Re: [Sursound] Speaker configs + subwoofers
On 05/11/2011 01:03 AM, Gerard Lardner wrote: There was a discussion about speakers for Ambisonics a few years ago. I can't remember exactly when. But I do seem to recall that it was suggested that speakers having a single axis (e.g. a single, wide-range driver or concentric drivers) would be better than speakers having drivers spread relatively widely over the front plane; following others on this list, i may have suggested that in the past, but it might not be too important after all, unless in extreme near-field conditions. the only coax system i've heard so far is the IEM cube, and the system sounds great, but that's probably due to careful acoustic treatment more than to the tannoy 1200 concentric drivers. i haven't had any bad experience with twin-axial designs. the only thing that happens is you get a slight change of timbre around the crossover frequency when you stand as opposed to when you sit down, and that's only for horizontal-only systems - as soon as the z-axis is added, those small changes are masked by the other speakers, in my experience. but of course a real point source is conceptually quite elegant if you can get it, and i know that richard lee has recommended the KEF eggs more than once, which are coax iiuc. they'd certainly be my HOA dream setup for home use... -- Jörn Nettingsmeier Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio) Tonmeister VDT http://stackingdwarves.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
On 05/11/2011 03:24 AM, Pedro Lopes wrote: The situation: ambisonics 3d setup for 3d audio. 8 channels, cube setup (a quad above the other). The room is 3x3 meters wide. be sure to try the bi-rectangle as well. Speaker choice/budget restrictions: active speakers. Yamaha hs50 or mackie mr5. 150 euros per speaker. or maybe two 5.1 surround sets? in that price range, you might find interesting alternatives. german manufacturer teufel used to have some quite competetitively priced offerings which are generally well-regarded among music lovers (as opposed to movie- or gaming-only users). this being said, what is the required wave propagation style for ambisonics? Is it better that the speakers radiate more smoothly and even, or more directional? each speaker should cover the entire listening area completely, with a reasonable flat response. ideally, speakers should have flat off-axis response, but in practice, the treble falls off faster than the low frequencies, which radiate almost omni-directional. that means the diffuse field will sound duller than the direct field. now if your room is dead in the treble but not much below that, you will exaggerate the dullness of the diffuse field. so too much cloth might be problematic - if you deaden the room, aim for broadband absorption, possibly with a hard surface on top that reflects some treble. but that is a general issue, not one specific to ambisonics. I'm leaning towards mackie, the only but is to clear if they will suit my needs for ambisonic. can't comment on this, but at 150,- you're not quite in the pro or semi-pro range for studio monitors, hence it might make more sense to look at reasonable consumer offerings and maybe profit from a kit deal. -- Jörn Nettingsmeier Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio) Tonmeister VDT http://stackingdwarves.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
On 05/11/2011 03:42 AM, Marc Lavallée wrote: I like this idea of a full-sphere bass setup. There would be 3 (small) subs on the floor (front-left, front-right, rear-center) and one on the ceiling (like a Z bass channel). i doubt the Z in bass will buy you much. it might even be detrimental, because bass sounds that fly around are often quite disturbing. i had the problem of a floating gran cassa on hemispheric decodes (which tend to pull up a bit), and it was quite irritating - somehow the ear expects bassy sounds to be grounded, at least for music. but john leonard and other connaisseurs of choice aircraft engines will likely disagree :) Questions: Is it acceptable if the mid-high speakers go down to 150Hz while the subs go up to 700Hz? What would be an appropriate upper frequency limit for the subs? How to adjust all the decoders to handle different and overlapping frequency ranges? Is is better to avoid overlapping? that is a can of worms. off the top of my head, i'd say don't do it and go for a sharper transition, because you will never get the time alignment right for a larger area. experience with PA systems shows that a smooth phase transition between basses and tops is quite worth the effort. so if you don't have a chance to get it right, then at least limit the effect to an octave or so. with a transition from 150 to 700, you basically leave the entire low-mid response to chance. and see if you can measure the overall system phase response and align it with some delay. -- Jörn Nettingsmeier Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio) Tonmeister VDT http://stackingdwarves.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
