SM7B suddenly sounding really tinny - only on recording ?!

[Sam the Scholar]

Hi

My Shure SM7B (brand new approx 1 year ago) has been working fine, I haven't used it for recording for a couple of months but it hasn't moved from its mix stand and never left my home - no damage, no drops, nothing.

Went to use it to record some vocals today - sounds fine through monitoring but the actual recordings are really tinny. Using Logic on a blank project through a focusrite liquid saffire 56 - have tried:

different channels (same problem)
different leads (same problem)
different mic (SM58 - sounds fine in monitoring and recording using same channels)
different preamp (was using direct into sound card, I know the SM7B doesn't need a pre-amp but thought I would try it) same problem.

It is driving me a bit strange.. it makes no sense that it sounds fine in monitoring but the actual recording sounds so tinny. Have used empty projects to make sure there is no strange plug in hiding somewhere

Can anyone recommend what else I should try ?

edit: have just tried recording on garageband (exact same setup) - sounds normal - what the hell is wrong with Logic ?!

Please ?!

[Hugh Robjohns]

An unexpected thin sound is often due to the signal being captured through two paths simultaneously, with a slight delay between them, which results in partial cancellation of the low frequencies.

I'd suggest you check your routing configuration as you may find the mic signal is being routed in a weird way.

[Aled Hughes]

As Hugh says above, double check that the recording is not reaching your outputs twice!
For example, if you're using something like Sonarworks correction software or any other processing on one monitoring feed (eg headphones) and not on another (speakers perhaps), then check that both feeds are not being sent to the same place (fairly easy to do if you're using comprehensive monitoring/routing utilities like RME Totalmix or something)

Does previously recorded material play back OK with the same settings?

It can be hard to evaluate the sound of a microphone on your own voice in real-time due to the vibrations of your voice through your head etc - do you have a way of recording the mic using a different setup, or check with a different mic to try and track down where the problem is?

Aled

[Sam the Scholar]

Thanks both.

This would make sense but I have re-wired routing (was going through a patch bay) to go direct into the sound card.

Focusrite do have an annoying routing section but nothing in this has changed and everything else works fine.

Tried the mic in garageband and it works fine.. so this is now a Logic problem but I don't know what routing to even check when I haven't made any routing changes - gah !

tried the SM58 on the same routing - works fine, just the SM7B causes this issue!

[Hugh Robjohns]

Have you checked the bass roll-off and presence boost switches on the SM7B?

[Sam the Scholar]

Thanks Hugh - yes, have tried that, makes no difference.. I don't understand how one microphone can sound tinny in this way (and its really obviously tinny - like a telephone plug-in) on this input path (as other ones work fine on the same path)

Is this more likely a Logic issue (as related to the fact it sounds fine in monitoring, only on playback does it sound tinny) ?

[Sam the Scholar]

I have now managed to use the mic with another interface, on another laptop (on garageband)- same issue, really tinny on playback.

Must be a mic deficit ?

I can't think of any other routing to test it

[sonics]

I have now managed to use the mic with another interface, on another laptop (on garageband)- same issue, really tinny on playback.

You said the mic sounds fine monitoring when recording. Is that still the case?

Does the audio waveform look as strong as the other mics? You should see a clear difference in intensity if the mic is faulty and the recording is "thin".

If you save a recording as a file and play it back on a known-good system does it sound tinny?

[Hugh Robjohns]

It might be helpful to record a test track, then export it and play it via different audio player to see if the problem is in the recording or the playback processes.

My guess is still on a sneaky routing issue in the DAWs output or the interface.

[Sam the Scholar]

So have tried test recording - exporting, sounds exactly the same (tinny)

It sounds normal when monitoring and recording - it is only on playback that it sounds tinny

Does the audio waveform look as strong as the other mics? You should see a clear difference in intensity if the mic is faulty and the recording is "thin".

Yes - waveform looks normal, is quite low (as I understand SM7Bs generally are) but have tried it both with low channel gain and high gain - same issue in regards to tinny-ness (just gets louder)

I have tried the same signal path on an SM58 and Rode NT1A - both work fine, no tinnyness.

