Genelec on audio science

[pirad]

Isn’t it that most models of Genelecs (and many other studio monitors)
have the tilt function on both ends of the curve?

 

[svart-hvitt]

Hats off to Genelec for doing that! And the "fazit" in the German review seems to be very positive, in spite of those measurements. I would guess that they could probably improve those two things quite a bit by making the speakers one size larger (and use larger versions of the oval woofers with better power handling and less distortion), and possibly working on the slot design. The Gearslutz user Pentagon (which seems to be very much in the know when it comes to speaker design) gave hints that he thought the 8341 and 8331 were improved designs compared to the 8351 (the 8351 was in some ways a first gen product). Perhaps this is what he had in mind.

The thing is, it seems, a speaker is a set of compromises. One example using the delay variation problem the @Cosmik referred to above. On this issue, Genelec write:

«On a more academic note:
These DSP loudspeakers (like all analog loudspeakers) have an increasing delay towards low frequencies. The loudspeaker delay increases below 400 Hz because the loudspeaker is a minimum- phase high-pass system and all such systems exhibit an increas- ing delay towards low frequencies. The limit of 400 Hz is there because the human auditory system is not very sensitive to the system throughput delay increases at low frequencies while in mid frequencies delay variation as well as absolute delay can be audible. The human auditory system is used to large delays at low frequencies presumably because all physical systems, in- cluding listening rooms, behave like this, and therefore increase in delay at low frequencies is not very audible. The specification reports the delay variation above 400 Hz because there it can be significant for hearing».
Source: https://www.genelec.com/documents/opmans/GLM_system_manual_rev_i.pdf

So it seems to be an issue about which the designer is in the know. Possibly a compromise among many other compromises.

It sort of reminds me of when I touched the vibrating Kiis. The Kii designer may have solved a problem on his computer, just to experience that his problem solving didn’t account for the characteristics of the enclosure material used and the assemble process. In other words, as you solve one problem, another arises.

 

[svart-hvitt]

Isn’t it that most models of Genelecs (and many other studio monitors)
have the tilt function on both ends of the curve?

You can manually manipulate the frequency response as you wish using the GLM software. You can let the computer do all of the the job. You can add some averaging for a tilt. Or you can bypass the room software altogether by a mouse click to compare with and without filter.

 

[oivavoi]

The thing is, it seems, a speaker is a set of compromises. One example using the delay variation problem the @Cosmik referred to above. On this issue, Genelec write:

«On a more academic note:
These DSP loudspeakers (like all analog loudspeakers) have an increasing delay towards low frequencies. The loudspeaker delay increases below 400 Hz because the loudspeaker is a minimum- phase high-pass system and all such systems exhibit an increas- ing delay towards low frequencies. The limit of 400 Hz is there because the human auditory system is not very sensitive to the system throughput delay increases at low frequencies while in mid frequencies delay variation as well as absolute delay can be audible. The human auditory system is used to large delays at low frequencies presumably because all physical systems, in- cluding listening rooms, behave like this, and therefore increase in delay at low frequencies is not very audible. The specification reports the delay variation above 400 Hz because there it can be significant for hearing».
Source: https://www.genelec.com/documents/opmans/GLM_system_manual_rev_i.pdf

So it seems to be an issue about which the designer is in the know. Possibly a compromise among many other compromises.

It sort of reminds me of when I touched the vibrating Kiis. The Kii designer may have solved a problem on his computer, just to experience that his problem solving didn’t account for the characteristics of the enclosure material used and the assemble process. In other words, as you solve one problem, another arises.

True. I do think that for a given price point, a given size and certainly a given anount of amplifier power, ported designs may often be the least bad option, in spite of the group delay at lower frequencies. With increasing availability of amplifier power and increasing cabinet volume, there might be a point where the equation changes.

As the ancient Chinese saying goes: "There are no perfect speakers, only more or less imperfect ones"!

 

[svart-hvitt]

True. I do think that for a given price point, a given size and certainly a given anount of amplifier power, ported designs may often be the least bad option, in spite of the group delay at lower frequencies. With increasing availability of amplifier power and increasing cabinet volume, there might be a point where the equation changes.

