A Mic below 50Hz? Why?

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Re: A Mic below 50Hz? Why?

Post by awjoe »

Airfix wrote: Thu Sep 23, 2021 11:10 pm Close mic - right?
Omnis are bitches - OK you know that - everyone knows that - Do you want to record the room?

Yes - close mic. My room's got nothing to offer except the information that says 'this source isn't anechoic' - so, I'm not interested in capturing the room much.
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Re: A Mic below 50Hz? Why?

Post by Ariosto »

ef37a wrote: Thu Sep 23, 2021 8:50 pm
The one place I don't hear VLFs is radio 3 except on the rare occasion there is an organ recital and even some of those don't go THAT low.

Dave.

You should have heard some of the TV broadcasts of the Proms this year. The bass is incredibly exaggerated! I could not listen on my hi-fi system with large speakers. I had to listen on the TV speakers where it sounded much better. I think they exaggerate the low frequencies below 100Hz by many dB to compensate for most TV speakers being small.

I think Radio 3 does not do this, and therefore it sounds good on a hi-fi system.
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Re: A Mic below 50Hz? Why?

Post by Hugh Robjohns »

Ariosto wrote: Fri Sep 24, 2021 11:55 amYou should have heard some of the TV broadcasts of the Proms this year. The bass is incredibly exaggerated! I could not listen on my hi-fi system with large speakers.

Are you thinking of any particular concerts? I watched several and none struck me as having overblown bass. I was listening in stereo from Freeview on PMC IB1s so if there was excessive bass I would have known about it!

Edited to add: That said, I think the TV sound mixes do tend to be a little more 'commercial sounding' than Radio3's mixes -- which means slightly more use of spot mics. The social distancing requirements this year have also made spot-miking more of a necessity.

But Mrs R has just reminded me that I did "bleet on" about double basses being too prominent on spot mics during the Bach St Matthew Passion Proms broadcast...

I think they exaggerate the low frequencies below 100Hz by many dB to compensate for most TV speakers being small.

I'd be extremely surprised if that were the case!

However, in previous years I have noticed that they often duplicate low end sources into the LFE channel (inappropriately in my view!) when creating surround mixes. That could easily create the impression of exaggerated bass for any some surround listeners.
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Re: A Mic below 50Hz? Why?

Post by ef37a »

Hugh Robjohns wrote: Fri Sep 24, 2021 12:08 pm
Ariosto wrote: Fri Sep 24, 2021 11:55 amYou should have heard some of the TV broadcasts of the Proms this year. The bass is incredibly exaggerated! I could not listen on my hi-fi system with large speakers.

Are you thinking of any particular concerts? I watched several and none struck me as having overblown bass. I was listening in stereo from Freeview on PMC IB1s so if there was excessive bass I would have known about it!

That said, I think the TV sound mixes do tend to be a little more 'commercial sounding' than Radio3's mixes -- which means slightly more use of spot mics.

I think they exaggerate the low frequencies below 100Hz by many dB to compensate for most TV speakers being small.

I'd be extremely surprised if that were the case!

However, in previous years I have noticed that they often duplicate low end sources into the LFE channel (inappropriately in my view!) when creating surround mixes. That could easily create the impression of exaggerated bass for any some surround listeners.

I too would like some examples I might find on iPlayer. I only caught a couple of proms this year and nothing stood out in that way.

I could listen to a download on both Tannoys and the 775s in turn.

While I am here? I am having trouble Hugh finding the balanced line drive modules. Sparkfun have them back ordered and no idea when they will be back in stock. I have searched extensively for other sources and can find nothing save very expensive 'pro' devices.

Dave.

Dave.
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Re: A Mic below 50Hz? Why?

Post by jimjazzdad »

3rdConstruction wrote: Thu Sep 23, 2021 11:12 pm I had the impression that a multi pattern mic set to omni did not have the same characteristics as a true single diaphragm omni. Am I mistaken?

You are not mistaken. A multi pattern switched to omni creates the pattern by electrically combining two cardioid diaphragms (typically large diaphragms). A true pressure type transducer micropone (i.e. 'omni') has a single diaphragm and, to quote the DPA website, "can result in a cleaner and more dynamic sound with a flatter frequency response". Also a small diaphragm omni will exhibit better omni-directionality with more even off-axis response at the cost of slightly higher self-noise.
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Re: A Mic below 50Hz? Why?

Post by Hugh Robjohns »

ef37a wrote: Fri Sep 24, 2021 12:22 pmI am having trouble Hugh finding the balanced line drive modules. Sparkfun have them back ordered and no idea when they will be back in stock. I have searched extensively for other sources and can find nothing save very expensive 'pro' devices.

