IK Multimedia iLoud Precision MTM Spinorama

[sarumbear]

Sound on Sound January 2023 issue has a review & test of the new IK Media iLoud Precision MTM active speaker. Full article is behind a paywall, hence I am posting only relevant bits about the effect of MTM configuration. Emphasis is mine.

Diagram [below] illustrates the Precision MTM axial and 30‑degree vertically off‑axis frequency response, and it provides a textbook example of the power of the D’Appolito format to narrow dispersion through the upper midrange, and similarly how the output of the relatively large tweeter dome falls away off‑axis above about 12kHz. Having pointed that out, I’d suggest it’s of more academic interest (no, really) than subjective significance. The D’Appolito midrange suck‑out is significant, however. It’s subjectively noticeable and makes the Precision MTM tonal balance a little variable with head position. Midrange balance dulls appreciably with head movement away from the central axis, which might sound like an issue — but if you’re aware of the effect, it can be factored in to working practices, and the midrange suck‑out probably reduces desk, floor and ceiling reflections in the critical midband.

Diagram [below] looks somewhat of a jumble, but stay with me and I’ll explain. Each curve represents a frequency response captured with the measuring microphone very close to its specific subject. The green curve is the close‑mic response of one of the Precision MTM bass/mid drivers, and the dip at 40Hz reveals the system’s reflex‑port tuning frequency. The red curve, meanwhile, is the port output captured with the mic at the port mouth. Apart from the port output peaking, as expected from the green curve, at 40Hz, the red curve reveals some output from 500Hz and above that really ought not be present. It appears to be midrange energy ‘leaking’ out through the port, but of course it could potentially be ‘crosstalk’ from the forward output of the bass/mid drivers. So in order to check that, the blue curve was generated by leaving the mic at the port mouth but blocking the port itself (with a duster, now you’ve asked). It confirms that at least some of the output revealed in the red curve, especially the peak at 900Hz and above, is port output, because it’s attenuated when the port is blocked. Stopping midrange energy inside a cabinet from making its way out through the port is a significant challenge in two‑way ported speakers. Using an ABR (auxiliary bass radiator) rather than a simple port can be a solution, as can locating the port in the rear panel of the monitor, as is the case with the Precision MTM, where unintended output is made less troublesome, but port output such as displayed by the Precision MTM will potentially contribute to the subjective character of the monitor.

The above chart is also a good example of how stuffing the vent is not the same as converting the enclosure to a closed box, like many on this forum falsely thinks so.

Here is the front & back view of the speaker along with the measuring microphone.

Pros​

• Fine, well‑rounded electro‑acoustic design.
• Great bass.
• Strong stereo imaging.
• X‑Monitor and ARC 3 add some very cool extras.

Cons​

• None.

Summary​

With the Precision MTM, IK Multimedia’s compact iLoud has grown up to become an extremely capable full‑size nearfield monitor. X‑Monitor and ARC 3 add significant extra capability and appeal.

Information​

€2399.98 per pair including VAT.

According to Sound on Sound there are no cons

This is even after the author confirms that "The D’Appolito midrange suck‑out is significant, however. It’s subjectively noticeable and makes the Precision MTM tonal balance a little variable with head position." What do you expect when that "suck-out" is a huge 40dB dip?

Just to remind you that some mute buttons only reduce the level by 20dB. Imagine ten times more reduction than that, right in the vocal range!

 

[Savi]

This is even after the author confirms that "The D’Appolito midrange suck‑out is significant, however. It’s subjectively noticeable and makes the Precision MTM tonal balance a little variable with head position." What do you expect when that "suck-out" is a huge 40dB dip?

Just to remind you that some mute buttons only reduce the level by 20dB. Imagine ten times more reduction than that, right in the vocal range!

It seems pretty obvious that this speaker target is advanced people listening nearfield and on axis and probably with a desk. In this specific use case I think the narrow vertical directivity is more an pro that a con.

 

[sarumbear]

It seems pretty obvious that this speaker target is advanced people listening nearfield and on axis and probably with a desk. In this specific use case I think the narrow vertical directivity is more a pro that a con.

So you think that having to adjust the height of the speakers when you swap seats with your partner who is a few inches shorter or taller than you, or if multiple people work on the same location, or the vocals reduced by more than 10dB when you lay back in your reclining seat to enjoy the track, is a pro?

 

[3125b]

No since it‘s not uniform that directivity is a big problem in any listening setup.

 

[Savi]

So you think that having to adjust the height of the speakers when you swap seats with your partner who is a few inches shorter or taller than you, or if multiple people work on the same location, or the vocals reduced when you lay back in your reclining seat to enjoy the track, is a pro?

