There are two points here, by ‘largely untreated’ I mean that my room is not a purpose built studio with 6 feet of rockwool in every direction I do however use RPG’s excellent Modex membrane traps,
http://www.rpgeurope.com/products/pr...odexplate.html
Which do work ,you just need a lot of them.
Secondly one of the 8Cs key design aims is that they are designed to work in domestic or largely untreated rooms, their boundary coupling , boundary filtering, cardioid response really contribute to better sound quality, enabling you to work in room that would be considered unsuitable for traditional loudspeakers.
Keith

We just bought a pair of 8cs does anyone have a recommendation for placement height? Should ear be exactly at speaker middle or should the be shifted slightly higher or lower? Any thoughts from people who have had experience with placement would be appreciated!

From the manual at https://tinyurl.com/wranz9v -

Listening height
The reference axis of the 8c is perpendicular to the baffle and
equidistant to the woofer and tweeter axes, 26.5 cm from the
bottom. The loudspeakers should ideally be positioned in such
a manner that the axis is near ear height. However, as long
as you are within around 15° of the vertical reference axis,
variations in frequency response are near imperceptible.

Does that just mean that ear level should be between the woofer and tweeter?

Yes,
Keith

'Brevity is the soul of wit'. (William Shakespeare, Hamlet)

Manual URL in my previous post now amended - see diagram re. height.

Although they do also have pretty decent vertical dispersion,
Keith

To be fair, any subwoofer source, when placed close to a wall is 'boundary coupled' and even better is a sub in a wall-floor corner (coupled to 2 boundaries) or placed in a wall wall floor corner (coupled to 3). It follows 1/4 wave theory, so within 1/4 wavelength and longer the source and the boundary are coupling. So at 100hz it only has to be about 2 1/2' or .8M to the boundary (or closer).

Each case removes potential sources of SBIR, but it should be noted that this is all it does. Room modes still dominate, decay times are all over the place and the need for serious absorption to achieve reference quality monitoring remains. The same is true with cardioid bass ala Geithan. There is a huge thread on DIYaudio including a lot of measurements that shows that directivity below the schroeder frequency does very little WRT decay times and overall modal activity.

Cardioid or other directivity above schroeder is great (I'm using half fig8, rear lobe completely absorbed- which is quite a bit narrower even then cardioid), especially with gear, desks and other reflection sources that can't be avoided. But while it may minimize early reflection sources, or treatment requirements, again it's best to actually measure, analyze the ETC and spectrogram and address issues as needed. Acoustic diffraction sources are also very commonly overlooked. Reflection is easier to intuit then diffraction.

All this to say that while the 8c is an excellent design, I hope nobody thinks they have subverted the value of taking acoustic measurements and addressing issues in their rooms...

I agree Dutch&Dutch haven’t rewritten physical rules just yet, the ability to adjust bass output ,according to position and add a delay on the mid/treble is useful though to maintain perfect step and phase coherence.
The cardioid response through the midrange decreases congestion and the internal PEQ is really valuable, I am experimenting here with a ‘sink source’ set-up using the 8Cs ‘sub’ outputs, the REW simulation suggests this will help with cancellations.
Keith

Sure, quite a bit more tweaky, but miniDSP OpenDRC series give full FIR control. With rephase, phase response can be freely adjusted. There are many software tools as well, and DIRAC and so on.

Worth noting that a user will never measure perfect step or phase response at the listening position in room that doesn't achieve minimum-phase response. Phase has to be invertible to be correctable. Achieving min phase response at the listening position requires extensive treatment, with special attention paid to early reflections/diffractions as well as modal treatment. No free lunches to be had there I'm afraid.

It would be super cool to see some of the mdats that you are measuring. By no means am I trying to disrespect the 8c's, and it's very interesting to me what you would be able to achieve with the sink source. This is a double bass array type of arrangement?

MiniDSP is decent kit , really good value, we were amongst the first to retail their equipment, Dirac, Trinnov, Illusonic, all really valuable tools especially if your speakers have no internal adjustability.
But in my experience an inherently good loudspeaker such as the 8C still sounds better that a traditional design with post corrective treatment.
I only correct minimum phase portions of the FR, REW is incredibly useful in this respect.
Keith

Yep cool stuff aye.

Makes sense, and it seems you have access to a lot of great speakers there. Keep us posted if you're able to upload some mdats. It would be really interesting to see.

Thank you feel I a bit of a nitwit for not looking at the manual

Is rew and the recommended umik-1 mic acceptable for taking measurements that will be needed to adjust to room?

I’m hoping to get a Skype session with Dutch for proper setup. They offered in a previous request so hope they are not to busy. I can’t seem to find detailed instructions on optimization. Not in the manual I did look

Not seeing anything on YouTube so depending on what’s involved I may make one if it would be helpful.

Well there - I am going to be at Team Dutch in future ...
Had a listening session in a mastering studio with them and I could take a bit of time playing around with familiar tools. I am really surprised with that clear image and be happy to get a tool which will be adaptable to my room!

Get them ordered tomorrow since it is Sunday today and I am going to read the rest of those 50 gearslut pages ;-)

Just for fun: which color combo do you prefer ?

B/B

I had the Oak/B as a demo pair. Nice looking, but not for me personally.

Not a fan of the white dudes.