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hello every one,

this is one great forum, i have been lurking around a few days, reading up, and my knowledge of sound and sound engineering has gone up like anything! :)

currently i am converting a collection of old LPs into DA.
i have a Sansui P-L40 Direct Drive Linear Tracking Turntable, and a Creative Extigy Card

i have a small question:
can you tell me how, why and for what a phase scope is used? or point me to somewhere where this info is available?

thank you for taking time to read my post,

do reply,
Ark!

Comments

Cucco Sun, 09/02/2007 - 13:38

A phase scope is a meter (often included in many DAWs) whose primary purpose is to give you a visual indication as to the phase relationship between left and right channels.

For transferring vinyl to digital, there shouldn't much be the need for this as it's difficult to alter the phase alignment of previously recorded material. However, if you intend to use one, you should note that you will likely see a random patter of dots in constant motion within the display window. If you see straight lines in any direction that means you have an issue. Either the recording is mono, or it's out of phase. This is a gross oversimplification of the use of this tool, however, so don't take everything as the law.

I have found that you are probably equipped with 2 far more accurate tools for determining phase alignment or lack thereof. They are attached to either side of your head...

anonymous Sun, 09/02/2007 - 13:52

greetings cuccu,

thank you for the info.
it was helpful.
is there any where i can get more in-depth info? i wouldnt want to bore you all with a bunch of inane theoritical questions :)

like what is phase shift?
the internet seems to be a little behind in imparting valuable theoritical knowledge to her users..

due to some cartridge problems on the turntable, i was having some lines on the phase scope in the recording software. but i repaired the cartridge as it was sounding a bit off...you are right those two tools are a godsend!

can you recommend some good speakers for my setup?
currently i am using the Sansui AUD33 with home built 2.0 speakers with dual channel 3 way crossovers in bass-reflex enclosures. the amp is rated at 135 watts RMS per channel.

thanking you for taking time answer my question,
in gratitude,
Ark!

Cucco Sun, 09/02/2007 - 14:06

Re: the speakers...
Are you comfortable with their sound? Do you know what recordings sound like through them? If so, I say stick with them. If not, I would say use whatever sounds good to you.

Some of my favorite speakers of all time are the NHT SuperZeros. They're amazing and cheap. You'd need a sub to do any serious audio work with them, but that's true of many a small speaker. That's just an example, not a suggestion.

As for the more in-depth info on the phase scope...not sure. Keep the topic open for a bit and I'm sure several people will weigh in.

Cheers-

Jeremy

anonymous Sun, 09/02/2007 - 14:48

dear jeremy,

thank you for answering.
regarding the speakers, i am not very comfortable with them.

for casual listening, it is quite okay, but for serious work, it doesnt cut the cake (the midranges suffer)
so i use a pair of headphones during editing.
but with headphones, you cant feel the sound, and that is the crux of my problem.
i was loking at the JBL 890 lineup, but i am bit unimpressed with it. people are saying that low frequencies are not faithfully reproduced.

i am thinking of building another set of enclosures with hydro-absorbers.

those NHTs look cool (nice specs) i can see why you love them!
wonder whether thay are available here (i am in india, btw), sending them a mail.

link555, thank you for the link. and here i was searching and searching about "phase scope" darn!
though it clears the basic point, it muddies up the concept even more, i think i ought to break out my old physics books! :)

has anyone here built their own boxes / monitors / speaker enclosures??
i would love to pick your brains for a little while, only if you agree, that is.

please let me know your thoughts.
thank you both for taking the time to help me.

in gratitude,
Ark!

Cucco Sun, 09/02/2007 - 15:18

No problem.

The NHT SuperZeros are no longer available except through ebay, etc. NHT has changed owners about 4 times in the past 12-15 years and in the shuffle, dropped the "super" line. They've got newer stuff now which is good in its own rights, but the true genius behind NHT is no longer there. (Although, he peeks in here every once in a while under a psuedonym, so I won't mention his name...sorry).

That was more of a thought and by no means a suggestion though. Please don't take it as any more than that. I LOVE NHT speakers, but they're not for everyone. (Think horribly clinical almost to a fault - though not true of the Super Zero. The best recording/playback I ever heard in my entire life was in a hifi shop in northern Virginia. I was going to listen to a pair of PSB Golds and when I walked in the door, I was blown away to plainly hear a 7' Steinway in the room, only I looked around and all that was there was a large pair of Quad electrostats and a little pair of Super Zeros and a big fat tube integrated amp (brand and model I don't recall but the price tag was over $20K!)

The sound was eminating from the diminutive little Super Zeros, not from the Quads and it was simply elegant!

Anyway...enough of a trip down memory lane...
The trick to good monitors is finding something you're comfortable with. That means a lot of listening.

The other approach (which I luckily and successfully pulled off a few months ago) was to say "I'll get a known good brand and learn to understand them as I go along." I bought the Adam A7's unseen and quickly learned them. Again, not a recommendation, just a flow of ideas.

Cheers!

