It’s widely known that loudspeaker choice can play a big part in your tone. What’s a little less well known is that many elements of the speaker cabinet’s construction also contribute. This includes the size of the cabinet, type of wood, thickness of baffle (the panel that the speaker is mounted to) and how the parts of cabinet are joined together.
Perhaps the most significant element of a cabinet’s construction, however, is whether the back is open or closed. Believe it or not the same amplifier will sound significantly different when driving speakers in either open back or closed back cabinets.
Open Back Cabinet
Most open back cabinets are actually just partially open, with upper and lower panels covering half or more of the back. They allow some of the speaker sound to radiate from the back and to a lesser extent, the sides.
In general open back cabs have a room filling quality that sounds open and natural. Without a complete back panel that compresses the speaker’s ‘voice’, open back cabinets might be considered a more organic representation of a guitar sound. High frequencies particularly benefit from this – they have lots of presence. The low end will tend to feel looser.
On stage, this wash of sound can be quite helpful when there are no monitors – your drummer might be grateful for that! In the studio it provides some excellent options in terms of microphone placement. A slightly different tonality will be available at the rear of the cab, and the use of an isolation booth can create a more complete soundscape than you could capture using multiple microphones.
Closed Back Cabinet
Unlike the open back cabinet, closed back cabs can really only project the sound forwards, meaning no back spill or side leakage from the cabinet. This tends to accentuate and harden midrange and bass sounds, giving them a greater amount of low end punch.
This increased directionality can make them harder to hear on stage unless you’re directly in front, but is a boon for sound-men who would otherwise have to contend with the ambient ‘wash’ produced by an open back cabinet.
Which is for Me?
At Celestion we’re often asked “which type of cabinet is best for me?”
As a rule of thumb, closed back cabinets tend to project the sound forwards and yield a punchier, more structured tone with crisper definition. Contrast that with open back cabinets that are much more inclined to fill the room they are in, providing a more natural and organic sound with a greater ambient quality.
Just like with all tone-based decisions, it ends up being subjective, it’s entirely dependent on what you like to listen to and the kinds of sounds you’re seeking. So with all the above information in mind, take every opportunity to play as many different types of cab as possible open back or closed back, as well as every kind of speaker you can find. Trust your ears and they’ll help you find what you like the sound of most.