Tue, 26 Jul 2011 10:14:50 +0200, Jörn Nettingsmeier <netti...@stackingdwarves.net> wrote :
> regardless of room size, they will require a bit of equalisation. if > the speakers are designed to be close to a boundary surface, the one > that's not against a wall needs (gentle) bass boost. vice versa, if > your speakers are designed to be free-standing, the five speakers > need some attenuation at LF. The smallest KEF "eggs" should be fine against the walls, as you already wrote me. Two will be free-standing (front and back) and will need a bit more electronic correction. > if you're still shopping for speakers, i found that the genelec 8030 > have a nice built-in bass eq which can be used to deal with this > issue. i was able to even out the bass response of a rig where most > speakers are next to two boundary surfaces and a few only next to > one. of course, you could also do this in software. I will do it in software. It's a domestic setup, so I don't need expensive active speakers and cabling; I prefer to use very small speakers with lamp cords. > the problem is that your listening room floor reflection will always > be different from and stronger than the recorded floor reflection, > which pulls the image towards the speaker circle. Then less reflections means less localization of the speakers? > the sad and simple fact is that _no_ surround rig can get the > distance unambiguously right in any but anechoic conditions. > and before you run off to shop for styrofoam, be warned that most > recordings would sound utter crap in anechoic conditions, because > nobody mixes for that. What follows is just my opinion. We are free to record and mix in any imaginable ways, so recordings sound "imperfect" in most situations. There's little a listening room can do to beautify recordings and reproduction systems, unless the room is considered as a musical instrument. Even in a small room with too much acoustic treatment, I may be pleasantly surprised by some very good recordings, and find some qualities in some very bad recordings; anything can happen in the middle, and low expectations is the key to happiness. What I expect from listening to ambisonic recordings is a better envelopment and a sense of realism not found in stereo recordings. I also expect some new experiences from field recordings and electroacoustic music for ambisonics. I also want to compare ambisonics to other reproduction methods; maybe stereo and 5.1 are not so bad... The other use for all those speakers is to add a bit of hall reverberation to some dry stereo recordings. > moreover, the phasing problems of our beloved ambisonic technique > would become very obnoxious indeed. Obnoxious phasing problems? Now I'm afraid! ;-) Maybe I spent decades listening to obnoxious problems I never noticed... I'll do my best to control phasing problems at the sweet spot. > the deader you make your room, the more hope you have to get precise > distance information. at the same time, the rig will sound less > pleasant and artefacts will become more obvious. since humans suck at > absolute distance perception anyways, your best bet is to be content > with some degree of distance discriminination. that is, you want to > hear the woodwinds _somewhere_behind_ the strings. you wouldn't > normally care how many metres. this usually works well if the > recording is ok. I found good acoustic panels, and I have to decide how much surface to cover. I once built large and thick panels to cover half of the walls and 2/3 of the ceiling. There was also a wool carpet with foam under it. The room was so dead that I was able to listen to my heart beat. I remember how sharp the stereo image was and how the speakers were not easy to localize with good recordings. Of course the room was a bit oppressive, almost like a recording booth... I hope to find a better compromise between analytic listening and listening for enjoyment. > when a listening room first reflection is strong and early, it will > dominate your sense of distance. in that sense, larger rigs have the > potential to be less intrusive wrt distance perception. Right: first reflections should be better controlled in a small room. > > if you're right next to the sound source, the floor > > reflection will have the longest delay. far away, the delay will be > > negligible. > > the general case is > > dly = 340 / (sqrt(ear_height^2 + half_distance^2) * 2) > > minus the straight-path delay of course: > > dly = 340 / (sqrt(ear_height^2 + (distance/2)^2) * 2 - distance) So floor and ceiling reflections also need to be controlled, even more in a small room. The difficulty is how to leave some harmless and lively reflections. Maybe that adding a few small diffusors would be a good compromise. Thanks! -- Marc _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
