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speakers & tweakers
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epsilon_iridani
Started Topics :
7
Posts :
167
Posted : Apr 14, 2004 04:22
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ive always wanted to know something, from a technical aspect - and maybe there are people here to help with?
Clubbing in england and europe, ive seen my fair share of amazing acts but ive found that in many clubs ive been to (& festivals) when the tunes are at their fullest, and the crowd is just about to "let go" with an almighty drop, then
...the speaker cuts out momentarily
this has happened many times inside and out but always, it seems, before a solid drop.
what is going on? am not complaining but wen this happenes its like "ZZIP!" out of trance and back to reality...
has anyone found this also?
x
<<(epsilon)>>
  It is by will alone I set my mind in
motion.
It is by the juice of Sapho that thoughts
acquire speed -
The lips acquire stains -
The stains become a warning - blah, blah , blah! |
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Mike A
Subra
Started Topics :
185
Posts :
3954
Posted : Apr 14, 2004 12:44
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Maybe it's a short silence before the big explosion?
Used quite a lot in fullon tracks 
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epsilon_iridani
Started Topics :
7
Posts :
167
Posted : Apr 14, 2004 13:35
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hey Mike from a musical standpoint, i can dig this explaination (in many ways its what defines psychedelic to me from other genres)
Im still a bit dubious - sum of my friends who've been there with me, wen cuttouts occur, thinks theres some interference coming from somewhere...
i will investigate further!
it means i will have to go to as many parties as possible...someone has to do it hey?
bom!
It is by will alone I set my mind in
motion.
It is by the juice of Sapho that thoughts
acquire speed -
The lips acquire stains -
The stains become a warning - blah, blah , blah! |
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nobody4
Inactive User
Started Topics :
21
Posts :
358
Posted : Apr 14, 2004 13:41
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almost every amplifier has a protection mechanism that 'clips' the level of output when certain levels are exceeded. Since audio output in PA is basically an electrical surge, there is a risk of actualy tearing the speakers and burning fuses in the amplifier.
Another possibility to the phenomenon you describe is a simple 'gate' device that has the same functionality as described above, only earlier in the chain of amplification (to prevent from the amplifiers to 'lock down' if exceeding levels are reached).
The main reasons for these occurances is incorrect balance setup when doing the sound-check. Gain levels of outputing devices (from CDJ/Turntables/PC soundcard to DJ mixer to the gate device and so on...) should be set to a maximum that cannot reach the 'clipping' level of the gate/amplifier.
This is a common case of DJs/artists who, in the excitment of the moment, raise the gain on the mixer and overflow the PA with too much output, of which distortion is the least of the problems - this can lead to tearing of speaker's membrane or complete shutdown of the system.
cheers,
A
auspexx@compact-records.com |
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simius m
Started Topics :
8
Posts :
48
Posted : Apr 14, 2004 18:18
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Quote:
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The main reasons for these occurances is incorrect balance setup when doing the sound-check. Gain levels of outputing devices (from CDJ/Turntables/PC soundcard to DJ mixer to the gate device and so on...) should be set to a maximum that cannot reach the 'clipping' level of the gate/amplifier.
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Can you explain me please how do i find the correct balance? I have blown up my speakers several times. I think i don't go to loud but they still blow, normally only the mids survive bass and highs BOOOM!!
Any advice?
2 MINUTE CLIMAX TRANCE!!! |
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TeDer
Offtopic posts:
1
Posted: Apr 15, 2004
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More power !!!  |
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CLAW
CLAW
Offtopic posts:
2
Posted: Apr 15, 2004
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motorik
IsraTrance Junior Member
Started Topics :
14
Posts :
153
Posted : Apr 15, 2004 09:55
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Do you have monitors? monitors mostly have a limit light (most of the times it's red) when you over the limit it start flashing and you know you should use less volume.
An hardware console mixer could help to easily control the volume (as long as you don't press the 'phantom' button suddenly while the system plays  )
salute
motorik
"one good thing about music is when it hits you , you feel no pain" - Bob Marley |
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nobody4
Inactive User
Started Topics :
21
Posts :
358
Posted : Apr 15, 2004 09:58
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Finding the correct balance in a PC is exactly why a professional sound technician should be present and maintain any PA handling. Since every PA is different (using different combination of amplification and sound gear), a different balance setup is needed.
In general, you go from the last element to the first, meaning you start from the speakers, check the OHMage (resistance) and voltage capacity, then adjust the amplifiers to maximum output that cannot exceed the level your speakers can handle (in general, the lower the OHMage, the greater level your speakers can take, since there is less resistance).
Same thing you do with the inputing devices - after you set you amplifier to a maximum 'safe' level, u need to set the DJ mixer to a maximum level that cannot exceed the capacity of your amplifier. Please note that every DJ mixer has a different output level (not talking about the 'Master' slider, but on the generic voltage output) and this should be considered as well. Pioneer mixers, for instance, have a very high output level comparing to Behringer, for instance.
now, your biggest problem will probably be the DJ. Since many DJs don't really understand the principles of PA, they will get excited during their sets and punch up the gain on the DJ mixer - this is the biggest NO-NO. Punching up the gain when your PA is set to a certain maximum level is like trying to open 12 bar water gauge into a 5 bar water hose - the PA elements have certain capacity for carrying the electric current, and if you try to exceed that you just get your gear to first distort the sound and then (if you dont use any protective gear like a Gate) to a breakdown of the PA elements (amplifiers lockdown / speakers crash).
