Yes, and not everyone agreed with that statement or approach. If I recall from someone in that group that posted here, there was quite a bit of pushback.
TI is huge and even National had many engineers. There are plenty of TI/ADI app notes with questionable advice, although they have gotten better as the years have gone on.
Yes, there are some great threads about speakers and to a lesser degree room acoustics, this isn't one of them. The new Room Acoustics and Mods forum isn't frequented much, understandably I think since most people here listen to their hi-fi's in their living rooms and don't wish to modify them too much, so most of the speaker threads touching on that aspect are more about how the speakers can mitigate room effects and which ones are really relevant, it makes for some very interesting reading and generally co-operative sharing of ideas and experiences.
This, times a trillion
A few more or a few less zeros on the playback electronics isn't interesting when one starts looking at the mechanical side of things.
Those are physically too big and the methods are too difficult for some audio guys to take on. So they convinced themselves that DAC chips and amp caps are where the action is at.
Hear one in double sighted test?
I suspect if you talked to the NSC guys on the day the LM3886 was signed-off and released for general production, they'd have offered the opinion that analog audio ICs would have a brief lifespan -- because Class D audio chips were coming that would render this analog crap irrelevant and obsolete.
And, from the point of view of a semiconductor manufacturer who offers a broad line of Class D audio chips, that opinion wasn't wrong.
And, from the point of view of a semiconductor manufacturer who offers a broad line of Class D audio chips, that opinion wasn't wrong.
Three of them in each of my speakers! I guess they don't sell many of them now, but they are nice chips and NatSemi should be proud of them.
Room acoustics!!! Perceptual issues!!! One could start with the Sabine equation, but as that is over 100 years old so to some here must be outdated. Of course the first Sabine made it big as a consultant on music rooms.
(Actually it is over simplified and has been enhanced many times and ways.)
Next one would have to consider early reflections vs late ones, but that is way too recent or is it too old as it first showed up in the late 1940s.
Then we get to the more recent 1960s attempts to measure and simulate acoustic spaces. Getting to be quite well done in some commercial products.
So do we add character with the room or do we do a neutral room and allow for the folks making the recording have the batton?
RNM the scoundrel (
) insists on reducing the influence of the room.
Now it is really not much harder to play with room acoustics than build your own circuit gizmo. One of my guys for his recordings picked up a few well used reclaimed doors. Hinged together they give him a portable hard wall. A step further would be shag carpet on one side. An easy way to change a bit the acoustics of a space.
For W.A.F. These can be used to determine what and if changes might be made and then replaced with furniture, drapes or mirrors to be acceptable changes.
As mentioned before I have a bit of art work in my place. A simple painting can be used as is or even have absorption hidden behind it. I also use windows, they can be treated with movable drapery that is to some shading to others variable acoustic absorbers.
For extra humor, I tend to buy some electronic components in quantities of 100 pieces. This has resulted in calls from manufacturers' representatives inquiring about usage.
Now one good fit was a felllow who represented the folks where I bought 25 of their DC to DC converter modules. ($15.00 ea.) he also represented folks who locally assemble circuitry. In addition he had a metal fabrication place that does just about nothing I do but pretty much the stuff I don't. (I punch and bend, they laser and water jet.)
So tomorrow A.M. I have the T.I. guys stopping by to discuss audio parts, should be interesting.
(Actually it is over simplified and has been enhanced many times and ways.)
Next one would have to consider early reflections vs late ones, but that is way too recent or is it too old as it first showed up in the late 1940s.
Then we get to the more recent 1960s attempts to measure and simulate acoustic spaces. Getting to be quite well done in some commercial products.
So do we add character with the room or do we do a neutral room and allow for the folks making the recording have the batton?
RNM the scoundrel (
) insists on reducing the influence of the room. Now it is really not much harder to play with room acoustics than build your own circuit gizmo. One of my guys for his recordings picked up a few well used reclaimed doors. Hinged together they give him a portable hard wall. A step further would be shag carpet on one side. An easy way to change a bit the acoustics of a space.
For W.A.F. These can be used to determine what and if changes might be made and then replaced with furniture, drapes or mirrors to be acceptable changes.
As mentioned before I have a bit of art work in my place. A simple painting can be used as is or even have absorption hidden behind it. I also use windows, they can be treated with movable drapery that is to some shading to others variable acoustic absorbers.
For extra humor, I tend to buy some electronic components in quantities of 100 pieces. This has resulted in calls from manufacturers' representatives inquiring about usage.
Now one good fit was a felllow who represented the folks where I bought 25 of their DC to DC converter modules. ($15.00 ea.) he also represented folks who locally assemble circuitry. In addition he had a metal fabrication place that does just about nothing I do but pretty much the stuff I don't. (I punch and bend, they laser and water jet.)
So tomorrow A.M. I have the T.I. guys stopping by to discuss audio parts, should be interesting.
TI do not have a listening room so we can possibly write this off as something that the app engineers came up with to give the punters what they wanted. Of course this will not stop people leaping on it as proof of their viewpoint
That was written before TI bought National. I have been in that room and met some of the players in their efforts to make better audio. That whole group is gone to other things now.
I gather even the late Bob Pease heard the differences between plastic and metal can variations. I'm sure that was an interesting conversation.
However I won't claim those were comparisons done under rigorous double blind conditions.
I seriously doubt that could be verified. In private he spoke of audiophilia in quite colorful terms.
But working on room acoustics is physically much more demanding than circuit building. It often is or almost equivalent to building construction work. Plus, for those without a dedicated room, working with W.A.F. makes the design that much more challenging.
New 'secret weapon' terminator, speakers typically run Fig-8 cable internally and depending on wire diameter, wire separation and insulation materials this causes characteristic impedance in the range of 90-100R or so, 120R for thicker insulation (= wider conductor separation).
Two back to back series 47R 1% 0.5W Metal Films is enough dissipation when running typical 100W amp on typical music.
When connected to all speaker driver terminals this network very nicely removes of a layer of noise that don't belong on two loudspeaker systems so far modified with both ends of the audio spectrum markedly extended and much improved clarity/resolution and subjective frequency response and consequent significant improvement in positioning and depth imaging.
I have not trialed Carbon Film but from previous experience I would expect colouration, warm colouration that gets boring.
Total cost less than a dollar and a bit of time.
Dan.
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