FUN: How well do you know your HT stuff?

[Kevin P]

I saw this on another forum and thought it might be a neat thing to try in here. The idea is to pose questions which have something to do with audio/video/home theater. Hopefully, it will provide a little entertainment for everyone as well as be a source of learning for those who might not quite be up to snuff on their technology terminology!

If you think you know the answer to something, you can click the Quote button under the specific post, to quote the poster's question, then type your answer underneath.

If you feel you've answered the question correctly, please feel free to pose a question of your own. We won't hold it against you if you were ultimately wrong!

Rules:
No Google! (well, not like we can enforce this, but just to be fair...)
Please don't hog all the answers; allow others a chance

Ok, here's the first question:
What is DLP?

[Bent]

DLP is Digital Light Processing...

What is SPDIF ???

[Bing Fung]

What is DLP?

DOH!


SPDIF

Something, something... Digital Interface

Be right back.........

Sorry had to google it... Sony Phillips :B

Close enough for a Gimme???


TosLink

[Brandon B]

How about the obvious one?

What is DVD? (There is more than the one obvious answer depending on the use of the disk.)

And more obscure - DiLA?

BB

[Bam!]

O.K. O.K. I have one!

LCOS ?

[David Meek]

LCOS = Liquid Crystal On Silicone.

DiLA = Dangerous In L A :

Try this: What's the difference between a di-pole and a bi-pole speaker?

[Kevin P]

DVD = Digital Video Disc, or Digital Versatile Disc.

LCOS = Liquid Crystal on Silicon (not silicone)

Dipole vs. Bipole - Both have tweeters on opposite sides, one has them wired in phase; the other has them wired out of phase. I don't remember which is which though.

Ok, trick question: how many channels are there in a Dolby Digital soundtrack?

[Bent]

OK, I have to!

A dipole speaker radiates it's front wave outwards and at the exact same time in it's stroke, it radiates it's back wave inwards, (ie, out of phase)

meanwhile a Bi-pole radiates it's front wave outwards and at the exact same time in its stroke, it radieats it's back wave outwards. (think of something that throbs....).

A dolby digital soundtrack can have as many discrete audio tracks as Dolby wishes, it can, in theory be 1.0, 1.1, 2.1, 3.1, 3.0,... you get the idea.



next one, what is the equivalent impedance of a 8 ohm speaker and a 4 ohm speaker wired in parallel?


I needed a calculator...

[David Meek]

what is the equivalent impedance of a 8 ohm speaker and a 4 ohm speaker wired in parallel?

Jeez Bent, you would ask a current question wouldn't ya? Uh, how 'bout 4 ohms? I was going to say 6, but. . .

[Bent]

Hey, I are an electrician, and I still needed a calculator...

the answer is NOT 3 ohms, like I thought before whipping out my handy-dandy calculator. (keep in mind, in a pararlelel cct the equivalent total resistance is always less than the lowest individual path's resistance) notice how I so capably can interchange impedance with resistance.

And it most certainly isn't 6 ohms, :LOL

[Kevin P]

My algebra is a bit rusty, but would it be 2.667 ohms? (2 2/3)?

Using Ohm's Law I=E/R, make E=1 for simplicity, I=1/4 for 4 ohm, I=1/8 for 8 ohm, add them together, get 3/8. Convert back to resistance/impedance using E=1 again (R=E/I), get 8/3, or 2 2/3, or 2.667.

[David Meek]

And it most certainly isn't 6 ohms, :lol:

What, you don't add them together and divide by two? :B

[Brandon B]

OK, DVD down, still looking for an answer on DiLA.

How about the difference between watts and Volt-amps (VA)?

BB

[Andrew Pratt]

Actually there's some debate on what DVD actually does stand for now...it was Digital Video Disc then Digital Versitile Disc but there's some that now say it doesn't stand for anything...at least in the sense of an acronym.

D-ILA®

Digital Direct Drive Image Light Amplifier

Ok here's my question...what was the first movie (in the theater) to use Dolby Digital? ...and What was the first DTS movie?

[Brandon B]

Hmmm. Don't know the DD/DTS ones, but I did see Blue Thunder as the first release in L.A. under the THX logo, as they had certified the theater for the next film to play there, The Empire Strikes Back.

Guessing: Dolby Digital - T2?

DTS - not even sure when this started.

BB

[aud19]

DTS...Jurrasic Park...?

How many Films (theatre) have been released or announced with Dolby Digital Surround EX coding as of May 19th? :lol:

Jason

[Andrew Pratt]

You're right about DTS...but not DD :W

[aud19]

Yay I got it right! arty: :B

[Bent]

Brandon, Watts are the product of volts multiplied by amps, then multiplied by the cosine of the relative angle between the two.

VA is just the product of Volts multiplied by Amps.

thus Watts can never be greater than true VA for the same cct.

I'm not asking the next question.

[DrBoom]

Never noticed this thread before, seems to be right up my alley

*without googling*

How about the difference between watts and Volt-amps (VA)?

