Soundsystem stuff pt. 1
Dancehall Reggae Sound Systems Flickr Pool
Reggae Soundystems Flickr Pool
Jah Tubby’s World System Photo Archive
And of course the Valve Soundsystem
Here is a compiled version of trevords awesome posts talking about sound systems:
Link to the Original thread from he TapeOp MB
(trevord)
Here goes – I didn’t want to Hijack the thread with an overly long post
I used to be involved in that scene (in Trinidad at least) since the 70’s and still do a little now – it was more DIY back then because the big guys had not taken the market seriously.
AFAIK – these days the super groups (sound-systems) make the circuit to all the big city Carnivals from Toronto to Miami to San Francisco and all points in between.
It is all top notch now.
The double 18’s are actually the “home systems” seeing that you can’t travel far with them and most of the big money comes from putting the systems on “big trucks” and playing the street during the Carnival parades.
Typical older/local system is made up of a number of bass/mid/his combos
typically the double 18 box , a big mid horn, and a bank of piezo tweeters.
Piezos are favoured for everything but the bass cause you can’t kill them – usually when you do – you fry the lead wires and solder them back and keep jammin. These are usually separately amped but the amp is not in speaker box but in a rack maybe 3 or 4 19” racks wide and 5′ tall (big enough for everything plus a dj “coffin” on top).
In my day we didnt use crossovers but did separate equalizers as crossovers – this gave more flexibility on the sound. Amps are not bolted but are free standing for cooling – the racks are surrounded by fans.
The systems that they travel with is more efficient – usually made up of the big multi 15”/12” columns with piezo tweeters. This way you can completely surround the truck with a wall of columns and have your rack in the middle. The newer systems also use compression and newer things like ultra low frequency rejection (u aint seen nothing till u see a double 18” bounce because of turntable rumble).
In the old days and on the older systems today the amp of preference were the 500 W per channel tube Crowns and McIntosh’s. The bigger tube Dynacos were also popular. These tubes bad boys would drive to distortion 24hrs a day (in the topic heat) and still sound “pleasing” .
The other thing with tube is you could distribute the hi-voltage (if you had really long speaker wire runs) and put the transformer at the speaker.
Another reason tubes were popular is you can pick the output impedance to match your speaker config – there were 4/8/16 Ohms taps on the output transformer.
There were are few transitor amps which were legends
1) Phase Linear – Never understood the reason but these amps sounded great under stress – and were typically under rated in power.
2) Carver – (later on) very efficient and sounded good under stress
3) Consumer Pioneers – hugely underated in power and had the extremely high damping factor that damped speaker movement. You could run low bass all day on these things.
I think all these lines share Carvers designs – nothing sounds like these amps – anything they have now will auto shut-off right in the middle of your clash Smile
But nowadays power effeciency is paramout- so newer qsc or mackies are used. But if your see a crown 500 tube or phase linear 700 – get it – thats the sound of bass Wink
With a system like this you have to run from the junction box of the building or use a generator. Of course the “big-trucks” always use a generator.
your team would be
1) selector – manages records and picks them
2) sound-boy – tweeks and fine tunes to get the best sound
3) sound-system – the guys who actually own the system and are responsible for transport and setup
4) electrician – responsible for all things power either a generator or knowing where to get enough power
5) You would usually have a dj chanting over home made dub plates
6) Promoter – Guys who organized the fete
All of these could be one team or independent – I used to be an independent sound-boy.
The big bass horns are popular for outdoor events – but you get a mid-bassy sound – but it is more efficient. You would arrange a pair of double 18” in a corner formation to get more concentrated projected sound outdoors.
These systems might be home made – but they were not guess work. There was a “bible” of the speaker design – I dont know if you guys remember the Radio Shack books on speaker design – the DIY speakers were usually made from the tables in those books.
The double 18 are usually 1” plywood or high or mid density fiber-board reinforced with 2×4s. Depending on the desired mobility the 18” were designed to be easily removable – to make things lighter for transport and you usually blew a couple during a “fete” anyway. If the double 18 was stay at home or extremely high-power speaker the botton was cast with concrete to prevent it from moving.
The new systems are all planned by the manfacturer representative – I think JBL had cornered the market for a while. There is nothing like every truck blaring JBL on Brooklyn Labour Day parade for advertising. But again the other manufacturers have caught on and the manufacturer/sound retailer is usually the “sound-system” for the super groups.
Of course the high-lite of being a dj like this is the “sound-clash”
There are two types of “sound-clash” the fixed place (”hall” or “basement” and the “big-truck”)
The “big-truck” is not too exciting – two trucks meet on the parade and one dominates and people dance to that one and the loser is “asked” to turn-off.
The more exciting “sound-clash” is the “hall” or “basement”. “Halls” are bigger rental spaces and “basements” are basements in homes.
Typically two or teams would battle with bass heavy songs and dj’s – in my day the crowd turn the speakers of the loser around. Smile
Typically a promoter would organize a fete – the money is made from selling of food (ital) and liquor (and other agricultural products Smile ). Depending on the size of the venue and expected crowd – you would involve more than one sound-system on your team. You are expected to arrive early and setup. Earlybirds got the corners for the bass boxes.
You were also expected to arrive early and play at max volume as advertisement. Depending on the geography around the venue – these things could be heard for miles – of course its different for a club or house in the city.
