How to achieve coherence

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Administrator
Joined 2004
Paid Member
How do you really know it does not sound like 3 drivers? It may be a silly question but we can easily be fooled into thinking anything......
For example I thought my speakers sounded pretty coherent. But when I heard another speaker, I was shocked at how incoherent they were in comparison.
Shrug. How can we every really know anything? I don't understand the question.

I've heard thousands of speakers of many types, I'm pretty sure I know when they sound disjointed or not. Just in case, I've asked most visitors if they sound like separate parts. Answer is always "No, I don't hear speakers at all". I always like to check. ;)
 
Shrug. How can we every really know anything? I don't understand the question.

I've heard thousands of speakers of many types, I'm pretty sure I know when they sound disjointed or not. Just in case, I've asked most visitors if they sound like separate parts. Answer is always "No, I don't hear speakers at all". I always like to check. ;)

So thousands, eh?

I guess you've been listening to dozens a day.

Or was that a few hundred a day?

How many thousands?

Do you often write in a detailed nature?

P

Of course you are a moderator. You must not be challenged.
 
Last edited:
I use arrays of 16 Foster 402S01 drivers as tweeters, and don't hear any "incoherece" with arrays of 8 x 4" drivers with poly cones and pair of 12" woofers in concrete boxes. I don't hear speakers at all, I hear stereo image. Why? Because if speakers "give away" themselves they "give away" because of their distortions. In arrays displacements are tiny, so distortions are much lower than from a single driver that produces the same pressure level.
 
Administrator
Joined 2004
Paid Member
Of course you are a moderator. You must not be challenged.
I get challenged plenty. No worries there. :D

I will admit that I have not counted the many speakers I've heard over the past few decades, so I'd have guess at the number. Just one new one a week would add up to 1000s. Speakers are kinda ubiquitous in our modern world. How many do you figure you've heard over your lifetime?
 
I use arrays of 16 Foster 402S01 drivers as tweeters, and don't hear any "incoherece" with arrays of 8 x 4" drivers with poly cones and pair of 12" woofers in concrete boxes. I don't hear speakers at all, I hear stereo image. Why? Because if speakers "give away" themselves they "give away" because of their distortions. In arrays displacements are tiny, so distortions are much lower than from a single driver that produces the same pressure level.

All those 4's and woofs sounds good. My experience with 180mm's and earlier tells me it's all about design. Tell us more.

What's the LxRxH on the room and where are they?
 
All those 4's and woofs sounds good. My experience with 180mm's and earlier tells me it's all about design. Tell us more.

What's the LxRxH on the room and where are they?

+ center channel: 2 x 6", and 64x12mm as a tweeter array. + 2x12" in horn subwoofer (concrete) under the floor.

The biggest minus is a wall close to the left speaker. Without it a stereo image would be much better.

An externally hosted image should be here but it was not working when we last tested it.
 
....Two or more sources of sound can add together like we think of when adding signals with resistors and get one result, they add coherently into one new source. They only do this when they are less than about one quarter wavelength apart.


The larger the speaker system, the harder it is to make coherent.......

Small speaker, cross very steep 1kHz, linear phase, and drivers 1/4 wavelength apart at crossover.

Coherence in information system is ability to get out at point B what was put in at point A. Knowing the system unit behavior allows for compensation so that coherency is maintained. MLS and swept sine are two systems that may be thought of as spreading an impulse response over time with the test signal, and that reconstruct correct temporal characteristic by correlation with inverse to test signal to get the system resonse. MLS produces noise like sound with chopped up phase, swept sine is smooth.


Andrew
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.