+4 dBu vs -10 dBV ??

[Bluewater]

I have an Audiofire8 and and AT 3035 mic that I use to record acoustic guitar. The Audiofire has an option to switch between +4 and -10. Aside from being "professional" vs. "consumer", and one being louder than the other, what is the difference and which is the better choice? Seems that with +4, I have a hard time getting high enough levels in Sonar (near 0 peak) without clipping the Audiofire, and with -10 I can hear a hell of a lot of ambient noise, in addition to the guitar.

 

Help!

 

Thanks.

[where02190]

Since you are going into the mic pres input sesitivity is moot.

 

However output sensitivity is crutial, and should be set to match whatever device you are connecting to. See the manufacturers specs for the specific device you connect to, and set accordingly.

[Bluewater]

 

Originally posted by where02190 Since you are going into the mic pres input sesitivity is moot. However output sensitivity is crutial, and should be set to match whatever device you are connecting to. See the manufacturers specs for the specific device you connect to, and set accordingly.

 

 

I'm sorry I'm so lame at this, but I don't understand. Input sensitivity seems to directly affect how "hot" my signal is going to Sonar. At +4 input, all other things being equal, the guitar (thru the mic) is not as loud as at -10 input. So if I were to record two tracks and change only the input settings in the Audiofire, the -10 setting is louder once recorded than +4. So how can input sensitivity be moot?

 

Output sensitivity seems to only effect how loud my monitors will be, and has nothing to do with what gets recorded. My understanding is that output sensitivity changes the 1/4" outputs to my monitors, but not the firewire output connection that actually goes to the computer (Sonar). Is this correct?

 

So if I have this right, what is the best input sensitivity for my mic?

[where02190]

Are you using an outboard preamp? If so then set the input sensitivity according to the preamps output sensitivity.

 

Same with your output to your monitors.

 

In both cases refer to the specific manufacturers specifications.

[Bluewater]

No preamp. Just mic directly into Audiofire. Don't have the manual for the mic, so I don't know if its +4 or -10. Is there a standard for large condensors?

 

Also, is there a sound quality difference between the two settings in terms of clarity, or is it simply about matching levels?

 

Thanks again.

[doug osborne]

If you have plugged your mic into the XLR input, you have this switched to Mic, you have the Phantom Power on, and you have the unit connected to the computer via FireWire, the +4/-10 switch should do nothing.

[Bluewater]

Originally posted by doug osborne If you have plugged your mic into the XLR input, you have this switched to Mic, you have the Phantom Power on, and you have the unit connected to the computer via FireWire, the +4/-10 switch should do nothing.

 

I have it connected exactly as you say. I send a steady signal into the mic, hit record, and then after a few seconds I flip the switch on the Audiofire console (software) from +4 to -10. THere is definitley an increase in level -- from about -21 average on Sonars meter to -15.

 

So what's going on? Why would there be an input sensitivity if it doesn't change levels going in?

[Bluewater]

double post

[doug osborne]

Originally posted by Bluewater I have it connected exactly as you say. I send a steady signal into the mic, hit record, and then after a few seconds I flip the switch on the Audiofire console (software) from +4 to -10. THere is definitley an increase in level -- from about -21 average on Sonars meter to -15. So what's going on? Why would there be an input sensitivity if it doesn't change levels going in?

 

What does Echo say about this?

[Bluewater]

 

Originally posted by doug osborne What does Echo say about this?

 

 

Haven't tried them yet. I'll do that now, thanks.

[doug osborne]

 

Originally posted by Bluewater Haven't tried them yet. I'll do that now, thanks.

 

 

I try not to deflect a question, but in this case, I think only they could give a direct answer to this.

[Phil O'Keefe]

The +4 / -10 switch should only relate to the levels of the analog line level I/O jacks. I can't really see why they'd have any effect / bearing on the levels the interface would send over the firewire connection directly to Sonar. I'd definitely call Event and ask them about that.

 

Your mic isn't +4 or -10... it's a mic, and has to go into a mic preamp in order to raise the level from mic level to line level - either an external preamp or one of the ones onboard the Event. If you're using the onboard preamp and an XLR - XLR cable to connect the mic to that preamp, the setting of a +4 / -10 switch shouldn't have any effect on the levels. If you're using an external mic preamp, and feeding a line output from that into the Event, then you would need to set the switch to the appropriate setting. IOW, if your mic preamp has a +4 balanced output, then feed that into a balanced input on the Event (assuming it has one - I'm not familiar with that particular interface) and set the switch to +4. If the external mic pre has an unbalanced -10 output, then feed that into an unbalanced input on the Event and set the switch to -10.

