JBL Master Reference Monitor

[Mostlydiy]

In my view, this really is a game changer for JBL, no matter what market (home or pro) and I say that after spending a couple of hours with them at Northridge. I can only wait to see what JBL can do with DSP applied to their current SOTA speakers like E2 and K2.

Two down, a few more to go...

Keep up the good work

/Mostly

[ivica]

Hi Don,

Mr. Widget's comments, quoted in the above post, coincide with the initial release of the system, when there was no feedback from people that had heard the M2's. Since then, there has been considerable feedback, and I believe it is a fair assessment to state that the M2 is a stunning performer in both home and studio environments.

Besides maximum output, one of the defining characteristics of many studio monitors has been controlled directivity. The intent is to maximize direct sound at the listening position to minimize the destructive interference of reflected sound. In a home environment, this can result in a very narrow sweet spot and a rather small virtual sound-stage. Thus leading to one of the major criticisms that studio monitors are sometimes deficient for home use.

Interestingly, but "old school" 43xx series monitors , owing to lenses used, had quite large horizontal dispersion...

In contrast, the M2's tackle the destructive interference issue in a manner that is 180 degrees opposite in approach. Instead of trying to limit sound dispersion and decrease the amount of sonic energy that will reflect off of a boundary, the M2' are designed for a very wide 120 degree dispersion at all frequencies.

The intent is to provide as uniform and wide a sound-field as possible so that destructive interference affects a smaller overall proportion of the overall sound-field.

for me, really unexpected was M2, quite large vertical dispersion (120deg) too , and I can imagine that the floor reflection can produce some troubles.
Some rumors emphasize that the need for sub-woofer is something well-come too.
May be one day each loudspeaker would be offered separately with its own DSP and power amplifier, so the customer can decide what would be his need, but in such situations, we are not talking about the loudspeaker box, but a kind of audio reproduction system.




regards
Ivica

[Don McRitchie]

Interestingly, but "old school" 43xx series monitors , owing to lenses used, had quite large horizontal dispersion...

Hi Ivica,

The lens used on all of the 43xx series was actually quite narrow in dispersion with an 80 x 40 coverage and I suspect that it would not be as uniform within its range as the M2 waveguide is within its range.

Some rumors emphasize that the need for sub-woofer is something well-come too

For home theatre - sure. For music - not that I can tell. The M2 has a more extended bass response than E2 which is not what I would consider a bass shy speaker.

May be one day each loudspeaker would be offered separately with its own DSP and power amplifier, so the customer can decide what would be his need, but in such situations, we are not talking about the loudspeaker box, but a kind of audio reproduction system.

The transition to that day is well underway. Speaker design has evolved to the point where a systems approach forms the basic design principle. The primary design concern is the sound that reaches the ear that not the sound that leaves a box. This means that transducers, crossovers, enclosures, amplification, DSP, room response and psycho acoustics are all wrapped up into a holistic design process. Physical integration is just the next step that is already widely in place in the pro sound world.

[Valentin]

For home theatre - sure. For music - not that I can tell. The M2 has a more extended bass response than E2 which is not what I would consider a bass shy speaker.

I agree
the M2 is not a bass shy speaker by any meens and if you disire some more you can always use DSP who did that coment does not own a pair and adaped to the room


Home Theater alway needs a Sub it the way it was intended

[audiomagnate]

Even if they went down to DC an extra sub or two helps tame the nodes and the antinodes.

[Dave_72]

Mr. Widget's comments, quoted in the above post, coincide with the initial release of the system, when there was no feedback from people that had heard the M2's. Since then, there has been considerable feedback, and I believe it is a fair assessment to state that the M2 is a stunning performer in both home and studio environments.

Besides maximum output, one of the defining characteristics of many studio monitors has been controlled directivity. The intent is to maximize direct sound at the listening position to minimize the destructive interference of reflected sound. In a home environment, this can result in a very narrow sweet spot and a rather small virtual soundstage. Thus leading to one of the major criticisms that studio monitors are sometimes deficient for home use.

In contrast, the M2's tackle the destructive interference issue in a manner that is 180 degrees opposite in approach. Instead of trying to limit sound dispersion and decrease the amount of sonic energy that will reflect off of a boundary, the M2' are designed for a very wide 120 degree dispersion at all frequencies.

The intent is to provide as uniform and wide a soundfield as possible so that destructive interference affects a smaller overall proportion of the overall soundfield. This combined with DSP, results in an in-room response that cannot be matched by any other current JBL loudspeaker that does not use DSP. In a home environment, these speakers have imaging that is as good as any speaker I have ever heard - they can truly just disappear. This trait is combined with dynamics and neutrality that very few speakers can match.

In my view, this really is a game changer for JBL, no matter what market (home or pro) and I say that after spending a couple of hours with them at Northridge. I can only wait to see what JBL can do with DSP applied to their current SOTA speakers like E2 and K2.

Did you hear them with Levinson or Crown amps. Or both.

[Ian Mackenzie]

"Originally Posted by Don McRitchie View Post

In contrast, the M2's tackle the destructive interference issue in a manner that is 180 degrees opposite in approach. Instead of trying to limit sound dispersion and decrease the amount of sonic energy that will reflect off of a boundary, the M2' are designed for a very wide 120 degree dispersion at all frequencies.

