Log in
Register
Home
Forums
New posts
Search forums
What's new
Featured content
New posts
New profile posts
Latest activity
News
Members
Current visitors
New profile posts
Search profile posts
Features
Log in
Register
What's new
Search
Search titles only
By:
Search titles only
By:
New posts
Search forums
Menu
Install the app
Install
Reply to thread
Home
Forums
Pro Audio
Junior Varsity
What is the audible effect of 180 polarity change between HF and mids?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
<blockquote data-quote="Langston Holland" data-source="post: 41405" data-attributes="member: 171"><p>Re: What is the audible effect of 180 polarity change between HF and mids?</p><p></p><p>Hi Jay:</p><p></p><p>I'm sure you're assuming proper crossover summation in either case. Obviously if you have a well designed crossover where adjacent passbands are inverted in polarity relative to one another, it'll sound terrible if you simply flip the leads on one of the drivers so that both are in normal polarity.</p><p></p><p>Study this: <a href="http://www.livesoundint.com/archives/2003/july/align/align.php" target="_blank">http://www.livesoundint.com/archives/2003/july/align/align.php</a></p><p></p><p>Our five senses are more aware of change than value. The typical phase trace of a loudspeaker system slopes downward indicating increasingly later arrivals of the beginning of the high frequency waveforms relative to the beginning of low frequency waveforms. This time/frequency modification of the electrical signal that went into the loudspeaker is called phase distortion. The steeper the downward slope is, the greater the time-smearing that has been added and the greater the chance that we'll hear it as a distortion. Additional slope changes over small portions of the phase trace present more opportunities for the ear to know something's wrong. In my experience, phase distortion results in removing depth from the stereo image, smearing of backing vocals such that it's hard to hear individual intonations, muddying of complex instrument waveforms such as piano and acoustic guitar, and a general "this sounds like a PA instead of a band" kind of thing.</p><p></p><p>EAW's KF730 inverts the polarity of the low and mid/high passbands relative to each other with standard processing (MX8750). The net result of this with this box using the chosen filters and frequencies is less overall phase rotation (change) over the combined output of both passbands. It's the big picture that matters.</p><p></p><p>With the UX8800 processor, the low and mid/high passbands are still inverted in polarity relative to each other, but the phase trace is horizontal from about 300Hz to 12kHz indicating no phase distortion. How is this possible? To be continued. Maybe. <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f642.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":)" title="Smile :)" data-smilie="1"data-shortname=":)" /></p><p></p><p>* Edit to correct my explanation what a downward sloping phase trace means in reference to the arrivals of the high and low frequencies.</p></blockquote><p></p>
[QUOTE="Langston Holland, post: 41405, member: 171"] Re: What is the audible effect of 180 polarity change between HF and mids? Hi Jay: I'm sure you're assuming proper crossover summation in either case. Obviously if you have a well designed crossover where adjacent passbands are inverted in polarity relative to one another, it'll sound terrible if you simply flip the leads on one of the drivers so that both are in normal polarity. Study this: [url]http://www.livesoundint.com/archives/2003/july/align/align.php[/url] Our five senses are more aware of change than value. The typical phase trace of a loudspeaker system slopes downward indicating increasingly later arrivals of the beginning of the high frequency waveforms relative to the beginning of low frequency waveforms. This time/frequency modification of the electrical signal that went into the loudspeaker is called phase distortion. The steeper the downward slope is, the greater the time-smearing that has been added and the greater the chance that we'll hear it as a distortion. Additional slope changes over small portions of the phase trace present more opportunities for the ear to know something's wrong. In my experience, phase distortion results in removing depth from the stereo image, smearing of backing vocals such that it's hard to hear individual intonations, muddying of complex instrument waveforms such as piano and acoustic guitar, and a general "this sounds like a PA instead of a band" kind of thing. EAW's KF730 inverts the polarity of the low and mid/high passbands relative to each other with standard processing (MX8750). The net result of this with this box using the chosen filters and frequencies is less overall phase rotation (change) over the combined output of both passbands. It's the big picture that matters. With the UX8800 processor, the low and mid/high passbands are still inverted in polarity relative to each other, but the phase trace is horizontal from about 300Hz to 12kHz indicating no phase distortion. How is this possible? To be continued. Maybe. :) * Edit to correct my explanation what a downward sloping phase trace means in reference to the arrivals of the high and low frequencies. [/QUOTE]
Insert quotes…
Verification
Post reply
Home
Forums
Pro Audio
Junior Varsity
What is the audible effect of 180 polarity change between HF and mids?
Top
Bottom
Sign-up
or
log in
to join the discussion today!