[Bluewater]

Originally posted by Phil O'Keefe The +4 / -10 switch should only relate to the levels of the analog line level I/O jacks. I can't really see why they'd have any effect / bearing on the levels the interface would send over the firewire connection directly to Sonar. I'd definitely call Event and ask them about that. Your mic isn't +4 or -10... it's a mic, and has to go into a mic preamp in order to raise the level from mic level to line level - either an external preamp or one of the ones onboard the Event. If you're using the onboard preamp and an XLR - XLR cable to connect the mic to that preamp, the setting of a +4 / -10 switch shouldn't have any effect on the levels. If you're using an external mic preamp, and feeding a line output from that into the Event, then you would need to set the switch to the appropriate setting. IOW, if your mic preamp has a +4 balanced output, then feed that into a balanced input on the Event (assuming it has one - I'm not familiar with that particular interface) and set the switch to +4. If the external mic pre has an unbalanced -10 output, then feed that into an unbalanced input on the Event and set the switch to -10.

 

Thanks, Phil. The Echo Audiofire8 has two balanced mic/line/inst inputs and 6 1/4" inputs. The unit also has its own mic pres. I plug my AT 3035 via XLR into input 1, using the Audiofire's mic pre-amp. It also has 48v phantom which I use. THe Audiofire is connected to my computer via firewire and 2 of the 1/4" outputs of the Audiofire go to my monitors.

 

All that said, selecting the input level between +4 and -10 most definitely changes sound evels: the recorded levels in Sonar, headphone levels in the Audiofire, and the monitor levels are all louder at -10.

 

I sent an email to Echo asking about this and I'll let you know what I learn. Thanks for your help.

 

P.S. I also have a Studio Projects VTB-1 that I haven't tried with this yet. It has a blanced out and a line out. Are you saying that on this unit, if I use the XLR balanced out the input on Audiorfire should be set to +4, and if I use the line out from the VTB-1, I should send it to an input on the Audiofire set to -10? Are all balanced line out signals +4 and unbalanced -10?

 

Thanks again.

[where02190]

The input sensitivity is for the line inputs only.

 

AFA your VTB-1 goes, the XLR and TRS outputs are most likely both +4, but AGAIN, see the manufacturers specs.

[Bluewater]

 

Originally posted by where02190 The input sensitivity is for the line inputs only. AFA your VTB-1 goes, the XLR and TRS outputs are most likely both +4, but AGAIN, see the manufacturers specs.

 

 

Yep, you're right, Studio Projects confirmed the +4.

 

However, I'm not sure what you mean by input sensitivity is for inputs only. Input sensitivity seems to affect output levels on this unit. Audiofire has 2 mic/line/guitar inputs on the front and 6 1/2" line inputs in the back. There is a consule switch for every input, including the mic line.

 

It's interesting that Doug and Phil both thought that the input sensitity setting would have no effect on the signal going via firewire to the DAW, but I've confirmed that it does. So my initial question remains: when not using the VTB-1 and going with my AT3035 direct to the XLR mic input on the Audiofire, is there any benefit of +4 over -10 other than the latter results in a louder recorded signal? I've asked Echo this question and await their response.

[Zooey]

Originally posted by Phil O'Keefe I'd definitely call Event and ask them about that.

 

I think Event stopped distributing Echo Digital products many years ago.

 

But I still call it Event sometimes, too.

[Bluewater]

UPDATE: Audio Technica says that the Audiofire input sensitivity should be set to -10 for mic level input and +4 for line level input. So when using the mic direct to the Audiofire pres, -10 is the proper choice. This seems to make sense, since when I used the +4, I had difficulty getting a hot enough signal into Sonar.

 

Still waiting for Echo to respond.

[wooden]

Ok, and oing to the very basics what does it mean "I work +4/-10"? I mean what does this numbers mean technically speaking about the hardware?

[wooden]

Originally posted by wooden Ok, and oing to the very basics what does it mean "I work +4/-10"? I mean what does this numbers mean technically speaking about the hardware?

 

So?

[Bluewater]

Originally posted by wooden So?

 

Well, that's what I was hoping to find out. It refers to the input sensitivity of the 8 channels on the Audiofire (and outputs have a separate ability to switch between +4 and -10 as well). All the manual says is that these are "nominal level" settings.