Le 12 mai 2011 13:46:56, Jörn Nettingsmeier a écrit : On 05/11/2011 03:42 AM, Marc Lavallée wrote: I like this idea of a full-sphere bass setup. There would be 3 (small) subs on the floor (front-left, front-right, rear-center) and one on the ceiling (like a Z bass channel). i doubt the Z in bass will buy you much. it might even be detrimental, because bass sounds that fly around are often quite disturbing. i had the problem of a floating gran cassa on hemispheric decodes (which tend to pull up a bit), and it was quite irritating - somehow the ear expects bassy sounds to be grounded, at least for music. but john leonard and other connaisseurs of choice aircraft engines will likely disagree :) If it sounds too disturbing, I suppose that I can disconnect the top subwoofer (of a tetrahedron) and only use the three subwoofers on the floor. Questions: Is it acceptable if the mid-high speakers go down to 150Hz while the subs go up to 700Hz? What would be an appropriate upper frequency limit for the subs? How to adjust all the decoders to handle different and overlapping frequency ranges? Is is better to avoid overlapping? that is a can of worms. off the top of my head, i'd say don't do it and go for a sharper transition, because you will never get the time alignment right for a larger area. What about small areas (3mx3m)? experience with PA systems shows that a smooth phase transition between basses and tops is quite worth the effort. so if you don't have a chance to get it right, then at least limit the effect to an octave or so. with a transition from 150 to 700, you basically leave the entire low-mid response to chance. and see if you can measure the overall system phase response and align it with some delay. At home I'd have the time to ajust it (if required). -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
On 05/12/2011 07:55 PM, Marc Lavallée wrote: Le 12 mai 2011 13:46:56, Jörn Nettingsmeier a écrit : On 05/11/2011 03:42 AM, Marc Lavallée wrote: I like this idea of a full-sphere bass setup. There would be 3 (small) subs on the floor (front-left, front-right, rear-center) and one on the ceiling (like a Z bass channel). i doubt the Z in bass will buy you much. it might even be detrimental, because bass sounds that fly around are often quite disturbing. i had the problem of a floating gran cassa on hemispheric decodes (which tend to pull up a bit), and it was quite irritating - somehow the ear expects bassy sounds to be grounded, at least for music. but john leonard and other connaisseurs of choice aircraft engines will likely disagree :) If it sounds too disturbing, I suppose that I can disconnect the top subwoofer (of a tetrahedron) and only use the three subwoofers on the floor. Questions: Is it acceptable if the mid-high speakers go down to 150Hz while the subs go up to 700Hz? What would be an appropriate upper frequency limit for the subs? How to adjust all the decoders to handle different and overlapping frequency ranges? Is is better to avoid overlapping? that is a can of worms. off the top of my head, i'd say don't do it and go for a sharper transition, because you will never get the time alignment right for a larger area. What about small areas (3mx3m)? wavelength = speed of sound / frequency. plus if you've got several octaves overlap, you'd need to align the phases over several octaves, which could be quite hard if not impossible, depending on crossover and speaker design. plus the alignment will only be valid at the exact center, and if you move, say, 50cm off-center, a 340hz wave will be at 180° relative to the center, while a 170hz wave will be at 90°. so you can't really win this one. -- Jörn Nettingsmeier Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio) Tonmeister VDT http://stackingdwarves.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
On 05/12/2011 10:42 PM, Fons Adriaensen wrote: I guess it depends all on the size of the array. If you're sitting 1.5 meters from a speaker then having the LF and HF drivers apart by 0.4 m or so isn't going to help and something like the KEF eggs would be a better idea. I've heard 32 of them in Southampton, they are quite good for the size. what kind of setup was that, and where? ambisonic? -- Jörn Nettingsmeier Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio) Tonmeister VDT http://stackingdwarves.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
Thanks for the responses Jörn, they area most helpful. I will try the bi-rectangle as well, I was talking bout that layout in another thread here by the way :) Best, Pedro 2011/5/12 Jörn Nettingsmeier netti...@stackingdwarves.net: Jörn -- Pedro Lopes (MSc) contact: pedro.lo...@ist.utl.pt website: http://web.ist.utl.pt/Pedro.Lopes / http://pedrolopesresearch.wordpress.com/ | http://twitter.com/plopesresearch ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
