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JBL M2 Reference Master Monitor Review

fredoamigo

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Is the 'disappearing as easily' comment about the 4349 based on personal experience or generally held expectations about horn/waveguide speakers?

I only ask because every other HDI horn/waveguide with which I have extensive experience (JBL 308p, 708p, M2) completely vanishes. It's like the speaker isn't even there.

You are obviously correct that room interaction also matters, but what you're describing would make the 4349 an outlier among it's relatives.
I did not say that they do not disappear from the listening but that it was more difficult than a direct radiator and they are much more dependent on the recording and mixing on this point there ... but it is true that I also bass a lot of my daily listening with the 4367 which do not really have the same horns as the M2 and 4349 ;
 

dasdoing

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I can't imagine this monster needing aditional sub(s). with room gain I doubt it can't be EQed flat to 20Hz without even compromising SPL. sub(s) might be needed for the Harman bass curve?
 

Bugal1998

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I did not say that they do not disappear from the listening but that it was more difficult than a direct radiator and they are much more dependent on the recording and mixing on this point there ... but it is true that I also bass a lot of my daily listening with the 4367 which do not really have the same horns as the M2 and 4349 ;
Ah... got it. I could see how unlike some direct radiators with very wide dispersion that can more easily create a halo of diffuse sound, the HDI waveguides may be a bit more room and recording dependent.
 

Bugal1998

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I can't imagine this monster needing aditional sub(s). with room gain I doubt it can't be EQed flat to 20Hz without even compromising SPL. sub(s) might be needed for the Harman bass curve?

I'm sure it depends on the size of the room, but I was able to EQ the M2 without subs to the Harman bass curve with no issue
 

Absolute

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It's very room dependent because the M2's port is tuned around 27 hz. There's two settings in the Crowns for bass extension, one that aims for extended bass by boosting about 4 dB centered around 21 hz or so. In my room I don't use that low-end boost and still have to cut the sub 30 hz by a considerable amount due to excessive room gain, but in larger rooms with less room gain there will be a steep cut-off below the port tuning and the boost will only result in more flapping of the woofer.

So "needing subs" is relative. In any case, the 2216 woofer is protected by extremely stiff suspension and will likely explode before bottoming out, making it perfectly suitable for PA and loudness, but not so perfect for hifi and accuracy due to modulation because of quickly stiffening suspension with increasing excursion.
If you decide that it's better to go more complicated with more ways, then off-loading the main effort to subs will allow for better suited mid-range drivers - and likely positive gains in sound quality because of it.
 

Bugal1998

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It's very room dependent because the M2's port is tuned around 27 hz. There's two settings in the Crowns for bass extension, one that aims for extended bass by boosting about 4 dB centered around 21 hz or so. In my room I don't use that low-end boost and still have to cut the sub 30 hz by a considerable amount due to excessive room gain, but in larger rooms with less room gain there will be a steep cut-off below the port tuning and the boost will only result in more flapping of the woofer.

So "needing subs" is relative. In any case, the 2216 woofer is protected by extremely stiff suspension and will likely explode before bottoming out, making it perfectly suitable for PA and loudness, but not so perfect for hifi and accuracy due to modulation because of quickly stiffening suspension with increasing excursion.
If you decide that it's better to go more complicated with more ways, then off-loading the main effort to subs will allow for better suited mid-range drivers - and likely positive gains in sound quality because of it.

The differential drive motor also has a self-braking mechanism, so it's very unlikely to be driven too far mechnically even if suspension had greater compliance.

I also suspect the risk of modulation distortion ever becoming audible is minimal in a domestic use case (smallish room with listening distances under 5M) for three reasons:

1) The excursion of the cone is actually decreasing as it gets closer to the port tuning frequency
2) Output would likely be very (dangerously?) loud before it would become an issue
3) The inner portion of the cone decouples from the outer portion attached to the surround as frequency increases, so midrange frequencies may not be as modulated by suspension stiffness due to low-frequency excursions.

All bets are off if the cone excursions aren't controlled below the port tuning frequency.

I've tried to hear an improvement in mid-range quality when loudly playing deep bass-heavy music with and without subs, and I can't say I've ever been able to hear a clear improvement. When I've done the same exercise with the 305p the improvement is revelatory.

