sunbeamgls wrote:Spannko wrote:
Thanks for the link sunbeam. I found it really helpful in understanding more about how speaker positioning affects the modal response of the room, even though I feel it's slightly academic in that I think there are other factors which have an influence on the optimum position for a pair of speakers too, such as the reinforcement of frequencies other than modal frequencies due to boundary effects, the affect of speaker positioning on first reflections, combing, and anything else I'm not even aware of. This creates a complex mix which is not easily modelled, which is why positioning by ear is the best approach.
You seem to be suggesting that by moving a speaker into a position which doesn't so readily excite a particular room mode, the bass can be cleaned up (by removing some of the overhang) which allows you to more clearly hear the notes being played which, in turn, allows you to follow the tune easier. It's true that you may be able to hear the notes easier, however with regard to being able to follow the tune, this is the biggest mistake people make when they say they are using Tune Dem to set up their system. The ability to be able to hear clearly the notes played on a guitar for instance, is very different to being able to hear the pitch relationships between the notes. One is about sound resolution, and the other is about pitch resolution. We all love a bit of sound resolution, but it's not necessary for us to be able to follow the rhythms and tunes in the music - my £90 Bush "HiFi" which I bought in a super market allows me to do that, even if the resolution is poor, coloured, under powered, only on the radio, etc. Also, the vast majority of high resolution systems are really bad tune players. So, Tune Demming speakers is about moving them to a position which allows the pitch of the notes to be heard more accurately, not the playing of the notes themselves, which I'm sure is influenced to some degree by mode excitation, but not exclusively.
With regard to it being easier to badly position/support a turntable in comparison to a DS, I have to say that is not my experience. Ive found the Linn DS's to be
very sensitive to their environment, in a very similar way to a turntable.
Thanks spannko a very thoughtful contribution, recognising there are many factors involved, one of which is likely to be obscuring of the pitch, amongst those many other factors. Do you consider relative timing of the notes, in addition to relative pitch to be critical to the tune or is it only pitch?
On the last point about source positioning, I was being holistic about set up, not just about how the equipment is being sited and supported. As setting up a turntable is a skilled operation, this is why I think its much easier to badly set up a turntable over a DS.
Yes, just to make things clear, I agree that modes can have an effect on a systems ability to reproduce pitch accurately, and not just low frequency notes. I wouldn't say that the pitch of notes is "obscured" by modes, I would say that the pitch is distorted. A subtle, but fundamental difference, I would say. However, I do think that this is very room dependant too. I base this on being in the unfortunate position of having an almost cubic listening room, so I've experienced a "modal sound" (a great phrase coined by Philbo!) more than most. With regard to SPACE, I've heard it improve tune playing, and I've heard it make things much worse - particularly when using the SPACE calculated settings. In order for SPACE to provide an improvement, the frequency has to be adjusted to an accuracy of 0.01 Hz, the gain by 0.01 dB and the bandwidth by 0.0001 octaves (I still can't get my head around that one!). SPACE is totally incapable of calculating the settings to this level of accuracy. For SPACE to work, it
has to be adjusted by ear using Tune Dem, or it's better to leave it off (from a rhythm and tune perspective).
I believe that accurate timing and pitch reproduction are critical. Fortunately, because we're talking about perceived pitch, listening to a systems tune playing ability allows us to ignore the timing whilst at the same time, totally nailing it! What we also end up with is "true" timing, and not forced rhythm. This is due the fact that a perceived pitch is made up of a fundamental and many harmonics with defined amplitudes and spacing (depending on the instrument). Therefore, the more accurate the pitch, the more accurate the timing. This
has to be the case, otherwise, by changing the timing relationship between the harmonics, the pitch will be altered.
Regarding the setup of turntables and DS's, I forgot about the setup of the turntable itself, which I agree is absolutely critical.