The term from singer's brain to listener's brain is used as the end product is satisfying the brain of the artist and the listener.
1st setup:
Kitchen half way up tiled room - male singer at various distances and registers - Shure SM57 Mexico - Pleiades low cut filters of various inductances - Canford 400mH primary inductance 1:14 input transformer - Pleiades V4 prepreamp - Realistic disco mixer mic input - Sennheiser HD580
Bass adjustment depends on singing distance and this is an advantage of directional mics.
With no external Pleiades filter ie just the 400mH primary inductance the sound may be bass heavy even at 12in. Adding 330mH in parallel (Pleiades 100Hz XLR filter) the sound is better. Adding another one ie (200Hz External but total more than 200Hz because of the 400mH transformer inductance) the sound is better. The mic can now be used much closer. 82 mH was then used and the mic could be used at 1-2in with very clear sound. The volume of course was increasing too. An inline transformer that gave a good result (save for its lower ratio and some noise induced) on its own is the inexpensive 96mH trasformer bought from eBay.co.uk described in an earlier euroelectron post.
If a high pitched song was sung such as Aquarious - 5th dimension more low cut was needed. A Pleiades filter of 54mH, overall about 47mH? taking into account the 400mH primary inductance was found to give a balanced and clear sound.
There may be a systematic effor as voice is monitored in real time, the singer and listener is the same person. The internal and external acoustic wave may lead to inaccuracy. (Analog or digital recordings were done in some previous experiments, not on this one).
2nd setup, signal path:
Kitchen half way up tiled room - Male singing voice at 0-1in - Beyer M55 - Pleiades filters - Canford transformer - Pleiades V4 - Realistic disco mixer - HD580
Although on low pitch male voice singing the sound is almost there with just the 400mH inductance, on singing Aquarious high pitch introduction the sound was bass heavy.
2 Pleiades filters of 330mH ie 100Hz+100Hz =200Hz solved the problem (total inductance 400mH\\330mH\\330mH giving a cutoff of more than 200Hz).
1 Pleiades filter of 82mH worked fine too.
The sound quality of the above was exceptional with very clean, loud sound and high frequency detail.
It is not always easy to say which type of mic, directional or omnidirectional performed better.
Low pitch male singing seems preferable on omnidirectional. The bass is there, clean with full detail.
High pitched male singing may sound good on directional microphones too if the correct distance and Pleiades filter is used.
They have the advantage that the cutoff frequency can be adjusted in real time by the singer by singing further from the mic as they sing higher notes. This is also an effective manual volume control ie compression.
This may be the reason that directional mics as more popular.
On omnidirectional mics there is no proximity effect and the cutoff frequency is fixed.
There is a trick to adjust it.
2 omnis can be used close to each other, out of phase and the singer singing to one of them.
This creates a noise canceling microphone as described on Lou Burroughs book.
On directional microphones the noise canceling effect is made by the proximity effect and tye Pleiades filter.
On the original Aquarious recording a ribbon RCA 77DX directional mic was used with its internal Pleiades filter (reactor or inductor in parallel) connected to a tap of the mic transformer (the transformer stepping up the ribbon). The switch setting was V1. See a previous euroelectron post or the 3rd reference of this post. Same for the Mamas and Papas recordings.
References:
Sound picture recoding and reproducing characteristics - Loye, Morgan - Journal of Motion Picture Sound Enginners
Microphones - Lou Burroughs
Sound on Sound classic tracks, Aquarious - interview of Bones Howe
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