I agree. Thats why I mentioned "specific". I expect people buying these kind of speaker knowing that. Maybe I am wrong but I guess its targeting pro working 95% alone nearfield. Adjusting seat height to speaker on axis position before a listening session on someone else working desk is not rocket science. I would be interested in +/- 10° directivity

 

[Berwhale]

So you think that having to adjust the height of the speakers when you swap seats with your partner who is a few inches shorter or taller than you, or if multiple people work on the same location, or the vocals reduced by more than 10dB when you lay back in your reclining seat to enjoy the track, is a pro?

What would the listening distance be for a few inches in height to make the listener 30 degrees off axis?

*edit* iLoud don't mention a preferred listing distance in the manual, but they are quite explicit regarding vertical alignment with your ears...

7. MTM design The MTM (Midwoofer-Tweeter-Midwoofer) design has a very uniform and smooth horizontal dispersion, and a more controlled, narrower vertical one.

This means that:

- ceiling and floor reflections are minimised, especially at mid and high frequencies, basically augmenting the focus the speakers can provide.

- in the same way, reflections from a desk are less problematic (causing less comb-filtering) than with a regular 2-way TM speaker.

This also means that the vertical alignment of the speaker with the listener’s ears is crucial: a bad vertical alignment can cause substantial drops in the mid and high frequencies.

For this reason particular attention must be paid to the positioning of iLoud Precision MTM.

Make sure that no obstacles are present between the monitors and your ears. You should be able to see the speakers completely. The speakers must be positioned on a firm surface or a stand.

Please note that vibration of nearby objects can mask the sound.

7.1 Desktop positioning The center of the tweeter should be positioned approximately at the height of your ears. In case you need to position the speakers in a significant lower or higher position, the monitors should be angled accordingly.

Page 20: https://download.ikmultimedia.com/p...cisionMTM/iLoud_Precision_MTM_User_Manual.pdf

 

[sarumbear]

What would the listening distance be for a few inches in height to make the listener 30 degrees off axis?

Trigonometry Calculator

Around 10 degrees between me and my partner at 1m distance.

 

[sarumbear]

Maybe I am wrong but I guess its targeting pro working 95% alone nearfield.

This is how the manufacturer demonstrates their speakers’ use scenario.

 

[Savi]

This is how the manufacturer demonstrates their speakers’ use scenario.

View attachment 252712

OK. You got me

 

[Berwhale]

This is how the manufacturer demonstrates their speakers’ use scenario.

View attachment 252712

So lets say that's 200cm, you'd have to move your ears 115cm (45 inches) vertically to get 30 degrees off axis.

Trigonometry Calculator

Around 10 degrees between me and my partner at 1m distance.

Is that using the difference between you and your partners height when standing or sitting down? (i'm guessing that its's not the same).

 

[sarumbear]

So lets say that's 200cm, you'd have to move your ears 115cm (45 inches) vertically to get 30 degrees off axis.

That’s to have a 40dB dip, which is like silence! How about an angle at a very audible 6dB dip?

 

[Berwhale]

That’s to have a 40dB dip, which is like silence! How about an angle at a very audible 6dB dip?

The graph you pasted only shows on axis and 30 degrees. One could crudely assume that the relationship between the angle of incidence and the worst case dip in sound pressure is linear, in which case the angle is 4.5 degrees. This corresponds to a 6" difference in height at 2m. Average sitting height to standing height seems to be a little over 0.5, so the height difference between you and your partner would need to be just under 12" (when standing).

Obviously, if the relationship is not linear and you or your partner does not sit in a char with their legs perfectly parallel to the floor, then all bets are off

 

[sarumbear]

This also means that the vertical alignment of the speaker with the listener’s ears is crucial: a bad vertical alignment can cause substantial drops in the mid and high frequencies.

For this reason particular attention must be paid to the positioning of iLoud Precision MTM.

Page 20: https://download.ikmultimedia.com/p...cisionMTM/iLoud_Precision_MTM_User_Manual.pdf

At least they are honest.

 

[sarumbear]

The graph you pasted only shows on axis and 30 degrees. One could crudely assume that the relationship between the angle of incidence and the worst case dip in sound pressure is linear, in which case the angle is 4.5 degrees. This corresponds to a 6" difference in height at 2m. Average sitting height to standing height seems to be a little over 0.5, so the height difference between you and your partner would need to be just under 12" (when standing).

Obviously, if the relationship is not linear and you or your partner does not sit in a char with their legs perfectly parallel to the floor, then all bets are off

I realise that you feel obliged to be an advocate but no speaker with a 40dB dip in the centre of the all important vocal range can be seen as a speaker that is fit for the purpose of critical listening, which this speaker is designed according to the manufacturer.

On axis frequency linearity alone is meaningless in a room. I hoped @amirm’s and Erin’s measurements with Klippel have demonstrated well enough that there is no reason left to debate it.

