Info needed

[Blueroomidiot]

Hi im new to this game and I was wondering if people could help me with some questions about sound. It would be really great if you could answer fairly simply but in depth if that makes sense? I asked someone a question the other day and they just baffled me with science!

 

Q1 What is the difference between balanced and unbalanced?

 

Q2 how do you work out speaker impeadance?

 

Q3 what is the difference between series and parallel?

 

Q4 direct/inject/matrix?

 

Q5 expander/compressor?

 

Q6 omi/cardoid/hypercardiod?

 

Q7 Diaphram/condencer?

 

Q8 Phantom power? what is it? why?

 

Q9 I know its called EQ and I know what it does (loosely) but whats Q? and HPF/LPF?

 

I know these may sound silly to you lot out therebut as I said some of the peope I have spoken too know to much if that makes sense!

 

There probably will be more questions in the future along the same lines but this is a start for my little brain!

[Pete McCrea]

Can I point you to the search function? A lot of these topics have been discussed on here before. I'd suggest having a good root through the old posts, and then posting questions to fill in gaps after you've had a good read.

 

A lot of the questions you ask are good basic questions, which have taken a lot of the people here a decent chunk of time to learn. To pass on answers to every question would take weeks.

 

Welcome to the Blueroom and happy learning!

[Bobbsy]

Another welcome from me!

 

Little DJ is right though... many of your questions would take quite a bit of typing to answer properly. The search function is one thing to try, though I suspect you come up with many hits USING these terms rather than defining them (if you see what I mean!). The other very good resource for you will be the Blue Room's very own Wiki (one of the RED links right at the top of the screen). That has a lot of the info you ask for.

 

Finally, may I suggest that you consider a bit of "book learning". There's a thread with some suggested titles, some of which cover the basics like this, HERE.

 

Please don't take this as a rebuff...lots of people here will be happy to help once we can get the number of questions down to a manageable level!

 

Bob

[jamesperrett]

Hi im new to this game and I was wondering if people could help me with some questions about sound.

 

What is the Blue Room policy towards student homework questions (which is what this sounds like)? I know that if this appeared in certain other forums the regulars wouldn't be as generous as the responses here have been.

 

Cheers

 

James.

 

 

Edit Blue Room policy is to be friendly to everyone, but to point out that our Terms and Conditions ask members to do a search first before starting a new thread. We'd also prefer it if people would stick to one, previously unanswered, question at a time.

 

Moderators

[Brian]

What is the Blue Room policy towards student homework questions...

The Blue Room has no policy on the matter; other members are free to answer or ignore the questions as they see fit.

[Yorkie]

Some of these questions are answered in the Blue Room Wiki

[Bobbsy]

What is the Blue Room policy towards student homework questions (which is what this sounds like)? I know that if this appeared in certain other forums the regulars wouldn't be as generous as the responses here have been.

 

In this case the OP is 22 years old and working (outside the industry) according to his profile. Also (and this is only speculation) it looks to me like most of the things he's asking about are terms he will have seen in fairly current BR threads.

 

Bob

[Blueroomidiot]

Thank you guys!

 

Been reading all afternoon somethings aint mentioned though like matrixs,expander,compressor,inject,series and parallel

 

Any ideas??

[beware]

Q1 What is the difference between balanced and unbalanced?

Balanced uses anotherwire, which is basically an inverted version of the signal to cut out noise and interference.

 

Q2 how do you work out speaker impeadance?

Read the back of the cab or driver.

 

Q3 what is the difference between series and parallel?

Series: input-component-output-input-component-output (input/output means the wires in this case...)

Parallel: inputs linked, outputs linked

 

Q4 direct/inject/matrix?

no simple answer here

 

Q5 expander/compressor?

see Q4.

 

Q6 omi/cardoid/hypercardiod?

types of microphone

 

Q7 Diaphram/condencer?

see Q6

 

Q8 Phantom power? what is it? why?

somewhere between 9-48V fed down a microphone (balanced) input, to power the microphone or other piece of equipment...

 

Q9 I know its called EQ and I know what it does (loosely) but whats Q? and HPF/LPF?

EQualisation. High Pass Filter, Low Pass Filter

[jayselway]

Q1 What is the difference between balanced and unbalanced?

Balanced uses anotherwire, which is basically an inverted version of the signal to cut out noise and interference.

This might be a more useful explanation of Balanced systems Linky

Q2 how do you work out speaker impeadance?

Read the back of the cab or driver.

or look at the data sheet on the manufacturer's website regarding the driver in question.

Q3 what is the difference between series and parallel?

Series: input-component-output-input-component-output (input/output means the wires in this case...)

Parallel: inputs linked, outputs linked

This one worried me a bit - I have visions of a new guy plugging his output of the amp into the input , and vice versa!

Link to Series and Parallel Circuits Help

Q4 direct/inject/matrix?

no simple answer here

A Simple Passive DI Box Schematic - notice how the signal goes in unbalanced, and comes out balanced.

Q5 expander/compressor?

see Q4.

I would suggest maybe reading a manual for a expander compressor unit, as many have an explanation of what the unit does, so that the user can use it well.