The intent is to provide as uniform and wide a sound-field as possible so that destructive interference affects a smaller overall proportion of the overall sound-field. "

Hi Don,

Can you walk us through the above as it seems to defy conventional wisdom.

[grumpy]

If you focus on what was meant by 'destructive' it's possible to see the intent as I -think- I understand it...
but sure, a walkthrough would be great

[Fort Knox]

If you focus on what was meant by 'destructive' it's possible to see the intent as I -think- I understand it...
but sure, a walkthrough would be great

I think "destructive" refers to a statement I once made "the smaller the room..The bigger the EQ.."
for if there's no room (outdoors) then there's no "destructive" at all

[Don McRitchie]

Did you hear them with Levinson or Crown amps. Or both.

Crowns only. I can't attribute any sonic characteristics to the amps either positive or negative since I could not isolate their contribution to the overall sound. Certainly the DSP features of the Crowns played a significant role in the overall response. Interestingly, the Crowns were located in a rack placed just outside of the room in a hallway. Others have pointed out the potential for fan noise in the Crowns and I'm guessing that's why they were out of the room. I couldn't hear any fan noise at idle when I walked out of the room, but I have no idea on the degree of audibility when they're working hard.

[Don McRitchie]

Hi Don,

Can you walk us through the above as it seems to defy conventional wisdom.

Hi Ian,

I’ll try. I’m the first to admit that my background in audio is not technical so I could easily be misconstruing what has been relayed to me. However the following is my understanding by way of an example.

Assume a 4m x 5m area is marked out in free space. Place two M2’s at one end of this area and measure the response at multiple points within the area. Now take two somewhat directional JBL monitors, like the 70's four-ways, and measure the response at multiple points within the area. They will be significantly less uniform than the M2's.

The M2's have the most uniform frequency response across the widest dispersion of any horn based JBL speaker. In particular, the LF directivity at the cross-over is a near exact match to the horn which maintains its wide directivity at a near constant throughout its range. In contrast, the classic four-ways have a near omni directional LF, a somewhat directional mid bass, a very directional midrange and a wide dispersion HF.

Now add room boundaries around the 4m x 5m area, and again measure the response across the room for both speakers. The response of both will suffer due to destructive interference. However, the four-ways will have the poorer overall room response given their significantly lower starting point in overall soundfield uniformity. JBL asserts that this greater overall room uniformity results in superior overall sound. This is JBLPro’s current design philosophy for monitors that continues on the LSR (Linear Spatial Response) approach that has been in use for over a decade.

[grumpy]

"Destructive" being that which contributes to a non-uniform room response,
with uneven spatial characteristics over frequency being part of the set of
addressed issues in this design. Reflections happen Thanks Don.

[Dave_72]

Crowns only. I can't attribute any sonic characteristics to the amps either positive or negative since I could not isolate their contribution to the overall sound. Certainly the DSP features of the Crowns played a significant role in the overall response. Interestingly, the Crowns were located in a rack placed just outside of the room in a hallway. Others have pointed out the potential for fan noise in the Crowns and I'm guessing that's why they were out of the room. I couldn't hear any fan noise at idle when I walked out of the room, but I have no idea on the degree of audibility when they're working hard.

Ok, cool. Thanks for the report and the review. Sounds good.

[Mctwins]

Even if they went down to DC an extra sub or two helps tame the nodes and the antinodes.

Hallo! Could you please explain here?

[ivica]

Hi Ian,

I’ll try. I’m the first to admit that my background in audio is not technical so I could easily be misconstruing what has been relayed to me. However the following is my understanding by way of an example.

Assume a 4m x 5m area is marked out in free space. Place two M2’s at one end of this area and measure the response at multiple points within the area. Now take two somewhat directional JBL monitors, like the 70's four-ways, and measure the response at multiple points within the area. They will be significantly less uniform than the M2's.

The M2's have the most uniform frequency response across the widest dispersion of any horn based JBL speaker. In particular, the LF directivity at the cross-over is a near exact match to the horn which maintains its wide directivity at a near constant throughout its range. In contrast, the classic four-ways have a near omni directional LF, a somewhat directional mid bass, a very directional midrange and a wide dispersion HF.

Now add room boundaries around the 4m x 5m area, and again measure the response across the room for both speakers. The response of both will suffer due to destructive interference. However, the four-ways will have the poorer overall room response given their significantly lower starting point in overall soundfield uniformity. JBL asserts that this greater overall room uniformity results in superior overall sound. This is JBLPro’s current design philosophy for monitors that continues on the LSR (Linear Spatial Response) approach that has been in use for over a decade.

Hi Don,

1.
it would be nice if You can support us about the measurements that would be a kind of confirmation of Yours words about the M2 horizontal and vertical dispersion characteristics. So it can be easy to compare with the "old school" models.
2.
As used 15-inc bass transducer (2216) I can guess that it behaves (in the polar response) as almost all the other JBL 15" LF ribbed-cone transducers, so starts "beaming" over 1kHz.
3.
I can expect a kind of interference between LH and HF section in VERTICAL plane as the LH and HF drivers are spaced about 17-inch (43cm) center-to-center. Such "problem" has been analyzed in some JBL papers too. Owing to the DSP supported drivers drive the horn length can be compensated, but even then the problem would persist.

Regards
ivica