Sound System How To...

[noname]

I've done some thinking, and bounced a few ideas off of Raj and Dr B on the creation of a (comprehensive) "how to" thread/section for sound systems, and thought I would post the ideas here for people to add their two penneth worth (and maybe even volunteer to help write...) I won't be starting until after our last outdoor party in any case, and any input would be greatly appreciated.

My plan is to split the info into a linked set of posts (sort of like web pages, but using the BBcode the forum uses). I've got a standalone editor for BBcode (using the basic tags like the formatting ones, url, quote, img etc), so I can make them up and then send them to one of the moderators or other volunteers for editing etc before they get posted... It's open source too, so anyone who wants to use it - it's called bbEditor...

The sections I've come up with so far are:


Basic audio theory

Characteristics of an audio wave, and how it is perceived/interpreted by our hearing.

1. The physics of audio transmission in air.
2. The biology of the human ear.

How audio is manipulated or created for the purpose of amplification.

1. Audio sources - string, reed, percussive, brass, voice and synthetic.
2. Acoustic amplification - the soundboard, and various forms of resonant chambers, tubes and horns.
3. Audio Electronics 101 - Reproduction in analogue form.
4. Audio electronics 01100101 - Reproduction in digital form.
5. Audio electronics 0065 - Compressing by various means.

Audio amplifiers and other processing equipment

1. Audio amplifiers (a basic introduction)
2. Crossovers, what they do, and why.
3. Mixers - what they do, and why.
4. Equalisation in it's various forms.
5. Compressors, expanders and exciters.

The speaker cabinet, and drivers.

1. Closed box designs.
2. Ported, or vented designs.
3. Thiele/Small ported radiators.
3. Horn and folded/scoop designs.
4. Other "exotic" designs (flat speakers, shell types - ie the "Ammonit" etc, and any others that don't fit the standard categories).
5. Types of speaker driver.
6. Multi driver cabinets and "drone cones".

Rig design

1. Planning for a particular purpose - what you should take account of, and what can be ignored.
2. Designing for modularity and robustness - why you should.
3. Efficient use of time - what to design and build yourself, and what to buy ready made.
4. Design flowchart, and how to estimate build cost and time.
5. Power - working out the requirements, and working within safe limits.
6. Matching amplifiers with speakers properly.
7. Speaker cabinets - designing the boxes, and matching the drivers.
8. Linking it all together.


Rig building and maintenance

Building and testing

Intro: Safety requirements, and some words of good advice to save you ending up deep baked and crispy....
1. Materials and equipment needed (and some good places to find them).
2. Building the speaker boxes and loading them.
3. Hardwiring into flightcases to save yourself endless plugging and un-plugging (and protect equipment obviously).
4. Ground up building of the electronics (places to find this info if you're wanting to do it hardcore style).
5. Testing out for the first time.

General maintenance and safety on the road

1. Things you need to check before every use.
2. Things you need to look out for and remedy if they happen.
3. Yearly check ups.
4. Fault tracing should it all go pear shaped at a gig.
5. Essential "road" toolbox list.




Rig Power (a generator survival guide)

This is not really my field of expertise (although thanks to DJ Richie, I now know a lot more than I used to...) but I think it is a fairly essential part of any sound system how to...



That's as far as I've got. Any input greatly appreciated (especially if you want to volunteer to do/help do any of the sections...)

[sheffield-junglist]

When this has properly got up and running this will be so useful. I'm startin to build a sound system as soon as I can and this will help me out as I know the basics but I'm not a genius or anythin. I'll probably end up blowing something up at some point

[Tek Offensive]

getting to know whats what a bit more now. a comprehensive guide would still be very useful though,

tho me and a few mates assumed we'd know what to do when we borrowed a behringer digital crossover the other day... did we fuck! we ended up using another mixer as a crossover! only a houseparty tho so did tha job.

Originally posted by Tek Offensive

getting to know whats what a bit more now. a comprehensive guide would still be very useful though,

tho me and a few mates assumed we'd know what to do when we borrowed a behringer digital crossover the other day... did we fuck! we ended up using another mixer as a crossover! only a houseparty tho so did tha job.

i aint got a clue about x overs still. i just dont use one coz i wouldnt know where to start.

[DaftFader]

this is a brilliant idea .. unfortunatly like tek any info i give you will probably allready know .. but will love to have a read of this ... n1 dude

Originally posted by DaftFader

this is a brilliant idea .. unfortunatly like tek any info i give you will probably allready know .. but will love to have a read of this ... n1 dude

great idea but it was an idea 12 months ago.... nowt came of it.

[Tek Offensive]

that said, its quite alot of effort to write something like this, and for free too. i know i wouldnt have the time.

the info is all out there. it just takes time to compile it into one.

good luck to him, hope it does get done at some point.

[Raj]

Every time he puts up a chapter it takes almost a week to write and proof it beforehand. Also to check that what he written is comprehensible to those without in depth knowledge of the subject already [he speaks fluent geek speak most of the time] As its a volunteering thing it has to be fitted in around the rest of his life and recently thats been well hectic.

It will get finished gradually [its also a well big subject and bits of it are pretty complex so bear with him] Of course if you would like to pay him to finish it that would put a whole different slant on the matter and it would likely be finished a lot sooner.

Originally posted by Raj

Every time he puts up a chapter it takes almost a week to write and proof it beforehand. Also to check that what he written is comprehensible to those without in depth knowledge of the subject already [he speaks fluent geek speak most of the time] As its a volunteering thing it has to be fitted in around the rest of his life and recently thats been well hectic.

