Focal Kanta No1 speaker positioning

[Crunchynut]

I recently upgraded to a pair of Kanta No1 speakers and set about positioning them in my room. I could find lots of advice on the web about speaker positioning but nothing pertaining to these speakers, so I thought I would record my experience for the benefit of others doing the same.

 

This is long post, so look away now if you’re not interested !

 

The first thing was to sort out my speaker stands. The Kanta 1’s are quite big and heavy stand mounts and I found my existing speaker stands wobbled (if gently pushed)  with them installed. I was confused by this, because the stands consist of a 4” pipe/column  on steel base plates and spikes to the concrete floor. They weren’t wobbling on the spikes and the column was surely too stiff to flex. They are also filled with lead so weighed 6 or 7 Kg. Eventually I worked out that the base plate to which the column is mounted (which is sheet steel pressed to form a flat centre with a 10mm ‘skirt’ around the perimeter) was flexing by a couple of mm, meaning the top of the stand was moving by 9 or 10mm. Hence I got some new stands that are more suitable.

 

The next consideration was speaker positioning. I don’t have a listening room so I was constrained by my living room, meaning I only had a couple of variables to play with.  Separation was fixed at 2.7m. Listening position was fixed at 2.7m from each speaker forming a nice equilateral triangle. Distance from the back wall was always going to be less then the preferred > 85cm, but I could experiment between 35 and 55cm (speaker front to wall). Toe-in could be whatever.

 

I had expected the bass to be a bit boomy in what is a relatively small room and the speakers being close to the back wall, but in fact the bass was mostly quite tight and well controlled. Just occasionally though I noticed it was a bit boomy. I couldn’t bring myself to use the foam port plugs - sticking a cheap piece of foam in the bass port of a $5k speaker feels just wrong. So I got more scientific.

 

Since I use an RME ADI-2 DAC FS that has a very useful DSP facility, I used the excellent Room EQ Wizard software to measure the speaker/room acoustics and make some adjustments. With the speakers closest to the wall at 35cm I measured left and right channels separately and was surprised so see how different the frequency response of the left and right channels were - so much so that I though my nice new speakers may be poorly matched - so I swapped the speakers over to check. With the speakers swapped I got exactly the same response, so what I was seeing was just a result of how the shape of the room and the furnishings etc affected the left and right channels (unless my amplifier is screwed, which I doubt). The first obvious room mode was at 50Hz on both channels, and also one at 80Hz that was stronger on just one channel. I think the 80Hz peak was actually the 2nd harmonic of a fundamental at 40Hz, but the speakers probably can’t produce much power at 40Hz so the fundamental didn’t show up.

 

The first thing I wanted to see was whether there was any effect of moving the speakers away from the wall as far as I could go. There was no difference in the measurement. This didn’t surprise me since even at 55cm from the wall, it isn’t far enough away to prevent wall effects. But at least I could rule out distance from wall as a variable to worry about. It is what it is.

 

Next I wanted to see whether toe-in affected the measurements. I used masking tape to mark 3 angles of toe-in ranging between an apex about 30cm in front of the listening position, in the ears of the listener and on the extreme shoulder tips of the listener. There was no difference in the measurements at the different angles, though I was really only looking at the plot in the range 20 to 1000Hz and since bass is omnidirectional the  toe-in shouldn’t have had an effect.

 

I played around setting filters in the DAC to attenuate the peaks in the 50-80Hz band, and a smaller one at 150Hz. On measuring again with EQ applied I got a flatter response. Looking good - but what did it sound like? On listening with EQ on and off I found it had definitely removed the boom. Very pleasing and thank goodness the port plugs can go in the bin.

 

Finally it was time to compare toe-in effects by listening to music! Focal implied that the optimum position was with tweeter pointing at the ears of the listener. I found the ‘extreme tip of the shoulders’ was better. I was surprised how just a small adjustment made quite a change to the sound stage. It was most noticeable in the clarity of centre stage vocals - when more toed in the vocals were slightly fuzzy - as if distorted by the accompaniment. When toed out to point just past the shoulders of the listener, vocals were pristine.

 

So, that’s it. No startling revelations but certainly worth taking the time to experiment, and be satisfied that the set up is as good as it can be in my room. I’m no audio engineer so if there are errors in my anything I have said, please let me know - I’m always eager to learn more on the subject and share knowledge.

 

By the way, the Kantas are fantastic!

 

 

 

[Crunchynut]

Just a follow up. The difference in L and R responses was quite stark, as I mentioned. I ruled out differences between the two speakers but I didn’t check for difference between the two amp channels.  This last uncertainty was bugging me so I have since driven my left speaker through the right channel of the amp, to make sure the differences between left and right are room and not system. The result was total consistency i.e. left and right measurements are unaffected by which speaker, or which channel of the amp are used , and hence they are room effects.

[GregWormald]

Unless your room and furnishings are completely symetrical then a L—R difference is bound to appear, and resonances can be difficult to tame. It's really nice you've got it all sorted.

 

My room is very asymetrical and there's a difference in overall volume L—R of about 1—>4 dB that varies with the overall volume. It's why I had to have a preamp with a balance control.😀  I also have major resonances at 50Hz and 100Hz that I've managed with the speakers dual stage parametric equaliser.

 

Now it's time to enjoy the music.✌️