Over the last week, I've rekindled an interest in DRC, purely as a further exploration, to see what the current state of play is.
Making an effort to modify the frequency response, i.e amplitude of frequencies, to meet a target curve, with a threshold, I have no issues with this aspect of speaker/room correction. There is pretty much consensus, that this is a good objective. And every single process or software or device that aims at some kind of room or speaker correction, of some kind, includes this effort, to correct the amplitude of frequencies. Some in software, some in the speakers, some in external devices like DEQX, or from MiniDSP, or via the custom Linux server in solutions like Trinnov.
Listening to this video - see link or video embed below, and reading through comments across related threads on this and other online forums, however, I feel a certain discomfort, with the alchemy of emphasis on time alignment, not because there is not a case for this, but some of the exponents as in the video who make a whole talk about this time alignment, without addressing an elephant in the room.
Assuming that time alignment is critical, and important to the end result, it begs the question, which time alignment is really important? Cos if we wish to align time of arrival, we have several places to deal with this, not one.
1. Aligning the time of arrival between the high frequencies and the low frequencies, from all the drivers in each speaker., in a scenario where you have more than one driver, with each driver taking care of a different frequency band. Some speakers already attempt to achieve this using their own internal method, such as physically aligning the center of the tweeter driver to the centre of the woofer driver, with the tweeter set further back into the cabinet, for example. But of course depending on the orientation of these drivers, unless you have a concentric or co-axial speaker like the Genelec 8531, as you move your head, especially in the nearfield, the possibility that you will hear one driver's output arrive ahead of another is increased, and this of course also alters the amplitude of the contribution of one driver over another, changing the tone of the overall sound, especially the nearer you are to the speaker. Other options would be to use a single driver. like the Avantone Mixcubes.
So the real solution to allow you reduce the difference in arrival time between different drivers, would be careful positioning, and angling, and more likely sitting at a minimum distance from the speaker to reduce this differential in time arrival. Assuming we have two drivers, on one speaker and draw a triangle between the two drivers and the listening position, the greater the distance from the speakers, the higher the probability that (for a human head which is not actually static when sitting upright to listen to speakers), the angles of the triangle at the speaker drivers, will be more equal, and this lead to an equivalent arrival time at the listener.
My point here being, the greatest differential in the time arrival of audio from a tweeter and a woofer to a listener, is influenced by the position of the listener, more than any other, and the best solution to solving this important differential is not an electronic one, or digital one, but simple clever placement of the speaker, and listener, and angling the speaker to achieve as much as possible an almost identical time arrival at the listeners ear.
So either you go concentric/coaxial to make this pretty much a non issue, or you use sensible placement. Unless of course, the time arrival of bass and treble frequencies in the same speaker are so far apart due to delays caused by digital or analog crossovers, which in theory make the woofer to appear to be coming from a location which is 10's of feet behind the tweeter i.e the bass is delayed by 10's of milliseconds i.e. approx. 1 foot per millisecond - as per the speed of sound in air.
But it then begs the question, would not any decent speaker manufacturer have sorted this out, in their speaker design, if this delay would affect the time arrival so significantly, between the woofer and the tweeter. i.e. the solution being also - buy a decent, well designed speaker, that by design reduces this difference in arrival time.
2. Next we have the need to ensure that there is not too much variance in the arrival time of audio at the listening position, from one speaker to another.
In a simple stereo setup, the ideal solution for this is not an electronic or digital one, but a simple physical one - sit as much as possible, in the center at an equal distance between the speakers. Yet it will never be exactly equidistant cos our heads are not static and rather than aim to stick our heads in one perfect spot, the better solution is to use speakers with a good dispersion, so that we have more latitude to move around from left to right and still hear each speaker well enough. i,e. buy speakers with this desired horizontal wide-ish enough directivity.
And if our subwoofer is brought into the picture, then time align, by delaying either the main speakers or the subs, depending on which is nearer to the listening position. But this does not need any esoteric DRC, a simple measure of the distances with a measuring tape, should give us enough info to dial in the delay close enough. Kind of similar what happens in PA systems, which have a subwoofer tucked away somewhere in the hall. Not much voodoo needed.
