Surround monitoring considerations

[Hugh Robjohns]

I'm also a bit concerned about the ergonomics of a center speaker that presumably can't be used on its side...

It depends what centre speaker you're using. A few can be electronically compensated to some extent (eg. PMC6). It also depends on how close you will be to the monitor and how much you move around... but ideally you want something with the tweeter vertically aligned with the mid-woofer.

...and wondering what I might lose by using the smaller KH80s as sattelites.

Depends on what bass management facilities you have.... but probably very little, in practice.

[Jez Corbett]

It depends what centre speaker you're using.

Well, if I go with the Neumanns, they dont have a center specific speaker design, so presumably it needs to remain vertical.

[Hugh Robjohns]

Either version of the 310 can be used as a centre... and the 80 isn't much taller than the 310...

[Jez Corbett]

FINALLY now getting the chance to audition some kh120s.

They sound very good, super clear, wide and precise in the highs but there seems to be a large hole in the low mids, comes back for a bit of sub, then vanishes.

Could be the very unideal room in a shop I'm listening to them in, but the bass is seriously lacking compared to my tb2s. Going to check they haven't done anything funny with dip switches but maybe I need the larger models.

They are also a lot smaller than I expected. Going to check they didn't accidently bring out the kh80s lol

[Drew Stephenson]

...but there seems to be a large hole in the low mids, comes back for a bit of sub, then vanishes.

Could be the very unideal room in a shop I'm listening to them in...

That does sound very much like room mode cancellation to me.
The KH80s are very small by the way, the frontal area is only a smidgen bigger than a sheet of A5 paper.

[Hugh Robjohns]

....but there seems to be a large hole in the low mids, comes back for a bit of sub, then vanishes.

Sounds like a classic rear-wall reflection or small room standing wave problem to me – ie a room acoustics issue rather than a speaker problem. Every measurement and review I've seen – including my own – reveal an impressively uniform frequency response.

They are also a lot smaller than I expected. Going to check they didn't accidently bring out the kh80s lol

They are not that different, actually. The KH120 measure 277 x 182 x 220mm (hwd) while the KH80s are 233 x 154 x 194 mm. So only about 20% smaller.

Both are more comparable in size to PMCs ancient DB1s than the (equally obsolete) fairly substantial TB2s.

[Jez Corbett]

Turns out the shop I tried them in has a very generous returns policy so I think I'll "rent" them for a couple of weeks and try them out in my studio next to my tb2s. They are also going to order in a pair of kh150s so I can have a listen to them. Shame they are 2x the price!

They've offered me a price of 2x 120s, 3x 80s and the 810 sub that perfectly lines up with the extra budget I've just gotten on the project i need them for so such a set up will be essentially "free", so i have scope to upgrade. Almost certainly going to push the 5.1 to 5.1.2 but those extra 2 are going to add a lot to the price in terms of extra hardware and installation issues.

[orange]

I dunno if you've tried this but you should give this a go:

https://professionalsupport.dolby.com/s ... uage=en_US

[James Perrett]

They are also a lot smaller than I expected. Going to check they didn't accidently bring out the kh80s lol

From the front they are almost exactly the same size as the BBC LS3/5a. I sometimes wonder if this was deliberate...

Whenever I've used them I've not noticed any deficiency in the low mids although they don't have the characteristic high bass hump that the LS3/5a has. The bass end is reasonably well extended too.

[Jez Corbett]

So I have a pair of KH120! Currently with an eye to either return after 2 weeks or upgrade to full surround set.

First thing - they have straight away made a huge difference to the 100-200Hz issues I've been having in my new (4.5m deep) workspace, and I am hearing stuff out of them I have never noticed in my TB2 pair. This was a good choice!

HOWEVER - I now have my next dilemma.

They do chuck out more bass than I expected based on my previous demo in a bad listening space, but not a huge amount.

When I order the surround set up, should I rely on the sub to extend the low end, or consider upgrading the front pair to KH150s or even KH310s to get full range at the front?

