Neumann KH 310A Review (Powered Monitor)

[napilopez]

For those wondering, here's the comparison between Neumann's data on its website(blue) and Amir's (Red). The differences are immaterial, especially if the bass is caused by termperature. This is the point of flatness where going any flatter doesn't really matter imo.

Fantastic speaker... great performance.

Final nail in the coffin for preference scores, for me. This gets a 6.2, top 5 speaker... fantastic, you'd think. That's only 0.03 ahead of a 4" monitor, 0.11 behind a 5" monitor, both of which roll off an octave higher, with the next third of an octave heavily degraded by distortion.

If the score is so heavily weighted towards directivity over response, rename it to something else. Time to go back to "Olive score" or "directivity rating" - preference score sounds far too empirical and definitive for a measure with such enormous flaws

Would just like to point out directivity has nothing to do with the score, at least not directly. In fact, one of the potential flaws in the original paper is that it doesn't take directivity into account as it relates to the PIR slope.

If the score did consider how directivity relates to the PIR, this speaker would have almost certainly scored higher.

Edit: For clarity, the biggest difference between the KH310 and, say, the Genelec 8030C is in the SM_PIR portion of the score. This is the portion of the score directivity has the most influence in, as it will affect the slope of the PIR. In this case though that seems to be hurt by the shelved bass and constant directivity highs, giving the neumann a less tilted PIR than the formula likes to see.

That said, I would have expected a bigger difference in the LFX portion of the score.

 

[LTig]

Thank you for the measurements and review!

As I wrote on Gearslutz, I used to own the O300 and had a mixed impression of it. I didn't like its high crossover point of 3.3 kHz and the woofer/bass felt somewhat constricted. It seems they fixed these issues with the O310 by significantly lowering the mid-tweeter crossover point to 2 kHz and using a better woofer. (and am I going crazy or did they change the highpass filter at the bottom of the bass range, I thought the O300 dropped off much steeper / rings more than ported speaker, the O310 seems more ok here)

The woofer of the KH310 is much better than the one in the O300. I've read somewhere that Neumann stated that its SPL capability in the lows is 7 dB higher which is a lot.

The O300D starts to sound boxy when driven hard in low bass. I fixed this by adding a sub below 85 Hz (Genelec 7060b) which improved the sound a lot (not only in low bass). That's why I haven't yet replaced the O300s by KH310s.

 

[Χ Ξ Σ]

I am a bit confused about using the tweeter center as the reference axis. Maybe this has already been discussed during one of the KH80DSP threads, but I have not read every single page of that extended discussion (that happened before I discovered this forum), so forgive me if this was addressed before.

According to Neumann's acoustical axis definitions document, the KH310' axis is located between the tweeter and the mid dome. Is there any specific reason that Kippel NFS needs to use the tweeter center as the axis? Since Amir consulted with Neumann on the results, they must have agreed with what Amir was doing, so I wonder the reasoning behind this decision. Is this just how the NFS works? For listening and room EQ calibration, do I go with the tweeter or the officially defined axis?

 

[amirm]

I am a bit confused about using the tweeter center as the reference axis.

That was a cut and paste error in the intro text which I just corrected. I indicated the proper reference axis on the spin graph:

 

[MZKM]

This gets a 6.2, top 5 speaker... fantastic, you'd think. That's only 0.03 ahead of a 4" monitor, 0.11 behind a 5" monitor, both of which roll off an octave higher, with the next third of an octave heavily degraded by distortion.

If the score is so heavily weighted towards directivity over response,

Please read the caveats I address:

This formula is based on far-field listening; as such, the ratings for near-field usage have leeway.

Let's compare it to the Genelec 8030C which scores 0.11 better:

8030C

KH 310:

As we see, the SM_PIR score, which favors narrow directivity, is much better on the Genelec, but it's helped because it behaves like a speaker meant for far-field listening. The Neumann PIR is pretty much flat from 1800Hz-18000Hz, which does it no good for the formula, but may be more ideal for near-field use. Also, the 90Hz dip causes the PIR to flatten out <200Hz, which also doesn't help.

