JBL M2 Reference Master Monitor Review

[tomtoo]

Do you have a dog picture for this BIG DOG? LOL

View attachment 149448

 

[tuga]

The upper-midrange and treble look shelved up by some 3-5dB and there’s something very weird happening below 500Hz.
Wasn’t this supposed to be le nec plus ultra?

 

[q3cpma]

@hardisj Check Voice Coil magazine. All compression drivers have elevated HD2 compared to rest of the HD spectrum.

Indeed, GGNTKT (using a Celestion CD driver) claimed the same here.

 

[tuga]

Well except that this nails flat DI from 800 to 8000hz in a way that not even Genelec or the D&D 8c do.

Which matters little in a studio room where sidewalls are treated...

The power of marketing

 

[tuga]

I don't know. In terms of controlled directivity over a big range, this may be the best we've seen so far. Also, we have to consider dynamics as part of the equation. These speakers will likely do almost 130dB with subs helping the low end.

Could the waveguide be masking some serious issues?

 

[tuga]

The distortion?

The D&D is a sealed bass 3-way, probably less in an average-sized studio?

 

[Jim Matthews]

View attachment 149454

Why is your horse wearing a collar?

 

[nerdoldnerdith]

It only needs to output 105 dB at the listening position to reach THX reference. Which means the Dutch and Dutch 8C is fine up to 4 meters away, sure you probably need the JBL M2 at longer distances but the D&D is more than capable of reference level too. At decent distances.

That just isn't true unfortunately. The cardioid design of the 8C's midrange makes it inefficient, and it has to be driven pretty hard to reach the same SPL as it would play without the vents. Dutch&Dutch specifies a max SPL of 106dB, which is only reference at a little over a meter. This limitation is the speaker's main weakness.

 

[amirm]

I'm out of the loop, why are links to Erin's site blocked on ASR?

By request from special member(s), the block has been removed.

 

[aac]

I don't think "THX reference" is any good, I think ATSC got it more right with reference level dependent on a room size.
How common are rooms larger than 20000 cubic feet in the US for a home theatre?

 

[nerdoldnerdith]

I don't think "THX reference" is any good, I think ATSC got it more right with reference level dependent on a room size.
How common are rooms larger than 20000 cubic feet in the US for a home theatre?

More common than anywhere else in the world lol

Have you seen our McMansions?

 

[aac]

More common than anywhere else in the world lol

Have you seen our McMansions?

Yes, but looking at places like avsforum I usually don't see dedicated rooms this large.

 

[jtwrace]

How common are rooms larger than 20000 cubic feet in the US for a home theatre?

Very.

 

[Kuba]

By request from special member(s), the block has been removed.

At least some common sense.

 

[PatentLawyer]

I don't think "THX reference" is any good, I think ATSC got it more right with reference level dependent on a room size.
How common are rooms larger than 20000 cubic feet in the US for a home theatre?

And I'll add, more common than you might think. My father's work took (and occasionally still takes, though he's technically retired) him to more real mansions than a Beverley Hills real estate agent would see. One of his observations was how large the rooms that are for "show" would be--drawing rooms, solariums, and yes, theaters. And yet the kitchens (where my family chooses to put a lot of resources into) were usually unimpressive! I guess the uber rich don't cook!

 

[Absolute]

The upper-midrange and treble look shelved up by some 3-5dB and there’s something very weird happening below 500Hz.
Wasn’t this supposed to be le nec plus ultra?

Not really surprising giving the rather variable responses I've seen concerning the D2430k compression driver. It seems the quality control is below par for those drivers resulting in a bit of a hit-and-miss with the factory dsp-settings.
Part of the story could very well be if there's some variances in impedance in the driver relative to the passive filter that acts as both a downpadding and part of the crossover.

A weak spot of the driver is the horse-shoe clad cable connecting the two membranes, it's really vulnerable to movement/vibrations. Any slack in the connection will lead to massive distortion. I experienced differences such as this just by shaking the cabinet a little between measurements;

@hardisj Thank you for the review! I just want to comment on that 5+dB shelving filter in the tweeter that looks intimidating in the EQ settings. This is the result of constant directivity horns, you'll get a steep decline no matter what driver you put in. Here's a non-eq'd comparison of the JBL M2 D2430k driver vs 18sound 4015 Beryllium driver on the M2 horn;

 

[oldsysop]

You can't compare a toy speaker like the D&D to a serious speaker like the JBL M2.
Thanks Erin.

 

[Absolute]

Oh, and I was really curious about one thing concerning the waveguide; how does it measure diagonally? Those knuckles horizontally and vertically pinches in a way that broadens the dispersion in those directions, but what about diagonally?
Can this be shown @hardisj?

 

[Shirazir]

By request from special member(s), the block has been removed.

Much respect. Erin, like you is a valuable member of the community. Good to have you both on here.

 

[Blumlein 88]

Very.

I don't think so.