Volt-amps (symbol S) is a power rating that doesn't include the phase alterations (or whatever the proper term in english is) that might occur.
I believe that VA only applies for purely reactive loads, not capacitive or inductive ones.
The formula for calculating it is (like the name suggests) S = U x I (volt x amps)
Watts (symbol P) do include the phase alterations, so P = U x I x cos phi.
If cos phi = 1 then S = P and you have maximum energy transfer.
If cos phi is lower, then you'll be using more power then you actually need.
I hope this makes sense, it's been a while since i've learned this, and it wasn't in english either

what was the first movie (in the theater) to use Dolby Digital? ...and What was the first DTS movie?

No idea about the DD movie, but i believe that Jurassic Park was the first DTS movie.

As for the 8 + 4 ohm question, the proper formula is this:

R1 = 8 ohm
R2 = 4 ohm
R = total resistance

R = (R1 x R2) / (R1 + R2)
R = (8 x 4) / (8 + 4) = 32 / 12 = 2.66666....7

this formula only works for 2 resistors in parallel, if you have more than 2 the formula becomes universal:

1/R1 + 1/R2 + 1/R3 + 1/R4 + .... = 1/R


My question:

I'm playing some music at a moderate level of 87 dB SPL, while my amplifier is putting out a mere 5W average.
Now I want to turn up the volume to get 103 dB, how much power will that require ?

*edit: looks like I took way too long writing this reply as it seems several people have already answered the previous questions *

[Chip]

Well, "Deep Impact" was MY first Dolby Digital Digital, Digital Versatile Disc. Can't be right.. 8O

[Gordon Moore]

What was the first movie to use DD...I have no idea why I know this but it was Batman (the first and still the best)...at least I'm 99.999% sure on this.



Q. What was the first theatrical movie to debut Dolby Digital Surround Ex?
(should be easier...)

[Andrew Pratt]

Yup gord you're right:T

1st DD:EX was The Star Wars: Episode 1 The Phantom Menace I think

What does NTSC stand for...and what about PAL...and what's different about them? And no NTSC isn't Never Twice the Same Color :lol:

[Kevin P]

NTSC = National Television Standards Committee (I think)

PAL, no clue. I know PAL has a few more scan lines and a different way of encoding color.

[David Meek]

Don't know about the PAL question.

Here's another one. What's the difference between a balanced and an un-balanced interconnect?

[Brandon B]

Unbalanced is standard signal and ground 2 conductor (ignoring exra shield/capacitor types), balanced carries two copies of the signal, one 180 degrees wih the other, and a ground, then uses the out of phase signal to detect and eliminate any noise picked up in the interconnect since it will be in phase wih itself on both signal lines, unlike the original signal.

How about full names of the terms MOSFET, SET, and just for kicks LASER?

BB

[Kevin P]

How about full names of the terms MOSFET, SET, and just for kicks LASER?

MOSFET = Metal Oxide Semiconductor Field Effect Transistor (a type of transistor used in some amplifiers)
SET = Single Ended Triode (a type of tube amp)
LASER = Light Amplification (by) Stimulated Emission of Radiation (it reads our shiny silver/gold discs!)

[P-Dub]

My question:

I'm playing some music at a moderate level of 87 dB SPL, while my amplifier is putting out a mere 5W average.
Now I want to turn up the volume to get 103 dB, how much power will that require ?

Isn't it for every 3db of SPL increase power must double? So that would give us:

87db - 5W
90db - 10W
93db - 20W
96db - 40W
99db - 80W
102db - 160W
105db - 320W

So something over 160W and under 320W? I'm sure someone must have the exact formula.

[DrBoom]

Close enough

My theory was: 10 dB extra requires 10x the power, and 3 dB extra requires 2x the power.
So 87 + 10 + 3 + 3 = 103 dB
and 5 * 10 * 2 * 2 = 200W

[Glen]

O.K., what was supposed to be the first Dolby Digital title to be released to the home market, and what title actually was the first ( due to release delays? {and yes we're talking laser discs here}.

Andrew, it's no fun if you use my jokes before I get a chance too. :B

[Bam!]

Glen!

Everyone's on that one like Kung on Fu!

Anyways...what does DVi stand for brainees ?

[Andrew Pratt]

digital visual (or video?) interface I think

[Kingdaddy]

What is OLCD?

Hint: supposed to be the greatest thing since sliced bread if they can get the 3 primary colors to degrade at the same rate.

[David Meek]

What is OLCD?

Object Language with Complement allowing Descriptive cycles. It's a discipline that is used for acquiring and validating schemas in a relational database. :

Okay I know, I know, that's NOT the OLCD Kingdaddy's referring to, but it's the only thing I knew. I had to Google for the correct answer so I can't play. That's some pretty cool stuff 'daddy-O! :T

[Shane Martin]

O.K., what was supposed to be the first Dolby Digital title to be released to the home market, and what title actually was the first ( due to release delays? {and yes we're talking laser discs here}.

Clear and Present Danger.

What is OLCD?

Are you talking about OLED? It's supposed to be the Plasma killer.

[David Meek]

Shane, nope it's OLCD. :yesnod:

[Shane Martin]

David,
I"m pretty sure I'm right here:

http://www.kodak.com/eknec/PageQuerier.jhtml?pq-path=1489&pq-locale=en_US

[Kingdaddy]

It's close, and in-fact based on this technology, but this is applied to the LCD products. So technically it wrong, if you google OLCD you will find the specific information that pertains to this use in a LCD.

[David Meek]

Yep, Organic LCD.