I understand the uncertainty of translating anechoic sound to room sound entails. The reassuring part is that the direct field (anechoic) component is the most important part, at least above 200 Hz. Many tests have repeatedly shown this (as we've discussed in the "what directivity" thread). For lower frequencies then the speakers sound can't be removed from the room, but, again it isn't as dire as it seems. Most of the rooms effect comes from the first few boundary reflections. An anechoic test with added floor and back wall boundaries would give a reasonably representative view of the system and would allow a pretty good bypass test.
As to speaker size, I lke a big system too, but I think it is like having a 300 horsepower car when you don't usually use over 150. It gets to move along effortlessly and the power is there when you (rarely) use it. I think a big system, capable of much higher spl, can just loaf along well within its capabilities and at lower distortion.
Do we perceive source size? I don't really think so. A 6 foot tall horn is radiating from its center. It always seems to me that the sound comes from back in the throat, not from the front edges. This is acknowledged as the mark of a good horn. It should be free from re-radiation from the edges. This means the edges can't be heard and the size can not be judged by ear (by eye, yes). I have noticed a similar case with line sources. You only hear the nearest tweeter as the source. All others are hidden behind it (standard Haas effect).
As to replicating the studio mastering experience, that has never been my goal. If the mix was made with a particularly bad monitor, will using that system improve my experience? (Did the mixing engineer incorporate a perfect inverse to his monitoring system into the recording process?) Wouldn't a more accurate monitor get me closer to the sound in the studio, heard by the microphone, not necessarily the sound in the mixing room. That sounds more desirable to me than transporting myself into the mixing session.
David S.
As to speaker size, I lke a big system too, but I think it is like having a 300 horsepower car when you don't usually use over 150. It gets to move along effortlessly and the power is there when you (rarely) use it. I think a big system, capable of much higher spl, can just loaf along well within its capabilities and at lower distortion.
Do we perceive source size? I don't really think so. A 6 foot tall horn is radiating from its center. It always seems to me that the sound comes from back in the throat, not from the front edges. This is acknowledged as the mark of a good horn. It should be free from re-radiation from the edges. This means the edges can't be heard and the size can not be judged by ear (by eye, yes). I have noticed a similar case with line sources. You only hear the nearest tweeter as the source. All others are hidden behind it (standard Haas effect).
As to replicating the studio mastering experience, that has never been my goal. If the mix was made with a particularly bad monitor, will using that system improve my experience? (Did the mixing engineer incorporate a perfect inverse to his monitoring system into the recording process?) Wouldn't a more accurate monitor get me closer to the sound in the studio, heard by the microphone, not necessarily the sound in the mixing room. That sounds more desirable to me than transporting myself into the mixing session.
David S.
That would be great if the mastering engineer never touched the EQ sliders or twisted the compressor knob as he listened to his Yamahas...
I just wish every recording could be released in two versions--the raw mix with no or minimal EQ and no compression, and the one intended to compete in the loudness races.
That would be great if the mastering engineer never touched the EQ sliders or twisted the compressor knob as he listened to his Yamahas...
I just wish every recording could be released in two versions--the raw mix with no or minimal EQ and no compression, and the one intended to compete in the loudness races.
I would pay extra for that (the former).
David S.
...the coiled vs. straight thing, I was thinking that there is something going on WRT either the way the wavefront changes going round and round and/or related to the way that sound when reflected off a surface (don't laugh and point now) as with a speaker like the Blows 901 is somehow altered (often for the better), as compared to a straight shot down the "barrel".
Apparently I am the only one who thinks this is of interest?
_-_-bear
Apparently I am the only one who thinks this is of interest?
_-_-bear
Bear,
See my post a while back. These simulations show what happens to wavefronts at various frequencies as they encounter the curve. Higher frequencies don't appear to fare to well...
But don't get me wrong--this isn't saying it doesn't sound great despite the lobes and cancellation.
See my post a while back. These simulations show what happens to wavefronts at various frequencies as they encounter the curve. Higher frequencies don't appear to fare to well...
But don't get me wrong--this isn't saying it doesn't sound great despite the lobes and cancellation.
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We know from the W.E. polar curves (somewhere in the thread) that the final dispersion pattern is somewhat downwards. That is, just because the mouth is perpendicular to the floor doesn't mean that the system projects out parallel to the floor. This is further evidence that the horn is radiating from further back in the spiral (some degrees of rotatation around the bend.
It is also well known that folded or spiral horns are going to lose HF in the bends. I forget the rule of thumb but isn't it something like "good for frequencies where the bend radius is greater than the radiated wavelength"? I've never built a curved horn so I haven't measured this directly.
As to whether the sound bounces from side to side as it traverses the horn, I'm not sure. I would think that the wavefront would spiral around the horn (at least the lower frequency components would) and for lowest frequencies the spiral would be immaterial. Higher Order modes? Probably.
A very low cutoff design will inherently have a slow expansion rate and HF beaming is inevitable, so whatever frequencies make it through the spiral will have to be fairly directional. This still wouldn't be like a Bose: bouncing off the walls, with lots of diffusion effect.
The one unit that I have seen measurements of that is physically similar would be the early RCA Victor Orthophonic acoustical phonographs. They were essentially a scaled down version of the spiral horn. They were a big step up from the earlier phongraphs. (Western Electric was involved in the electrical recording conversion.) Longer true exponential horns. Wider bandwidth transducer with a better diaphragm design and a nominal phase plug. Still, they only spanned about 3 Octaves, if I remember correctly.
David S.
It is also well known that folded or spiral horns are going to lose HF in the bends. I forget the rule of thumb but isn't it something like "good for frequencies where the bend radius is greater than the radiated wavelength"? I've never built a curved horn so I haven't measured this directly.
As to whether the sound bounces from side to side as it traverses the horn, I'm not sure. I would think that the wavefront would spiral around the horn (at least the lower frequency components would) and for lowest frequencies the spiral would be immaterial. Higher Order modes? Probably.
A very low cutoff design will inherently have a slow expansion rate and HF beaming is inevitable, so whatever frequencies make it through the spiral will have to be fairly directional. This still wouldn't be like a Bose: bouncing off the walls, with lots of diffusion effect.
The one unit that I have seen measurements of that is physically similar would be the early RCA Victor Orthophonic acoustical phonographs. They were essentially a scaled down version of the spiral horn. They were a big step up from the earlier phongraphs. (Western Electric was involved in the electrical recording conversion.) Longer true exponential horns. Wider bandwidth transducer with a better diaphragm design and a nominal phase plug. Still, they only spanned about 3 Octaves, if I remember correctly.
David S.
I was typing while you where posting. Interesting plots and they do show that the higher frequencys tend to favor the outside wall of the spiral and exit more or less in line with the outer surface.
This is probably why you frequently see pictures of the units tilted back for listening.
David
Yep. And you'll see a dotted line painted on the side that shows the acoustic line. It's not at 90 degs to the mouth. We always put a felt mat at the bottom of the mouth, too. I don't remember what it was supposed to do.
My "don't point and laugh at me" guess is that the coil works as a nice low pass filter and maybe a "homogenizer". The fregs that would beam badly just don't get thru.
My "don't point and laugh at me" guess is that the coil works as a nice low pass filter and maybe a "homogenizer". The fregs that would beam badly just don't get thru.
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