There is more interesting stuff
At home – the first thing we did was varnish (yeah thats right as in poly-urethane) the paper cones of the 18 to protect them from rain, spilt beers and also to strenghten them. We also added paper re-inforcements from an old 12” to strengthed the joint from the cone to the core.
We also added multiple leads to the core and extra insulation.
AS far as the bass boxes go the the big problems were usualy the cores over extending and getting stuck – a quick slap to the cone would put them back. Other than that the cone would catch fire – then you just popped a spare 18” in.
The piezos would take almost anything you threw at them – the main problem would be frying the lead wires – many piezos are fixed right on site – the solder remover tape serving as a temporary lead. Or a big 4.7 uF in series kept the bass out – but most of the time that was one more thing to blowup.
As far as quality – you are right about the distortion especially the tube amps – that was the sound to get. I remember me and my “sound-boy” friends use to laugh that we were just gating the 60Hz power supply with the bass. But these are meant to be listened in a huge crowd in the outdoors. A “block-o-rama” – it was these systems that gave birth to rap in the ’70s.
Those were fun times – nothing like telling a gang of rastas stop smoking the big blunts by your system because the long ash was getting in and shorting things Wink
Interesting side note: The same mentality has combined with the American car audio contest to produce a strange phenomenon. The idea is to have a small sedan – packed with enough equipment to sound like a full “sound-system”. The thing is – you are partyin in the street – but the desired thing is the source of the sound should not be identifiable – they are are usually the simplest hand painted (in a single color) sedans. Its amazing what they pack into these “sound-system” on wheels.
Hope I didnt stray too much from the topic. It was fun reminiscing.
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For the older/cheaper systems i think the faults were in order of frequency
1) Any coil driver in a mid-horn or tweeter – might as well walk with a box of them. Use piezo-electric drivers or spend the night replacing coils in your horns.
2) 18” speaker repair kits – there were two problems with these
a) edge failure – the expected excursion of an 18” for high SPL is relatively small – and the edges were usually deteriorated from sun/heat, moisture and use. Even the newer edges deteriorate in the sun/heat, and there isn’t much you can do to protect it.
b) leads and cores – usually an 18 would knocked out of alignment by someone hitting the cone or dropping the box and the weight of the magnet shifting everything out of alignment – the core would then rub and short out (if you are lucky – if not – the cone would catch fire)
3) Low frequencies getting thru and blowing speakers
4) replacing tubes/transistors
When you get speakers – get the ones which can be taken completely apart by bolts.
But the need for hot repairs depended on the situation – if it was you alone with a big system in a smaller venue — hardly anyone noticed (one 18 out of 6 or 8 double 18” boxes)
Its funny – it wasn’t the bass that gave the most problems – its was the mids. In spending on your system spend on the mids – thats the perceived “quality” of your sound.
You bass could be 100% undiluted distortion but as long as people heard the melody and recognized the tune – it didn’t matter.
Also this is reggae/soca/latin music – the bass doesnt “hit” that often – almost all the time you will see your bass power amp vu meter return to zero – while the mids power amp will be continuously driving. Plus when the venue gets packed the thing you compensate by turning up is the mids/highs.
If you have 500w RMS amp and 300W RMS amp put the 500W on mids and 300W on bass – the bass amp will be peaking a high value but running 200W RMS while the mid will be running 300W RMS.
So usually the thing to fix (because it immediately affects the sound) was things to do with the mids – horn/speaker going, amp overheating etc.
In a “sound-clash” its different tho – you go for it – hopefully you start sounding like crap before things begin blowing up. Smile
The other big cause of failures was unexpected resonances in the space you are in. You would be surprised at what 6 double 18 would find in a room – from the floor going into resonance to bass build up actually moving speakers. More often than not you got bass feedback going thru the floor which cause your amps to overheat in one venue but not in another – this is why dj “coffins” are usually suspended from the “rack” by springs . Not to mention, when things are going good and the whole crowd is jumping in perfect synchronization (for calypso/soca) and the whole crowd “dip” in sync in reggae – thats a very low freq bump going thru your system
The other failures was people tripping over cords – one thing we learned early was how to wrap cords and connect cords/cable. It is one thing I dont see anyone do in America. Our way is – any cord going to the rack is first looped with the tie point of the loop at the top – this does two things – strain relief – if the line gets snagged (some one tripping over it) the loop just gets tightened – if water drips down the line – it would fall off the bottom of the loop before getting to the rack.
The amps were very reliable – but back then power amps were huge and simple – take the phase liner 700 for example
thats 50lbs of meaty transformer and heat sink – any of the driver transistor go – just unscrew them and replace them. Plus the heat sink was the perfect place to put “roti” (Indian wraps) to warm them up Smile
New amps seem to have the transistors hidden – but with all the modern auto shut-offs you should not need to change anything in an amp.
The big tube amps seem to sound better as they died – you knew they were dieing because the sound got really crunchy and the tubes changed from healthy red/orange to blue/violet – but they kept on jammin – nothing could stop a mono-block 500W McIntosh – that mutha would drive a short without complaining – you just noticed the lights in the village were dimming in time to the music Wink
Hey – I didnt know there were so many fans here
I’ll try and set up a little treat for you fans.
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Kinda makes you want to hit Parts Express and start buildin…
More links, pics and video in pt. 2…