Cool Components in the UK was the source I used, but they are showing no stock either.

https://coolcomponents.co.uk/collection ... s-breakout

https://coolcomponents.co.uk/collection ... s-breakout

The makers, Sparkfun inthe US are showing the balanced input card being available:

https://www.sparkfun.com/products/14002

...but not the balanced output card:

https://www.sparkfun.com/products/14003

It might be worthwhile registering with Sparkfun's website and clicking on the 'keep me informed' button so that your interest in the product is logged. That way they'll be less inclined to think there's no market interest in running a new batch! Same with Cool components!
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Re: A Mic below 50Hz? Why?

Post by Hugh Robjohns »

3rdConstruction wrote: Thu Sep 23, 2021 11:12 pm I had the impression that a multi pattern mic set to omni did not have the same characteristics as a true single diaphragm omni. Am I mistaken?

No you're not mistaken. There are some compromises involved in a mutli-pattern mic's omni polar response.

... but whether those compromises are significant depends very much on what you're trying to use the multipattern mic for! For many applications the inherent compromises are irrelevant.

But there is no doubt that small diaphragm single-capsule omnis perform better* and much closer to the theoretical ideal than any multi-pattern mic's omni mode.

* Better... but with the possible exception of the noise floor which is always slightly worse in a small diaphragm mic relative to a large diaphragm mic which most multi-pattern mics are, of course.
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Re: A Mic below 50Hz? Why?

Post by forumuser840717 »

jimjazzdad wrote: Fri Sep 24, 2021 12:27 pm A multi pattern switched to omni creates the pattern by electrically combining two cardioid diaphragms (typically large diaphragms)

Most multi pattern mics do it this way but not all. There are a few switchable pattern mics which use a single capsule/diaphragm and change the pattern mechanically. However, they're generally limted to two or three polar patterns rather than the 4-9 patterns typically found on electronically switched dual diaphragm mics.
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Re: A Mic below 50Hz? Why?

Post by Ariosto »

Hugh Robjohns wrote: Fri Sep 24, 2021 12:08 pm
Ariosto wrote: Fri Sep 24, 2021 11:55 amYou should have heard some of the TV broadcasts of the Proms this year. The bass is incredibly exaggerated! I could not listen on my hi-fi system with large speakers.

Are you thinking of any particular concerts? I watched several and none struck me as having overblown bass. I was listening in stereo from Freeview on PMC IB1s so if there was excessive bass I would have known about it!

Edited to add: That said, I think the TV sound mixes do tend to be a little more 'commercial sounding' than Radio3's mixes -- which means slightly more use of spot mics. The social distancing requirements this year have also made spot-miking more of a necessity.

But Mrs R has just reminded me that I did "bleet on" about double basses being too prominent on spot mics during the Bach St Matthew Passion Proms broadcast...

I think they exaggerate the low frequencies below 100Hz by many dB to compensate for most TV speakers being small.

I'd be extremely surprised if that were the case!

However, in previous years I have noticed that they often duplicate low end sources into the LFE channel (inappropriately in my view!) when creating surround mixes. That could easily create the impression of exaggerated bass for any some surround listeners.

Sorry to be so long in replying, but I've been in hospital with sudden strangulated hernia.

There were two outstanding proms that I heard on TV. (1) The Philharmonia playing Prokofiev Classical Symphony and Shostakovich Symphony No 9. Sound on Hi fi system very bass heavy and sounded much better on TV speakers. Wonderful playing and great music.

(2) London Symphony Orchestra Simon Rattle - Stravinsky Symphony in C and Stravinsky Symphony. Plus a wind piece. Great playing - but as above, sound too bass heavy on Hi Fi system. (Not a great fan of Rattle but on this occasion the orchestra was great and mostly in charge ...)

Normally music like this sounds great on my system - from CD's to Radio 3. I have no way of adjusting the bass/treble controls on my amp (it's a Cyrus - about 14 years old. Good sound but I would not buy another as its not user friendly and has stupid connectors).
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Re: A Mic below 50Hz? Why?

Post by James Perrett »

ef37a wrote: Fri Sep 24, 2021 12:22 pm While I am here? I am having trouble Hugh finding the balanced line drive modules. Sparkfun have them back ordered and no idea when they will be back in stock. I have searched extensively for other sources and can find nothing save very expensive 'pro' devices.

Farnell are showing the chips as out of stock and no new supplies expected until the week beginning the 28th of November.
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Re: A Mic below 50Hz? Why?

Post by ef37a »

James Perrett wrote: Thu Sep 30, 2021 9:59 am
ef37a wrote: Fri Sep 24, 2021 12:22 pm While I am here? I am having trouble Hugh finding the balanced line drive modules. Sparkfun have them back ordered and no idea when they will be back in stock. I have searched extensively for other sources and can find nothing save very expensive 'pro' devices.

Farnell are showing the chips as out of stock and no new supplies expected until the week beginning the 28th of November.

Thanks James. I am in no rush and should be getting on with more vital but boring jobs. End of Nov suits me, solves my birthday prezzie to me!

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