Guitar cabinets play a critical role in the tone that guitar players can obtain, together with guitar speakers. While their designs and constructions are far less sophisticated than their HIFI counterparts, their size, design and speakers association provide different results and will be more or less suited to your tone goals. Geared at the beginner guitar player, this first blog post provides an introduction to the main types of cabs and how speaker association and implantation make a difference.

Basics

Guitar cabinets are often built like simple « boxes » : they are most often using a rectangular shape with a front panel carrying 1, 2 or 4 guitar speakers (the « baffle »). The wood used is most often made of multiply wood or MDF. One of the most common wood for guitar cab is the Birch plywood as it provides a very rigid enclosure. The thickness of the cabinet panels can range from 12 to 15 or 18 mm …. The baffle is usually a little bit thicker in order to properly support the weight and vibrations of the speaker(s).

A Palmer empty cab (check reference here : 212 Palmer)

The size of the “box” is driven by the number of speakers. The standard guitar speaker size is 12 inches : a “112” or “1×12” will host one 12 inches speaker, a 212 will host 2 of them, and a 412 will host 4. The power handling is the sum of the individual power supported by each speaker :  modern 12 inches guitar speakers typically handle 60 to 70 watts, so a 412 using 4x 60 watts speakers will handle 240 watts. Another example : a 412 using 25 Watts Greenback will handle 100 Watts.

Design : size of cabinets

The cabinet size, design and construction have a strong impact on the tone you get. The size of the cabinet is driven by the number of speakers mounted on the baffle, which, in turn, imparts a certain enclosure size.

Popular design options include using closed backs, open backs or semi-open backs, where you can remove the back panel of the cabinet either completely or only parts of it. An open back cab produces a different tonal balance compared to a closed cab : it slightly reduces the amount of bass, including the bass projected to the front of the cab. 

Conversely, a closed cab leverages the back panel to produce more bass resonance : the bass sound waves are trapped within the cabinet and produce resonance, increasing the overall level of bass produced by the cabinet.

This is generally obvious when listening to the cab in the room or on stage.  It can increase as well the projected bass level to the front of the cabinet and this will make a difference in a recording or when performing an IR capture of the speaker.

With closed backs, the deeper the cab, the more bass resonance and bass projection you usually get.  That’s why guitar cabinets used for metal or heavily distorted tone are often closed cabs and are also often the deepest ones or the ones with the biggest volume : metal players usually need a strong bass level and/or a scooped tone. And raising the level of bass projected by the cab changes the tonal balance : it tends to produce that mid-scooped tone. Closed cabs that are jointed and carefully sealed will trap more bass. Together with thick wood and dovetail or finger joints, a robust construction will ensure that minimal unwanted cabinet vibrations and rattlings are generated.

Some vendors offer extra large variations of their cabs for more bass and more heavily scooped sounds (these are the « XXL » or « oversized » models).

Orange PPC 412 (46 kg)

Front-loaded versus rear-loaded

it seems that a vast majority of guitar cabinets uses a rear-loaded design. That is also mostly the case for combo amplifiers, which are typically open backs. Rear loading means that speakers are attached to the rear of the baffle. As most speakers have a rubber band on their edge, the result is that speakers are sealed to the back of the baffle.

Front-loaded cabinets are less common : the speaker is mounted to the front of the baffle, with a rubber joint added in-between (or not). It can make a big difference in the tone : front-loading will project more high-mids and treble, resulting in a more airy sound and possibly a more scooped sound, depending on the cab volume. Front-loaded cabs can typically produce that « in-your-face »  sound with distorted guitars

A front-loaded Diezel 412 cabinet : https://www.diezelamplification.com/cabinets/

Which one is better ? Well, I guess it is a matter of taste and gear association. What is sure is that front-loaded speakers are way more convenient when it comes to swapping speakers : with a rear-loaded one you have to unscrew the back panel and remove it to get access to the speakers.

Some vendors clearly states the mounting type they use, for others it may be mentioned in the feature list or you may have to figure that out from the cabinet pictures.

Check those two links for more explanations on differences between rear-loaded and front-loaded cabinets : https://www.diezelamplification.com/cabinets/ and https://celestion.com/speakerworld/guitartech/1/215/Should_I_front-_or_rear-mount_a_speaker_onto_the_cabinet_baffle?_/

Examples of rear-loaded cabs : 

  • Diezel 412 RC 
  • Orange cabs 
  • Mesa-Boogie cabs
  • Zilla Cabs

Example of front-loaded cabs : 

  • Many Engl cabinets
  • Diezel 412 FC : front loaded
  • Some Harley Benton 212 cabs
  • Some Palmer cabs

Ported cabs

Some guitar cab makers use ported designs (a.k.a bass reflex). The port will increase the low frequencies output, so these cabs produce slightly more bass than non ported ones for the same volume. The port dimensions have an impact on the frequencies that are boosted.

Example of ported cabs :

  • The E112 VB  from Engl
  • The Zilla 112 Ported
  • The HESU Wizard W112
  • The Bogner 112CP (dual ports)
Engl E112 VB : check the port, bottom front right of the cab

The speakers

The size and depth are not the only parameters that drive the cabinets tone : the speaker is -of course- a major component, with its specific frequency response, which is more or less its tone identity.

The cabinet size, wood -and wood thickness to a certain extent-, and using front or rear loading will produce slightly different tone balance for a given speaker or a given set of speakers. So the speaker matters and the cabinet matters as well : for example, a Vintage 30 should sound more or less the same in different cabs, but actually you get many different flavors of the Vintage 30 with important variations in overall tone, depending on the cab design and construction. You’d be surprised, if you never experienced this, to hear the differences you can get only by using a single cab and by testing and recording the individual speakers of the cab : they can produce very different variations of the base tone, especially when recorded using close miking techniques. And some speakers/positions may sound better than others….

212 and 412 cabinets can use a single type of speaker or use a mix of speakers: for example speakers combinations like G12-T75 + V30, G12K100 + V30, or Demon + V30,….

If you are looking for new, different sound, or if you are unhappy with your current tone and before buying another amp or cabinet, you could give a try to install different speaker(s) in your existing cabinet. There is a used market for speakers and you can often buy them for approximately half or 60% of the price of the new ones.

Conclusion

Metal and rock guitar players may often focus on their guitar pickups, overdrives and amps, and it is easy to overlook the guitar cabinet (« I need a cab, let’s get a V30 one »). I think the cab weighs as much as all the others combined and it really plays a major role in guitar players tone. For instance, I am still surprised today to hear the differences in results and feel by changing only the cab and speakers (well, at least virtually, by changing IRs). And to go from situation like : « wow, this tone sucks, it must be these pickups and my amps settings », to :  « wow, it is actually a great tone and a great match with this speaker and cab »… 

Explore (virtual) cabinets and speakers : you may find very great tone on your way ! 🙂