My methods include, but are not limited to, addressing issues that are not (rpt not) related to the audio signal anywhere in the system. Also, my system minimizes the deleterious effects of cables, transformers, fuses, and eliminates fuses, power cords, interconnects, speaker cables and obviously room acoustic anomalies. Battery powered CD player and Vintage Sony headphones minimizes system mass, complexity, plus all the things I just mentioned that increase noise and distortion in the system.
I employ Schumann 7.83 Hz signal pre listening and while listening, acoustic version, and demag CDs thoroughly using the Walker Audio technique. CDs and player extensively tweaked, scattered laser light absorption, disc stabilization, purifying the clear polycarbonate layer (hush, hush). Rome wasn’t built in a day.
Geoff Kait
Machina Dynamica
Not too chicken to change
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That would be somewhat OK for a flat 2D soundstage, like with cheap stereo in car. Good soundstage is not only position left to right, but precise depth position must be present. So, you hear sounds coming exactly from the instrument’s and artist’s positions on the “stage”, several meters or even 20 m behind your loudspeakers, not only from various directions (angles) between loudspeakers.
Thats why the proposed mic would be at the listening position. Basically, if a performance is recorded with stereo mics, then each performer will have a loudness and a difference in loudness between the pair. If this can be picked up by stereo mics at the listening position after being played back by the speakers, it would then measure the position, placement. Would it pick this up correctly if everything including phasing and such weren't very right with the speakers? If the test mics can pick up each performer in a step sweep then the speakers image would be measured
Any specific key active ingredients? And explanation how it worked?
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Randy, The first test I would do in preparation for such an experiment would be to set up a mic in one room, and the proposed set of speakers in another room. First play the stereo condenser mic through the speakers with a very high quality fully analog signal chain. Walk between rooms and judge if you think the system is good enough to continue. Then try again with ADC->DAC inserted into the chain. Is the sound already mangled? Or is the ADC/DAC good enough to continue? If after some initial evaluation you think the system is good enough to proceed in a single room, you could try. The only point is that when you want to do an experiment its important to try to find some way to qualify the experimental apparatus to be used. If it passes some subjective testing, then you may want to proceed with measurements of the system. However the subject test phase may point to some issues that you weren't initially planning on measuring.
Also, IME it takes a very good system to do a good job with sound stage imaging, particularly for depth. IMHO most people probably don't have a system at that level.
Also, IME it takes a very good system to do a good job with sound stage imaging, particularly for depth. IMHO most people probably don't have a system at that level.
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Man I am very spoilt, I have had a pair of Aaron AP-3's since mid 90s and the room to run them. Being able to basically recreate each instrument in a mix into a mental sequencer table with pan and vol. These were really cheap when new speakers btw. Since then I have lost the option of room size but my current nrearfields do a fine job too. I don't see the point of buying or building without imaging being a priority
The thing is that the image has to be recorded first. The only way for it to come out is what the transducers do by moving back and forth. There is no magic additional phase shifters. Whatever the room is doing is the room's problem to speaker location. Locate right and the recorded image will be coloured by the room, not broken. The speakers just have to print the recorded image by moving back and forth, they can't do anything else. This can be picked up by a pair of Samson Q7 mics that can pick up mostly one speaker each if pointed towards the speaker from the listening position. Just need to adjust overall volume until they do.
The thing is that the image has to be recorded first. The only way for it to come out is what the transducers do by moving back and forth. There is no magic additional phase shifters. Whatever the room is doing is the room's problem to speaker location. Locate right and the recorded image will be coloured by the room, not broken. The speakers just have to print the recorded image by moving back and forth, they can't do anything else. This can be picked up by a pair of Samson Q7 mics that can pick up mostly one speaker each if pointed towards the speaker from the listening position. Just need to adjust overall volume until they do.
They don't have the sensitivity, frequency response, linearity, low noise, etc., as compared to mics normally used for mic'ing a room and its reverberant decays. If you want to see if the speakers can reproduce that you need mics that are significantly better than the speakers. Otherwise you might learn something about your gear, but you probably won't learn things that apply more generally. For instance, in another thread a member described performing listening tests and found nobody could distinguish AAC lossy encoding from CD. Well, he was using an RPi hat dac and didn't seem to be aware of all the problems with that. Those problems can be mitigated but it can be complicated and expensive to do very well.
Well it's a bit more complicated than that: each kind of mic stereo pair ( MS, Blumlein,X/Y, A/B, ORTF, NOS,...) have a different kind of stereo rendering.
You would first have to decide which one to choose and given every kind introduce some kind of stereo distortion too ( angular distortion is not the last in what is of interest in here not even talking about SRA or angular compression!)...
