What would you donate for us to test speakers?

[cshake]

Regarding that testing system from the video: I'm curious why they have the giant arm rotate, when you could just rotate the speaker platform and have the mic move up/down and in/out in front of it, it would take up much less space. Maybe to make the room effects math easier?

 

[Blumlein 88]

Regarding that testing system from the video: I'm curious why they have the giant arm rotate, when you could just rotate the speaker platform and have the mic move up/down and in/out in front of it, it would take up much less space. Maybe to make the room effects math easier?

I wondered the same exact thing, but guessed like you it has something to do with separating room reflection from speaker sound. My other thought was moving the arm keeps you from having to build a turntable for precision positioning of what might be a 500 lb speaker.

 

[Wombat]

That bulky rig is close-up to the test speaker and somewhat reflective. I would think that some clever software makes it transparent for all test configurations.

 

[amirm]

My other thought was moving the arm keeps you from having to build a turntable for precision positioning of what might be a 500 lb speaker.

That is exactly the reason they give. They say for example that you could hang large speakers by a crane/ceiling and measure them. Position can also be more accurate when we are talking about a microphone versus a heavy speaker rotating. And finally, the platform reflections are not as much of a factor. Here is a slide from their ALMA presentation:

 

[amirm]

That bulky rig is close-up to the test speaker and somewhat reflective. I would think that some clever software makes it transparent for all test configurations.

The field separation processing will take care of them although for most of the audio band, the wavelengths are too large relative to the rails to matter.

 

[amirm]

Respectfully it would be interesting to know out of the 50 or so speaker manufacturers in the US how many have stepped up.

Let me put it this way: it is less than 20 and more than 10. Companies buying it though are beyond speaker companies and likely includes likes of Apple, Google, etc. to test their smart speakers, laptop and tablets, etc. They also have the deep pockets unlike many speaker companies.

 

[cshake]

That is exactly the reason they give. They say for example that you could hang large speakers by a crane/ceiling and measure them.

Makes sense. I hadn't thought about outdoor concert speakers; I figured the rig would only do household speakers based on the demo unit in the video. I see they mention the room interaction too, as I assumed.

 

[Wombat]

Let me put it this way: it is less than 20 and more than 10. Companies buying it though are beyond speaker companies and likely includes likes of Apple, Google, etc. to test their smart speakers, laptop and tablets, etc. They also have the deep pockets unlike many speaker companies.

Do you still have Bill Gates' contact details?

 

[Blumlein 88]

I think this is the presentation Amir is referring to from ALMA.

http://warkwyn.com/wp-content/uploads/2015/01/NFS-ALMA-2015-PPT.pdf

Interesting if you haven't read over it. Fairly simple 35 page powerpoint.

 

[Wombat]

The field separation processing will take care of them although for most of the audio band, the wavelengths are too large relative to the rails to matter.

Are treble frequencies not relevant in such testing? Wavelength @ 3kHz is ~1inch and reducing proportionally above that frequency.

 

[amirm]

Are treble frequencies not relevant in such testing? Wavelength @ 3kHz is ~1inch and reducing proportionally above that frequency.

It does field separation to get rid of reflections in general. Accuracy of that algorithm goes up though to the extent the power from reflections is low which would be the case for a lot of the audio frequency.

 

[Wombat]

It does field separation to get rid of reflections in general. Accuracy of that algorithm goes up though to the extent the power from reflections is low which would be the case for a lot of the audio frequency.

Thanks.

 

[Juhazi]

I am still wondering how this measures and handles bass outpt from vents and passive units which are often scattered around the box. Some speakers have separate bass units too. Boundary effects must not be forgotten.

How will mechanical build quality be evaluated? Obviously there won't be any kind of listening tests.

 

[amirm]

Obviously there won't be any kind of listening tests.

Oh, I plan to listen. And set up some kind of blind testing with younger ears than mine.

 

[Blumlein 88]

I am still wondering how this measures and handles bass outpt from vents and passive units which are often scattered around the box. Some speakers have separate bass units too. Boundary effects must not be forgotten.

How will mechanical build quality be evaluated? Obviously there won't be any kind of listening tests.

Look at the powerpoint presentation I linked to earlier. This system is really something in what it can do. You also might search for prior work by Klippel about buzz, cone rubbing, spider asymmetry and a host of other issues with speakers.