Calibration issue - recommend an interface

djgizmo · 16th December 2010

I'm trying to recalibrate my room and I'm trying to resolve an issue that's always been a problem.

Please don't flame me too bad (even if I deserve it)

I'm using an mbox 2 pro. When I try to calibrate to 1.228v of course the output of those don't seem to cut it.(no output trim) (same with my central station)

Since PT is now open, can anyone recommend an interface which has 6 dedicated outputs, has output trim control, and is under 1000$? (or an interface that is pre-calibrated for 1.228v)

I was thinking about the new mbox pro or even used 003 but neither seem to have output trim controls.

mikevarela · 17th December 2010

the mbox, 003 and 96io are all calibrated to the same level (14 db of headroom from 0vu), only the 192 is set to professional dbu at 0vu - and is calibrate-able.

For most instances it's ok, because if you've calibrated the room via spl, then -20dbfs is -20dbfs somewhere else (provided that's calibrated too)

The only option would be to insert a transformer, but I don't suggest it. Most don't even pay attention or know of the difference. Just focus on calibrating your -20dbfs blue sky files with an spl meter to match room size of style of mixing (i.e. film vs. TV). Check out the sticky at the DUC forum for help

As far as I know, most interfaces out there aren't configurable. You might be able to go the 'Black Lion' route and have them configure it right for you.

http://www.blacklionaudio.com/content.php?p=8

----- From the getting started guide-----

"All 003 and 003 Rack audio inputs and outputs
are set for 14dB of headroom below 0dB, or full
code. This means at the nominal reference input
level (+4dBu or –10dBV) you can have up to
14dB of headroom before input or output clip-
ping occurs.
The maximum input and output of 003 or
003Rack using balanced TRS cables on any of
the +4dBu, 1/4-inch connectors is +18dBu
(6.15 Vrms). "

SDDP · 17th December 2010

Can you recommend a good SPL meter?

djgizmo · 17th December 2010

Quote:

Originally Posted by mikevarela

For most instances it's ok, because if you've calibrated the room via spl, then -20dbfs is -20dbfs somewhere else (provided that's calibrated too)

Yea ive calibrated my room via an spl meter, just hate to modify my master fader just to get the right dbv.

If the new mbox pro has the same headroom as the 003 that's probably my next best option for my price range.

Also discovered that my multimeter may not be able read above 500hz which is why my calibration is out of whack.

djgizmo · 17th December 2010

Quote:

Originally Posted by SDDP

Can you recommend a good SPL meter?

Radio shack has several, iPhone, behringer test mic with eq room wizard.

mikevarela · 18th December 2010

the behringer test mic is pretty standard. and room eq wizard is great, but more for room eq calibration... though it'll do spl as well. I also just have a radioshack spl meter around for general spl level setting.

Oh, and I called Black Lion and they stated that the upgrade does not effect the output voltage so that kinda sucks. I wish they'd match the specs on all the devices in this respect, or at least the mboxpro and up.

rfnoise · 18th December 2010

Hi,

First post from me here, please forgive my butt in.

Radio Shack SPLs are pretty common. My old analog RS meter still works okay. If you happen to have a SyncheckII, it's SPL meter also works.

I own a Behrenger calibration mic too. It is useable but has response roll off above 7kHz. It came with a calibration paper and graph that doesn't show that and the mic's actual level output at 1kHz is different than the sheet says. Maybe your luck is better. I bought a mic calibrator and another cal mic to figure it all out.

The reason so many recent interfaces don't operate up to +24dbu is because of costs. +18dbu can be easily produced from 12 volt supplies, and produces .06 watts (of heat) into a standard 600 ohm load. +24dbu signals require 18 volt supplies and pushes .25 watts into the same load. That is 4 times more power per channel for the extra 6db of output level. Black Lion cannot increase output level of interfaces without putting in MUCH beefier supplies, which are larger, heavier, and may not fit, and of course would dramatically increase the cost.

Hope this is useful, not a

.

16th December 2010	#1
djgizmo Lives for gear Joined: Aug 2007 Location: Tampa, FL Posts: 1,062 Thread Starter 1 Review written	Calibration issue - recommend an interface I'm trying to recalibrate my room and I'm trying to resolve an issue that's always been a problem. Please don't flame me too bad (even if I deserve it) I'm using an mbox 2 pro. When I try to calibrate to 1.228v of course the output of those don't seem to cut it.(no output trim) (same with my central station) Since PT is now open, can anyone recommend an interface which has 6 dedicated outputs, has output trim control, and is under 1000$? (or an interface that is pre-calibrated for 1.228v) I was thinking about the new mbox pro or even used 003 but neither seem to have output trim controls. __________________ ^Always Learning ~ Always Paying it Forward^

17th December 2010	#2
mikevarela Gear addict Joined: Apr 2008 Location: Hollywood, CA Posts: 412	the mbox, 003 and 96io are all calibrated to the same level (14 db of headroom from 0vu), only the 192 is set to professional dbu at 0vu - and is calibrate-able. For most instances it's ok, because if you've calibrated the room via spl, then -20dbfs is -20dbfs somewhere else (provided that's calibrated too) The only option would be to insert a transformer, but I don't suggest it. Most don't even pay attention or know of the difference. Just focus on calibrating your -20dbfs blue sky files with an spl meter to match room size of style of mixing (i.e. film vs. TV). Check out the sticky at the DUC forum for help As far as I know, most interfaces out there aren't configurable. You might be able to go the 'Black Lion' route and have them configure it right for you. http://www.blacklionaudio.com/content.php?p=8 ----- From the getting started guide----- "All 003 and 003 Rack audio inputs and outputs are set for 14dB of headroom below 0dB, or full code. This means at the nominal reference input level (+4dBu or –10dBV) you can have up to 14dB of headroom before input or output clip- ping occurs. The maximum input and output of 003 or 003Rack using balanced TRS cables on any of the +4dBu, 1/4-inch connectors is +18dBu (6.15 Vrms). " __________________ NuanceTone.com

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17th December 2010	#3
SDDP Gear nut Joined: Nov 2009 Location: Beverly Hills Posts: 141	Can you recommend a good SPL meter?

18th December 2010	#6
mikevarela Gear addict Joined: Apr 2008 Location: Hollywood, CA Posts: 412	the behringer test mic is pretty standard. and room eq wizard is great, but more for room eq calibration... though it'll do spl as well. I also just have a radioshack spl meter around for general spl level setting. Oh, and I called Black Lion and they stated that the upgrade does not effect the output voltage so that kinda sucks. I wish they'd match the specs on all the devices in this respect, or at least the mboxpro and up.

18th December 2010	#7
rfnoise Gear Head Joined: Dec 2010 Posts: 53	Hi, First post from me here, please forgive my butt in. Radio Shack SPLs are pretty common. My old analog RS meter still works okay. If you happen to have a SyncheckII, it's SPL meter also works. I own a Behrenger calibration mic too. It is useable but has response roll off above 7kHz. It came with a calibration paper and graph that doesn't show that and the mic's actual level output at 1kHz is different than the sheet says. Maybe your luck is better. I bought a mic calibrator and another cal mic to figure it all out. The reason so many recent interfaces don't operate up to +24dbu is because of costs. +18dbu can be easily produced from 12 volt supplies, and produces .06 watts (of heat) into a standard 600 ohm load. +24dbu signals require 18 volt supplies and pushes .25 watts into the same load. That is 4 times more power per channel for the extra 6db of output level. Black Lion cannot increase output level of interfaces without putting in MUCH beefier supplies, which are larger, heavier, and may not fit, and of course would dramatically increase the cost. Hope this is useful, not a .