As the ancient Chinese saying goes: "There are no perfect speakers, only more or less imperfect ones"!

Still, the perceived difference between 8351a and Kii Three in my room was so little (different dispersion, heavier, more present bass in 8351) in daily life I really couldn’t make a strong case for the sound of the one versus the other.

Most of the time, we’re making big issues out of peanuts.

Speakers are to be used, primarily..., not discussed...if you see my point...

 

[oivavoi]

Still, the perceived difference between 8351a and Kii Three in my room was so little (different dispersion, heavier, more present bass in 8351) in daily life I really couldn’t make a strong case for the sound of the one versus the other.

Most of the time, we’re making big issues out of peanuts.

Speakers are to be used, primarily..., not discussed...if you see my point...

I agreee. Modern well-designed loudspeakers, which don't number in enormous numbers but still make out a handy little bunch, tend to sound fairly similar.

I find that dispersion type and loudspeaker type - together with size, bass extension and dynamics - makes the biggest difference. Omnis sound very different from horns and/or electrostats, with box speakers somewhere in the middle between those extremes.

 

[svart-hvitt]

I agreee. Modern well-designed loudspeakers, which don't number in enormous numbers but still make out a handy little bunch, tend to sound fairly similar.

I find that dispersion type and loudspeaker type - together with size, bass extension and dynamics - makes the biggest difference. Omnis sound very different from horns and/or electrostats, with box speakers somewhere in the middle between those extremes.

On omnis, electrostats and other «exotic» designs. At least, then we can know that the production process never involved their «signature» when the music was made. That may be of importance to some hifi wise.

Given your financial interest in omnis - heavily exposed in the omni speaker futures market as you are - did you read Watkinson’s article series at Broadcastbridge. 15 articles, and counting, till now. Maybe food for its own dedicated thread? FWIW, he posts many things that are highly critical of Genelec’s design choices as well.

 

[oivavoi]

On omnis, electrostats and other «exotic» designs. At least, then we can know that the production process never involved their «signature» when the music was made. That may be of importance to some hifi wise.

Given your financial interest in omnis - heavily exposed in the omni speaker futures market as you are - did you read Watkinson’s article series at Broadcastbridge. 15 articles, and counting, till now. Maybe food for its own dedicated thread? FWIW, he posts many things that are highly critical of Genelec’s design choices as well.

Hehe - yeah; I'm heavily exposed to the omni futures!

I read some of them. The rest are put on my reading list. Most excellent stuff.

 

[Cosmik]

The thing is, it seems, a speaker is a set of compromises. One example using the delay variation problem the @Cosmik referred to above. On this issue, Genelec write:

«On a more academic note:
These DSP loudspeakers (like all analog loudspeakers) have an increasing delay towards low frequencies. The loudspeaker delay increases below 400 Hz because the loudspeaker is a minimum- phase high-pass system and all such systems exhibit an increas- ing delay towards low frequencies. The limit of 400 Hz is there because the human auditory system is not very sensitive to the system throughput delay increases at low frequencies while in mid frequencies delay variation as well as absolute delay can be audible. The human auditory system is used to large delays at low frequencies presumably because all physical systems, in- cluding listening rooms, behave like this, and therefore increase in delay at low frequencies is not very audible. The specification reports the delay variation above 400 Hz because there it can be significant for hearing».
Source: https://www.genelec.com/documents/opmans/GLM_system_manual_rev_i.pdf

So it seems to be an issue about which the designer is in the know. Possibly a compromise among many other compromises.

It sort of reminds me of when I touched the vibrating Kiis. The Kii designer may have solved a problem on his computer, just to experience that his problem solving didn’t account for the characteristics of the enclosure material used and the assemble process. In other words, as you solve one problem, another arises.

But the phase and timing can be brought into line with a sealed speaker using DSP - the 'natural' characteristics of the transducer and box can be corrected. This, however, requires some latency that would be unacceptable in many monitoring applications but which would be perfectly fine in domestic audio. The Kii, apparently, has a low latency mode for monitoring.

 

[Cosmik]

I think that the Genelec blurb about flattening the in-room response is in complete contradiction to what was being recommended by Dr. Toole in this thread earlier (and my rants on many occasions in other threads!).

Once GLM has served you a flat in-room frequency response on a silver plate, the result might be brighter than you like. While a flat frequency response is necessary as a reference, it may not be perceived as the best option with all types of content and environments, particularly when working long hours and monitoring above 80 dB SPL.

There you have it: the speaker is being set up wrongly (in the opinion of some of us) yet being used as a "reference" in the recording industry. I do wonder if this is responsible for some of the recordings over the years that I have heard that are mysteriously unsatisfying at the top end, with the engineers compensating for the over-bright sound (for as long as they can bear to listen to the 'reference setting') by shaving off the top end.

And after they've had enough, the 'science' is overridden with some ad hoc arbitrary tweaks that may make the sound more bearable:

I therefore typically roll off gently by around 3 dB above 10 kHz, but that's a question of personal taste, and may be influenced by room and listening distance also. Anyway, it's easy to add such manual trimming in GLM, once the response has been auto-calibrated to flat, so that's what I generally do.

Clearly they are confused by the awfulness of the sound of their own automated 'room correction' system, but they continue to sell it it.

 

[Blumlein 88]

You won’t find anything in their material on SS vs DS. They just talk about the frequency response, not the measurement method

Why not reach out to Genelec in email. Point them to this discussion. Perhaps they'll elaborate on the SS vs DS issue.

 

[Floyd Toole]

I guess Toole was himself victim to «circle of confusion» bacause Genelec use DS - which is supoosed to be flat - and not SS in their room compensation DSP. That’s what happens when you base a comment on general knowledge and not knowledge on a specific matter or product.

I attach a file that ought to settle this matter. Genelec has explained it all, and it is in my book.

QED, I hope!

 

[oivavoi]

I attach a file that ought to settle this matter. Genelec has explained it all, and it is in my book.

QED, I hope!

This kind of illuminating posts is what we get when someone like dr. Toole contributes to the forum. Very thorough and very interesting. Thanks!

 

[Purité Audio]

Thank you for the clarification,
Keith

 

[Guermantes]

I attach a file that ought to settle this matter. Genelec has explained it all, and it is in my book.

QED, I hope!

Yes, indeed. Thank you for such a great summary. If it is the standards at fault, then I hope your work among others will eventually bring about some changes. Unfortunately in some industries we have a responsibility to adhere to standards, even if they are wrong.

And to this point in the PDF:

Consequently, Genelec uses broad “tone control” like spectral tilts and undulations rather than
the high resolution “room EQ” schemes that are (incorrectly) promoted by some other
providers. They depart from this only at low frequencies, where individual room modes need
attenuation. All of this is sensible.
​

This is precisely what I am seeing in the GLM EQ curve (blue) for my room:

 

[svart-hvitt]

I think that the Genelec blurb about flattening the in-room response is in complete contradiction to what was being recommended by Dr. Toole in this thread earlier (and my rants on many occasions in other threads!).

There you have it: the speaker is being set up wrongly (in the opinion of some of us) yet being used as a "reference" in the recording industry. I do wonder if this is responsible for some of the recordings over the years that I have heard that are mysteriously unsatisfying at the top end, with the engineers compensating for the over-bright sound (for as long as they can bear to listen to the 'reference setting') by shaving off the top end.

And after they've had enough, the 'science' is overridden with some ad hoc arbitrary tweaks that may make the sound more bearable:


Clearly they are confused by the awfulness of the sound of their own automated 'room correction' system, but they continue to sell it it.

@Cosmik , I am a bit pressed on time, and I am not quite sure what you mean. Do you mean recordings are sounding too bright or too "dark"? The reason I ask is so many people complain about digital "brightness" and such.

 

[Cosmik]

@Cosmik , I am a bit pressed on time, and I am not quite sure what you mean. Do you mean recordings are sounding too bright or too "dark"? The reason I ask is so many people complain about digital "brightness" and such.

I think that recordings played at home would sound not bright enough if the recording engineer had compensated for over-bright sound in the studio. @Floyd Toole 's comment attachment suggests this also.

 

[Thomas Lund]

This is a highly relevant discussion. Without standardised anchoring, content creation would be left to self reference, allowing time to render perfectly good recordings unlistenable for no good reason.

Ilpo Martikainen’s remarkable professional life was all about improving monitor-anchoring step by step. Even from the earliest models 40 years ago, he included compensation switches for in-situ boundary loading. Having had the privilege of working with Ilpo, I also know how much he appreciated discussions with Floyd Toole back at a time when knowledge about such phenomena was less common.

Making a room contribute as part of a predictable sound-mirror is far from trivial, and it involves balancing a number of objective and subjective factors. One of the goals were discussed here, namely to prevent a precision monitor from exhibiting a perceived frequency response tolerance of +-20 dB outside an anechoic room. The red and green GLM curves are estimates of the perceived direct sound frequency response, after measurements performed at one or more locations, before and after compensation.

From a physiological point of view, one should distinguish between frequencies below and above around 700 Hz. A palette of factors are taken into account when GLM resolves what to compensate and what not, but only minor adjustments are normally suggested at higher frequencies. The program is furthermore designed and updated based on research and data from professional applications, which may be different from home requirements. For instance, what a listener “prefers” doesn’t really matter; and users sit or stand at one defined location.

It would be unreasonable to require a sound-mirror to be coloured, as this would promote the opposite result, and chance-translation to other playback conditions. However, pro users listen for long hours and a flat frequency response promotes certain types of listener fatigue. That’s one reason professionals tend to listen with a gently rolled-off HF response. For instance, GLM enables easy switching between in-situ tilted and flat frequency responses. A 3 dB roll-off halves the HF energy received, i.e. enabling double the listening time before that factor influences acuity adversely.

A flat, predictable in-room frequency response point is key in reference monitoring. Further tuning is down to physiology, bridging previous experience or hedonism.

 

[amirm]

Warm welcome to the forum Thomas. Thanks for your contributions. I hope we hear more about you in the future about Genelec products. Keith Yates is a personal friend and he always speaks very highly of your products. I have personally owned Genelec gear for many years but alas, it is the older series (circa year 2000).

 

[oivavoi]

This is a highly relevant discussion. Without standardised anchoring, content creation would be left to self reference, allowing time to render perfectly good recordings unlistenable for no good reason.

Ilpo Martikainen’s remarkable professional life was all about improving monitor-anchoring step by step. Even from the earliest models 40 years ago, he included compensation switches for in-situ boundary loading. Having had the privilege of working with Ilpo, I also know how much he appreciated discussions with Floyd Toole back at a time when knowledge about such phenomena was less common.

Making a room contribute as part of a predictable sound-mirror is far from trivial, and it involves balancing a number of objective and subjective factors. One of the goals were discussed here, namely to prevent a precision monitor from exhibiting a perceived frequency response tolerance of +-20 dB outside an anechoic room. The red and green GLM curves are estimates of the perceived direct sound frequency response, after measurements performed at one or more locations, before and after compensation.

From a physiological point of view, one should distinguish between frequencies below and above around 700 Hz. A palette of factors are taken into account when GLM resolves what to compensate and what not, but only minor adjustments are normally suggested at higher frequencies. The program is furthermore designed and updated based on research and data from professional applications, which may be different from home requirements. For instance, what a listener “prefers” doesn’t really matter; and users sit or stand at one defined location.

It would be unreasonable to require a sound-mirror to be coloured, as this would promote the opposite result, and chance-translation to other playback conditions. However, pro users listen for long hours and a flat frequency response promotes certain types of listener fatigue. That’s one reason professionals tend to listen with a gently rolled-off HF response. For instance, GLM enables easy switching between in-situ tilted and flat frequency responses. A 3 dB roll-off halves the HF energy received, i.e. enabling double the listening time before that factor influences acuity adversely.

A flat, predictable in-room frequency response point is key in reference monitoring. Further tuning is down to physiology, bridging previous experience or hedonism.

Warm welcome to the forum, Thomas! It's a huge asset to the forum to have experts like yourself contributing here!