More to the point, with the exception of possibly Trinnov, and I think Sonarworks, have not heard much about other tools, addressing time alignment between the different speakers, at least not in their main marketing info - if it was that important a feature, it should have been front and center in their publicity info. Furthermore, without a special 3D microphone like Trinnov uses, or the triangulation that Sonarworks by sending the same audio to both speakers, which for example is not measured in REW, how does one using a DRC technology approach, fix any timing differences in arrival between speakers?
Point of all this is - there seems to be so much hot debate and mention of time alignment, when some of these DRC solutions that are well touted, have no solution to detect or fix variations in timing, thus their exponents, in my view focus on the minutiae, and not much evidence of the import of their "time alignment efforts", when the simple things, like placement, can be achieved with a inexpensive tape measure, a string, or a laser based distance measuring device, not 300 dollars worth of complex software, and 500 dollars of consulting to hand hold the end user, to use the software properly.
Glad for all those who are making a nice tidy income from aiming and claiming to solve "timing problems" via confusing, difficult to use DRC software, when basic diligence with speaker placement would have achieved a whole lot more, and there is far more value in buying speakers that have been designed properly in the 1st place. Rather than trying to fix "time alignment" problems that should not have existed in the 1st place due to poor speaker design or wrong speaker placement and positioning.
Now that frequency/amplitude correction is pretty de rigueur, today, i.e. nothing new here, is there an emergence of "solutions" and consultants, claiming to add value through esoteric "time alignment", aiming to use technology to solve timing problems that should not have needed esoteric analysis and solutions, in the 1st place. Just good speaker design, and common sense needed.
What makes this whole issue even worse, is that no matter how well we time align drivers within a speaker cabinet, or arrival time from different cabinets, to a single spot in space, no human head is static, so all this herculean accuracy, will be overridden. minute by minute, by small head movements, anyway (unless of course you have used excellent design and consumer intelligence to buy a coaxial speaker, then all this time alignment effort is a total waste of time - pun intended).
And even with a coaxial set of speakers, due to head movements, the coincidence from one speaker to another in time arrival at the listening position, will never be identical. i.e. there is a threshold beyond which all further efforts to time align, are simply chasing ghosts, that add no value, but its ok to make claims and offer services for delivering improvements that are at best hard to prove, in a real world where heads and ears are not static, and these minute timing improvements are possibly irrelevant.
Making an effort to modify the frequency response, i.e amplitude of frequencies, to meet a target curve, with a threshold, I have no issues with this aspect of speaker/room correction. There is pretty much consensus, that this is a good objective. And every single process or software or device that aims at some kind of room or speaker correction, of some kind, includes this effort, to correct the amplitude of frequencies. Some in software, some in the speakers, some in external devices like DEQX, or from MiniDSP, or via the custom Linux server in solutions like Trinnov.
Listening to this video - see link or video embed below, and reading through comments across related threads on this and other online forums, however, I feel a certain discomfort, with the alchemy of emphasis on time alignment, not because there is not a case for this, but some of the exponents as in the video who make a whole talk about this time alignment, without addressing an elephant in the room.
Assuming that time alignment is critical, and important to the end result, it begs the question, which time alignment is really important? Cos if we wish to align time of arrival, we have several places to deal with this, not one.
1. Aligning the time of arrival between the high frequencies and the low frequencies, from all the drivers in each speaker., in a scenario where you have more than one driver, with each driver taking care of a different frequency band. Some speakers already attempt to achieve this using their own internal method, such as physically aligning the center of the tweeter driver to the centre of the woofer driver, with the tweeter set further back into the cabinet, for example. But of course depending on the orientation of these drivers, unless you have a concentric or co-axial speaker like the Genelec 8531, as you move your head, especially in the nearfield, the possibility that you will hear one driver's output arrive ahead of another is increased, and this of course also alters the amplitude of the contribution of one driver over another, changing the tone of the overall sound, especially the nearer you are to the speaker. Other options would be to use a single driver. like the Avantone Mixcubes.
So the real solution to allow you reduce the difference in arrival time between different drivers, would be careful positioning, and angling, and more likely sitting at a minimum distance from the speaker to reduce this differential in time arrival. Assuming we have two drivers, on one speaker and draw a triangle between the two drivers and the listening position, the greater the distance from the speakers, the higher the probability that (for a human head which is not actually static when sitting upright to listen to speakers), the angles of the triangle at the speaker drivers, will be more equal, and this lead to an equivalent arrival time at the listener.
