making headphones less different than speakers

[hooty2]

Greetings all,
Having gained more practical experience of recording orchestras & choirs in large venues & Cathedrals, i have been revisiting the books by Michael Williams recommended to me some years ago on this forum.
Theory & practice start to relate a lot better now and i start to understand why i'm getting the results i do. Some good results, but too many would not pass muster here i think!

to my question:
RE: Microphone Arrays for Stereo & Multichannel Sound Recording / Michael Williams
Vol 1 - chapter 1.4 - page 8, 'Monitoring with Headphones'
Concerning using DSP to introduce a degree of 'crosstalk' into L/R headphone channels to closer emulate (my words) the experience when monitoring on loudspeakers.

Quote: ".....however, this discussion is for the time being, purely academic, as this process of crosstalk injection is not generally available. It seems we will have to wait a few years before it becomes a standard 'black box' correction for headphone monitoring..."

Is this available?
Is it a good idea?

Regards

[Hugh Robjohns]

Yes, it's available. There are plugins that do it and hardware headphone amps from the likes of Grace Design and SPL have the facility, amongst others. As to whether it's a good idea, I think views vary... But I find it useful.

Ideally, the crosstalk parameters (HRTF -- head related transfer function) should be personalised as we all have differently sized heads and ear positions! But, while it is possible to measure and implement a personal HRTF few offer that facility, although some systems offer various alternative settings so a close match can be found. However, the effect -- even with crosstalk -- is not quite the same as real speakers in a real room and while useful some learning and experience is required to interpret what is heard.

It's also possible to learn to interpret the sound from conventional headphones pretty well... Although I find supplementing the audio with a visual display in the form of an audio vectorscope works well!

H

[The Elf]

I'd contend that it's NOT a good idea. It never ceases to amaze me that headphones are deemed to present a 'problem' that needs 'correction'!

And when that correction is artificial fiddling I think it puts yet another barrier between listener and audio - one more barrier for our ears to muddle through to find the truth.

[Hugh Robjohns]

It is a fact that headphones and speakers interact with the human hearing apparatus in very different ways. Both ears hear both speakers, and the inherent inter-aural time delays enable the creation of a stereo image with stable localisation.

With normal headphones each ear only hears its own earpiece, and that results in an extreme stereo image with little localisation of the stereo image. Crosstalk systems improve upon that by emulating the inter-aural frequency-dependent time delays of normal speaker monitoring. It's not complicated, but the crosstalk parameters are personal and critical for a good result.

Of course, if you are of the persuasion that subtle stereo imaging is for cissies and things should only be panned hard left, right or centre (and nowhere else) then headphone monitoring becomes a lot easier and more practical...

[The Elf]

Then perhaps we should be looking at 'correction' for speakers, whose 'problem' is that they don't sound like headphones?!

I think this is a holy grail that no-one truly needs. If you want the sound of speakers, use speakers!

[Hugh Robjohns]

I think this is a holy grail that no-one truly needs. If you want the sound of speakers, use speakers!

Couldn't agree more!

[Mike Stranks]

In the almost 50 years I've been doing location recording of audience-present concerts/events I think I could count on the fingers of one hand when I've been able to have the luxury of monitoring on speakers.

And these days it's much simpler with affordable digital multitracks. Each mic gets its own channel and is recorded flat with a good amount of headroom. Headphones are just for checking for buzzes, hums and other anomalies during set-up and rehearsal. Any serious work that might need compensated headphones is done back in the studio when the treated room and monitors obviates the need for cans anyway.

But that's just me... We all have our preferred ways of working...

[Elephone]

[quote="The Elf"]Then perhaps we should be looking at 'correction' for speakers, whose 'problem' is that they don't sound like headphones?!

Didn't Bell Labs or IRCAM establish decades ago that the best way to listen to stereo is through 3 speakers, with the central speaker conveying the mono content?

[Sam Spoons]

The perfect 'stereo' for a live rock band concert would be like the Grateful Dead's 'wall of sound' with a separate speaker (stack) for each instrument and vocal. Of course you'd have to move them around when you played a recording of a different band but the stereo imaging would be fantastic

[Hugh Robjohns]

Didn't Bell Labs or IRCAM establish decades ago that the best way to listen to stereo is through 3 speakers, with the central speaker conveying the mono content?

No. Not quite.

Bell Labs demonstrated in the early 1930s that if the complex acoustic wavefront emitted by large scale source like an orchestra was captured by a large array of a microphones placed in a line in front of said orchestra, and then reproduced directly by a corresponding array of speakers in a different room, a very good portrayal of the natural sound staging and positioning could be recreated.

However, such a system was impractical as a consumer or broadcast format at the time because high channel-count multitrack recording and/or transmission paths weren't available... So they were forced to simplify, and they eventually found that three channels was as low as they could go (two channels suffered from a hole in the middle and unstable imaging for off-centre listeners) -- and three channel recorders and transmission paths were viable at the time. The centre channel was fed from a central mic; a mono sum of left-right in the middle tends to narrow the image.

As to being 'the best way'... The format certainly has its advocates and it delivers a pleasingly spacious sound. But with just three (or two) channels the imagining tends to be vague and unstable. Meridian (the hi-fi manufacturer) offer a listening me called Trifield which emulates the format from suitable stereo sources onto three speakers.

Alan Blumlein -- working independently in the UK at the same time -- discounted Bell's approach and demonstrated that accurate and stable imaging could only be obtained using coincident mic arrays, or by using a shuffling circuit to convert the LF phase shifts from spaced mic arrays into amplitude variations. And that accurate imaging with two speaker stereo required only amplitude differences between the channels as the speaker-listener interface inherently generated time of arrival differences to replicate natural directional hearing cues.

[Ariosto]

Would it not be better to just record everything in MONO and have done with it?

[Hugh Robjohns]

There is a small band of enthusiasts that argue strongly in favour of mono recordings... Some of them keep writing to me about it, too!

[Elephone]

There is a small band of enthusiasts that argue strongly in favour of mono recordings... Some of them keep writing to me about it, too!

I was going to ask about mono but thought I'd better not. The point is, surely, that you don't have to worry where the listener is situated as much. Isn't that why it's important to mix in mono first? I know it's useful for separation, etc.

But I have to admit, I'm just as blown away by mono records as ever I am by stereo. Sometimes I even find the stereo aspect of mixes a bit distracting from the overall production, especially on drum kit.

[Sam Spoons]

The wonderful Gordon Giltrap's "Heartsong" being a prime example (though, TBF, I do love the track but the mix is very much of it's time).

[Hugh Robjohns]

The point is, surely, that you don't have to worry where the listener is situated as much. Isn't that why it's important to mix in mono first? I know it's useful for separation, etc.

The reason for balancing in mono before panning into a stereo image is to ensure that any issues with one sound spectrally masking others can be spotted and dealt with -- something which is easily missed if similar sounds are spread apart in a stereo image from the outset.

But I agree; the music and performance come across perfectly well in mono. Stereo just adds a better impression of the performance space and can provide more detail of individual elements through their spatial separation.

[The Elf]

The wonderful Gordon Giltrap's "Heartsong" being a prime example (though, TBF, I do love the track but the mix is very much of it's time).

You want to seek out the mixes done last year (including the 'all-star' version), undertaken by, ahem, one of this parish...

I never felt that the original mix did justice to that song. I feel my version finally allowed it to breath. Nothing added, nothing taken away...

[Ariosto]

There is a small band of enthusiasts that argue strongly in favour of mono recordings... Some of them keep writing to me about it, too!

It might be interesting to know their reasons for favouring mono over stereo?

[Mike Stranks]

The wonderful Gordon Giltrap's "Heartsong" being a prime example (though, TBF, I do love the track but the mix is very much of it's time).

You want to seek out the mixes done last year (including the 'all-star' version), undertaken by, ahem, one of this parish...

I never felt that the original mix did justice to that song. I feel my version finally allowed it to breath. Nothing added, nothing taken away...

Just to add to this... The Elf now works very closely with Gordon on various projects including new albums and the occasional 'live' foray...

For instance: https://www.giltrap.co.uk/cds/f/CDs/4880

... in which another forum member was also very minimally involved...

[hooty2]

hello,
my apologies for not replying earlier & with thanks for all these 'useful' & very 'interesting' responses and general discussion.
I have been away from home & a bit under the weather; to put it mildly!

My specific interest as hinted at in my OP (should i have been more explicit?)...
Was to see if i could make any discernible difference or appreciable improvement in my headphone monitoring when away from home and working on headphones 'post recording'.

Sometimes the opportunity to carry on with a project when back home presents itself and i wanted to also consider minimising the differences between the headphone/speaker systems etc.

Thanks again for very informative thread.

[Mike Stranks]

Hope you're fully recovered, or at least well on the mend...

[hooty2]

Cheers for that Mike.
A mix of age and foreign lands and taking on board when 'rest' means just that!
On and up as they say:)

[MOF]

Have you thought of taking a pair of small active speakers or little Bluetooth/plugin external computer speakers to have a quick playback of rehearsals?

[hooty2]

Good bit if synchronicity there friend.
I just ordered some iloud micro monitors.