 

[abdo123]

I like how @sarumbear has become a point source advocate since he upgraded to the KEF in-wall speakers.

Honestly MTM cancelations in the vertical directivity are “Fine”, most speakers in the industry have vertical lobes and we’re not as sensitive to vertical directivity the same way we’re sensitive to horizontal directivity. And if the speaker is designed with the cancelation in mind (Genelec the ones come to mind) it becomes a feature.

 

[Berwhale]

I realise that you feel obliged to be an advocate but no speaker with a 40dB dip in the centre of the all important vocal range can be seen as a speaker that is fit for the purpose of critical listening, which this speaker is designed according to the manufacturer.

On axis frequency linearity alone is meaningless in a room. I hoped @amirm’s and Erin’s measurements with Klippel have demonstrated well enough that there is no reason left to debate it.

It's a 40dB down @1500Hz, 30 degrees off the vertical axis. According to the manufacturer, the Precision MTM is designed to be used very much on (or very close to) the vertical axis. This is clearly stated in the manual (as you have already accepted).

The Precision MTMs are near field monitors. As far as i'm aware, Amir's Klippel results show the estimated in-room response far field listening. I believe that Amir has stated several times that these results are not directly applicable for near field listening. For example in the iLoud MTM review...

IK Multimedia iLoud MTM Review (active monitor)

This is a review and detailed measurements of the IK Multimedia iLoud MTM Monitor (active speaker). I purchased it when it was on sale for US $299 on Amazon. Normal cost is US $350 (each) with the calibration/EQ microphone. Despite being quite narrow and rather small, the iLoud MTM has a...

www.audiosciencereview.com

 

[sarumbear]

I like how @sarumbear has become a point source advocate since he upgraded to the KEF in-wall speakers.

The in-wall KEFs are in my HT, which is almost only used for TV and films. Music listening is in the background as it’s also the living room / kitchen. My music room has a pair of Salon2. This has been clearly explained in my About page.

Honestly MTM cancelations in the vertical directivity are “Fine”, most speakers in the industry have vertical lobes and we’re not as sensitive to vertical directivity the same way we’re sensitive to horizontal directivity.

There’s no such thing as insensitivity to vertical directivity. Any off-axis FR irregularity will affect the FR in the room. Just look at any speaker tested on ASR. Maybe you can show us another speaker that has a 40dB lope, which is “fine”? If you think in the near field that’s not the case, look at the studio picture I posted above: How will the reflection FR from the desk surface will be when there’s a 40dB lope in the FR?

And if the speaker is designed with the cancelation in mind

How, please explain?

(Genelec the ones come to mind) it becomes a feature.

Please explain how you compare this speaker’s off-axis and band limited dip to Genelec One series?

 

[sarumbear]

It's a 40dB down @1500Hz, 30 degrees off the vertical axis. According to the manufacturer, the Precision MTM is designed to be used very much on (or very close to) the vertical axis. This is clearly stated in the manual (as you have already accepted).

What I’m saying are my opinions. Just because the manual explains the limited way the speakers should be used, otherwise the advertised values will not be met, is not acceptable — for me.

I wish you enjoyment from your speakers.

 

[Berwhale]

What I’m saying are my opinions. Just because the manual explains the limited way the speakers should be used, otherwise the advertised values will not be met, is not acceptable — for me.

I wish you enjoyment from your speakers.

Thank you

 

[AnalogSteph]

In order to qualify as a "true" D'Appolito, this speaker would have to be crossed over at about 1 kHz, rather than an already-low 1.9 kHz. That is virtually impossible, but as-is nobody should be surprised by typical MTM issues cropping up (as doumented time and time again by our host's center speaker measurements). Physics speak louder than words or something. At least it's in the vertical, but even that is still somewhat inconvenient.

The smaller iLoud MTM is saved from embarrassment to this degree by having a relatively low XO frequency of 2.1ish kHz (the 3.1 kHz spec must be a typo).

IK Multimedia iLoud MTM Review (active monitor)

This is a review and detailed measurements of the IK Multimedia iLoud MTM Monitor (active speaker). I purchased it when it was on sale for US $299 on Amazon. Normal cost is US $350 (each) with the calibration/EQ microphone. Despite being quite narrow and rather small, the iLoud MTM has a...

www.audiosciencereview.com

As usual, salvaging an MTM is not easily done. The Precision MTM is going to stay a bit of a "head in a vise" type deal. This may be a worthwhile tradeoff for some, as they are clearly not bad speakers otherwise. Aiming for something like a 6"/3"/1" (or 2x 5" / 3" / 1") 3-way might have been the smarter choice, but obviously that would have been a different design altogether...