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Neumann KH80+KH750 'Unvarnished Review'

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Re: Neumann KH80+KH750 'Unvarnished Review'

Postby Hugh Robjohns » Mon May 11, 2020 3:07 pm

Which specs are you referring to, please?

The 805 delivers 110.7dB max SPL in half space, while the 750 manages 105dB SPL, both having their maximum level defined as the point of 3% THD at 1m. The figures seem plausible given their relative sizes.

I can also see a spec for the SPL at 0.5% for the 805, which is at 95dB SPL, but I can't see the equivalent figure for the 750 on the website. The manual for the 750 gives even fewer specs than the website!
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Re: Neumann KH80+KH750 'Unvarnished Review'

Postby badboygolf16v » Mon May 11, 2020 4:38 pm

Thanks for the reply.

I was looking at the Harmonic Distortion graphs that can be found in the Data tabs here: https://en-de.neumann.com/kh-750-dsp and here: https://en-de.neumann.com/kh-805.
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Re: Neumann KH80+KH750 'Unvarnished Review'

Postby ro5 » Fri May 15, 2020 10:16 pm

I noticed that KH750 DSP can also process the audio going to the analog Neumann monitors (like the KH120 and KH310) and I was wondering if that would also work well with other analog monitors from another vendor, like a cheaper pair of IKM iLouds or JBL 30xP's or 104's.

I doesn't look like the DSP software/app calibrates itself with a microphone (like e.g. Sonarworks) and this needs to be done either by preset guestimates or manually by ear. Is there any guidance on how to best achieve this?
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Re: Neumann KH80+KH750 'Unvarnished Review'

Postby Hugh Robjohns » Fri May 15, 2020 11:08 pm

badboygolf16v wrote:Thanks for the reply.

I was looking at the Harmonic Distortion graphs that can be found in the Data tabs here: https://en-de.neumann.com/kh-750-dsp and here: https://en-de.neumann.com/kh-805.

Oooh.. sorry.. I forgot all about this question.

I'll enquire of someone who will know, but I suspect the reason the 750 produces more is because it's a smaller vented box working the driver harder to achieve the same (high) SPL.
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Re: Neumann KH80+KH750 'Unvarnished Review'

Postby Hugh Robjohns » Sat May 16, 2020 3:51 pm

So, here's the knowledgeable response from someone who genuinely knows his onions on this subject:

The KH 750 and KH 805 are quite different acoustically both in physical cabinet size and design (vented vs. sealed), and that basically explains the difference in distortion.

However, the driver in the KH 750 is actually a bit better as it is a newer design.

Something to remember, though, is that there are two other major factors affecting distortion: how loud are you playing, and what kind of material? Loud bassy hip hop is clearly going to demand way more effort from the subwoofer than some gentle Val Doonican*.

Also, if the subwoofer is correctly calibrated to the room it is most likely not working so hard at some frequencies, significantly lowering the distortion compared to that measured in flat anechoic conditions (as shown on the published plots). Usually, it is necessary to roll off the lower frequencies to compensate for room gain, as well as attenuate narrow bands to compensate for resonances, and turn the whole subwoofer down to compensate for wall loading.

So in a practical listening room, rather than an anechoic measurement chamber, the sub will not be working as hard for the same perceived SPL, and so will generate lower levels of distortions anyway.

And if the system is playing at sensible levels most of the self-generated distortions will be below the threshold of hearing or masked by other frequencies in the content itself, and thus not audible.

My correspondent also told me that he uses a pair of KH 80 with a KH 750 in a 3 x 4 m room, and can play the system VERY loud without noticing any distortion from the subwoofer (and he would know what to listen for, believe me!)

So in conclusion, his advice is not to worry about it: the KH 750 paired with KH 80 is an excellent combination.

Hope that helps put your mind at rest.

*Definitely not my choice of listening material, I hasten to add, but the example given by my correspondent! :-) He lives somewhere where the sun rarely shines, so you shouldn't really blame him!
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Re: Neumann KH80+KH750 'Unvarnished Review'

Postby Hugh Robjohns » Sat May 16, 2020 4:49 pm

ro5 wrote:I noticed that KH750 DSP can also process the audio going to the analog Neumann monitors (like the KH120 and KH310) and I was wondering if that would also work well with other analog monitors from another vendor....

Again, from my consultant speaker guru:

No! Every monitor design has its own unique magnitude and phase responses. The DSP compensations in the KH 750 are designed specifically only for those Neumann models.

Of course, you might get lucky and find it delivers a reasonable compensation with another product, but in all likelihood there is a far great chance it will actually make the situation worse, not better!

I doesn't look like the DSP software/app calibrates itself with a microphone (like e.g. Sonarworks) and this needs to be done either by preset guestimates or manually by ear. Is there any guidance on how to best achieve this?

There's no automatic calibration (yet) but Neumann's Guided Alignment method via the Neumann.Control App does quite a good job without needing a measurement mic (and for free)!

The compensations it introduces are based on carefully modelling of typical installations and there is a lot of calculation used to generate the applied correction curves from the user’s input. Of course, there is nothing to lose in trying it and seeing how it sounds -- it's certainly much better than doing nothing!
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Re: Neumann KH80+KH750 'Unvarnished Review'

Postby badboygolf16v » Sun May 17, 2020 1:11 pm

Hugh Robjohns wrote:So in conclusion, his advice is not to worry about it: the KH 750 paired with KH 80 is an excellent combination.

Thanks for the detailed reply Hugh.

I would like to upgrade from my KH80 to the KH310 at a some point and the phase linearisation that the KH750 offers is a selling point. In my opinion, the phase linear crossover in the KH80 makes a noticeable difference to the stereo presentation.
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Re: Neumann KH80+KH750 'Unvarnished Review'

Postby Hugh Robjohns » Sun May 17, 2020 10:36 pm

badboygolf16v wrote:I would like to upgrade from my KH80 to the KH310 at a some point and the phase linearisation that the KH750 offers is a selling point. In my opinion, the phase linear crossover in the KH80 makes a noticeable difference to the stereo presentation.

Yes it certainly does. I suspect the KH310 will be replaced or supplemented by a DSP-based three-way at some point in the not too distant future. It seems a logical supposition given the benefits exhibited by the KH80.

But if the motivation for upgrading to the KH310s would be for more volume or to handle more bass-heavy material, you may well find you'd either need a pair of KH750s (as a single one probably wouldn't have sufficient headroom), or upgrade the sub as well to one of the larger models.
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Re: Neumann KH80+KH750 'Unvarnished Review'

Postby dickiefunk » Sun Nov 08, 2020 10:03 am

This thread has been a very interesting read. I’ve been using an Eve TS108 sub with my KH120’s and this setup has been working well for me. I’ve noticed apart from gaining the obvious extra depth of bass there is a little more clarity in the low mids on my KH120’s. The Eves use a passive radiator, have the same 105dB Max SPL and also have a brilliant remote control that gives you 100% control of all the subs features including powering it on and off (which means no crawling around on the floor to turn it on and off). I In terms of output the TS108 has more than enough power for my small room with lots of headroom left.
The benefits of the Neumann KH750 are it is designed to work specifically with the Neumann range of monitors. They also go an extra 15hz lower but the Eve is already filling my room so not sure if the KH750 would be too much? Perhaps with the Neumanns room optimisation DSP it would integrate even better than the Eve?
Im a little reluctant to give up the remote control feature of the Eve as it just works so well! Also, the small things like not having to crouch down on the floor to turn the sub on and off makes a difference.

Would the KH750dsp offer a worthwhile step up from the Eve TS108?
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