Topic: MetaRecorder gain control vs inline attentuator

[Bentapes]

Hi all. I am experimenting with recording setups and was curious if anyone more knowledgeable than myself could shed some light on if there is any difference between using an inline attenuator (SP-ATEN-1-15) vs the adjustable gain control in the MetaRecorder app? Both would be used to limit the oncoming signal to prevent overloading the recorder, would there be any expected difference in recording quality when using one vs the other? Thank you!

[opsopcopolis]

If you can get the signal low enough with recorder gain, sounds like you don’t need a hardware attenuator

[breakonthru]

You should always try to avoid attenuators if possible because basically you’re lowering the signal that will effectively amplify the input noise of whatever you’re plugging into. Good recording practice is always to maximize the level at an input as much as possible (within reason given adequate headroom to avoid overloading.)

With all the different possible combinations of recording equipment out there, real world testing is still the primary way to determine if a given set up is going to work. It’s pretty easy to hold your mics up within a foot of the loudest home speaker setup you have and get an idea how it’s going to perform in a concert PA situation. Apart from aggressive stack taping right up front, generally the sound in the venue doesn’t get much louder than what you can simulate at home. You can look at the waveform to see oddities and use that to supplement your own ears' take. i personally find it easier to "see" distortion in a waveform than hear it. A lot of things like asymmetric waveforms or signal clipping are immediately apparent upon listening

[Bentapes]

You should always try to avoid attenuators if possible because basically you’re lowering the signal that will effectively amplify the input noise of whatever you’re plugging into. Good recording practice is always to maximize the level at an input as much as possible (within reason given adequate headroom to avoid overloading.)

With all the different possible combinations of recording equipment out there, real world testing is still the primary way to determine if a given set up is going to work. It’s pretty easy to hold your mics up within a foot of the loudest home speaker setup you have and get an idea how it’s going to perform in a concert PA situation. Apart from aggressive stack taping right up front, generally the sound in the venue doesn’t get much louder than what you can simulate at home. You can look at the waveform to see oddities and use that to supplement your own ears' take. i personally find it easier to "see" distortion in a waveform than hear it. A lot of things like asymmetric waveforms or signal clipping are immediately apparent upon listening

Thank you very much! I’ll be sure to test this out with my home stereo, that’s a really helpful tip.

The in-line attenuator I have is adjustable, so I should still be able to dial in the level of the incoming signal. I’ll play around with both options and see what works the best.

[Scooter123]

Jerry is right--a home stereo set up might work, although some rock bands perform at over 100db which is ear bleeding for me, and he is further correct that simply using your volume-gain control on the recorder generally works.  The best is go to a bunch of shows and run your rig.  You'll figure it out eventually in post.  The only time I've wanted an attenuator is recording on a line level soundboard output, which for reasons I don't fully understand is usually pretty hot. 

[Bentapes]

I ended up turning a guitar amp up to ~100 decibels and recorded a take using my attenuator, and then a take using the in-app gain control. I set both the attenuator and in-app gain control such that the recording level peaked around -12 db.

Looking at the wave forms, I believe I ended up with brickwalling using the in-app gain control (Take 2), while the attenuator looks and sounds to have recorded more cleaner audio (Take 1).

My setup right now is MS-EHB-2 -> SP-SPSB-10 -> SP-ATEN-1 -> MetaRecord iPhone app.

Thanks for everyone’s feedback, I’m just getting started here and appreciate the help!

[aaronji]

They both look brick-walled to me, actually. It's just a matter of degree.

[EDIT:] I blew up the first image and maybe not actually brick-walled. Still very strange looking, though. What was being played through the amp?

[Bentapes]

I was just playing a guitar riff with the mics about 1 ft away from the face of the amp. There is noticeable distortion in the 2nd take, the 1st sounds OK played back through a speaker (to the ear of a newbie).

[aaronji]

Was the riff at pretty constant volume? Typically, there are more noticeable troughs and peaks than in the first image.

The second one sounding distorted is no surprise. Definitely the dreaded "butter bar". Maybe it is possible to reduce the gain enough not to overload, but I would kind of doubt it...   

[Bentapes]

Yes, that riff was fairly even in volume. I’ve attached another wave form from something with some more variation - does this look reasonable? Thanks for taking a look!

[breakonthru]

Looks like it’s overloading before it gets to the phone. My version of MetaRecorder drops red markers for 0db

[Bentapes]

I see that now, thanks for pointing that out. That makes a lot of sense. I’ll have to play around with it some more tomorrow and see if I can address that. Do you have any recommendations outside of the attenuator I’m already using?

[breakonthru]

what kind of mic? what gain setting in metarecorder?

[Bentapes]

Just following up - it looks like I’m in the clear. It looks like the red markers got flagged when I was setting my levels and hit 0 bd. I was able to record after setting my levels, and everything looks OK.