The difference is very audible, not absolute value. That is where all the misunderstanding comes from.
PMA said:
Give that man a Ceegar!!!!
I've been avoiding the use of the term "differential localization criteria"....
Cheers, John
Hi Alex,
Yes, those sandwich heads are often out and the bias level can "rotate" the phase. Cool.
The Tascam 122 MKII had an additional rec head azimuth adjustment. Nakamichi is really the only manufacturer that set up heads correctly. They treated the tape path exactly the way a three head open reel is set up. Complete with entirely separate heads and full adjustment in free space. Additionally, the pressure pad was pushed back, eliminating the FM scrape noise from the pad to tape contact.
Most people don't ever understand that you must get the tape path bang on before doing anything else on alignment.
-Chris
Yes, those sandwich heads are often out and the bias level can "rotate" the phase. Cool.
The Tascam 122 MKII had an additional rec head azimuth adjustment. Nakamichi is really the only manufacturer that set up heads correctly. They treated the tape path exactly the way a three head open reel is set up. Complete with entirely separate heads and full adjustment in free space. Additionally, the pressure pad was pushed back, eliminating the FM scrape noise from the pad to tape contact.
Most people don't ever understand that you must get the tape path bang on before doing anything else on alignment.
-Chris
OK I deleted a lot of Off topic posts to Texas, including my own about trucks.
Let's only post stuff that has some relevance to this thread.
scott wurcer said:
This would not work, but the attempt would sound really cool in the marketing blurb. Using a thermistor is an interesting choice as well.
This is a case where any conventional attempt to measure would disturb the results. There are ways to do this (or maybe I should be clear and say that you could monitor the interface between the stylus and the groove) but the cost of the hardware would be considerable relative to the value of answering the question.
Mike
anatech said:
Hi Chris,
I made my first cassette tape deck in 1979, and even now I have in my house Nak BX300, Hitachi D909, three r2r, including Tascams 32 and 38, and few more decks of smaller stature 🙂 . Tape recorders are a little hobby of mine.
Cheers
Alex
john curl said:
Hi John,
sorry if it looks off-topic. However a tape recorder is a good example of what a delay mismatch between channels could do to the imaging.
Alex
I designed my first cassette electronics in 1978 for HK, for real money. However, they dropped the project after I had finished my design due to transport problems. I took this electronics package, beefed it up, and made master 30 ips recorders for Mobile Fidelity in 1979, and later for Wilson Audio. I find some of this 'alignment' to be amateur at best.
john curl said:
John,
As far as I can see from my posts I did say very little about "alignment" as such. I've just recalled my experience of fixing a faulty sandwich head - if it is made with an angle between recording and playback sections it will introduce a delay difference between channels. In this case the delay was about 20 us and was clearly audible in switching between source and tape. That's all. As you may see I was making electronics for tape recorders also quite a long time and some of it was pretty good 🙂 .
Cheers
Alex
X-pro, I am not singling you out. Of course, you will get a delay if you have a physically spaced difference between the record and the reproduce gap.
john curl said:
John,
It looks like I need to change my nickname 🙂 . As I am now officially back into audio business:
http://www.ant-audio.co.uk/reviews/Kora_3T_SE.pdf
Cheers
Alex
P.S. to moderators - if I am breaking the rules by posting this link, please remove it.
john curl said:
“Sometimes the questions are complicated and the answers are simple.”
“Be who you are and say what you feel because those who mind don't matter and those who matter don't mind.”
“I have heard there are troubles of more than one kind. Some come from ahead and some come from behind. But I've bought a big bat. I'm all ready you see. Now my troubles are going to have troubles with me!”
--Dr. Seuss.
jneutron said:
Bass is an interesting issue. It 'appears' to be a locational consideration coming off the HF/Mid-HF from the tweeter. But not quite.
Pad hits skin, sound begins in tweeter..goes through the mid, down to the woofer and then back up to the tweet. Ie, kickdrum has aspects that come out to 4khz. So the spectral considerations of a kickdrum are why we tend to feel that a better, low jitter clock improves bass in digital systems. This is also the point that makes three way passive crossover design such a rotten barsteward. As well, it is a known phenomena that spaciality in recording can be improved, with the addition of a phase aligned LF bass response.
In the end, spaciousness in a recording, when attached to the human in the listening seat..turns out to be a very wide bandwidth consideration with perfection in phase (time) over that entire huge range..over time. Ie placement of harmonic structure as well. This. of course..leads straight into S/N ratios as well... ug.
Which is why I keep pushing for a dynamic and transient over time- as a complex signal over time, then analyzed against the original. (FFT..but with a twist as mentioned) weighted measurement system for audio gear analysis and to hell with any steady state measurements - for the larger part.
As for the 'inter-aural' (interchannel) sensitivity in humans as a measured phenomenon..It's good to see that someone else is 'getting it', John! I've been fighting that battle all by myself (at least in terms of publicly mentioning it) for what, 15 years now?
h_a said:
Like STD's..it's stuff I've picked up over the years and also pieced together myself...and then done the tests (simple ones, that is) in order to prove the given point to myself.
The articles and similar information are out there. JNeuton seems to have the references.
I read voraciously, and seldom mark down or catalog anything. I also have a policy of never writing anything down, unless it is a patent application. Notes, believe it or not--are a new thing to me. I always build on what came before..so I carry no piles of old notes with me, no baggage. To each our own. I accept the point that some folks need copious references and notes to get things done, I accept the point that I personally do not.
This is why I cannot tell you where I read these things.
Some where and are in print, some are things I've put together on my own and then they are 'discovered' by others years down the road-and put into print by/via a given study. For example, I'm about to apply for a few patents on some stuff I've been sitting on for ..uhm..14 years..as I'm finding that science is starting to get close to these areas and I will loose my ability to get a patent for a large swath of scientific and technological pursuit 'areas' in science. It would be shame to loose such after sitting so long. I keep a close eye on websites like physorg.com and then decide what to patent based on what I read there.
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