Erae Touch Sensitivity

Erae Touch
21

Here are some more pressure tests with different devices.
This time I have tried to measure both the minimum and the maximum weight, but it is not easy to do and I was limited to 1 kg …
The result are of course far from being reliable, but however they give a good idea of the range and its variations, and they are consistent with my feeling.
In fact, except for the EraeTouch which show extreme variations depending on the area, the values are generally equal enough.

Roli Lightpad Block 1st version : minimum touch 400g / the maximum is over 1kg, which gives a value about 30
Roli Lightpad Block M : minimum touch 180g / maximum to get a value of 127 600g (more sensitive but not a wider range)
Sensel Morph with the Innovator Overlay (high sensitivity setting): minimum 30g / value 127 800g, it can be different with other overlays
EraeTouch : minimum from 70g to 200g / maximum from 250g = 127 up to over 1kg (70)!
Zoom ARQ-96 : minimum 250g / 1kg = 90

I wonder how the Striso Board acts like in this domain?

2 Likes
22

Another point that can be important when using pressure is the influence that one area can have on another.
I remember that it had been discussed on this forum about the Joué and it also happens with the Morph: the pressure of a second finger on the same horizontal line lowers the value of the first. It doesn’t happen if they are shifted vertically.
With the Lightpad or the EraeTouch this phenomenon does not exist.

1 Like
23

thats quite a variation.

I did some tests with a small static weight, and indeed there is variation throughout the surface… some of it was ‘expected’ e.g. at edges, some quite unexpected.
also its something if I ‘measure’ I can see, but in playing has never really bothered me.
(I guess, the point being, I play pressure relatively… so I play till I hear what I musical result I want… so naturally compensate for sensitivity differences to some extent.)

however, of course the ‘drawback’ with that, is it doesn’t work with something instantaneous like velocity (which is obviously derived from the same sensor measurements) - so it is an ‘issue’, no denying that.

really Id love to know how the calibration is working (*)
my feeling, given auto calibration takes no input, is its using the sensors resting reading, as a kind of base line to form some kind of biasing map…
this is important as we need to bias so as to avoid ghost touches caused by noise.

but to me that seems it assumes that every sensors response rate is the same… perhaps some respond differently to others? a different ‘rate’.

that said, I do think its difficult to allow user calibration… since we don’t have access to precision devices to apply know pressure etc.
(those of us with Eigenharp’s know how much trouble EigenLabs went into factory calibration… its non trivial!)

@embodme , Id love to see a some support in the API for this…
in particular (some assumption of working here :wink: )

  • raw sensors values ( I assume the current api take into account calibration data)
  • ability to download and upload a calibration map to the Erae Touch.

Then we could create a small desktop app, that could perhaps show us whats going on with our own ET … what is auto calibration calculating? what are particular regions of the surface doing?

I think if we gathered some good information, then this could really help improve calibration.

(*) I’d really love to see the Erae Touch firmware be made open source… this could lead to some really interesting developments.
… even if we have to sign some kind of ‘developer’ disclaimer, in case of bricking it… but my experience of MCUs etc, is that there is not a huge risk of this.

MOD NOTE: Ive adjusted title of this topic, as its moved on more generally to sensitivity compared to other devices (rather than just Roll block as original topic was titled)

1 Like
24

Yes, the variation can be huge, but for small keys such as the ones which are given with the current objects, I think that a simple curve edition for each of them could make it very acceptable.
For sliding movements it is another matter.
Keeping the pressure value on a XYZ pad inside a +/- 30 range will already be a great improvement!
But given the seriousness of the people I am rather confident and I am not in a hurry since I have the Morph :wink:
So I can wait.

25

Yes. My most useful percussion setups are mostly symmetrical to accommodate playing techniques, but when I do multi-stroke rolls on a similar kit piece under the opposite hand and get 50% dropout because of the sensitivity difference, it’s very dissatisfying. Approaching the Erae as a beta tester, I’ve been using other tricks to compensate for sensitivity differences, but the results are mixed enough that it looks 50/50 that I abandon the Erae completely.

My concern is that user-customizable curves won’t save the day for me because we’ll end up having to decrease the sensitivity in different locations for the sake of a more homogeneous overall response. That lowest common denominator of sensitivity might work for a lot of people, but would be unacceptable to me. If these sensitivity variations are considered within-tolerance variation on the manufacturing side (and not defects per se), I would have no use for a percussion controller that requires so much force for the minimum velocity level. It would kill my technique and whole reason to use the device in lieu of what I already have.

26

Nice experiments @PrS, reminds me of my own testing before I made a calibration robot! An alternative is to put the whole instrument on a scale, then you can see how much pressure you apply with your finger. Or mount a load cell on a stick and use that to press down (as in our robot).

On the Striso board all keys are calibrated with a robot that measures the curve from 0 to 1500g. The minimum pressure needed is around 30g. Up to 300g the reaction of the keys is pretty consistent, about 10% deviation. Above 300g the consistency and linearity is worse, so consistency is important the high sensitivity setting is better, which reaches 127 with about 400g (±50g). With default sensitivity that would be around 1000g, but with a lot more variation. This is something that’s changed in different firmware releases, with early firmware it wasn’t even always possible to reach 127 :blush: .

