Phase
09-22-2004, 03:58 PM
#32
50 Watt CAFz'r
Join Date: Mar 2004
Posts: 146
Here is my take on imaging...I think that even with a decent center image...the image can shift to the left or right during specific musical transients...unless you have a processor that can delay specific frequencies when the image does shift, then the laws of physics will always win in this battle.
I haven't heard of a processor that can delay specific frequencies like a 30 band eq or something...
Let's say that your image tends to shift to the right at around 2KHZ...set a time delay for this frequency so when it does shift it will be closer to the center image when it occurs...
...good idea?
[ September 22, 2004, 05:01 PM: Message edited by: Halo1 ]
I haven't heard of a processor that can delay specific frequencies like a 30 band eq or something...
Let's say that your image tends to shift to the right at around 2KHZ...set a time delay for this frequency so when it does shift it will be closer to the center image when it occurs...
...good idea?
[ September 22, 2004, 05:01 PM: Message edited by: Halo1 ]
09-28-2004, 07:18 AM
#33
1000 Watt CAFz'r
Thread Starter
Join Date: Oct 2003
Posts: 1,783
Halo,
What you are talking about is the next frontier in system tuning. I've talked to a few people in the high end home market, and people are looking at trying this. It will however, be application specific.
I'd gamble that Meridian will probably be the first to offer this type of signal manipulation in their products. It's not too far off what they are doing now with their digital loudspeakers.
I think the key thing to understand here, is that changing the "timing" of the input signal at specific frequencies is the next step. NOT, changing the driver's relative phase across it's entire working bandwidth as done by most Time Alignment modules or processors. As mentioned above, driver's phase response changes across their bandwidth. I think exploring this issue more could realize significant gains in SQ by further understanding how this affects what we hear.
Adam
What you are talking about is the next frontier in system tuning. I've talked to a few people in the high end home market, and people are looking at trying this. It will however, be application specific.
I'd gamble that Meridian will probably be the first to offer this type of signal manipulation in their products. It's not too far off what they are doing now with their digital loudspeakers.
I think the key thing to understand here, is that changing the "timing" of the input signal at specific frequencies is the next step. NOT, changing the driver's relative phase across it's entire working bandwidth as done by most Time Alignment modules or processors. As mentioned above, driver's phase response changes across their bandwidth. I think exploring this issue more could realize significant gains in SQ by further understanding how this affects what we hear.
Adam
09-29-2004, 12:10 AM
#35
If changing of phase with bandwidth is a naturally occuring phenomenon with transducers (speakers) why would you want to process the naturality of the sound right out of it? Sometimes with all this high-tech wizardry and gadgets we have and want to have, you gotta take a step back and ask: how and why would this improve things?
Kinda reminds me of that Simpsons episode where they go to the US embassy in Austrailia and they proudly show the toilet that reverses the direction of the water rotation to match that of the USA. Massive amounts of money and time into a machine that reverses what occurs naturally and in the end you say: what a waste of time and money!
Kinda reminds me of that Simpsons episode where they go to the US embassy in Austrailia and they proudly show the toilet that reverses the direction of the water rotation to match that of the USA. Massive amounts of money and time into a machine that reverses what occurs naturally and in the end you say: what a waste of time and money!
09-29-2004, 05:11 AM
#36
1000 Watt CAFz'r
Join Date: Aug 2002
Posts: 1,239
Wouldn't phase be an issue at crossover feq`s rather than the drivers natural shift?
Drivers roll off (mechanical or electrical)
causes a phase issue and therefore freq issues in freq bands that are considered important.
Funny how adjusting your HP freq and slope(150hz and below) can affect your midrange.
Just recently I was experiencing sum awful
sibilance.. I adjusted my HP on my mid
and it went away.
Drivers roll off (mechanical or electrical)
causes a phase issue and therefore freq issues in freq bands that are considered important.
Funny how adjusting your HP freq and slope(150hz and below) can affect your midrange.
Just recently I was experiencing sum awful
sibilance.. I adjusted my HP on my mid
and it went away.
09-29-2004, 06:07 AM
#38
1000 Watt CAFz'r
Thread Starter
Join Date: Oct 2003
Posts: 1,783
Sux,
You have a very valid point in my eyes. That is why I view this phenomenon as a learning opportunity, rather than a final solution to system tuning.
There are lots of unexplained issues when tuning a system, I'm reaching the edge of my knowledge envelope trying to figure these things out. Right now, I'm finding that I don't know alot about tuning phase in a system. (I'm not talking about how to work the H900) Things aren't adding up, and I'm questioning that rather than shrugging my shoulders and passing that off as a "car issue".
I've heard a quote before that kind of fits into this catagory.
"If you can't scientifically measure an audible improvement, than you are measuring the wrong thing."
I think all of us fall into this catagory sometimes.
