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audioXpress article topic suggestions

amirm

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I like to see quantification of cabinet diffraction. Take a simple 2-way bookshelf and simulate with rounded edges vs sharp. There is expense involved in the former so would be nice to see what the benefit is.
 

tuga

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I like to see quantification of cabinet diffraction. Take a simple 2-way bookshelf and simulate with rounded edges vs sharp. There is expense involved in the former so would be nice to see what the benefit is.

Something like this?

 

Sokel

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I would like something much simpler,the right way to integrate subs with mains.
I've seen enough suffering in the 100-200Hz region and people trying to deal with that crossing them way above 50Hz.That would benefit a lot of people.
 

Mario Sanchez

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This might be a bit too general of a question, but I am very curious as to how the breakup modes of a speaker diaphragm can be altered/managed by its physical profile (cross sectional and shape-wise)? There's got to be a better way to make a speaker driver behave at higher up in frequency aside from the cold-war-ish approach of just throwing more stiff, light, exotic material at the thing... right?
 

SIY

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Thanks, tuga. I am not that measurement oriented but it could be turned into a topic in some modelling sense.
You know, AX does have a measurement guy who can help validate model predictions. Ahem. Cough, cough.
 

Killingbeans

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This might be a bit too general of a question, but I am very curious as to how the breakup modes of a speaker diaphragm can be altered/managed by its physical profile (cross sectional and shape-wise)? There's got to be a better way to make a speaker driver behave at higher up in frequency aside from the cold-war-ish approach of just throwing more stiff, light, exotic material at the thing... right?

I think he mentioned something like that in the interview Erin did with him. Not just the possibility of getting better control over the breakup modes, but also the idea of designing cones with optimized rolloffs, alowing the use of much simpler crossovers.
 

egellings

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I think he mentioned something like that in the interview Erin did with him. Not just the possibility of getting better control over the breakup modes, but also the idea of designing cones with optimized rolloffs, alowing the use of much simpler crossovers.
You'd have a part mechanical, part electrical crossover then.
 

captainbeefheart

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I personally would love to see an article on stability and some real world testing on popular amplifiers and how it can correlate to sound quality.

I think this could account for some of the differences we hear in amplifiers although they may test the same on the bench. The reason for testing the same on the bench is because of the use of a non-reactive load for testing. People always ask the question "will two amplifiers that test the same sound the same?". In the real world our amplifiers are driving reactive loads and so a reactive load test in the specifications I think would be helpful.

This also may be a good test for Amir to add to his arsenal of tests when reviewing amplifiers. In addition to the standard tests add some reactance to the bench load and shoot some square waves through the device. I personally do this all the time with amplifiers because I feel it's an important quality of an amp but I rarely see it done in reviews or tests online.

This also could account for why people hear differences in speaker cables. Different LCR parameters of the cable may alter the phase margin and cause audible changes. That and speaker cable manufacturers are adding RC networks into their cables, this changes the loading the amplifier would normally see and also change the phase margin much more so compared to the intrinsic LC properties of just the cable conductors alone.

Thanks!
 

SIY

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I personally would love to see an article on stability and some real world testing on popular amplifiers and how it can correlate to sound quality.

I think this could account for some of the differences we hear in amplifiers although they may test the same on the bench. The reason for testing the same on the bench is because of the use of a non-reactive load for testing. People always ask the question "will two amplifiers that test the same sound the same?". In the real world our amplifiers are driving reactive loads and so a reactive load test in the specifications I think would be helpful.

This also may be a good test for Amir to add to his arsenal of tests when reviewing amplifiers. In addition to the standard tests add some reactance to the bench load and shoot some square waves through the device. I personally do this all the time with amplifiers because I feel it's an important quality of an amp but I rarely see it done in reviews or tests online.

This also could account for why people hear differences in speaker cables. Different LCR parameters of the cable may alter the phase margin and cause audible changes. That and speaker cable manufacturers are adding RC networks into their cables, this changes the loading the amplifier would normally see and also change the phase margin much more so compared to the intrinsic LC properties of just the cable conductors alone.

Thanks!
In my amp reviews, I often do multitone and distortion vs frequency runs with an actual loudspeaker load. Nothing pathological, but certainly typical. I just haven't seen any engineered amps do anything funny or unexpected that didn't show up in dummy load testing.

Still waiting to find out specifics on two amps that "test the same on the bench" but have demonstrated audible "differences." I've been asking that same question for decades with no answer yet. Bayesians can draw the appropriate conclusions.

No need to invoke anything exotic for audible differences in speaker cables. That was covered completely 40 years ago by Fred Davis and Dick Greiner.
 

captainbeefheart

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In my amp reviews, I often do multitone and distortion vs frequency runs with an actual loudspeaker load. Nothing pathological, but certainly typical. I just haven't seen any engineered amps do anything funny or unexpected that didn't show up in dummy load testing.

Still waiting to find out specifics on two amps that "test the same on the bench" but have demonstrated audible "differences." I've been asking that same question for decades with no answer yet. Bayesians can draw the appropriate conclusions.

No need to invoke anything exotic for audible differences in speaker cables. That was covered completely 40 years ago by Fred Davis and Dick Greiner.

I'm not a speaker cable believer and my post came across like that. What I meant to say wasn't differences between normal speaker cables with minor differences in LC properties and sized in diameter and length appropriately. Too thin and too long can have audible differences, other than that no audible difference. What I was referring to was exotic cables where these LC parameters may start to be enough to cause audible differences, especially the cables that have RC networks in them. I'm not saying it's night and day and in most cases probably not even audible, I just meant it's a possibility with extremes where the extremes. For example I have seen some cables being sold as "low inductance" speaker cables yet the capacitance of these were so much more than you would normally see in standard old zip cord type wires.

I like you worded your response this way: "I just haven't seen any engineered amps do anything funny or unexpected that didn't show up in dummy load testing."

I agree, amps that are engineered usually work very well even into tough loads like ESL's. But in today's world of "boutique" small company amplifiers I have come across amplifiers that were rang like bells with tons of overshoot and even oscillations under capacitive loads. This is almost exclusively boutique tube amplifiers from the very niche small companies. People with zero electronic engineering understanding seem to gravitate to tube amps since they are fairly simple and one can copy a schematic online and even tweak it as these circuits are very forgiving compared to transistor designs.
 

captainbeefheart

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Went back and had a look at "effects of cable, loudspeaker, and amplifier interactions" by Davis.

Page 4 they even state "Well designed amplifiers are not affected by this amount of capacitance, but some amplifiers may become unstable."

This was in regard to some of the flat ribbon type cables with high capacitance.
 
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René - Acculution.com

René - Acculution.com

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The January audioXpress issue is out now, and features an article by yours truly. Link: https://lnkd.in/djQFqgYh

1670915867480
 

Curvature

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@René - Acculution.com Is simulating reflection behaviour for a quadratic diffuser of interest? I'd like to know more about the FR differrences between incident/reflected waves.
 
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