GGNTKT Model M1

[Maiky76]

Thanks a lot!
With score you mean the preference score (6.45)? Pretty neat, isn't it?

As with your EQ numbers: +/- 1 db is within the drift of the drivers, so you are trying so compensate the variations of the parts. This can't be done ex factory, since every single speaker had to be calibrated. Well, it could be done, but would need half a day to get that precision right, which would drive costs probably + 20%. We might have a look at the PEQ at 1883 and 2917 Hz though ;-)

But it makes more sense to calibrate at the listeners place via room EQ (also build in). This way you will correct everything at once.

(I have to check with engineering as for the raw data.)

Hi,

As explained the calculated Predicted Preference Rating, i.e. the score, is only an approximation.
If I you were to publish the raw Spinorama data I could provide you with a more accurate result.
The data should have a resolution of at least 1/20th octave in the 20 - 20kHz range for the 70 curves.
6.45 is very good, but 7.32 after EQ is great, FYI with a similar process I got 7.21 for the JBL M2 that is obviously EQed for flat LW.

With regards to driver to driver tolerance vs. system EQ, only your team can decide but measuring the LW for each unit compared to the average of the production should be a very cost effective way to implement a factory calibration.
The only difficulty may be adjusting the sensitivity of the LF drivers for the cardioid pattern, which should be done within +/-1dB from some simulations I've done but I might be wrong...

 

[kaka89]

What is "LW" stand for?

 

[phoenixdogfan]

What is "LW" stand for?

What is "LW" stand for?

What is "LW" stand for?

Listening Window.

 

[abhijitnath]

For a surround setup, there will (in most rooms) be space behind the surrounds (for the optimal
120 degrees next to mlp). How would the m1s work in such a setting (since they need to be close to a wall)?

 

[Maiky76]

Thanks a lot!
With score you mean the preference score (6.45)? Pretty neat, isn't it?

As with your EQ numbers: +/- 1 db is within the drift of the drivers, so you are trying so compensate the variations of the parts. This can't be done ex factory, since every single speaker had to be calibrated. Well, it could be done, but would need half a day to get that precision right, which would drive costs probably + 20%. We might have a look at the PEQ at 1883 and 2917 Hz though ;-)

But it makes more sense to calibrate at the listeners place via room EQ (also build in). This way you will correct everything at once.

(I have to check with engineering as for the raw data.)

Hi,

I just compiled the data for the monopole setting.
Score 6.45 identical to the cardioid version.

I forgot to mention that the ER calculation for the the NFS seems off so the scores are definitively not accurate.
With the raw set of measurements (70 curves) we can make a correct calculation.
Any chance we can get the raw data to make a better comparison/scoring?

 

[TheHighContemplator]

Any updates?

 

[Da cynics]

Sounds interesting.

https://ggntkt.de/en/model-s1/

 

[BDE]

Indeed!
A depth of 96mm and an on-wall mounting will already cause some issues, however in-wall it is fine. From my perspective the goal should be an in-wall speaker with an asymmetrical horizontal dispersion to mimic an angled speaker and reduce side wall effects.

 

[q3cpma]

Sounds interesting.

https://ggntkt.de/en/model-s1/

Interesting is the word.

 

[roland{at}GGNTKT]

Indeed!
A depth of 96mm and an on-wall mounting will already cause some issues, however in-wall it is fine. From my perspective the goal should be an in-wall speaker with an asymmetrical horizontal dispersion to mimic an angled speaker and reduce side wall effects.

Well, we thought a lot about that.
In home theaters some speakers need a symmetric dispersion (center, surrounds in 7.1) and we wanted a universal speaker that fits all locations. Furthermore these rooms are most likely acoustically treated, so that the horizontal reflections will be absorbed, at least in the HF range. Also as for dedicated multichannel-music content these relflections in the horizontal plane are sometime welcome, as the listening experience benefits – I guess that's a matter of taste.

However we might come up with a solution, that shields the waveguide in one direction (as seen in PA speakers). Unfortunately this will only work in a limited frequency range > 2kHz. I'm not sure if there will be a real benefit.

Feel free to open a new thread for Model S1 so that things are not getting mixed up too much.