There was a discussion about speakers for Ambisonics a few years ago. I can't remember exactly when. But I do seem to recall that it was suggested that speakers having a single axis (e.g. a single, wide-range driver or concentric drivers) would be better than speakers having drivers spread relatively widely over the front plane; also that phase coherence between drivers is important. I have never tried concentric speakers, e.g. Tannoy Dual-Concentric; too expensive for me; but I have been able to collect eight Wharfedale Diamond Pro 8.1 Active speakers for my Ambisonic set-up. They seem to me to be good, but I have not heard a reference Ambisonic set-up to compare them with. Gerard Lardner On 10/05/2011 01:54, Marc Lavallée wrote: I found very little information about domestic Ambisonic speakers setups. All I know is that it's better to use the same speakers and amplifiers for the whole setup... I adopted the layout proposed by Bo-Erik Sandholm (10 speakers), and now I have to find the right speakers. Here's some random thoughts (comments are welcome): - Speaker design really is an art form; I can't build very good speakers myself, so eventually I will buy two for my main stereo system (and they will sound much better than they look). - I can build good enough speakers based on tutorials and software. I did it and it's worth the effort. Bass-reflex enclosures are easier to design and build than quarter-wave enclosures. - The frequency response of some good full-range drivers is about 70Hz-20Khz. They are perfect for near-field listening, and probably appropriate for a small Ambisonic setup. - For Ambisonic reproduction in a small room, I can't afford to buy or build fancy speakers (like quarter-wave), but I can build many (10+) speakers using full-range drivers in sealed enclosures. - I learned that it's possible to use subwoofers with Ambisonic; but a minimum of four subwoofers are required with a dedicated FOA decoder. That's a reason why I'd like to build small enclosures for small drivers with a limited bass response instead of larger enclosures with bass extension (either bass-reflex or quarter-wave). - Bass reproduction is important for directional cues. It is influenced by the room response (or modes) and the placement of the subwoofers (more than their size and quality). - Digital room correction and EQ are useful tools; we should use them instead of looking for speakers with the best frequency response. Is there any web site (article, book) on how to build speakers specifically for Ambisonic reproduction? -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
Nice tips. I have a related question regarding how should speakers radiate sound waves, in ambisonic situations. I'd like to get some feedback on my difficult choice between yamaha hs50 vs. Mackie mr5. The situation: ambisonics 3d setup for 3d audio. 8 channels, cube setup (a quad above the other). The room is 3x3 meters wide. Speaker choice/budget restrictions: active speakers. Yamaha hs50 or mackie mr5. 150 euros per speaker. Problem (which is related with the topic of this thread, since it discourses about sound waves radiating from speaker cones): the mackie mr5 states that: Minimum-Diffraction Molded Baffle: When it comes to baffle design, shape matters; it plays a role in how sound waves travel. Our baffle is precisely molded to minimize diffraction, so sound waves radiate smoothly, and are dispersed optimally. Our precision waveguide is designed to ensure broad, even dispersion, and a smooth transition between highs and lows. The result is a crystal clear image of your mix, with an ultra-wide, even sweet spot. Whether you’re in mix position or not, on axis or off, you’ll always hear an accurate representation of your mix. this being said, what is the required wave propagation style for ambisonics? Is it better that the speakers radiate more smoothly and even, or more directional? I'm leaning towards mackie, the only but is to clear if they will suit my needs for ambisonic. Best, pedro On May 10, 2011 11:29 PM, chris boozer chrisboo...@yahoo.com wrote: Kef also has a concen... There was a discussion about speakers for Ambisonics a few years ago. I can't remember exactly whe... -- next part -- An HTML attachment was scrubbed... URL: https://... ___ Sursound mailing list Sursound@music.vt.edu https://... -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20110511/bacf6fa1/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
Tue, 10 May 2011 11:07:14 -0600, Martin Leese martin.le...@stanfordalumni.org wrote : Marc Lavall?e m...@hacklava.net wrote: ... Here's some random thoughts (comments are welcome): ... - I learned that it's possible to use subwoofers with Ambisonic; but a minimum of four subwoofers are required with a dedicated FOA decoder. As subwoofers handle frequencies well below 700 Hz, you need a minimum of only three (in a triangle) for horizontal, or four (in a tetrahedron) for full-sphere. Also, the decoder needs to be a velocity decoder, so is about half (the low-frequency half) of a dedicated FOA decoder. I like this idea of a full-sphere bass setup. There would be 3 (small) subs on the floor (front-left, front-right, rear-center) and one on the ceiling (like a Z bass channel). Questions: Is it acceptable if the mid-high speakers go down to 150Hz while the subs go up to 700Hz? What would be an appropriate upper frequency limit for the subs? How to adjust all the decoders to handle different and overlapping frequency ranges? Is is better to avoid overlapping? -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
