Erik
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Any chance Geddes wrote a paper on this, or any links to where he goes into more detail? Thanks.
Any chance Geddes wrote a paper on this, or any links to where he goes into more detail? Thanks.
Yeah, it does work somehow after I moved my chair around to the exact "sweet" spot in my room. The effects are indeed wider than the speaker geometry but, in my system, not beyond 180° (nothing in the rear...). I found that the best way to test the process is to use the Qsound demos. Quite immersive actually. Work with my headphones too.Yeah, you're right, it should come from the sides. You can find a list of all (not many) of the recordings using Qsound. A lot of crap, but now I need to get hold of some of them.
I think the reason the technology never caught on is that it only works when sitting in the sweet spot. But it's a cool party trick.I've had a look at the artists using Qsound and I noticed that most of the records predate year 2000. Obviously, these effects have not been the recording engineers preoccupation recently, probably not adapted to the loudness war trend?
Can we have a chart on that please?At my main seating area they are 75 degrees apart. I can move to 90 degrees or move backward until they are 40 degrees.
Seems to me the Qsound is more consistent and works best at speaker angles of no more than 60 degrees.
I think the reason the technology never caught on is that it only works when sitting in the sweet spot. But it's a cool party trick.
Ok, okay.Can we have a chart on that please?
Speaker angles from 0 degrees being straight ahead?
I'm so confused.
So what I did was simply moving closer to or further from the speakers effectively changing their angle vs my listening position.
Does that make sense?
@svart-hvitt, I remember you posted a link to a Genelec presentation on this topic that I'd been meaning to watch but have now lost... Do you remember what it was I was talking about?
Just noticed this question.It does. How are your speakers aimed (toed-in)?
Just noticed this question.
The speakers axis would cross somewhere between the 75 degree listening position and the 60 degree listening position. So they cross behind the listener at 75 degree LP and in front of all the others.
Also the speakers in this case are Revel F12s. So they have relatively good directional characteristics though not point source.
The F12's are fantastic. They get a large portion of the Harman magic. I purchased these, made in the last month of production for a very low price on ebay. They are efficient, very well balanced, and sound good over a wide listening angle. I have a Wyred4Sound ST-500 driving them. Harman is onto something with their design process.Interesting.. My LP has a total angle toward speakers app 50 degrees and speakers are toed-in to cross at a point which is app 1 meter behind LP. MY speakers are app 4m away from each other and LP is a little more toward each speaker hence the angle is app 50 degrees.
I would like to have my LP at an angle like yours, at 60 degrees or a little more, but it is not possible do to the shape of the room and furniture.
Btw, how are you satisified with Revel F12?
The F12's are fantastic. They get a large portion of the Harman magic. I purchased these, made in the last month of production for a very low price on ebay. They are efficient, very well balanced, and sound good over a wide listening angle. I have a Wyred4Sound ST-500 driving them. Harman is onto something with their design process.
@andreasmaaan , sorry for taking so long to reply. I wanted to elaborate on this but I will have to make it «short». I think also @Cosmik may have interest in this answer (from another thread where I didn’t come back to him on the same topic).
It will take a bit of time for you to go through it all but I hope you’ll get my point.
First, take a look at the horizontal/vertical directivity plots of Genelec’s The Ones:
https://www.genelec.com/sites/default/files/media/Studio monitors/SAM Coaxial Studio Monitors/gen_theones_brochure_210x279_12pager_lowres_0.pdf
See how symmetrical they are, and how flat the curves are. The Ones are Genelec’s attempt at point source.
Then, take a look at the same diagram for 8260, page 10:
https://www.genelec.com/sites/default/files/media/Studio monitors/SAM Studio Monitors/8260A/genelec_8240_8250_8351_8260_opman.pdf
8260 was Genelec’s first attempt on coaxial point source and the speaker is a predecessor of The Ones. The mid and tweeter are coaxial but the woofer is mounted below. The diagrams are no longer as beautiful, are they?
Then, take a look at Genelec’s brand new S360, a two-way with compression horn (for high SPL) and a 10 inch woofer, page 9:
https://www.genelec.com/sites/default/files/media/s360_operating_manual.pdf
Even if this is a two-way, which means information summation is easier, it’s clear that the information summation is not as robust off axis as on axis.
Then, take a look at Genelec’s flagship, 1236 (page 7):
https://www.genelec.com/sites/default/files/media/Studio monitors/SAM Studio Monitors/1236A/1236a_operating_manual_0.pdf
This is a full-range speaker, but the off-axis directivity diagram is not beautiful at all.
What we learn from this tour of diagrams is that information summation becomes a problem as soon as you diverge from the point source design. This is not a big problem in a studio where one man sits in sweet spot, and where the room is dead in terms of reverberation from walls. However, in domestic situations, you wish for a wider sweet spot both on and off axis, and you want as little colouration from reflecting sound, right?
In theory, point source is ideal. These diagrams show that Genelec’s point source implementation works. So colouration is minimized, the radiated and reverberated sounds are robust.
Interestingly, very few are interested in point source. And those who use mathematics and physics in other situations, resort to undocumented psychoacoustics («colouration from reverberated sound doesn’t influence perceived sound», etc.) to continue their love affair with traditional driver design. However, if you use a microphone to record the sound in the room - both from a traditional three-way speaker and a point source speaker - you would easily hear how a traditional three-way design colour off axis sound.
Because theory (on point source) and empirical tests (recorded sound in room) support the case of the point source idea, I am baffled that so few wish to hear the sound of a point source and instead continue using legacy design.
Legacy design with conventionally mounted drivers is the ELEPHANT IN THE ROOM.
Thanks @svart-hvitt.
Actually, I recall us having this discussion before now! I'm not quite as sold on coaxials as you are, mostly because I think the disadvantages often outweigh the advantages.
I think I've mentioned before that I might prefer coaxials where there are strong early vertical reflections, e.g. when the speakers are sitting on a desk, but that in a properly setup room I'd probably tend to take a good non-coaxial design for the (all else being equal) lower distortion and higher SPL. YMMV though....
In theory, most certainly. However, the engineering seems far from obvious. Several manufacturers have tried, Tannoy, Cabasse, Devialet to name a few that come to my mind. They don't seem to attract a lot of praise, do they? The Genelec Ones are though. Anyone has tried them?In theory, point source is ideal.
In theory, most certainly. However, the engineering seems far from obvious. Several manufacturers have tried, Tannoy, Cabasse, Devialet to name a few that come to my mind. They don't seem to attract a lot of praise, do they? The Genelec Ones are though. Anyone has tried them?
Coaxial's seem to be making a minor comeback. The KEF LS50 variations have been very successful and the HSU CCB-8 has been well reviewed.In theory, most certainly. However, the engineering seems far from obvious. Several manufacturers have tried, Tannoy, Cabasse, Devialet to name a few that come to my mind. They don't seem to attract a lot of praise, do they? The Genelec Ones are though. Anyone has tried them?
Looks as though the latest path is to use DSP to offer both or multiple options via switching on the same speakerThe obvious choice is therefore to have two different systems, one wide and one narrow! Or to choose a boring compromise with speakers that are neither true omnis nor narrow-dispersion speakers. Or multichannel, as has already been pointed out.
Looks as though the latest path is to use DSP to offer both or multiple options via switching on the same speaker