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Faulty Tube Mic?

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Faulty Tube Mic?

Postby Mick C » Tue Feb 23, 2021 12:13 pm

Hi All,
I’m hearing problems with my tube mic - would anyone be kind enough to listen to these two audio examples of a vocal and help me identify the cause and the corrective action? They’re only a few seconds long!

File “SE Example” is the problem one. It’s an SE Z5600a MkII, about 8 years old but hasn’t had much use, always stored in its original wooden box and flight case.
The audio has a kind of ‘flanging’, like it’s going in and out of phase – this is particularly noticeable after about 8 seconds with “do they say, do they even care to know her name”. There’s also a general “roughness” to the overall recording in my opinion.

File “Stealth V1 Example” is the same phrase recorded on the V1 setting of a new Aston Stealth with the phantom power on. This sounds great.

Both are recorded in identical conditions: same room and position in the room (the room is well treated acoustically), SE Reflexion filter used on both, same pop shield, same vocalist distance from the mic, cable and input channel on the Focusrite Clarett 8 Pre (with the SE going through its own power supply first). The SE mic had been on warm up for minimum 30 mins before use

This weTransfer link to the files is a total download of 13MB: https://we.tl/t-ok6phRXo0a

Any thought and insight at all would be very much appreciated!
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Re: Faulty Tube Mic?

Postby Hugh Robjohns » Tue Feb 23, 2021 12:47 pm

Mick C wrote:The audio has a kind of ‘flanging’, like it’s going in and out of phase – this is particularly noticeable after about 8 seconds with “do they say, do they even care to know her name”. There’s also a general “roughness” to the overall recording in my opinion.

I agree about the 'general roughness'. I'm not getting a flanging effect here, though, or anything like that.

...a new Aston Stealth with the phantom power on. This sounds great.

It certainly lacks the edginess of the sE mic, but this track is also about 3dB louder, which is going to influence the opinion somewhat!

SE Reflexion filter used on both

Reflexion filters are notorious for adding unwanted 'phasy' colourations if placed too far forward around the mic (or the mic is set back too far into the 'filter'). Perhaps this is part of the issue you are having -- make sure the mic capsule is slightly forward of the front edge of the reflexion filter.

As for the roughness... I fear that is down to the combination of your voice with that mic. I'm not familiar with that sE model , but although I don't hear anything obviously 'wrong' with it it does have an obvious high-end/presence lift that isn't flattering to your voice.
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Re: Faulty Tube Mic?

Postby Mick C » Tue Feb 23, 2021 4:53 pm

Hugh Robjohns wrote:I agree about the 'general roughness'. I'm not getting a flanging effect here, though, or anything like that.

Its hard to find words that describe the sound and flanging was the best I could think of.. Maybe a better description would be the sound is a bit 'swishy' (not helping I guess :D )
But whatever we call it then its not present on the Aston version. I honestly don't think any difference in loudness is creeping in with this one, its an audio quality thing to my ears

But your point about the Reflexion filter 'phasy-ness' is very interesting. Notably due to the Aston being an end fire mic its forwards of the filter by a good 6" or so, compared to the SE which was indeed level with the front edge of the filter. I'll play around with the filter's positioning and mic position in the room.

Thanks for your help Hugh :thumbup:
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