There's also the Yahoo group Quarter-Wave (http://tech.groups.yahoo.com/group/quarter-wave/), where there is discussion of loudspeaker design, and the related website Quarter Wavelength Loudspeaker Design (http://www.quarter-wave.com/) where there is Mathcad software for loudspeaker design. Mostly for transmission-line designs. Seems to be good; but I haven't built any yet myself. Gerard Lardner On 09/05/2011 07:12, Bo-Erik Sandholm wrote: A bit out of topic but if anyone else is into building their own speaker cabinets. Let me point you to a document that is very good in explaining the design choices in a cabinet for the bass frequencies. http://www.sonicdesign.se/optimum.html Regards Bo-Erik -Original Message- From: sursound-boun...@music.vt.edu [mailto:sursound-boun...@music.vt.edu] On Behalf Of Bo-Erik Sandholm Sent: den 4 maj 2011 13:48 To: Surround Sound discussion group Subject: Re: [Sursound] Minim AD7 for sale - Speaker configs. From http://en.wikipedia.org/wiki/Sound_localization#Evaluation_for_low_freq uencies Evaluation for low frequencies For frequencies below 800 Hz, the dimensions of the head (ear distance 21.5 cm, corresponding to an interaural time delay of 625 µs), are smaller than the half wavelength of the sound waves. So the auditory system can determine phase delays between both ears without confusion. Interaural level differences are very low in this frequency range, especially below about 200 Hz, so a precise evaluation of the input direction is nearly impossible on the basis of level differences alone. As the frequency drops below 80 Hz it becomes difficult or impossible to use either time difference or level difference to determine a sound's lateral source, because the phase difference between the ears becomes too small for a directional evaluation. ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Speaker configs + subwoofers
I found very little information about domestic Ambisonic speakers setups. All I know is that it's better to use the same speakers and amplifiers for the whole setup... I adopted the layout proposed by Bo-Erik Sandholm (10 speakers), and now I have to find the right speakers. Here's some random thoughts (comments are welcome): - Speaker design really is an art form; I can't build very good speakers myself, so eventually I will buy two for my main stereo system (and they will sound much better than they look). - I can build good enough speakers based on tutorials and software. I did it and it's worth the effort. Bass-reflex enclosures are easier to design and build than quarter-wave enclosures. - The frequency response of some good full-range drivers is about 70Hz-20Khz. They are perfect for near-field listening, and probably appropriate for a small Ambisonic setup. - For Ambisonic reproduction in a small room, I can't afford to buy or build fancy speakers (like quarter-wave), but I can build many (10+) speakers using full-range drivers in sealed enclosures. - I learned that it's possible to use subwoofers with Ambisonic; but a minimum of four subwoofers are required with a dedicated FOA decoder. That's a reason why I'd like to build small enclosures for small drivers with a limited bass response instead of larger enclosures with bass extension (either bass-reflex or quarter-wave). - Bass reproduction is important for directional cues. It is influenced by the room response (or modes) and the placement of the subwoofers (more than their size and quality). - Digital room correction and EQ are useful tools; we should use them instead of looking for speakers with the best frequency response. Is there any web site (article, book) on how to build speakers specifically for Ambisonic reproduction? -- Marc Mon, 09 May 2011 23:24:17 +0100, Gerard Lardner glard...@iol.ie : There's also the Yahoo group Quarter-Wave (http://tech.groups.yahoo.com/group/quarter-wave/), where there is discussion of loudspeaker design, and the related website Quarter Wavelength Loudspeaker Design (http://www.quarter-wave.com/) where there is Mathcad software for loudspeaker design. Mostly for transmission-line designs. Seems to be good; but I haven't built any yet myself. Gerard Lardner On 09/05/2011 07:12, Bo-Erik Sandholm wrote: A bit out of topic but if anyone else is into building their own speaker cabinets. Let me point you to a document that is very good in explaining the design choices in a cabinet for the bass frequencies. http://www.sonicdesign.se/optimum.html Regards Bo-Erik -Original Message- From: sursound-boun...@music.vt.edu [mailto:sursound-boun...@music.vt.edu] On Behalf Of Bo-Erik Sandholm Sent: den 4 maj 2011 13:48 To: Surround Sound discussion group Subject: Re: [Sursound] Minim AD7 for sale - Speaker configs. From http://en.wikipedia.org/wiki/Sound_localization#Evaluation_for_low_freq uencies Evaluation for low frequencies For frequencies below 800 Hz, the dimensions of the head (ear distance 21.5 cm, corresponding to an interaural time delay of 625 µs), are smaller than the half wavelength of the sound waves. So the auditory system can determine phase delays between both ears without confusion. Interaural level differences are very low in this frequency range, especially below about 200 Hz, so a precise evaluation of the input direction is nearly impossible on the basis of level differences alone. As the frequency drops below 80 Hz it becomes difficult or impossible to use either time difference or level difference to determine a sound's lateral source, because the phase difference between the ears becomes too small for a directional evaluation. ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
