David Lee Blog

January 1, 2014

David Lee Blog

January 1, 2014

Speaker Alignment

BASSBOSS ZV28 and Z5/D Powered Subwoofers at ULTRA 2013
The physical path length is far from the only factor involved in correcting the time alignment.

Tips for aligning your speakers

The physical path length is far from the only factor involved in correcting the time alignment. Crossover frequencies, filter types and filter slopes along with the phase response of the other boxes in the system will have a major effect on the time alignment. One of my customers found this free software which will allow you to do an impulse response measurement. Using the impulse response you can align the various components of your system.

Using the impulse response measurements you can make adjustments in the crossover filters and delay times to achieve the best possible alignment.  To suggest a delay time based on the path length of the horn without considering the crossover frequencies and slopes would be essentially misleading. Further, if you’re using certain kinds of amplifiers the net time alignment could be further offset by up to 2ms.  There is a super-simple method for aligning speakers that doesn’t involve analyzing graphs. It’s not absolute but it works a lot better than guessing.  And it’s also free. www.holmacoustics.com/holmimpulse


Put the speakers next to each other facing the same way with the sound sources as close to each other as possible. Using a tone, which can be sourced from an app for a phone or a track downloaded from a website, drive both speakers to the same level. (Higher level makes it easier but don’t blow your speakers!)  If both speakers operate in the same passband, the frequency of the tone should be near or below the center frequency of the operating band (If your subs run from 30 to 100 Hz then you would use a tone of 45 Hz or 50 Hz for example.) If the two speakers operate in different pass-bands then the tone used should be the crossover frequency.

Hold a thin piece of paper, such as normal printer paper, between the two sound sources and adjust the delay until the paper doesn’t move at all. (You may also need to polarity invert one of the boxes to get a better alignment.) If the pressure on one side of the paper matches the pressure on the other side of the paper then the sound sources are aligned in time.  It’s an analog concept in a digital world…


Once you have them aligned in that position, if you then move one speaker backwards relative to the other you can measure that distance and apply delay of that distance to the forward-most speaker.

This should allow you to align practically any two woofer-type boxes together, if you have a method for delaying them….

If you need any help please let me know all the components of your system and all the settings you’re currently using and  I’ll see if I can make any suggestions.

Have fun and let me know how it works out…

Music Made Physical

Production Subs

Mobile Subs

Production Tops

Mobile Tops

Shop

Kraken

Quad 21" Subwoofer

BASSBOSS ZV28-MKII Powered Subwoofer

ZV28-MKII

Double 18" Subwoofer

BASSBOSS SSP218 Powered Subwoofer

SSP218

Double 18" Subwoofer

SSP215-MKII

Double 15" Subwoofer

VIEW ALL

VS21

Single 21" Subwoofer

SSP118-MKII

Single 18" Subwoofer

BASSBOSS DJ18S Powered Subwoofer

DJ18S

Single 18" Subwoofer

BASSBOSS BB15 Powered Subwoofer Hero

BB15

Single 15" Subwoofer

VIEW ALL

MFLA

Dual 12" Line Array

BASSBOSS AT312 Powered Top Loudspeaker

AT312

3-Way 12" Top

AT212-3K

2-Way 12" Top

VIEW ALL

DV12-MKII

Single 12" Top

DiaMon 112

Single 12" Coaxial Top

BASSBOSS SV9 Powered MicroMain Loudspeaker

SV9

Single 9" Top

VIEW ALL

LOUDSPEAKERS

APPAREL + ACCESSORIES