Edit: Despite the commentary above, I still get peace of mind from running subs

Edit: typo (breaking to braking)... I hope the 2216 isn't self-breaking! :facepalm:
 
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Absolute

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For most people the technical limitations mentioned will be purely academical. For some people there might be too many compromises in a full-range high capacity large two-way regardless of how well executed the design is.

I'm not lucky enough to find the capacity at any range lacking.
 

Bugal1998

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For most people the technical limitations mentioned will be purely academical. For some people there might be too many compromises in a full-range high capacity large two-way regardless of how well executed the design is.

I'm not lucky enough to find the capacity at any range lacking.
Same here (though I'd say I'm lucky enough to not find it lacking)... As you've well articulated here and in other threads, the trade-offs are real, it's just a question of audibility in the specific application and for the specific listener.

One should always listen and decide for themselves whenever possible. And certainly don't take my personal satisfaction with any speaker as worth anything more than a random opinion on the internet (which is all too often worth less than nothing!).
 

Absolute

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Same here (though I'd say I'm lucky enough to not find it lacking)... As you've well articulated here and in other threads, the trade-offs are real, it's just a question of audibility in the specific application and for the specific listener.

One should always listen and decide for themselves whenever possible. And certainly don't take my personal satisfaction with any speaker as worth anything more than a random opinion on the internet (which is all too often worth less than nothing!).
I'm not lucky enough in the sense that I don't have a huge dedicated listening room where the capacity in the lower range is found lacking. I wish I had ;)
 

FaFaFa

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Yes, I've had the mother of all "holy shit" moments when the M2 preset in the Crown cdi 4/1200 failed to load properly and the Crown sent full power of white noise to the woofer in one speaker.
It took me a second or two to shut it down, but my ears was ringing like crazy for hours and my heart was beating heavily for an hour or two before I settled down. I've never been so scared in my entire life, I thought the building was coming down.

These things will kill your ears long before you run into any headroom-issues. Apart from the low-end in a large room, of course.
Is there any way to prevent this? I think I would die of fright and heart attack!
 

Absolute

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Is there any way to prevent this? I think I would die of fright and heart attack!
Yes, disconnect the speaker from the amplifier when you fiddle with the dsp. Audio architect will show the level of input and output in the amplifier, so if there's something wrong you'll see it on the level bars.
 

ThomasGT

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Well it’s not a real CD in the way a TAD 3001, Altec 288 or JBL 475 at all! It’s more like a ring-radiator and not at all happy below 1500 hz but for the output very effective over 10 k Hz. Trying to match up with a 15” is the weak point of the M2 and 4367 that really needs to have a 500 hz crossover point. The M2 is more a measuring exercise than audiophile speaker imo and I have had both M2 and 4367 in my living room.
Why500 Hz? How long the drivsrs break in period?
 

Pearljam5000

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What's the cheapest amplification possible for M2?
The price of the monitors is not so bad @$12K
But with recommend amps it's around $28K
 

Ata

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What power do you need to drive the speaker with, and what is your application (distance/SPL)? This is a very sensitive speaker, at 92db, so unless you need it to go very loud in a very large room, you may be able to use the much less expensive and objectively excellent performing alternatives that have been measured in these forums?
 

Absolute

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What's the cheapest amplification possible for M2?
The price of the monitors is not so bad @$12K
But with recommend amps it's around $28K
My suggestion would be Icepower AS1200 for bass and some low-noise Topping for treble. You don't need many watts for treble, but you need power for the bass.
Should be possible to achieve perfect amplification for below 1k.
 

Pearljam5000

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Genelec 8361 are $10K
M2 are $12K
So they seem like bargain considering their size
But the amps and DSP matching makes it complicated
 

Pulkass

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You can build such loudspeakers DIY, spending 2k and make them more braced, more mass inside, more :drivers decoupled. 12.ooo dollars is a rip off. Make a frontal baffle 2 inches with gum and metal dampening. You won't regret it.
What's the cheapest amplification possible for M2?
The price of the monitors is not so bad @$12K
But with recommend amps it's around $28K
 
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