Jeremy

anonymous Sun, 09/02/2007 - 15:43

oh thank you link555!

well, the thing is that, from what i understand, phase shift can occur, when the two wave forms are exactly the same, but shifted along the timeline. right?

but in a stereo setup, the two channels ARE different. suppose i have a violin playing the melody in the center, a pair of drums in the left making up the beats, and some cymbals in right. there goes the waveform similarity and the phase tossed right out of the window.

so with two different waveforms in the two channels, on what points are phase shift computed.

elementary physics says that phase shift be a value expressed in time, positive or negative, depending on how the sync is out. but here on a phase scope i get a pattern of dots, like multiple points rendered on a dual xy axis, like x,y + x,-y + -x,y + -x,-y in real-time.
right?
so how does it come together?

Jeremy:
sad that they dropped it, i looked at the specs of the superzeros.
http://nhthifi.com/2006/store-international.html
they even have an office in india!
what do you think of the M-00??

do you think investing in a pair of Bose's would be better, for monitoring and mastering?

money wise i am not good right now, but in a couple of month's time (end of the year) i should be having a considerable buying power in my grasp.

let me cross my fingers for Mr. NHTgenius to drop in.

20K is too much for me. i cant spend more than 3k for my speakers.
building them shouldnt cost more that 1000 i guess. my current 135 watt behemoths were built for less than $250 :D
the speakers were another 300 though.
i got bolton 12" drums and 6" mids and philips 4" brass horn tweeters
its completely 2 inch MDF with glasswool dampeners, and a 11.5*4 inch bass reflex port!
and it measures 24*24*48 INCHES on the inside!!!

i like it when someone thinks back to the good old days. do remicise, i get a lot of ideas from there!

thank you both for your time.
do write,
Ark!

Link555 Sun, 09/02/2007 - 15:52

well, the thing is that, from what i understand, phase shift can occur, when the two wave forms are exactly the same, but shifted along the timeline. right?

Simple answer no- it can happen with two very different waveforms as well. However both waveforms need to be periodic, in order to determine there delay or phase difference.

before we go on the to the phase meter, does that make sense to you?

Link555 Sun, 09/02/2007 - 16:04

I am sorry now I don't understand ;) what do you mean by down to beats? Are you referring to zero crossings in the time domain?

Fast Fourier Transform? I don’t follow you, but can I suggest that you first look at the time domain information before looking in to the frequency domain. It might make it a bit easier :)

anonymous Sun, 09/02/2007 - 16:17

oops! now we are both confused! :lol:

let me try to explain what i meant to say:
you said that "waveforms need to be periodic"
so naturally i though there was beats coming into play for the large range shifts. beats as in beat frequency, not beats of the drum and cymbals!

but then i thought, then how can a shift of just a tiny little bit be calculated?
i thought of FFT like in its most basic application, breaking up a waveform into its harmonics and giving out the basic sine frequencies that make up the waveform so shifts could be calculated in the time domain itself.

shift calculation from the time domain without FFT? how?

you are probably thinking, this bugger is absolutely horrible in his theories.
i will let the cat out of the bag, and say it. i AM horrible in my theory part!

thanks for reading my rambles
do write,
Ark!

anonymous Sun, 09/02/2007 - 16:29

Cucco:
hehe. but my father absolutely adores them Boses!
but back on topic, getting professional speakers from abroad seems out of my reach. i just checked, the customs duty is 135%. unh uh, no can do. a 200 dollar speaker will cost 475 dollars (which is 18,800 rupees here) oh my!

i think i will import the basic speakers and build my own enclosure, that would cheaper and better - i am handy with carpentery.

your thoughts on the matter?

could you recommend some good speaker manufacturer? my current speakers are bolton, but i am thinking of getting MISCOs or Pioneer. but you would now better.

thank you!
do reply,
Ark!

anonymous Sun, 09/02/2007 - 16:34

Dear Link555,

big movies, blow out my ear drums, frying pan till crisp?
i am afraid i didnt understand that post

and why are you shocked?

most probably because its 5:30 in the morning and i am feeling VERY sleepy.

so goodnight to both of you kind folks, who have taken out a lot of their precious time to help me out.

i'll get back tomorrow.
thank you.
strength and wealth,
Ark!

Link555 Sun, 09/02/2007 - 16:45

Sorry Ark- you right I was very unclear-it was a really bad attempt at humor. What can I say I am geek not a comedian ;)

I was in the West Edmonton Mall a few years back, and they have a Bose store there. The sales guy showed me the 'white cube' home theatre system. He had it cranked the movie ICE AGE so loud I covered my ears. Super sharp 5k's and run away 60 Hz thuds. My impression of the system was not that good, mainly because it hurt. But the white cubes were cute.

anonymous Mon, 09/03/2007 - 01:25

no worries, link555, and theres nothing to forgive. :D

note to self: if i stay up beyond 2 am, dont talk to people. !!!

arent we all geeks and nerds here?

i cant seem to get a freq response chart from Bose for their line-up. wonder why?

was i able to clear your confusion regarding beats and FFT?

cucco,
tomorrow i would be going to the city (i live in the suburbs) and i would visit bolton, and another component shop, and see if they carry speakers from the companies you mentioned

any particular model you recommend?

thank you for your time,
Ark!