Shure sm81 troubleshooting

[smilan]

Hi, I got a second hand sm81 mic which I'm think have a problem of not enough high frequencies. Here's a comparison of the sm81 to a sm58 on acoustic guitar. Are you agree with me that the 81 is faulty?
And if so, there's a way to determine if the problem is in the capsule or in the mic circuit?

sm81 sound clip:
https://drive.google.com/file/d/1SFf2ROJC1WfNO6aPS4jqLxmjaqZVYqrv/view?usp=sharing

sm58 sound clip:
https://drive.google.com/file/d/1AS2mjv8i8_Us1Yb9C-jfKjymjSLMiFYJ/view?usp=sharing

 

[rackmonkey]

I don’t agree with your assertion that there’s something wrong with your 81. The SM-81 is known for having a flat response up to 20kHz. You’re comparing it with an SM-58, which has a significant presence lift for vocal intelligibility. Apples to oranges. Sounds 81-ish to me.

If you’re used to mics with a boosted high end (like very many dynamics and inexpensive modern condensers have), it’s possible that flat response mics might sound dark to you.

 

[smilan]

I don’t agree with your assertion that there’s something wrong with your 81. The SM-81 is known for having a flat response up to 20kHz. You’re comparing it with an SM-58, which has a significant presence lift for vocal intelligibility. Apples to oranges. Sounds 81-ish to me.

If you’re used to mics with a hyped high end (like very many dynamics and inexpensive modern condensers have), it’s possible that flat response mics might sound dark to you.

Thanks, you're right, I used to work with AKG 451 with ck1 capsule as a pencil  condenser which have very bright sound with a lot of high frequencies.
But yes, it seems like my sm81 is working as it should  .

 

[Whoops]

Sounds good the SM81 to me,
it has more bottom than the SM58, seems to not have the High mids boost and has more info above 12khz.
So it seems right comparing to an SM58.

But if you have doubts the best thing would be to get another SM81 from someone and A/B them.