Q6 omi/cardoid/hypercardiod?

types of microphone

Dynamic, Capacitor, Electret - microphone types

Omni, Cardioid, HyperCardioid - Microphone Pickup Patterns

Linky about Mics

Q9 I know its called EQ and I know what it does (loosely) but whats Q? and HPF/LPF?

EQualisation. High Pass Filter, Low Pass Filter

On the "ACS - Church Audio & Acoustics Glossary", Q is defined as

The range of frequencies affected by a control. The "width" of a control. How wide a range of frequencies is affected when you adjust a specific control such as on a graphic equalizer. A parametric equalizer includes a "Q" control which allows the user to make changes to a wide range of frequencies or just a narrow band of frequencies.

 

A lower Q setting involves a wider range of frequencies, and a higher Q setting involves a more narrow range.

 

Jay :D

 

P.S. I have no contacts with the sites mentioned, such as membership or affiliations. However, Google is a beautiful thing! :huh:

[Big_L]

This Site, which has been posted before around here I'm sure, is written by Bath Uni Technical Society (To which, I must add, I have no affiliation) and I've found it really useful in explaining just the sort of thing you're asking about, paticularly in explaining Balanced Vs Unbalanced Cabling.

 

Lewis

[p.k.roberts]

And yet another site worth looking at;

 

http://www.rane.com/library.html#rnotes

 

oodles of reading to fill those long winter evenings!

[soundo26]

Thank you guys!

 

Been reading all afternoon somethings aint mentioned though like matrixs,expander,compressor,inject,series and parallel

 

Any ideas??

 

Without going into massive detail, a matrix is a system that allows you to take a given signal and direct it several ways, they can sometimes be found on the output stages of a mixer as well as being standalone units.

 

A compressor and expander can usually be found within the same unit, difficult to explain quickly but with a compressor you can set a level and quieter passages will be lifted to a higher level to match the louder bits, an expander does something similar but in reverse, you'd be better off looking these up as they often have other functions built-in.

To inject a signal you would usually use a DI (Direct Injection) box. These devices allow you to do many things and are great life-savers. It will allow you to turn an unbalanced input which should only be run over a short distance into a balanced signal which is cleaner and can be run over longer distance without picking up interferences. It will allow you to "pad" the signal i.e. to reduce the gain of a strong signal which is overloading your input, and it will allow you to "lift" the earth in the event of an earth loop creating a hum. An Active DI is usually powered by a battery or phantom power from the desk and can provide some gain and a passive di has no power or gain.

 

Series and parallel are ways to connect speakers (in our application).if you can imagine you have some speakers, let's say four. if you wire two to the output of your amplifier's left and right channels and these are 8 ohm speakers, each channel will give its rated output at 8 ohms to each speaker, so if your amp is rated at 100watts at 8 ohms, each speaker will theoretically deliver the 100watts. If those speakers have outputs allowing you to chain another speaker and you connect another speaker of the same rating 8 ohms, your resistance will halve to 4 ohms and your amp will double it's output (to the pedants out there, I know that that's not strictly true but for the purposes of simplicity and all that........). This is because that output is connected in parallel to the input i.e. it is joined to the input, negative to negative & positive to positive. If you were to attach another speaker onto the second speaker, the resistance would reduce even further and the amp would eventually overdrive itself out of existence.

 

When speakers are connected in series, the first speaker's positive connection goes to the positive on the amp, but the negative connection goes to the positive of the next speaker then the negative connection of the second speaker goes to the negative connection of the amp, this has the effect of doubling the resistance so your two 8 ohm speakers will give a combined resistance of 16 ohms and the amp will halve (roughly) it's output and so on.

You can appreciate that by using these methods, certain numbers of speakers can be connected to an amplifier and the amp can be operated within it's comfortable parameters without damage.

 

Be careful when calculating that that the amp shouldn't be operated with a resistance that is too low as this will cause damage (it's a bit like over-revving a car engine with the gearbox in neutral as opposed to having a load on it)!

 

Hope this has explained it to your satisfaction, there are other factors involved in the calculations which mean that the figures aren't exactly doubled or halved etc. but if you work on those terms it helps to keep it simpler!!

[ianl]

Q1 What is the difference between balanced and unbalanced?

its all to do with mental health or possibly whether you see things in the way you are expected to

 

Q2 how do you work out speaker impeadance?

apply a constant voltage and measure the current flow then do some math

 

Q3 what is the difference between series and parallel?

ones for your mouse, ones for your printer

 

Q4 direct/inject/matrix?

show people the way to go/ method of drug taking/ film writen by people on too many drugs

 

Q5 expander/compressor?

makes it bigger / makes it smaller

 

Q6 omi/cardoid/hypercardiod?

god / an oid made of card / a faster oid made of card

 

Q7 Diaphram/condencer?

contraceptive / makes it smaller

 

Q8 Phantom power? what is it? why?

its power but your not sure where it comes from

 

Q9 I know its called EQ and I know what it does (loosely) but whats Q? and HPF/LPF?

qualiser

 

hth

[bigglesuk]

SFL Group do some basic training course that cover most of what you are asking and it's a hands on course so you'll get to play with a mixer etc. Mark Payne from SFL is a regular poster on the forum and always happy to help.

 

Have a look at their courses on www.sflgroup.co.uk

 

 

Adam