And as stated, the bass shelf may not be real (too cold in Amir's garage), so while that 90Hz dip would still remain, the score likely will be better.

 

[soekris]

What a set of Monitors, do all things correct:
3 way, with dome center and high - check
Analog crossovers and class AB Amplifiers - check
Switch Mode power supply - check
Balanced input to match my new dac2541 - check
No digital stuff or DSP - check
Now on my shortlist when I decide to update my Focal Alpha 80 set....

 

[detlev24]

For those wondering, here's the comparison between Neumann's data on its website(blue) and Amir's (Red). The differences are immaterial, especially if the bass is caused by termperature. [...]

It would be great to know under which conditions they [and other manufacturers] perform measurements. If in a semi-anechoic environment and if without 'Klippel NFS' or another model, that would entirely compensate for reflections: below ~100 Hz might not be accurate.

In such a scenario, combined near-/far-field measurements might have been published.

 

[MZKM]

Best of all, I could turn up the level as high as I wanted.

With a pair, how far back would you guess one could sit and it would still be loud enough?

 

[MarsianC#]

It would be great to know under which conditions they [and other manufacturers] perform measurements.

Class 1 room with perfect conditions. I guess same as S&R:

The following measurements of frequency response, directivity and distortion values come from the measurement laboratory, with anechoic conditions. The class 1 measurement chamber permits measurement distances of up to 8 m, and provides free-fieldconditions for the range of 100 Hz upward. All measurements are performed via a B&K 1/4" 4939 measurement microphone with a 96 kHz sam-pling rate and 24 bit resolution, with the aid of the Monkey Forest audio measuring system. Measurements below 100 Hz are performed as com-bined near-field/far-field measurements.

Last line highlighted by me.

 

[MZKM]

No digital stuff or DSP - check

They sell a pair with AES connections.

 

[JustIntonation]

The woofer of the KH310 is much better than the one in the O300. I've read somewhere that Neumann stated that its SPL capability in the lows is 7 dB higher which is a lot.

The O300D starts to sound boxy when driven hard in low bass. I fixed this by adding a sub below 85 Hz (Genelec 7060b) which improved the sound a lot (not only in low bass). That's why I haven't yet replaced the O300s by KH310s.

Yes that makes sense. Distortion is high in the bass and while it may not be high enough to consciously hear the distortion products it's likely this does impact mid quality as it's sure to give IMD with the mids as the woofer goes all the way up to 650 Hz, also with the KH310.

 

[amirm]

It would be great to know under which conditions they [and other manufacturers] perform measurements. If in a semi-anechoic environment and if without 'Klippel NFS' or another model, that would entirely compensate for reflections: below ~100 Hz might not be accurate.

They have a calibrated anechoic chamber.

 

[amirm]

With a pair, how far back would you guess one could sit and it would still be loud enough?

I don't know how to predict. A wild guess would be 6 to 9 feet.

 

[pozz]

What a set of Monitors, do all things correct:
3 way, with dome center and high - check
Analog crossovers and class AB Amplifiers - check
Switch Mode power supply - check
Balanced input to match my new dac2541 - check
No digital stuff or DSP - check
Now on my shortlist when I decide to update my Focal Alpha 80 set....

This was a dream speaker of mine for a long time. Sealed, nice dome mid, no lack of power.

I do look forward to a version with DSP crossover using extreme slopes (I understand Neumann was experimenting with 96dB at one point as a way to prove that their designs are superior to coaxials).

 

[MarsianC#]

They sell a pair with AES connections.

DAC only. The old O300D had an optional external FIR controller, the Pro C28. Connected via a beefy multicore cable. Internal analog crossover would then be bypassed. Same tec as in O500C, multiple option for phase response/delay.

