07 pm

WOK wrote:
where02190 wrote:
WOK wrote:Insert a DI-Box with ground-lift.
Absolutely the wrong answer.
Absolutely not. I bought a (used) Edirol USB-Interface, and after connecting to my notebook, the digital noise was awful - I could hear every HD access. I thought it came from the bus-power, so I soldered a stable power supply to it - useless. At the end I had the idea with the DI-box (for the ground-lift) and - everything clear without any hiss. The hiss came from the ground / shield of the computer (don't know why) and so was transfered to the audio-cable via the shielding.

So you plug a mic level output into a line level input and think it sounds just fine? Best be considering a new career, as you obviously are completely ignorant of the most basic of electronics, and have no ears for this business.

What you should use is a 1:1 transformer with a ground lift, or simply lifting the shield from the balanced cables connecting DA to speakers.

lshea · Post by **lshea** » Tue May 08, 2007 10:19 am

where02190 wrote:
So you plug a mic level output into a line level input and think it sounds just fine? Best be considering a new career, as you obviously are completely ignorant of the most basic of electronics, and have no ears for this business.

Troll02190, does your studio's commercial strategy rely on advising everyone else to get another job.

Just think, with all those pesky kids who eq whilst tracking through their Behringer mixers gone the world will be miiiiiinnnee Muahahaha...

where02190 · Post by **where02190** » Tue May 08, 2007 4:48 pm

Isheaidiot, running a +4 line output into a DI and taking the balanced mic level out to your +4 input control room monitors is about as wrong as it gets, but then with your lack of basic understanding of anything electronic, you won't hear the difference anyway, so just keep wondering why your music sounds like ass.

stoolz · Post by **stoolz** » Wed May 09, 2007 5:08 pm

earth loops can also cause this after some research, i get a buzz on my old laptop with my old usb card, when i disconnect the earth it goes, obviously its a good idea to earth it elsewhere, then again the americans seem to get by :, i'd still get those ati drivers up to date first as noise with mouse movements can be caused by this as i've had it with numerous new installs before i get all the drivers on.

BertKoor · Post by **BertKoor** » Thu May 10, 2007 4:21 pm

where02190 wrote:Isheaidiot, running a +4 line output into a DI and taking the balanced mic level out to your +4 input control room monitors is about as wrong as it gets

If it comes to who's wrong or right: I'd say the lines are probably at -10 instead of +4

And maybe that specific DI can be used for line levels (TRS line in, TRS line out, pad switch set to 0... they DO exist!)

hissing on the monitors?