Skip to content

Trying a Different Approach to a Djing Gig. Part 2

June 19, 2011

For part 1 visit HERE

Practicalities

Trying anything like this it’s a great advantage knowing a few people with sound systems. Ideally what you want is somebody who’ll get enthusiastic about the projects possibilities and jump onboard. So I was lucky enough to know people who’d fit the bill. Muc is one of the primary members of Untz, a local sound system. Untz had twin double 18″ woofers, four double 15″ woofers and 2 sets of matching mids/tops at that point, and enough amps to make two independent rigs which I needed. We decided against the double 18″ subs due to that way the room shape and floor reinforced bass, it would of lacked definition once it reached a certain level (I could have been wrong, very heavy speakers to be testing theories with, and up two flights of stairs too!). One mid/top set was much more powerful than the other, after experimenting it was decided they would go to the back (System A in the picture below) as we wanted the sound at the back not just to be distant but to become huge and ominous (best heard on the recording during Seamonkey mixed to the back with its remix to the front).

Muc pointed out something to me I hadn’t considered at this stage. The back speakers (A) sound would have to travel about 10 meters more than the front speakers (B) sound before they both hit the crowd. The back would sound slightly delayed.

Slight delays could destroy any coherent image (which was already under pressure from the room acoustics) or rhythm between the two systems but time delaying the first speaker would mean all the sound waves could stack up properly. Most sound system crossovers have delays built in, which have measurements in distance as well as time. These delays are usually for more precise distances (e.g. synching bass scoops with other front facing drivers, say half a meter or so) but it could handle the 10 meters or so. Fixing this had a note able impact on the sound which beforehand had sounded like bad beat matching with phasing and it now snapped into an instantly impressive, spacious, and tighly synced 3D effect. Of course if you walked to behind the front speakers (B) and towards the back of the room the sound got progressively worse as you walked towards the back wall, but nobody would be allowed in this area apart from any crew and Conrado as the long suffering visual artist and projectionist.

Music Selection

I tested the room by setting up monitors there and trying various different types of music and found that a lot ofthe rules I followed in production, regarding reverb, held true in this setting. Snappy percussive sounds made lovely reverb tails and anything like a pad or string sound became huge and grand. I found the lower midrange seemed to vanish on some tracks so I decided not to use any tracks that were very dependent on this area. Anything that sounded muddy was going to sound muddier. Some tracks were dropped from the pool I make my set from and some new ones were sought out. As my dj set, at the time, had a dubby element I didn’t have to make too many changes. Also the crowd wasn’t going to be all electronic music diehards so I tried to build in enough variety in my limited range to try and include something everyone might like. The set wound up being composed of electro, idm, dubstep and some techno, old and new all hovering around the 140 bpm mark. I also found as many multitrack sets (the type where artists share their projects) as I could. This enabled me to change these tracks to different tempos and to take out layers to place over other material, enhancing the amount of colour available to me while staying true to a focused direction. I also did something I always steer away from in my production and that was to include many third-party loops from packs I bought specifically for the show. I considered the pros and cons of this last step a lot as I’ve been quiet anti pre-rolled loops in the past, more about that later.

Digitally Compensating for the Acoustics (skip unless you like this sort of thing)

Whilst my speakers where set up I tried something I had only previously known in theory, a way of testing for room nodes (Room modes are the collection of resonances that exist in a room when the room is excited by an acoustic source such as a loudspeaker.) Room nodes are dependent on a rooms shape and act like an EQ, outside your control, with wild boosts and cuts in different frequencies. The typical way of testing for them is to sweep a sine tone of constant amplitude up the audible frequency spectrum through a speaker in the room and record the sound in the room with a microphone (which should have as flat as possible response). You then examine the recorded sound. Areas of higher amplitude will indicate the rooms shape boosts at the frequency present during that part of the recording and areas with lower amplitude indicate attenuation of the frequency present during that part of the recording. I found a slow sweep gave the best results. The room was far from flat in its response but none of my EQ’s had a narrow enough Q factor to compensate without also hampering neighboring frequencies. Another sound man (in all respects, good man Spud!) recommended Room EQ wizard which produces an impulse response based on the room which when phase reversed cancels any nodes. However further research showed that such treatments only work for the point in which the measurement microphone is placed and stepping away from this ‘sweet spot’ the room EQ may actually make the experience of room nodes worse. Aside from room nodes it would have been interesting to see if room EQ wizard would have allowed me to cancel the room reverb with phase inversion but seeing as my set wasn’t even close to completion, I have a day job and the gig was two weeks away I thought it best to press on. So, for the moment, I’m leaving room compensation alone and sticking with room exaggeration only.

Next post I’ll talk about the set itself from rack effect set ups, slicer devices, drum machines and synths to harmonic mixing with percussive loops and rigid control versus total freedom.

For information on harmonically mixed live sets visit HERE

 

 

Advertisements
No comments yet

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: