• The Vendor's Bazaar forum is for commercial offers and transactions. Only unmoderated members can post here.

    diyAudio provides this forum for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members. Use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Modulus-86: Composite amplifier achieving <0.0004 % THD+N.

Jump to Latest
#1,866
Normally I would ask to switch the polarity, and just let them listen. Some will start asking to switch the polarity after that. Basically polarity change were not the subject of test, rather, the goal of the sessions were "tell me what you think about this design configuration". Then they will express whatever they feel. Some purposely just stick with whatever polarity because they do not think customers will care to do switching. If I ask them what they hear different between the different polarities, they will tell me and also express which they feel is more preferred. There were a few tests where the preferred were different from my list. There was one test unit where I myself preferred a different polarity, but when other problems were fixed, the polarity preference became consistent.
 
#1,867
My feeling is that:
Some musical instruments when recorded using some microphones (and some mic techniques) and played back with some loudspeakers will have audible differences.

But some recording consoles have polarity switches on each channel and the engineer may switch some of the channels. That's to reduce mic to mic bleed-through.
 
#1,868
I did notice in one album that some instruments were inverted but some not, but since I could not decide which polarity was better, I just did not worry about it. Once I asked in a mic builders group how they determined the mic were not inverting, seemed like most had ignored the issue. I asked the question when I discovered I was always getting inverted phase in speaker measurements. Finally discovered the way the mic capsule was connected to the mic preamp would result in the inversion.
 
#1,873
What if the situation that is most likely to give a positive is when your system (mostly the speakers) have significant asymmetric nonlinearities. Asymmetric waveforms in the recording will result in different levels of distortion from your speakers. Not only about clipping/bottoming out as proposed earlier (ref to Winer).

In such case bragging about hearing this (golden ears, hi rez speakers..) is bragging about your shitty speakers.

That would be a bit fun.

According to the studies I've seen (and own tests) the range around 100Hz to 300Hz is where we are most sensitive to waveform polarity/absolute phase. Try listening to a 150Hz ramp signal/sawtooth on a good speaker or headphones.
 
#1,875
When listening to vocals, listening to how the vocalist uses lip, teeth, throat, etc. skills to express a song, the relationship in the sequester these characteristics are expressed is very important to feeling the emotion of the singer. The wrong polarity will cause somewhat softer teeth related sound. Other queues are also subtle...

I was evaluating possible adoption of binaural recording earphones and listened to some of the demo recording through EarPods, I did discover that they have inverted polarity. Comparatively the sound would feel like it was ballooning your head rather than having the sound field extending around you. I also listened to I TACEL CD which demonstrates various recording techniques which more correctly expressed the special queues when played in the correct polarity; when played back in the other polarity, the same ballooning your head feeling occurred.
 
#1,876
Dan, George,

I located a plug in for Foobar to switch polarity and tried different kinds of music, as well as a saw tooth signal at multiples of 60 Hz. I am not saying that it is inaudible, but to me it is. Lucky me, one complication in life less.

Have you ever Foobar ABX-ed yourselves with two identical, except for polarity, files? Just to make sure your confidence also translates into real life statistics.
 
#1,877
vacuphile said:
Dan, George,

I located a plug in for Foobar to switch polarity and tried different kinds of music, as well as a saw tooth signal at multiples of 60 Hz. I am not saying that it is inaudible, but to me it is. Lucky me, one complication in life less.

Have you ever Foobar ABX-ed yourselves with two identical, except for polarity, files? Just to make sure your confidence also translates into real life statistics.
Click to expand...
I'm waiting for a thread/poll where such a pair of files (better, several pair, with it being random which is inverted) are made available and votes are cast.

Make 'em FLAC files, for several reasons (lower storage space, more easily played than loaded into a waveform editor).
 
#1,878
vacuphile said:
Dan, George,

I located a plug in for Foobar to switch polarity and tried different kinds of music, as well as a saw tooth signal at multiples of 60 Hz. I am not saying that it is inaudible, but to me it is. Lucky me, one complication in life less.

Have you ever Foobar ABX-ed yourselves with two identical, except for polarity, files? Just to make sure your confidence also translates into real life statistics.
Click to expand...


You are fortunate enough not to worry about it. I specifically setup Jriver Media Center too deal with polarity switching for my normal listening. I did not worry about it until I improved driver CSD decay characteristics. So I can appreciate it when people do not find polarity of concern. The first person I demonstrated it to had been in the audio design business for a long time. He was amazed at the difference when I first demonstrated it to him at my place. I feel there are lots of things that need to be explored. I do take care to make sure drivers have pretty good BL and Km curves over the excursion, the only models that seem to be better in this aspect are a handful of Scan drivers as far as I am have seen. There are lots of other nonlinearies in drivers that are asymmetric, but are common among about all of the dynamic drivers.

The real interesting part of audio development is that different people find different aspects that they focus improvements on. For drivers, I focus on linearity and spectral decay characteristics, lot of these data are not published by the manufacturer and cannot be conveniently corrected for electronically.
 
You must log in or register to reply here.
Top Bottom