I have requested a repair from Shure but just seems like the oddest problem - I have trouble shooted as much as I can logically think of, old tracks using the mic all sound fine, all other channels sound fine, other mics sound fine - it can only be the SM7B..?!

Its the mic sounding fine when monitoring that is completely throwing me.. I agree how this can clearly look like a routing issue but I have now tried enough things (including different system) for it to suggest it can't be.. Logic has no-way of registering this specific mic when plugged in (when using same input path as other mics) so it leads me to conclude it can only be the mic..

Again, thanks for the responses - can be so maddening when things go wrong!

[Drew Stephenson]

Where are you based Sam? Sometimes a second set of eyes on things can help and there might be a forumite near you who could help?

[Wonks]

Though it sounds like you’ve done it, can you confirm that you’ve simply unplugged the SM7b, plugged in the SM58 and the recording went from tinny to normal? No changes to the monitoring path?

Are you using a direct monitoring facility on the interface or software monitoring via the DAW?

Phantom power on at all on the SM7b channel?

[sonics]

Are you using a direct monitoring facility on the interface or software monitoring via the DAW?

The fact that the monitor signal sounds normal doesn't seem possible, so that is the question I'd ask next, too. However, you'd get the same issue when using another mic, which you say you're not. If you were to record the monitor signal you could prove beyond doubt that it's okay.

It sounds like the monitoring signal AND the recorded signal are somehow both being recorded. I think that scenario has already been suggested.

[Sam the Scholar]

I would welcome anyone to help with this problem - I'm based in Essex, near Cambridge

can you confirm that you’ve simply unplugged the SM7b, plugged in the SM58 and the recording went from tinny to normal? No changes to the monitoring path?

Absolutely can confirm exactly this - with 2 different mics (SM58 and NT1A)

Are you using a direct monitoring facility on the interface or software monitoring via the DAW?

Have tried both

Phantom power on at all on the SM7b channel?

Have tried it with and without (even though it doesn't need it) just in case !

[Hugh Robjohns]

Clutching at straws here, but have you swapped out the XLR cable? A broken leg can lead to tinniness.

If it sounds normal on monitoring and recording that implies to me that the mic signal itself is fine, as is the mic preamp in the interface and the interface monitoring path.

And if the recorded file sounds thin then that suggests the problem is on the way into Logic itself -- a high-pass filter on an input channel perhaps, or some kind of routing mess up on the way in to Logic where it's receiving two signals via different routes.

If it was a PC I'd suggest deleting and re-installing the interface driver... but that wouldn't be appropriate in a Mac as everything uses the stock driver anyway. Nevertheless, it might be worth reinstalling any control panel for the interface and checking for firmware upgrades. Same with your version of Logic -- make sure it is updated to the current version.

Definitely a perplexing issue, but probably something that's really annoyingly simple but obscure!

[Sam the Scholar]

Have recorded 20 second clip, SM7B then SM58 then NT1A - all exact same signal path, no changes between mics (except plugging them in)

http://sndup.net/mf59

http://sndup.net/mf59

Again - big thanks to all the replies

[Sam the Scholar]

Hugh - Have tried 5 different XLR cables, as per the example in the last post, these cables are working fine with other mics !

[Hugh Robjohns]

Well, I did say I was clutching at straws...

Listening to your track, I'd say that's a broken SM7B... but you've said it sounds fine when used with a different DAW through the same interface, so it can't be broken!

I'm really struggling to think why just swapping mics at the end of an XLR cable would result in such an obviously broken sound. It has all the hallmarks of a cabling issue, but you say you've tried five different cables. Were these all commercial cables or home-made ones?

Is there any sign of damage to the cable/XLR on the mic itself?

Have you recorded the mic while switching the bass-cut and presence boost switches? Do they work as intended?

[Matt Houghton]

Hi Sam,

This all sounds a bit weird... if what you say is correct, there has to be another factor here that you've not spotted/reported

You're in Cambridge UK, right? I'm circa half an hour away, near St Neots. I'm focused on some deadlines now but need to pop over to Cambridge at some stage next week. If diaries can align I'll happily swing by and take a look!

Drop me a line on email if you'd like to explore further. You can find me here.

Cheers,

Matt

[Drew Stephenson]