John Curl's Blowtorch preamplifier part III

Status
Not open for further replies.
Reed relays are marginal for several reasons. Low level relays are somewhat better. I still vote for the Shallco switches over everything else. I KNOW that they work well.

Just so that you can measure the end result with an AP filled with ..... low level relays. Just avoid reed relays and presto.

professional life, being paid for my little technical competencies and verified, by results, correctness, do-you really think you can teach-me something on this point of good methods ?

I explained why it is not good to mix dynamic and condensor microphones on the same source, which you admit you did. That might have given you a Joshua Bardwell moment.
 
Your assertion looks reasonable/plausible but obviously that does not ensure that it is correct.
Therefore we generally need to do some tests to examine if such hypothesises can find corrobation.
The only thing I asserted was that you can't sit in the same place within 1mm each time!
Just as an example (not exactly the same but related), from studies we’ve learned that it makes a difference in localization experiments if the listener is moving or the sound sources are moving (same degree of variation in both conditions).

Understood, but a synthetic stereo scene is not a 'sound source' in that sense. We've all had cases of moving our heads and the 3D illusion fails. In some cases it doesn't which is always pleasing, even if its not real.
 
Tests have been done for electronically replaying sound in room.

Do you have a relevant example of electronically replaying sound in room?

Unfortunately i don´t understand what these sentences wrt to my post mean, could you elaborate?

The only thing I asserted was that you can't sit in the same place within 1mm each time!

You´re right, it was a conclusion not an assertion. 🙂

, but a synthetic stereo scene is not a 'sound source' in that sense. We've all had cases of moving our heads and the 3D illusion fails. In some cases it doesn't which is always pleasing, even if its not real.

Don´t get me wrong, we obviously do need experiments also to examine if positioning to this precision is really perceptable. (might be room dependent, might be that an extra safety margin is includede)

ImE the "normal" movement of the head or torso does not lead to total collapse of the 2D/3D-illusion; quite often even position differences of 20 cm (for example) do not destroy the illusion, stage scene shifts in the direction of the movement though.

There is good reason to question such an accuracy requirement, otoh it is often reported that loudspeaker coupling to the room can be a matter of "hot spots" , iirc romy the cat maintains that for quite some time, but isn´t alone in that.
As usual, sound sensory tests are missing.....
 
IAgain, please explain how a 2 mm movement in speaker positioning affects the sound.

Please, no videos or other advanced phsychological stuff. Just explain it in simple physics terms.

Some may call me an a-whole, but I just want to keep the discussion rooted in reality.
I was asking myself exactly the same questions.

On my side, I put my enclosures WHERE I CAN in my listening room, depending of its configuration, geometry, and aesthetic of layout.
Keeping the requested equilateral law as the requisite.

Sometimes (litle enclosures on a feet) you can try to vary their height. Not when you are using columns.

The only trick, for me, is to adjust their angles by directing their axes more or less to the center.
 
If I modify to say ' is a big leap of faith without some context' does that help? For someone not expert in the research on human hearing assuming reciprocity is not a huge sin!



When talking of speaker/room interaction I always like to go back to the works of Linkwitz. His conclusions may not cause universal agreement but his methods and data were well presented and explained. http://www.linkwitzlab.com/AES'07/AES123-final2.pdf
 
If I modify to say ' is a big leap of faith without some context' does that help? For someone not expert in the research on human hearing assuming reciprocity is not a huge sin!

At least not a deadly sin.... 🙂
I did not mean it as an accusation just as an explanation why i was wondering about the "no conclusion, but observation" part.


talking of speaker/room interaction I always like to go back to the works of Linkwitz. His conclusions may not cause universal agreement but his methods and data were well presented and explained. http://www.linkwitzlab.com/AES'07/AES123-final2.pdf

Thanks for the link.
 
Unfortunately i don´t understand what these sentences wrt to my post mean, could you elaborate?
billshurv readdressed it on post #16607 and the example you called "related" (quoted below) isn't really related to room mode when reproducing sound through speakers in a room.
Just as an example (not exactly the same but related),

ImE the "normal" movement of the head or torso does not lead to total collapse of the 2D/3D-illusion
You did hear difference, right? That's what we were talking about.
"total collapse", straw man argument. 🙄
 
Total collapse was my wording. I have had some odd experiences where there were sounds coming from 6' to the right and 6' behind the right speaker and I did twist my head to look round the back in confusion. In this case the sound stage remained (dipoles well away from boundaries). But that hasn't been replicated in 20 years so I was most likely fooling myself.
 
Well T, I am with you. I typically put my speakers where they fit. In my case, I have a very large video screen that gets obscured if I put my best speakers in their 'best' position. I just live with dual mono, rather than fantastic imaging.
Why these 'critics' should attack the very idea of optimum placement, without even trying it, due to 'laws of physics' is laughable.
My primary criteria for good sound is: No listener fatigue, and realistic sounding voices.
The Met7 speakers are 'easy listeners', and they 'forgive' amps and even more importantly, compromised sources like radio and TV. They don't have any significant highs or lows. It is like driving my Acura.
My bigger system uses speakers that cost 40 times as much, an amp and preamp in the $20000 region and if useful, an ultrasonic tweeter, triode driven. It is almost impossible to get a truly uncompromised source, either from analog or digital. It is closer to driving a Porsche, boring and even annoying with normal stuff, wonderful with special opportunities to show its stuff. Why you guys insult us with 'laws of physics' etc most be from 'Sophomoric' tendencies of some.
 
Status
Not open for further replies.