The 4 Hour Transformation Of A Linn System

[Craigas]

Since room modes are independent of listening position, it would be all positions.

I ask this because my wife think the latest SO optimization I performed makes the back of the room sound more 'hall" like than before. I say the bass and sound is now more accurate and "right". It should be easy to test, change listening position and re-calculate. 

Is it just the higher frequencies then that get updated to listening position or timing or??? and nothing below 80hz impacting room modes is getting changed?

There is certainly more going on, what can we agree upon here?

 

[sunbeamgls]

Since room modes are independent of listening position, it would be all positions.

Yes, but if SO addressed a room mode NOT at the listening position, it will make the sound at the listening position sound "wrong".

If SO addressed a mode at the back of the room which was not present at the listening position, to make the response flat at the back of the room, it would create a dip in the frequency response at the listening position.

Take a look here: https://amcoustics.com/tools/amroc?l=500&w=600&h=250&r60=0.6

Click on some of the frequencies in the upper diagram and you get a map of where / how they affect different parts of the room.  Fixing a mode issue away from the listening position will create a problem in the FR at the listening position.

 

[Clavius]

Since room modes are independent of listening position, it would be all positions.

Why do you think every room correction system in the world including Space requires you to give listening position?

 

[akamatsu]

Addressing the problem by EQ:ing the main speakers like all other room mode contouring systems like Dirac, Audyssey, REW+Equalizer Apo etc, etc is the wrong way around imo. Miked or not, the approach is the same, trying to tame room modes by shaping the signal.

The difference with SO is that it takes into account the specific characteristics of the speakers. , It factors in the effect of the speakers to the correction made.  What is left is the effect of the room only.

 

[andrew s]

Why do you think every room correction system in the world including Space requires you to give listening position?

I would think it a halfway house. If the system cuts the energy to a mode it will probably improve the result everywhere but if you can still optimise the outcome at a specific spot.

Regards Andrew 

 

[akamatsu]

This fascinating and worthy of learning more.

Did you use SOv1 to address modes that are augmenting each other at positions in the room other than the listening position, as SO would normally ignore those?

I have a 55Hz mode situation where this frequency is augmented about 2-3ft in front of the listening position.  SOv1 addresses it too severely for the listening position, but makes it much better if you're sitting on the couch along the side wall.

It sure is fascinating. It just happened, much to my surprise and delight. But after thinking about it for roughly 7 seconds, it became obvious as to what was going on. I will look into this further with more listening later today and report back. Your intellectual curiosity is refreshing. .

 

[sunbeamgls]

 specific characteristics of the speakers

Can you define these please?

 

[sunbeamgls]

It sure is fascinating. It just happened, much to my surprise and delight. But after thinking about it for roughly 7 seconds, it became obvious as to what was going on. I will look into this further with more listening later today and report back. Your intellectual curiosity is refreshing. .

Can you capture that in writing in 7 seconds too? 

 

[sunbeamgls]

I'm not familiar with this phenomenon.

Fascinating

 

[Clavius]

The difference with SO is that it takes into account the specific characteristics of the speakers. , It factors in the effect of the speakers to the correction made.  What is left is the effect of the room only.

No that's not how it works, sorry.

 

[akamatsu]

Can you define these please?

No. I don't know off the top of my head. But we could both look it up. But I have a feeling you know better than I on this topic.

But this is what Linn have to say:

[SIZE=18.1818px]Space Optimisation takes account of the[/SIZE][SIZE=18.1818px] characteristics of your speakers,......[/SIZE]

I tried copying and pasting, but it left out the spaces between words. So the letters and words are Linn's. The spaces are mine.

Here's the document; https://docs.linn.co.uk/wiki/images/8/82/Linn_Account_Space_Optimisation.pdf

 

[Craigas]

So we agree on one thing, that we agree to disagree on everything. :fight:

 

[sunbeamgls]

No. I don't know off the top of my head. But we could both look it up. But I have a feeling you know better than I on this topic.

But this is what Linn have to say:

[SIZE=18.1818px]Space Optimisation takes account of the[/SIZE][SIZE=18.1818px] characteristics of your speakers,......[/SIZE]

I tried copying and pasting, but it left out the spaces between words. So the letters and words are Linn's. The spaces are mine.

Here's the document; https://docs.linn.co.uk/wiki/images/8/82/Linn_Account_Space_Optimisation.pdf

Understood.

Is it possible that you could ask questions and make postulations for discussion rather than making definitive statements when you don't know what's actually going on please?

 

[akamatsu]

No that's not how it works, sorry.