DJs are your wildcards, best advice is to stick next to the stage and lower the gain every time they cross the maximum you set in your balance.
hope this helps, since PA engineering is a big topic and you should let professionals handle it. from your side I'd highlight keeping the correct gain level that was set to you by the engineer. Trying to exceed a set level when there is a gate is only gonna make your output distorted.
cheers,
A
auspexx@compact-records.com |
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simius m
Started Topics :
8
Posts :
48
Posted : Apr 15, 2004 22:17
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A correct gain level means do not exceed the green lights(-4db) or the yellow ones(2db). I've heard that i should not pass the 0db. Wich one is correct?
2 MINUTE CLIMAX TRANCE!!! |
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TeDer
Started Topics :
7
Posts :
32
Posted : Apr 16, 2004 01:50
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I was serious when i said more power . Dont know why you think it is off topic ! stronger amp's can handle more power and wont activate their protections so soon !
When you work with dj's that dont know how to work with the p.a.'s limits you can put a limiter on his channel and then he can rotate his gain knob as much as he want but he cant pass the level you dictate to him .
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epsilon_iridani
Started Topics :
7
Posts :
167
Posted : Apr 16, 2004 05:56
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i think you've hit it TeDer - WE NEED MORE POWER!! I feel myself thinking back...
..TO SAMOTHRAKI 2002 ! I REMEMBER HALLUCINOGENS SET AT THE END... AND MAN, THE DUST WAS FLYING BELIEVE ME!! ONLY PROBLEM WAS, THE SYSTEM (80,000 WATTS - puuuuure psychedelic!) WAS RUN RAGGED UP UNTIL THIS POINT - and Mr Posford had the pleasure to dismantel the rig - with a storming set (but cuttouts were frequent) I imagine what happened was the amps couldnt take it (i guess) But alls well that ends well!! And Hallucinogen wrote finish to another great chapter...
bom
It is by will alone I set my mind in
motion.
It is by the juice of Sapho that thoughts
acquire speed -
The lips acquire stains -
The stains become a warning - blah, blah , blah! |
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nobody4
Inactive User
Started Topics :
21
Posts :
358
Posted : Apr 16, 2004 16:05
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Teder - you can have as much "power" and as many amplifiers as you wish, but if your PA is not balanced also on the speaker side you gonna end up shooting membranes at the crowd...
And believe me, it takes 10 minutes to change a burned fuse in an amplifier, but a torn speaker is a dead issue.
A PA system should be balanced according to its various parts: amplifiers should match the voltage and ohmage of the speakers etc'.
As for the limiter clipping on the highlight/explosions - probably because of the excessive use of EQ to 'aid' the buildup (tweaking the high & mid knobs to create a 'peaking' sound) - please remember that an EQ is also a sort of amplifier (for specific freqs), and punching it up can cause the same result as adding more volume (only more lethal, since the limiter/gate is probably set to limit the bass/lower mid and can in many times let the higher frequencies pass to the speakers, hence your little pyrotechnic performance with the membrane...).
DJs and artists should also have some basic knowledge about sound and PA, its always good to know the tools of the trade...
A
auspexx@compact-records.com |
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TeDer
Started Topics :
7
Posts :
32
Posted : Apr 16, 2004 16:41
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Dear helen . just to let you know i'm working with profesional PA systems for 18 years now ... this is how i make my living ...
The right balance amp's and speakers is very important never thought it isn't .
To put it simple :
The person who open this topic asked about p.a. systems cutting out at peak volumes . The very simple answer to that situation is that the system cant supply the demands of the user ( the dj ) . One way to solve this problem is using more powerfull systems and give the user what he wants . you can limit the user and try to teach him how to behave ( ) but that is not answering the demands of the situation ...
As someone who knows both sides , dj and soundman , i know that there are points in the set when you simply need more power to highlight some part in the music ( maybe bass part or mid or hi or whatever ... )
When i'm dj'ing i always keep my self alittle bit off the limit of the system so when i want more power i can use this space . ( TIP ! )
peace and love
( sorry for my english ... ) |
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nobody4
Inactive User
Started Topics :
21
Posts :
358
Posted : Apr 19, 2004 09:08
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I totaly agree with you on keeping a bit lower than the max set level, I use the same method when I play. I think we are both a good example for my point about educating or at least keeping an eye over rogue DJs...
The main idea is to prevent the limiter/gate from kicking in, since that in itself shites the sound (on the least) or clips it completely. A good PA user (meaning the DJ, not the technician) should know the limits of the system and act according to it. Exceeding these limitations is the same as driving a child's bike - you can do it but you will probably ruin the bike sooner than later because they cannot handle the weight (workload).
Again, the CDJs, Mixer and general PA are the tools of our trade, and its sad to see DJs who have only knowledge in the former devices but no regards to the later (PA) - I'm sure one of the reasons Michael Schumacher is racing world champion is because he knows the limits of his car and do not exceeds them...
cheers!
auspexx@compact-records.com |
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