 

[NTomokawa]

discounted to US $2,200 (each)

One of these days I'll be able to afford a set...

 

[AudioJester]

Thanks for the review.
Is this mainly a studio speaker? Or do people use it in far field domestic environments?

 

[Billy Budapest]

For those wondering, here's the comparison between Neumann's data on its website(blue) and Amir's (Red). The differences are immaterial, especially if the bass is caused by termperature. This is the point of flatness where going any flatter doesn't really matter imo.

View attachment 94768



Would just like to point out directivity has nothing to do with the score, at least not directly. In fact, one of the potential flaws in the original paper is that it doesn't take directivity into account as it relates to the PIR slope.

If the score did consider how directivity relates to the PIR, this speaker would have almost certainly scored higher.

Edit: For clarity, the biggest difference between the KH310 and, say, the Genelec 8030C is in the SM_PIR portion of the score. This is the portion of the score directivity has the most influence in, as it will affect the slope of the PIR. In this case though that seems to be hurt by the shelved bass and constant directivity highs, giving the neumann a less tilted PIR than the formula likes to see.

That said, I would have expected a bigger difference in the LFX portion of the score.

Measured response is consistent between Amir and Neumann from 10k to approx 18k, but otherwise there is little correlation between the frequency response dips and valleys. I wonder why?

 

[napilopez]

It would be great to know under which conditions they [and other manufacturers] perform measurements. If in a semi-anechoic environment and if without 'Klippel NFS' or another model, that would entirely compensate for reflections: below ~100 Hz might not be accurate.

In such a scenario, combined near-/far-field measurements might have been published.

I forget where they say it, but Neumann uses an anechoic chamber for the highs and ground plane for the lowest lows (because all but the largest anechoic chambers suffer from issues at the lowest frequencies). Back in the days of the Great War of KH80, Neumann sent their KH80 to be measured by Klippel, the company itself, in order to confirm the accuracy of their setup. After cooperation between Neumann and Amir, it was ultimately found that the differences in the bass were due to the fact the KH80 was measured in a cold environment.

Not to say there can't be something wrong with the KH310 measurements -- each new speaker is a new set of measurements after all -- but the ground plane method has been shown to be as accurate as the NFS (with at least one speaker).

 

[ROOSKIE]

Elimination of bass port (I think) has resulted in very clean low frequency response.

I am a hobbyist speaker designer so perhaps after my comments a more experienced human can chime in.

Speaker systems can have equally low distortion whether sealed or ported. (look at the big Revel)
Much is depended on the drivers properties and the over-all design goals.
In fact around the port resonance frequency Fb, the system can have incredible out-put and very clean bass as long as the port is well designed. At fb the port is doing the vast majority of the work. And the driver very little. Below tuning frequency the driver begins to flap in a quickly increasingly uncrontroled manner.
I am designing a 3-way active now, in this speaker I chose a ported design because in my case it will actually have lower distortion and play at higher SPL with much, much less power than a sealed version would. The caveat is that below the port tuning of 38hrz, distortion would blast of the charts and xmax is easily exceeded if I did not use DSP and a high-pass filter. So this speaker will drop of a cliff out-put wise below 38hrz but it will sound superb right down to 38hrz.
F3 is around 35hrz
F6 is around 33/34hrz
F10 is around 32hrz
as you can see it drops fast.
This speaker will require a big sub for the bottom octave but it will be the jam the rest of the way.

This Neuman speaker has low distortion down to under 50hrz, that is for sure. It also hits a wall and fast, looks like Neuman is using DSP to boost the sealed woofers bass down to f3 and then they seem to let it run rather than cut it off.

No doubt this is an awesome speaker but it still shows that 15inch drivers have a place in this world and so do 4 way systems.
Any bass down low is going to be zero fundamental.

For the excellent price of a nearly complete reference system you don't have to make yourself, be a dear and high-pass those tens at 45-50hrz to a set of 15inchers.