My point here being, the greatest differential in the time arrival of audio from a tweeter and a woofer to a listener, is influenced by the position of the listener, more than any other, and the best solution to solving this important differential is not an electronic one, or digital one, but simple clever placement of the speaker, and listener, and angling the speaker to achieve as much as possible an almost identical time arrival at the listeners ear.
So either you go concentric/coaxial to make this pretty much a non issue, or you use sensible placement. Unless of course, the time arrival of bass and treble frequencies in the same speaker are so far apart due to delays caused by digital or analog crossovers, which in theory make the woofer to appear to be coming from a location which is 10's of feet behind the tweeter i.e the bass is delayed by 10's of milliseconds i.e. approx. 1 foot per millisecond - as per the speed of sound in air.
But it then begs the question, would not any decent speaker manufacturer have sorted this out, in their speaker design, if this delay would affect the time arrival so significantly, between the woofer and the tweeter. i.e. the solution being also - buy a decent, well designed speaker, that by design reduces this difference in arrival time.
2. Next we have the need to ensure that there is not too much variance in the arrival time of audio at the listening position, from one speaker to another.
In a simple stereo setup, the ideal solution for this is not an electronic or digital one, but a simple physical one - sit as much as possible, in the center at an equal distance between the speakers. Yet it will never be exactly equidistant cos our heads are not static and rather than aim to stick our heads in one perfect spot, the better solution is to use speakers with a good dispersion, so that we have more latitude to move around from left to right and still hear each speaker well enough. i,e. buy speakers with this desired horizontal wide-ish enough directivity.
And if our subwoofer is brought into the picture, then time align, by delaying either the main speakers or the subs, depending on which is nearer to the listening position. But this does not need any esoteric DRC, a simple measure of the distances with a measuring tape, should give us enough info to dial in the delay close enough. Kind of similar what happens in PA systems, which have a subwoofer tucked away somewhere in the hall. Not much voodoo needed.
More to the point, with the exception of possibly Trinnov, and I think Sonarworks, have not heard much about other tools, addressing time alignment between the different speakers, at least not in their main marketing info - if it was that important a feature, it should have been front and center in their publicity info. Furthermore, without a special 3D microphone like Trinnov uses, or the triangulation that Sonarworks by sending the same audio to both speakers, which for example is not measured in REW, how does one using a DRC technology approach, fix any timing differences in arrival between speakers?
Point of all this is - there seems to be so much hot debate and mention of time alignment, when some of these DRC solutions that are well touted, have no solution to detect or fix variations in timing, thus their exponents, in my view focus on the minutiae, and not much evidence of the import of their "time alignment efforts", when the simple things, like placement, can be achieved with a inexpensive tape measure, a string, or a laser based distance measuring device, not 300 dollars worth of complex software, and 500 dollars of consulting to hand hold the end user, to use the software properly.
Glad for all those who are making a nice tidy income from aiming and claiming to solve "timing problems" via confusing, difficult to use DRC software, when basic diligence with speaker placement would have achieved a whole lot more, and there is far more value in buying speakers that have been designed properly in the 1st place. Rather than trying to fix "time alignment" problems that should not have existed in the 1st place due to poor speaker design or wrong speaker placement and positioning.
Now that frequency/amplitude correction is pretty de rigueur, today, i.e. nothing new here, is there an emergence of "solutions" and consultants, claiming to add value through esoteric "time alignment", aiming to use technology to solve timing problems that should not have needed esoteric analysis and solutions, in the 1st place. Just good speaker design, and common sense needed.
What makes this whole issue even worse, is that no matter how well we time align drivers within a speaker cabinet, or arrival time from different cabinets, to a single spot in space, no human head is static, so all this herculean accuracy, will be overridden. minute by minute, by small head movements, anyway (unless of course you have used excellent design and consumer intelligence to buy a coaxial speaker, then all this time alignment effort is a total waste of time - pun intended).
And even with a coaxial set of speakers, due to head movements, the coincidence from one speaker to another in time arrival at the listening position, will never be identical. i.e. there is a threshold beyond which all further efforts to time align, are simply chasing ghosts, that add no value, but its ok to make claims and offer services for delivering improvements that are at best hard to prove, in a real world where heads and ears are not static, and these minute timing improvements are possibly irrelevant.
Last edited: