Sound Quality Vs. Measurements

[john curl]

If everyone here would just do a bit of 'Data mining' with what we have already found with amplifier and speaker design, it would me much less confusing.

[tvrgeek]

Yes, a nice envelope would probably provide a nice pretty test. I am looking for something that causes a difference and to see if it correlates to the subjective test. Something extraordinary, a stress test if you will. All the nice "reasonable" tests I know of don't show anything different. Hey, I could be so far off in left field I am totally lost. I did see a difference. Relevant? Don't know. Just a difference.

If I can reliably reproduce the difference, than I can hypothize what parameters could be driving it and change that in an amp to see if it correlates to the subjective test. I suspect making a "good" amp bad is easier than making a bad amp good. Only then can I draw a conclusion with enough substance to have others reproduce the experiment and draw their own conclusions.

Tangent thought. You may have noticed I have them. We all know the original Fletcher-Munson experiments and how those evolved into the ISO standard for relative loudness. What I have never seen is the deviation across the tested population. We "know" the fair gender hears higher frequencies and likely the critical 4K range with greater sensitivity that we do. By how much? All I can find is the normalized curves. Has anyone seen the data correlated to differences in the population? Has anyone done any measurements on brain activity to determine if there is a difference in what we detect, and what we process as sound? I my not be using the best search terms.

[tvrgeek]

benb,
Data mining is old school. We have been doing it with data warehouse products like IQ for a long time. Where it gets interesting is when we shift to big data. THAT is something I actually do know a bit about. Multi-petabyte is one thing, but doing sliding window analysis on data bigger than can fit in memory for near real time analysis gets fun.

[tvrgeek]

P6302's seem out of my price range. Anyone have suggestions on current probes with a more limited bandwidth? I have been out of the lab so long I don't know what is out there. They were really expensive back then. I guess I could just rig a hall effect transistor to a op-amp or something to give relative difference measurements. Butcher an old Bosch ignition module maybe?

[revboden]

[venting]Why does this discussion remind me of the metaphor of 'the blind men and the elephant'

I'm so glad the micro analysis of topologies is over...whew. When I set up a system for live performances. You know, the ones you like to recreate in a bedroom then complain about the timber of the drivers being wrong. It takes a long time to learn how to tune a room. If the amps are good enough*, then I say "good, next problem". (problems mostly created by architects, grrr) btw, I hate large hanging panels and Jumbotrons. Thanks for the large sonically reflective surface, .

*(btw, my definition of "good enough", is stunningly transparent, crowd pleasing and very very clean)

can you tell what I did today...

Tuning the room takes much more effort and makes much more of a difference than tweaking the output of the HF drivers or adding a soft filter and a notch filter to kill a standing resonance.

I wonder why designers get sucked into the minuta trap. ie. it could be .00000002% better if I just changed this resistor... why, it's good enough. I guess it would take a renaissance man to stop designing the amp and move on to design the drivers, cabinets and room. Well that and you can't sell the whole system just most of it.

I need a beer.
[/venting]

Sorry guys, I needed to get that out.
cheers,
revb.

[revboden]

Tvrgeek,

just a thought, have you tried taking one of the amp speaker combinations that your wife likes and moving it somewhere else. Say, outside, or in a bathroom or unfinished basement?

I wonder if it's the amp-driver or the amp-driver-room-number of people in the room- humidity level-time of day-etc etc.. you get my drift.

[Wavebourn]

Revb;

after tuning the room to sound how can you use it for taking a shower?

[tvrgeek]

Originally Posted by revboden

Tvrgeek,

just a thought, have you tried taking one of the amp speaker combinations that your wife likes and moving it somewhere else. Say, outside, or in a bathroom or unfinished basement?

I wonder if it's the amp-driver or the amp-driver-room-number of people in the room- humidity level-time of day-etc etc.. you get my drift.

Yup. It seems independent of the room. She does appreciate the tuning I have done in some of our rooms. I can't say enough about what large absorbers can do for imaging when behind the speakers, all of what I have done for the bass and so on. That seems independent of the harshness she hears. I would agree with the comment room tuning is a lot harder than system tuning. Doing it in a room and making it look not dominated by the sound system is even more of a trick. We try and keep our living room looking like a living room.

[tvrgeek]

I need a refill.

[Wavebourn]

If the singer has say sour throat it is room independent. He / she would sound as having a sour throat even in bathroom. So it is room independent.