Originally my budget was €10k, a 5.1 setup with 2x 120, 3x 80 and 1x 810 will cost me €5k. A 7.1.4 setup with 2x 310, 2x 120, 7x 80s and the 810 may well still fit that €10k budget, although I realise I need to factor in audio hardware with more outs and anything else I might need to do atmos and other 3D audio content, which could be a LOT more ... but that's maybe a different question.

[Drew Stephenson]

I would just ask, that if you're considering 310s and a sub, why you're going with a pair of 120s and why not 80s all round?

[Hugh Robjohns]

When I order the surround set up, should I rely on the sub to extend the low end, or consider upgrading the front pair to KH150s or even KH310s to get full range at the front?

It depends how much bass you need, but the spl and extension will always be limited with 80s or 120s. I've not tried the 150s yet... but a sub will be needed if you want genuine full range and LFE capability.

The 310s are a different kettle of fish. The bass from a sealed cabinet has a different rate of roll-off, but again if you want high spl you'll need a sub. It just gets more complicated matching a sub with 310s and 80s or 120s...

Of course, whether or not you get a smooth bass response in room depends not on the speaker but on the room acoustics and, particularly, speaker positions and bass trapping.

In your situation, if dobley atmos is important, I'd prioritise matched speakers everywhere, so 11 KH80s and a sub, say.

[Jez Corbett]

I'll mostly be doing stereo, hence thinking not relying too much on the sub, especially as the stuff i do in surround / 3D will also want to be stereo compatible, I'd think i might want to be able to get a complete picture from the L & R.

I might be barking up the wrong tree though.

Studio is fairly extensively treated, but needs more work. I'll post some photos.

[Jez Corbett]

[James Perrett]

Looking at the pictures, I'm wondering if the lack of bass is down to reflections from the desk. Have you tried them in free space or mounted higher? While the KH120s don't have real deep bass, it would only be something that I would notice if I had some much bigger speakers to compare them with.

[Jez Corbett]

I should get stands. The tb2s were a lot higher.

[Jez Corbett]

Meant to add, spl isn't too big a deal, i don't tend to monitor at high levels

[Jez Corbett]

Maybe the smaller sub would have been fine

[Drew Stephenson]

I think I'd have gone with the smaller one...

[Hugh Robjohns]

I've been caught out with that before too. The pictures make it look almost cubic, when its actually the size of a wardrobe!

Still, you won't run out of headroom, and will be able to keep the Seismology department amused at your local university....

[Jez Corbett]

Lets think of it of a good way to break the ice with the other residents of the studio complex.

[Jez Corbett]

Ok, got it set up, done some test sweeps.

Doing some sweeps, it all sounds, from an initial casual listen, reasonably flat. However I'm getting a weird phenomenon where, at my listening position, the bass seems to pan left then right briefly around 120-130Hz or so.

I've got more treatment to do, but does this suggest anything I should specifically look into?

Also a bit concerned Im even hearing those frequencies as I've set the sub to cut below 120Hz but I guess the rolloff is quite long. From testing I can still hear stuff up to about 500Hz.

[Drew Stephenson]

Doing some sweeps, it all sounds, from an initial casual listen, reasonably flat. However I'm getting a weird phenomenon where, at my listening position, the bass seems to pan left then right briefly around 120-130Hz or so.

I've got more treatment to do, but does this suggest anything I should specifically look into?

Check the same sweep on headphones set to a mono output. Our ears don't have the same frequency response on each side so it might be an artefact of your hearing rather than the sub or room.

[Hugh Robjohns]

However I'm getting a weird phenomenon where, at my listening position, the bass seems to pan left then right briefly around 120-130Hz or so.

Probably a nodal resonance issue in the room. More bass trapping, doctor!

Also a bit concerned Im even hearing those frequencies as I've set the sub to cut below 120Hz but I guess the rolloff is quite long. From testing I can still hear stuff up to about 500Hz.

The low-pass crossover slope is, I believe fourth order, so it should be 24dB down at 240Hz and 40dB or so down at 500Hz — quite audible in isolation, and perfectly normal.