Hardware & signal path
Sub stack
A sub stack is the group of subwoofers handling the lowest octaves, usually on the floor and often in a block or a line rather than spread out. It carries the part you feel more than hear.
In practice
Walk the floor once a night. The booth is one seat in the room and the subs make it an unrepresentative one.
Take thirty seconds during a track you know well and listen from where people are dancing, then trust that rather than the booth. If the low end there is heavier than you expected, stop pushing the bass EQ; if it is thinner, the answer is usually the venue’s processor rather than your channel. Above all, do not compensate for a booth null by boosting — you are adding energy the floor already has plenty of, and the system will limit to remove it again.
Floor
Where subs live
Power alley
What two stacks create
30 s
The walk that settles it
Where these come from: Standard subwoofer deployment behaviour in live sound — established acoustics, not catalog figures. For what we can measure, see the frequencies involved.
Why it matters
How the subs are arranged changes the room more than almost anything else in it. Two stacks either side of the stage produce a power alley up the middle and cancellation at the edges; a centre block or a cardioid array gives a far more even floor. That is why the bass can be enormous in one part of a room and thin twenty feet away.
For a DJ the consequence is that where you stand decides what you believe. If the booth sits inside a null, you will hear no bass and add some; if it sits in the alley, you will hear too much and take some away. Both mistakes are audible on the floor and inaudible where you made them.
Frequently asked
Why is the bass different in different parts of the room?+
Two or more sub positions produce interference — reinforcement in some places and cancellation in others. It is geometry rather than a fault, and it is why walking the floor matters.
Should I boost the bass if the booth sounds thin?+
No. Check the floor first. Boosting to fix a booth null adds energy the dancefloor already has and pushes the system’s limiter harder for nothing.
What frequencies does a sub stack cover?+
Broadly the bottom two octaves, below where the main speakers hand over. The exact crossover point is set in the venue’s processor and varies with the rig.
Related terms
Club sound system
A club sound system is the whole chain after the mixer: processor, amplifiers, subwoofers, main speakers and often delay or fill speakers, tuned together for one room by an engineer who is not in the booth.
Sub-bass
Sub-bass is the lowest band of a record, roughly below 60 Hz — the part a club feels through the floor rather than hears. It is where most of a track’s physical impact lives.
Amplifier
An amplifier takes the line-level signal leaving the mixer and raises it to the power a speaker needs. In a club it lives in a rack you will never see, usually behind a processor that handles crossover, delay and limiting.
DJ booth
The DJ booth is the space the equipment sits in: the table, the monitor, the power, and where all of it sits relative to the floor. It is part of the instrument, because it decides what you can hear.
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