Ishiwata Toe In (Extreme Toe In), have you tried this?

[BobbyTimmons]

Ishiwata toe in or extreme toe in where the speakers cross over in front of the listening position. Made famous by the audio industry legend Ken Ishiwata of Denon/Marantz. Ken Ishiwata used it not only to tame untreated rooms during Marantz demos where he would stream songs from his iPhone. It was even used in his critical listening room which had $160,000 of acoustic room treatments.

 

[StigErik]

Typically, you get less reflection off the nearest side wall, but more from the other side wall. Which means less early reflections, and more late reflections. It may benefit clarity and soundstage in my opinion, I do this with my #2 setup in our living room, where acoustic treatments have been banned ……

 

[CapMan]

I wonder what an REW impulse plot would show between extreme toe in more conservative ‘normal’ toe in. Would reduced early reflections show up …

I can’t be arsed to move my speakers to find out

 

[StigErik]

It depends on the speaker, room, distance to the walls….

In my case I managed to eliminate the nearest wall reflection with extreme toe-in. My speakers are dipoles, and more or less dead at 90 degrees off axis.

 

[sergeauckland]

Not Ishiwata! This method was proposed by Hugh Brittain of GEC Research Laboratories in the 1950s, in the early days of stereo.

We know it as the Brittain method.

S

 

[CapMan]

I imagine visual bias might play a part in how our brain perceives the sound - i.e. the brain interprets the speaker toe in it sees as a narrow image … just speculating

 

[StigErik]

More toe-in actually gave me a wider and at the same time more defined stereo image.

 

[CapMan]

More toe-in actually gave me a wider and at the same time more defined stereo image.

Is there a systematic way to measure stereo width and precision without introducing expectation bias?

Unless you did it unsighted how can you be sure ?

 

[DSJR]

Silly old man - I suspect, judging by the often dire products he'd 'breathed' over, that his hearing was well gone, but he was worshipped as some kind of deity in this industry and certainly helped get later Marantz noticed. Not aure older Q Acoustics speakers needed this 'treatment' in the first picture as the ones I heard were hardly 'hot' in tweeter output to start with.

Over-toeing in a set of speakers just looks so daft, but then, to me, so does facing them straight ahead into the room as so many audiophiles do. Back in the 80's, even Martin Colloms suggested over-toeing in one or two models with ragged hf response.

 

[BobbyTimmons]

Silly old man - I suspect, judging by the often dire products he'd 'breathed' over, that his hearing was well gone, but he was worshipped as some kind of deity in this industry and certainly helped get later Marantz noticed. Not aure older Q Acoustics speakers needed this 'treatment' in the first picture as the ones I heard were hardly 'hot' in tweeter output to start with.

Over-toeing in a set of speakers just looks so daft, but then, to me, so does facing them straight ahead into the room as so many audiophiles do. Back in the 80's, even Martin Colloms suggested over-toeing in one or two models with ragged hf response.

The effect of the extreme toe in is on the imaging, not much on the frequency response. The speakers are not being listened to all that off axis after the toe in.

 

[CapMan]

The effect of the extreme toe in is on the imaging, not much on frequency response. The speakers are not being listened to all that off axis after the toe in.

Hypothesis - for the first wall reflection with extreme toe in, the sound will have travelled further and presumably the higher frequencies will be attenuated commensurately more (vs shorted path length for a more normal toe in)

So perhaps greater hf roll off as well?

Or perhaps the opposite is true - the reflections make a smaller contribution to the MLP because they have been attenuated more so more direct sound in the mix ??

 

[DSJR]

The effect of the extreme toe in is on the imaging, not much on frequency response as the speakers are not being listened to all that off axis.

So an attempt to further narrow dispersion off to the sides and boost it in between. I understand what you're saying, but back then, directivity wasn't discussed or even bothered about and my own boxes for example need all the help they can get in the sensitive lower kHz region.

Sorry for being a miserable old git here, but this is where speaker-room optimisation should come way before messing with toe-in, especially as now we have speakers with narrow directivity/dispersion to help in lively rooms as well as speakers with wide directivity for well to over damped rooms I believe.

Having said and moaned above, my own sitting room has a window off to the side which can skew the upper mids to that side a little if the speakers aren't 'just so.' I don't use them in the evenings with curtains drawn either.

 

[BobbyTimmons]

Hypothesis - for the first wall reflection with extreme toe in, the sound will have travelled further and presumably the higher frequencies will be attenuated commensurately more (vs shorted path length for a more normal toe in)

So perhaps greater hf roll off as well?

Or perhaps the opposite is true - the reflections make a smaller contribution to the MLP because they have been attenuated more so more direct sound in the mix ??

Wouldn't it have the opposite effect of hr roll off if it's used in a room where the speakers are near the corners? The toe in should reduce the proportion of early reflections you hear

 

[sergeauckland]

What Hugh Brittain proposed was a way of widening the 'sweet spot'. A listener on the left would hear more of the left loudspeaker, but would be more on-axis to the right 'speaker, somewhat restoring the central image. Ditto for a listener on the right. Note that loudspeakers of the 1950s had a fairly narrow HF dispersion due as much to the cone tweeters then generally used. As image position is influenced more by higher frequencies than lower, this makes a lot of sense, and was a way of ameliorating the criticism of stereo that it was only suitable for one listener sitting in the centre.

What this shows is that there's nothing new under the sun, and old techniques are constantly being 'rediscovered' and attributed to later publicisers.

S

 

[CapMan]

Wouldn't it have the opposite effect of hr roll off if it's used in a room where the speakers are near the corners? The toe in should reduce the proportion of early reflections you hear

I think I confused myself with my own logic

 

[StigErik]

Is there a systematic way to measure stereo width and precision without introducing expectation bias?

Unless you did it unsighted how can you be sure ?

Of course not. Can you really "measure" a subjective experience?

 

[CapMan]

Of course not. Can you really "measure" a subjective experience?

But why is it different in hearing differences in cables and Dacs - there will still be expectation bias .

 

[StigErik]

Unless it's a double blind A/B test, there will of course be some expectation bias. We are after all human beings, not measurement gear.

I can't hear any difference between cables at all, even if I wanted to. I just recently did a level matched A/B test between two DACs with 10 dB different SINAD. Couldn't hear any difference there either, even if I expected the slightly better measuring DAC to sound "better".

My subjective experience with playing around with the room acoustics is not the same. The effect of changing a speaker's toe-in is very obvious on measurements, and it can be heard. But how do I know what to expect from say - a reflection off the back wall arriving 12 ms after the direct sound with a level of -15 dB? How does that sound? What should I be expecting?

 

[Purité Audio]

If I recollect Grimm recommended severe toe-in crossing a metre in front of the mlp, I think there was even an option in the software to optimise,
it’s here under ‘positioning’.

https://www.grimmaudio.com/wp-content/uploads/Manual-LS1-EN-V3.00.pdf

Keith

 

[Mnyb]

This is not new have been sugested for ages as an alternative to try , cant remember any special occasion when i tried , so i cant controbute any anectdotes about it . It was a while ago