It will get finished gradually [its also a well big subject and bits of it are pretty complex so bear with him] Of course if you would like to pay him to finish it that would put a whole different slant on the matter and it would likely be finished a lot sooner.

granted, wish the bit on x overs would get done soon though lol

[Raj]

Originally posted by MrAHC

granted, wish the bit on x overs would get done soon though lol

Duly noted

[Tek Offensive]

Originally posted by MrAHC

granted, wish the bit on x overs would get done soon though lol

ennit!

[elretardo87]

Standard practice is.....buy crossover....read manual....do as manual says.

As daunting as they look they ain't difficult in the slightest, as long as you know what frequencies you are intending to send to each speaker.

Originally posted by elretardo87

Standard practice is.....buy crossover....read manual....do as manual says.

As daunting as they look they ain't difficult in the slightest, as long as you know what frequencies you are intending to send to each speaker.

now were arguing weather to buy a mono or sterio x over.

[DaftFader]

Originally posted by MrAHC

now were arguing weather to buy a mono or sterio x over.

if you are running sterio then mby get a sterio one .. but alot of rigs use briged mono on there amps .. if you use bridged mono .. theres no point in having a sterio cross over ..

Originally posted by DaftFader

if you are running sterio then mby get a sterio one .. but alot of rigs use briged mono on there amps .. if you use bridged mono .. theres no point in having a sterio cross over ..

We dont bridge as a rule though we stack the speakers when usin a smaller rig.

got bad feed back probs at the mo so need a x over asap.

[elretardo87]

Originally posted by MrAHC

now were arguing weather to buy a mono or sterio x over.

Most are stereo when used 2 or 3 way (as in Hi/Lo Left and Right or Hi/Mid/Low Left and Right) but if your try and use them 4 way they will only do it in mono so you get Hi/Mid/Bass/Sub but only one channel for each.

If its just a cheap but effective solution you are after then I'd suggest either the

Behringer CX3400 (arround £80-100) or the Samson S Class S 3 Way (which can be found for arroudn £130)

Originally posted by elretardo87

Most are stereo when used 2 or 3 way (as in Hi/Lo Left and Right or Hi/Mid/Low Left and Right) but if your try and use them 4 way they will only do it in mono so you get Hi/Mid/Bass/Sub but only one channel for each.

If its just a cheap but effective solution you are after then I'd suggest either the

Behringer CX3400 (arround £80-100) or the Samson S Class S 3 Way (which can be found for arroudn £130)

a x over would get rid of my feedback problem wont it?

[DaftFader]

Originally posted by MrAHC

We dont bridge as a rule though we stack the speakers when usin a smaller rig.

got bad feed back probs at the mo so need a x over asap.

i know it sounds silly . but you tryed putting hte decks futher away from the speakers ... or isolating them ?

Originally posted by DaftFader

i know it sounds silly . but you tryed putting hte decks futher away from the speakers ... or isolating them ?

its not that, its since i upgraded my amps i think. though in this room a 3.5k rig dont leave you much space

[DaftFader]

i get the same problems with a pair of 200 watt speakers i got ... small room and on certain frequencys theres is stupid amouts of feed back from the decks .... but if it wasn't doing it before ..then as you say it might not be that

[elretardo87]

Originally posted by MrAHC

a x over would get rid of my feedback problem wont it?

Explain what you mean by feedback? (I know what it should mean but I'm just checking)

Originally posted by elretardo87

Explain what you mean by feedback? (I know what it should mean but I'm just checking)

when i put the gain up on eather the 2.4kw amp that runs my w bass bins i get awfull feed back.

just bought a beringer cx3400 btw

[BioTech]

Originally posted by MrAHC

when i put the gain up on eather the 2.4kw amp that runs my w bass bins i get awfull feed back.

just bought a beringer cx3400 btw

I think he means what is the type of noise that you hear? Is it a buzzing sound, a deep rumble, a static sound, a loud hum? Does it devlop or does it come on instantly?

Originally posted by BioTech

I think he means what is the type of noise that you hear? Is it a buzzing sound, a deep rumble, a static sound, a loud hum? Does it devlop or does it come on instantly?

higher piched hum louder with the turn of the gain. theres a slight buzz from the tops also

[Raj]

Sounds like an earth problem - check all the earthing in all your kit. Since it comes out of both speaker sets I would go for a common piece of kit the two share. The mixer, decks and crossovers if you have any are where I would start checking.

Do you actually earth your genny? That could be your trouble if you dont.

Do you use balanced line? if not you could just have rf interference being picked up by your cables [which is why we use balanced line everywhere we can] and sanitising it could be challenging

If I come up with any more ideas I will post them here

[DaftFader]

Originally posted by Raj

Sounds like an earth problem - check all the earthing in all your kit. Since it comes out of both speaker sets I would go for a common piece of kit the two share. The mixer, decks and crossovers if you have any are where I would start checking.

Do you actually earth your genny? That could be your trouble if you dont.

Do you use balanced line? if not you could just have rf interference being picked up by your cables [which is why we use balanced line everywhere we can] and sanitising it could be challenging

If I come up with any more ideas I will post them here

some times doggy connections/leads can make a hum as well (by dodgy i mean broken)... try swaping around any leads you can to see if that stops it ..(i had a phono lead that used to hum .. changed it and now its fine)