If interested in limitations of setero pair here is a brief summary:
https://www.google.com/url?sa=t&sou...cQFnoECBsQAQ&usg=AOvVaw3XMCMAWW_Qmk7D-QjsyUYn
I've set up a test ( with Wesayso) with panned signals but it seems to be a lack of interest about it... take a look at Wesayso's thread ( the 2 towers) around september past year there is some example he published and we did not use sweeps, too boring!
We have very fine accuity regarding placement of stereo. It was nescessary because we were prey to many things during evolution ( and we have poor vertical ability for obvious reasons... less predators coming from the sky!).
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@krivium Bad link at fiternet.fr
EDIT: this one works for me https://fiternet.fr/wp-content/uploads/2021/03/Stereo-zoom.pdf
EDIT: this one works for me https://fiternet.fr/wp-content/uploads/2021/03/Stereo-zoom.pdf
Corrected Mark.
And if i may: hypercardio won't be an issue if the kind of couple selected have a correct SRA and is carefully crafted to not induce too much angular distortion or compression.
But in the end... in ear mics binaural is the best bet for this kind of things imho.
Mainly because it mimics our auditory system ( delta amplitude+delta phase+ shadowing of our head+HRTF) and it's important if we want to explore this imaging thing ( especially HRTF).
Got a Neumann 'dummyhead'?
And if i may: hypercardio won't be an issue if the kind of couple selected have a correct SRA and is carefully crafted to not induce too much angular distortion or compression.
But in the end... in ear mics binaural is the best bet for this kind of things imho.
Mainly because it mimics our auditory system ( delta amplitude+delta phase+ shadowing of our head+HRTF) and it's important if we want to explore this imaging thing ( especially HRTF).
Got a Neumann 'dummyhead'?
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No, as a manufacturer it’s a little tricky for me to get into ingredients and explanations, but I can get more specific with Schumann 7.73 Hz. Fire at will.
Wow Mark... that seems almost exactly what was suggested to some "perfect sound forever" crowd of digital promoters about 35 years ago now, if such suggestion of "perfection" was true. Doubt that it was that close back then. As I recall now it could have been to use something like using a real piano.
By the way condenser mic's seem the only thing to use for measurements, calibration, etc., though not sure for doing musical recordings. How about those vocal recordings with ribbon microphones?
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How about a microphone that's - say - a 90 deg flat array of "shotgun" or other type of highly directional microphones, arranged so that the outer most pair point to the outside of the speaker L / R placement. Those would detect any "beyond the speaker" soundfield placement.
The N microphones between these would be listening to spots spanning across the soundstage, where the apparent sound levels "are". So, this begs the question, where you hear sound germinating from an apparent location in between your speakers, is it really louder in the apparent physical space there, or does your brain just perceive it to be louder there?
That's left to right. I dont know what you'd do for front / back.
I was playing with the Reaper N band dynamic range compressor plug in, in expansion mode. Listening to a big band recording where, as those players will do, a few horn players stand up in the middle of the bandstand. They were clearly more dynamic with the multiband expander, but what was really cool is they remained in place spatially, but were more clearly defined in their location by the dynamics of their toots. So now we have a dynamics-in-place/position quality - you wouldnt want the image elements to smear as things get louder in transient, then go back into focus - would you.
The N microphones between these would be listening to spots spanning across the soundstage, where the apparent sound levels "are". So, this begs the question, where you hear sound germinating from an apparent location in between your speakers, is it really louder in the apparent physical space there, or does your brain just perceive it to be louder there?
That's left to right. I dont know what you'd do for front / back.
I was playing with the Reaper N band dynamic range compressor plug in, in expansion mode. Listening to a big band recording where, as those players will do, a few horn players stand up in the middle of the bandstand. They were clearly more dynamic with the multiband expander, but what was really cool is they remained in place spatially, but were more clearly defined in their location by the dynamics of their toots. So now we have a dynamics-in-place/position quality - you wouldnt want the image elements to smear as things get louder in transient, then go back into focus - would you.
jjasniew,
It doesn't matter where the sound emanates from, it only matters what the pressure is at your ears.
Regarding the effect in Reaper using a dynamics expander, what you describe doing is probably not necessary on a better system to hear where the horns are located along the sound stage. If there is some mud/correlated-noise/other problems in a system then doing something to selectively raise certain signals above the din may make existing localization cues more easily audible. That would be my guess without listening alongside you and hearing what you are hearing on the same system with same recording.
It doesn't matter where the sound emanates from, it only matters what the pressure is at your ears.
Regarding the effect in Reaper using a dynamics expander, what you describe doing is probably not necessary on a better system to hear where the horns are located along the sound stage. If there is some mud/correlated-noise/other problems in a system then doing something to selectively raise certain signals above the din may make existing localization cues more easily audible. That would be my guess without listening alongside you and hearing what you are hearing on the same system with same recording.