Using an RTA in the frequency domain to blindly set up system response is a good example of this. The point of this thread was to open up a new can of worms...and now everybody appears to have opened up a bottle of JD!!!!
Jeeze....
You have a very valid point in my eyes. That is why I view this phenomenon as a learning opportunity, rather than a final solution to system tuning.
There are lots of unexplained issues when tuning a system, I'm reaching the edge of my knowledge envelope trying to figure these things out. Right now, I'm finding that I don't know alot about tuning phase in a system. (I'm not talking about how to work the H900) Things aren't adding up, and I'm questioning that rather than shrugging my shoulders and passing that off as a "car issue".
I've heard a quote before that kind of fits into this catagory.
"If you can't scientifically measure an audible improvement, than you are measuring the wrong thing."
I think all of us fall into this catagory sometimes.
Using an RTA in the frequency domain to blindly set up system response is a good example of this. The point of this thread was to open up a new can of worms...and now everybody appears to have opened up a bottle of JD!!!!
Jeeze....
09-29-2004, 06:59 AM
#39
Guest
Posts: n/a
the phase response of identical drivers in 2 different vehicles would be completely different at the listeners ears. the sound coming from the speaker would be the same but the inherent phase and response changes brought on by each vehicles interior would make a parametric phase adjustment tool perhaps useful, could it amke things worse possibly, could it make things better, possibly. nonetheless i would try one if such a thing were available in car audio.
the sun is just coming up over the mountains and shining onto okanagon lake and reflecting right im my kitchen window. i am far to lucky to live where i live, anyone who hasnt visited kelowna and the okakagon, should, at one time in their life get around to it, it truly is a magnificent place to live and see [img]smile.gif[/img] sorry to get off topic
the sun is just coming up over the mountains and shining onto okanagon lake and reflecting right im my kitchen window. i am far to lucky to live where i live, anyone who hasnt visited kelowna and the okakagon, should, at one time in their life get around to it, it truly is a magnificent place to live and see [img]smile.gif[/img] sorry to get off topic
09-29-2004, 11:44 AM
#40
Guest
Posts: n/a
If you think that speaker phaze is a problem, you are only consider 1/3 of the problem.
Before we dive into that, let me clarify things. Phase, Polarity and time-alignment are all discussions of the same occurance.
Polarity is the response of an item relative to positivity or negativity. Ie: A speaker moves inwards or outwards relative to the flow of electrons through the voice coil.
Phase refers to a portion of a complete cycle as measured from a reference point. Being 180 degrees out of phase has the same result as having reverse polarity - EXCEPT, there is also a time delay involved.
Time alignment adjustments are the same as phase adjustments. The PPI PSC-221 Phase Shift Controller and the Audio Control 24XS with the SWAT (Speaker Wave Alignment Technology) are analog phase shift adjustments. I haven't tested these in terms of performance across the entire frequency range.
Ten years ago, time alignment was available through products like the Clarion ACDS and the original Rockford Symmetry system offered digitally controlled analog time alignment.
In the past few years, time alignment has run rampant through the mobile audio industry. The OE radio in Chryslers has time alignment. The Sony DSO or any deck with 'seating position' adjustments use rudimentary time alignment.
Serious system processors like the H900 offer 0.1mSec adjustment steps. The Clarion DXZ9255 has time alignment in steps of 0.02mSec (or 7.15mm).
Time Alignment is used simple to delay the signal. For example, delay the output of our front stage relative to your subwoofers so that the sound arrives at your ears at the same time.
Before we dive into that, let me clarify things. Phase, Polarity and time-alignment are all discussions of the same occurance.
Polarity is the response of an item relative to positivity or negativity. Ie: A speaker moves inwards or outwards relative to the flow of electrons through the voice coil.
Phase refers to a portion of a complete cycle as measured from a reference point. Being 180 degrees out of phase has the same result as having reverse polarity - EXCEPT, there is also a time delay involved.
Time alignment adjustments are the same as phase adjustments. The PPI PSC-221 Phase Shift Controller and the Audio Control 24XS with the SWAT (Speaker Wave Alignment Technology) are analog phase shift adjustments. I haven't tested these in terms of performance across the entire frequency range.
Ten years ago, time alignment was available through products like the Clarion ACDS and the original Rockford Symmetry system offered digitally controlled analog time alignment.
In the past few years, time alignment has run rampant through the mobile audio industry. The OE radio in Chryslers has time alignment. The Sony DSO or any deck with 'seating position' adjustments use rudimentary time alignment.
Serious system processors like the H900 offer 0.1mSec adjustment steps. The Clarion DXZ9255 has time alignment in steps of 0.02mSec (or 7.15mm).
Time Alignment is used simple to delay the signal. For example, delay the output of our front stage relative to your subwoofers so that the sound arrives at your ears at the same time.