 

[detlev24]

[...] There should be some graphs on the website: https://ggntkt.de/en/model-m1/technische-daten/ or as PDF
We will provide the Klippel NFS measurements next month, since there is a new software revision and minor tweaks we want to cover. [...]

Would you mind to add some distortion graphs at different target SPL, as well?

Thank you!

 

[roland{at}GGNTKT]

Would you mind to add some distortion graphs at different target SPL, as well?

Yes, I have pre-processed 80, 90 and 95 dB SPL plots, anything else would need another processing. I adjusted the scale to the same 5% that @amirm is using, so you could easily compare to his plots.

THD @80 dB

THD @90 dB:

THD @95 dB:

Also have a look on what I wrote about THD hearing thresholds and K2, K3 components regarding the compression driver: https://www.audiosciencereview.com/forum/index.php?threads/ggntkt-model-m1.12959/page-5#post-472356

 

[detlev24]

Thank you @roland{at}GGNTKT, this indeed looks well for such a compact and closed design. To be honest, I never had the chance to experience possible benefits of a cardioid design before, but yours [effective >200 Hz, right?] made me curious - based on your standardized measurements.

I, personally, do not compare THD measurements to @amirm's of other loudspeakers, as I would prefer to see the whole magnitude of distortion down to a loudspeaker's lower limit. The 5% cut-off is not meaningful [<300 Hz], due to a much higher tolerance of our hearing in the bass region, as I am sure you are well aware of.

I guess the "dB SPL" state a 1-m-equivalent? I agree that around three targets between roughly 80 - 100 dB SPL would give a good overview of behavior: in most (home) listening scenarios. While I generally would welcome 'CEA-2010' specified measurements to be additionally provided for every loudspeaker, not just mainly for subwoofers; at least a few more SPL targets >100 dB would be required in case of a design that is intended to be "home theatre proof" - or likewise suitable for more demanding types of music or cinema post production. IMHO, that would certainly include every loudspeaker that holds a HF compression driver.

I can understand possible "issues" with releasing graphs at higher scales and/or higher target SPL; at least when people just look at those superficially or do not understand their meaning. However, a wrong impression could probably be mitigated by [education and] marking the graphs in another color >5% THD, maybe with a grey-transparent background, so people could still easily perform their comparisons to amirm's measurements.

In any case, your products really caught my interest and thank you for sharing - especially as a manufacturer!

 

[q3cpma]

Yes, I have pre-processed 80, 90 and 95 dB SPL plots, anything else would need another processing. I adjusted the scale to the same 5% that @amirm is using, so you could easily compare to his plots.

THD @80 dB
View attachment 94509

THD @90 dB:
View attachment 94510

THD @95 dB:View attachment 94511


Also have a look on what I wrote about THD hearing thresholds and K2, K3 components regarding the compression driver: https://www.audiosciencereview.com/forum/index.php?threads/ggntkt-model-m1.12959/page-5#post-472356

Quite good, very similar profile to the 8030C at 96 dB SPL (higher H2 but lower H3 after 100 Hz and going berserk a bit later in the LF). I did expect a bit more in the bass departement, but that's what small sealed enclosures can do.

 

[roland{at}GGNTKT]

Well, one has to take into account, that Model M1 is a small speaker with its 560-inch³ / 9 l internal net volume and doesn't have the support of a reflex port. So it does its SPL purely out of displacement volume and amp power. Also the THD over frequency doesn't tell you whole story, since there is a lot of EQ going on (in our case a dynamic limiter), which can put a lot more load on the drivers than the SPL indicates.

As @detlev24 stated (and I showed in that plot ), the ear is not very sensitive to THD at low frequencies, so you might not be able to detect 20 or 30 % K2 @90 dB <200 Hz. Thats why most limiters are set up to allow 10-20 % in the bass area, because that magnitude indicate that you are driving into non-linear realm (of course limiters can't detect THD, but one has to measure THD over RMS, to define the thresholds).

A better why to show how capable the bass reproduction is, is to plot the max. SPL at a given THD Level. Typically these limits are set to 3 or 10 % in LF (<300 Hz) and 1 or 3 % in HF. As for Model M1 it looks like this:

As you can see Model M1 can deliver almost 95 dB @50 hz within a 10% THD limit. Thats the electrical and mechanical limit, just physics. Also you see a dip 300 - 550 Hz because the drivers in the back do suck SPL in cardioid mode. As for HF the compression driver easily puts up to 115 dB.