Also note that with 30g minimum sensitivity there are some false note triggers, which is not a problem when playing a synth where the volume is pressure dependent, but it is when a non MPE synth is used, or for score editing. Then the minimum should be set a bit higher. The Striso board also suffers from crosstalk, that pressure on one location can change the sensitivity on other locations. When pressing multiple notes, especially when they are corners of a rectangle, the accuracy goes down. When playing one handed it’s harder to notice, as fingers are not that independent either, but with two hands it can be noticeable. This is also something that greatly improved with the Striso v2.1.x firmware.

As a developer I definitely have hope that the Embodme developers will improve this in firmware, though it can be very frustrating matter to work on. (Less frustrating though than having to order your chips more than a year in advance, as with the current chip scarcity, everything is relative :wink: )

2 Likes
27

Thank you very much for these explainations, very interesting about the Stiso and about yourself of course.
What I read is that it would be perfect for one aspect of what I need.
When it was launched for the first time, I hesitated, but now I regret it a bit …
I’m going to wait for a user to sell theirs (it’s still a significant amount of money for me), but I have the impression that it might take a long time :wink:

28

Lightpad Blocks are not very flexible,
I haven’t found a way to change layouts during a live set using midi messages.
So that’s a big turnoff. Also the surface is way to small to use them properly so I usually just use them as mega triggers for sound Fx.
Also lot’s of problems with there software & drivers (detection in DAW/Ableton)
And a lack of support.

To be honest reading thru this community pages and seeing the Embodme Support page (very simular to Roli Support) I hope they will keep supporting this, cause there is nothing sadder then a bricked piece of hardware. (Wouldn’t be my first experience)

Still waiting on the June batch to get my Erea touch.

29

Id not say the Erae Touch will be ‘bricked’…

I think at the moment, the concern (at least for me) is that the ET is not as ‘precise’ as it could be, and that is problematic for expressive play…
(basically pressure values, ghost notes, calibration)

it’s not ‘unplayable’ , but also not great, compared to other (in fairness, more premium) devices e.g. linnstrument, eigenharps, continuums, striso.

I think the ‘concern’ is, will @embodme address these? to make it the expressive controller we want.

my ‘fear’ is that the Erae Touch is currently a bit, jack of all trades.
and there is a bit too much focus on its other functionality… things like generic controller (sliders, buttons etc)
(look at the current promo shots from @embodme , and you’ll see what I mean… not a lot of expressive performances being shown using mpe … its mostly used as simple keyboard/drum/controller)

but this is just because this not my reason for buying it, but perhaps this is why others have it.

the other fear is, we haven’t seen quite as many updates as we had initially hoped…but this could change.

we will see…

as for Striso vs Erae Touch ,
@pierstitus visited me recently, so we had a chance to compare side by side.
they are very different beasts, and take very different approaches.

but I will say, you can ‘feel the difference’, the striso was beautiful to play… Id highly recommend it.
(Im sorely tempted myself :wink: ) - it’s responsive and enjoyable to play.

its a good example of ‘playability’, yes things like pressure sensitive are important BUT more important, for an instrument, is to to play reliably… if YOU play the same way, you expect it to react the same.

the striso is great for this, you feel like you can learn to play it.

the erae touch feels a bit ‘unreliable’… will this touch respond ‘correctly’? mostly yes, but sometimes no… and that makes it frustrating to play (imho)

but as Piers says above, its the kind of thing that can be improved in firmware IF they spend the time and effort!

note: Ive not loaded the current 1.2 firmware yet, as was using ET as for a project, so needed it ‘stable’, warts and all… so hope to update soon… though posts here and the change log, dont seem to imply it’ll solve my main issues… and introduces new issues
(mpe on a new usb midi port is problematic for me in places)

1 Like
30

I installed version 1.2, and the possibility of adjusting the sensitivity globally is interesting, but alas until we can apply it locally to each of the objects it does not resolve the pressure disparities which makes a good number of unplayable areas when this aspect is important.

On the other hand I fell for the Striso, and there, what happiness!
With the Morph the two constitute in a different way what I currently find to be the best in terms of sensitivity, range and reliability of touch.
I hope that the Embodme team will devote itself seriously to the question, otherwise too bad, despite its qualities I will sell my EraeTouch. If it is to have faders, a tablet is at least as effective…

31

yeah, that was not the issue… the issue is with different sensitivity across the board.
and that is something that needs to be handle by some kind of ‘calibration routine’

the soundplane used to have a process where you would run your finger over the board, it would track the min/max pressure at each point, and so and that would help it get a ‘feeling’ for the pressure required on different areas on the board.

later, Randy found this was not really necessary… as there wasn’t the disparity across the board,
but it feels like this would be necessary with the ET.

anyway… they need to take a look at it !