I didn't think I was explaining how it works, rather the difference with SO in that it does take into account the characteristic of the speakers. Just measuring the sound energy in the room would, according to Linn, be less accurate for reasons that are documented by Linn. I trust that you are already familiar with all this as it is clearly explained.


Why does Space Optimisation not use a microphone measurement?




The aim of Space Optimisation is to remove the effects of your room, in order to uncover the unique acoustic characteristics of your speakers; after all, this is what you fell in love with when buying your speakers. In order to do this, Space Optimisation needs to understand both the interactions between your speakers and room and the unique acoustic characteristics of your speakers; the unique acoustic characteristics of your speakers are then subtracted from the interactions between your speakers and room, leaving only the effects of your room.
 





An acoustic measurement of the interactions between your speakers and room can have many sources of error which may affect the accuracy and repeat-ability of the measurement, including: the choice of measurement stimulus, such as MLS or a log chirp; external noise, such as traffic noise and vibration; quality and calibration of the microphone, which can introduce distortion; and the microphone location, which can be sensitive to within a few centimetres. The use of acoustic modelling removes these sources of error: the model can apply an ideal impulse as stimulus; the modelling domain is free from noise; the model can use an ideal microphone; and the listening location is well-defined. It can thus be seen that acoustic modelling has a clear advantage over acoustic measurement in understanding the interactions between your speaker and room.
 





The unique acoustic characteristics of your speakers depend on many factors, including: the shape and size of the drive units and ports; the constructive and destructive interference between the drive units, ports and any cabinet-edge diffraction sources; and the angle between the listening location and your speakers. Therefore, a simple on-axis anechoic measurement of your speakers is insufficient information; what is actually required is an anechoic measurement with your speakers in the exact same configuration as you have them in your home. While some manufacturers do publish anechoic measurements of their speakers, both on- and off-axis, it is extremely unlikely that they will have performed an anechoic measurement of your speakers in the exact same configuration as you have them in your home. The acoustic modelling of such a scenario is, however, straightforward; the model can simply turn your room into an anechoic chamber to obtain the unique acoustic characteristics of your speakers in the exact same configuration as you have them in your home. It can thus be seen that acoustic modelling once again has a clear advantage over acoustic measurement in understanding the unique acoustic characteristics of your speakers.



From the above, it is clear that acoustic modelling is the best approach to Space Optimisation.



Here is the original: https://docs.linn.co.uk/wiki/index.php/Linn_Account_Space_Optimisation#Why_does_Space_Optimisation_not_use_a_microphone_measurement.3F

 

[Clavius]

No. I don't know off the top of my head. But we could both look it up. But I have a feeling you know better than I on this topic.

But this is what Linn have to say:

[SIZE=18.1818px]Space Optimisation takes account of the[/SIZE][SIZE=18.1818px] characteristics of your speakers,......[/SIZE]

I tried copying and pasting, but it left out the spaces between words. So the letters and words are Linn's. The spaces are mine.

Here's the document; https://docs.linn.co.uk/wiki/images/8/82/Linn_Account_Space_Optimisation.pdf

Now you're confusing marketing marketing claims with science.

 

[akamatsu]

Understood.

Is it possible that you could ask questions and make postulations for discussion rather than making definitive statements when you don't know what's actually going on please?

The definitive statement that I made was that SO does account for characteristics of the speakers, which it does. I just figured this was common knowledge. I'm always open to correction, discussion, etc. This is, after all, a forum.

 

[sunbeamgls]

Now you're confusing marketing marketing claims with science.

The truth is somewhere in between

 

[akamatsu]

The definitive statement that I made was that SO does account for characteristics of the speakers, which it does. I just figured this was common knowledge. I'm always open to correction, discussion, etc. This is, after all, a forum.

To add to this, I was merely drawing contrast between SO and other methods of room correction. I don't know of other methods that factor in speaker characteristics. This is especially profound with SO+.

 

[sunbeamgls]

The definitive statement that I made was that SO does account for characteristics of the speakers, which it does. I just figured this was common knowledge. I'm always open to correction, discussion, etc. This is, after all, a forum.

It was the bit afterwards "It factors in the effect of the speakers to the correction made" that concerns me, although it could just be down to grammar.  I read it as the speakers having an effect on the correction that has been made, which would not be correct.  Did you intend to mean that the correction calculations take into account a limited number of characteristics of the speakers? If so, then that would be correct.

 

[akamatsu]

Now you're confusing marketing marketing claims with science.

I tend to trust the engineers at Linn over opinions that I read on this forum. My experience with SO tells me that their product, Space Optimisation, does perform as advertised.

But this is only my experience.