To put that in context, here is a plot of the bigger Genelec 8351using the same method:

Looking at the blue 10% line you can see that even a bigger speaker does not necessarily deliver more SPL @50 Hz. So Model M1 has of course its physical limits, but its performs very well within its size and class.

 

[roland{at}GGNTKT]

Just saw another maxSPL with THD limit measurement of the Neumann KH310 which @amirm reviewed... also a closed cabinet und displacement volume (8-inch/20 cm driver) should be similar to Model M1, so are the numbers (92 dB @50 Hz):

 

[q3cpma]

Well, one has to take into account, that Model M1 is a small speaker with its 560-inch³ / 9 l internal net volume and doesn't have the support of a reflex port. So it does its SPL purely out of displacement volume and amp power. Also the THD over frequency doesn't tell you whole story, since there is a lot of EQ going on (in our case a dynamic limiter), which can put a lot more load on the drivers than the SPL indicates.

As @detlev24 stated (and I showed in that plot ), the ear is not very sensitive to THD at low frequencies, so you might not be able to detect 20 or 30 % K2 @90 dB <200 Hz. Thats why most limiters are set up to allow 10-20 % in the bass area, because that magnitude indicate that you are driving into non-linear realm (of course limiters can't detect THD, but one has to measure THD over RMS, to define the thresholds).

A better why to show how capable the bass reproduction is, is to plot the max. SPL at a given THD Level. Typically these limits are set to 3 or 10 % in LF (<300 Hz) and 1 or 3 % in HF. As for Model M1 it looks like this:
View attachment 94547

As you can see Model M1 can deliver almost 95 dB @50 hz within a 10% THD limit. Thats the electrical and mechanical limit, just physics. Also you see a dip 300 - 550 Hz because the drivers in the back do suck SPL in cardioid mode. As for HF the compression driver easily puts up to 115 dB.

To put that in context, here is a plot of the bigger Genelec 8351using the same method:
View attachment 94549

Looking at the blue 10% line you can see that even a bigger speaker does not necessarily deliver more SPL @50 Hz. So Model M1 has of course its physical limits, but its performs very well within its size and class.

Please remember that the 8351A was basically a beta version, the woofers having been completely redesigned after that.

See the 8361A or much cheaper 8350A, for example:

 

[MarsianC#]

I'd love to max SPL measurments for M1 (and all other to come). Or send a M1 to S&R

 

[Chippy]

Just saw another maxSPL with THD limit measurement of the Neumann KH310 which @amirm reviewed... also a closed cabinet und displacement volume (8-inch/20 cm driver) should be similar to Model M1, so are the numbers (92 dB @50 Hz):

Hi Roland,

The measurement shown is done for 1% and 3% THD whereas the M1 was done with 5 and 10%. Someone measured the KH310 also with 3 and 10% THD:

Taken from here: https://www.audiosciencereview.com/...-sam™-studio-monitor-review.11652/post-336120
This looks like the KH310 has some >5dB more below 80Hz when comparing 10% vs 10%?

You said the rear drivers do suck some SPL in cardioid mode, so I guess the measurement was done in cardioid mode. Do you also have one done in not cardioid mode? Would be interesting to see

Rock on
Chippy

 

[roland{at}GGNTKT]

I'd love to max SPL measurments for M1 (and all other to come). Or send a M1 to S&R

There already is, three posts above.
Model S1 was already at Anselm and Michaels place (Anselm does the S&R mesurements)

This looks like the KH310 has some >5dB more below 80Hz when comparing 10% vs 10%?

Looking @50 Hz I see both speakers doing about 95 dB maxSPL. So I would say, they are basically in the same league. This is remarkable because Model M1 has only about half the internal volume that KH310 has (9 vs. 16l), so we need al lot more EQ to deliver similar output.

You said the rear drivers do suck some SPL in cardioid mode, so I guess the measurement was done in cardioid mode. Do you also have one done in not cardioid mode? Would be interesting to see

Yes, as I stated before this measurement was done in cardioid-mode. To compare with monopoly-mode you just have to add +6 dB, because 3x drivers are playing in parallel. See post #148.