Has anyone ever used a speaker as a mic?

I know Paul McCartney once experimented by placing a speaker in front of his bass speaker and  took the signal from that, but has anyone ever tried to record vocals with a good mid-range?  I checked it out on the scope and the signal looks good and level was up to 10mV depending on how close you got.

My logic is that if we trust decent speakers to reproduce our sounds, shouldn't the speakers be trusted to work in reverse?

A good mid-range can cover the frequency range of the male voice, a small tweeter could pick up the fast transients.

I'm interested to hear your opinions.

DaveP

I've used speakers for a kick drum and it's cool.
I doubt it would work well for vocals mainly because you'd need someone who can sing VERY loud.

A good set of Headphones  might be better for voice

IIRC the album Dreams Less Sweet by Psychic TV was recorded entirely with headphones instead of conventional mics.

Never used a speaker as a vocal mic, but I've used a kids drumset as a kick drum mic.

Cool 8)

DaveP

I sometimes use my headphones as a mic while DJing.
It sounds shitty, but fair enough to order a drink!

DaveP said:

My logic is that if we trust decent speakers to reproduce our sounds, shouldn't the speakers be trusted to work in reverse?

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I don't think so. They areally not optimized to work in that situation. I think the mechanical resistance of the spider woukd be the number 1 issue for getting a reasonable sensitivity out of it.

Also, what's the idea for an amplifier for this beast? Time to design a preamp for an 8 ohms source impedence? One thing is certain, Johnnson noise will not be a huge threat.  ;D

I'm pretty sure we've discussed this before...

Yes, old school intercoms routinely use speakers as mics... not very hifi but good enough for the application (long before Sir Paul tried it).

As has been shared, Yamaha has a successful drum mic that is just a speaker hung in front of the kick drum. Again not hifi but that doesn't seem to be the goal for many, it will have a unique sound characteristic.

JR

PS Sir Ringo?

Yes, as a mic for vocal-effect, could possibly get something cool with a speaker. Placid Audio kinda has those effect- bases covered; not with speakers though... For DIY, I’d probably  start looking in their direction for inspiration on trying your own thing out.

A single 15" bass cabinet placed in about 4 feet or so in front of a kick drum in conjunction with a Telefunken M82 or similar mic inside it is how I usually record drums. Sounds really great if the kick drum/drummer is worth anything.

Thanks!

Paul

we use to use 10" -12"  Celestions for backing vocals!

I tried it about 50 years ago. Small loudspeaker (about 5 inches diameter) wired to a regular valve output transformer the primary of which I connected to the input of a valve tape recorder. It worked OK but the top end response was poor.

Cheers

Ian

ruffrecords said:

I tried it about 50 years ago. Small loudspeaker (about 5 inches diameter) wired to a regular valve output transformer the primary of which I connected to the input of a valve tape recorder. It worked OK but the top end response was poor.

Cheers

Ian

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I also did that when I was a kid, and microphones were too expensive for me, while loudspeakers could be found more easily (people used to dispose of their old TV's at the curb). Indeed HF response is somewhat poor and directivity is noticeable. It's in essence a fig-8 (bi-directional), but due to the large size of the diaphragm it also narrows significantly with frequency. The experiment was fun, but since my interest was in live applications, I didn't relish the idea of having a big circular thing isolating me from the audience.

I was told to take a PA sub frequency driver and to wire it in reverse into a DI. The idea was to catch the ULF spectrum and then combine it with the normal kick mic signal. It's a nice big diaphragm..

*originally typed VLF, meant to type ULF

buildafriend said:

I was told to take a PA sub frequency driver and to wire it in reverse into a DI. The idea was to catch the ULF spectrum and then combine it with the normal kick mic signal. It's a nice big diaphragm..

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However, the VLF response is not so great, because the mechanical resonance of a speaker is much more significant than in a microphone, where intensive damping is used to linearize the fequency response.
The efficiency of a loudspeaker-as-a-mic is so great, due to the large diaphragm's area, that the signal's amplitude allows all sorts of processing, in particular EQing to death in order to extract VLF information.

Using loudspeakers as mics for kick drums is old; at Barclay Studios, in the 70's, there were coffee-machine discussions about just doing that, because someone heard it was done in some English studios.

It seems the origin was with some experiments by Peter J. Baxandall, who produced a paper on the subject (AES Library:
Loudspeakers as High-Quality Microphones). If I understand well his intro (The work described here started several years ago, merely as the result of idle curiosity - what sort of equalization would be required for good-quality results, how good would the quality turn out to be, and what would the signal-to-noise ratio be like?) and conclusions (When a first-rate loudspeaker is used as a microphone in the above manner, it is found that speech quality fully up to the standards of the best studio microphones is obtainable. This does not mean, however, that such results will be obtained in more normal circumstances of use, with off-axis sound sources and reverberant surroundings - indeed an ordinary loudspeaker must be regarded as a rather poor microphone when its directional characteristics are taken into account. Nevertheless it is on the whole surprising what very geed musical quality can be obtained, especially under stereo conditions, when the direct sound sources can be arranged to be more-or-less on axis for one or other of the two "microphones".)
I believe that's the reason why he didn't pursue.

Personally, I'm not very interested in those so-called "sub-kicks", since all information below 40Hz is garbage used to shake your trouser's legs while you're under the influence of E-bombs. 

I completely agree with the using the "sub kick" method of trying to capture frequencies less than 50Hz is for the most part not necessary. I get amused and simultaneously annoyed when I hear FOH guys insist that they need all those sub frequencies so their kick drum will punch in the PA, then watching them carve all the 250 to 100Hz out of the system.

For the single 15" speaker method, I listen to the kick to find where the 1/4 wave develops and place the speaker there. When this is low passed to 180-200Hz, it compliments the inside mic very nicely adding more impact without the need for a plug in to artificially manufacture what can be accomplished by an actual recorded track.

Thanks!

Paul

Potato Cakes said:

I completely agree with the using the "sub kick" method of trying to capture frequencies less than 50Hz is for the most part not necessary. I get amused and simultaneously annoyed when I hear FOH guys insist that they need all those sub frequencies so their kick drum will punch in the PA, then watching them carve all the 250 to 100Hz out of the system.

For the single 15" speaker method, I listen to the kick to find where the 1/4 wave develops and place the speaker there. When this is low passed to 180-200Hz, it compliments the inside mic very nicely adding more impact without the need for a plug in to artificially manufacture what can be accomplished by an actual recorded track.

Thanks!

Paul

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I have always felt that the subkick is too easy to abuse. It seems to me like its a good idea to blend it in just enough so the difference is perceptible, but not immediatly obvious or audible. Of course, I know some live engineers that seem to think the sub kick IS the only kick mic they will ever need. I try to pretend they dont exist.  ;D

iampoor1 said:

I have always felt that the subkick is too easy to abuse. It seems to me like its a good idea to blend it in just enough so the difference is perceptible, but not immediatly obvious or audible. Of course, I know some live engineers that seem to think the sub kick IS the only kick mic they will ever need. I try to pretend they dont exist.  ;D

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We have also discussed the sub kick mic here before too. The bass/kick drum basically sounds the fundamental note (thump) sound, so not much higher frequency content to speak of except for leakage from stage wash and pedal squeak.

JR

JohnRoberts said:

We have also discussed the sub kick mic here before too. The bass/kick drum basically sounds the fundamental note (thump) sound, so not much higher frequency content to speak of except for leakage from stage wash and pedal squeak.

JR

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I think this depends on the style of music too. Have you ever seen drummers that play with "click" pads? Fairly poplar in the metal/hardcore scene. I dont think any other style of music depends so much attack out of kick drums.