Category Value Rating
Features 20% 3.5 Stars
Usability 25% 4 Stars
Sound 25% 4 Stars
Documentation & Support 10% 2.5 Stars
Price 20% 3 Stars

OVERALL RATING = 3.6, which earns it a WIHO Award!

3.6 stars or better: Outstanding, WIHO Award
3 stars or better: Worth considering
2 stars or better: Suited to specific needs
1 star or less: Not recommended

3rd Power created quite a splash when founder/designer Jamie Scott introduced the company’s premium line of amps and cabinets a few years ago. Before anyone took a moment to listen to 3rd Power’s great sounding amps, they were already captivated by the unique looking HLH312 3x12 speaker cabinets housed in triangular enclosures.

More than skin deep, this beautiful design was an outgrowth of both studio near-field monitor and live sound reinforcement design principles, arranging speakers in a tightly coupled array within an enclosure that eliminates right angles (and thus standing waves).

The Switchback SB312 cabinet reviewed here, like the original HLH312, is nothing short of revolutionary! Utilizing 3rd Power’s patent pending triangular chamber housed in what appears to be a typical 4x12 cabinet, the age old problem of poor sound dispersion is resolved, along with the need to use devices such as “beam blockers” to ensure people standing directly in front of your rig don’t get their heads blown off.

The sound from these cabinets is huge, with significant extended low frequency response, and the triangular speaker array delivers a much larger sweet spot than any 4x12 cabinet we’ve ever had the opportunity to perform with. No longer are electric guitar players confined to the stage area directly in front of their cabinets in order to enjoy their guitar tone at its best, and everyone around you (both on stage and in the front couple of rows) will appreciate the difference in your stage sound.

3rd Power HLH 3x12 Speaker CabinetWith a variety of speaker types available as an option, there’s an SB312 ready to suit your style of play, whether or not your tastes call for a triangle or a square. 


3.5 Stars

Inside the outer SB312 enclosure, a triangular-shaped acoustic chamber houses the speakers. Taking a cue from the studio environment, this design is based on the principles of eliminating parallel surfaces against which sound reflections can overlap, causing banding issues and standing waves that degrade the sound of the audio signal.

By arranging the speakers in a tightly coupled array (the edge of each speaker rim touches the other speakers) and placing them in a triangular enclosure, the cabinet delivers a big and smooth sound that has fantastic dispersion, unlike the narrowly focused (beaming) sound of typical 4x12 enclosures.

The SB312 cabinet is made from 15mm Baltic Birch primarily (with 18mm cleats), and it houses three Celestion speakers in a triangular enclosure within a rectangular outer shell or frame (our review model featured the popular G12H speaker). This provides the sonic advantage of a triangular speaker array with the ability to actually set your amp head on top of the cabinet, something we wouldn’t advise attempting with the triangular-shaped HLH312 cabinet unless you’re incredibly wealthy and incredibly stupid.

The cabinet features a removable triangular section in the middle of the rear of the cabinet to deliver an open-back sound for players seeking a looser, vintage tone from the cabinet. Operation of the cabinet is strictly mono, though it would be cool to see an array of speaker jacks for players to use a single 3x12 cabinet in a wet/dry/wet rig.

Casters (included) are of the stick-them-in-the-socket variety. We would have preferred that they mount on quick-release plates rather than this more rigid approach (useful when loading gear in a car/SUV). 


4 Stars

The SB312 cabinet is full sized, but at a glance, you’d never know that it isn’t a 4x12 design, and most standard-sized heads should fit just fine on top of the 29” wide cabinet. We loved the recessed handles built into the top corners. Some 412 cabinet designers don’t like to use these types of handles because they intrude on the interior cabinet design, impacting tone (in fact the triangular-shaped HLH312 cabinet uses external handles), but as this cabinet is really an external shell surrounding the triangular enclosure, you get the best of both worlds: the best handle design without any compromise of the cabinet’s tone.

Measuring 29” x 26” x 14” (without casters), the SB312 is a few inches shorter and narrower than a Marshall 1960 cabinet, but in actual cubic feet, this is a 23% space savings (and 9% smaller than an ENGL Pro 4x12 cabinet we had nearby in the studio for additional comparisons). This subtle difference can mean a huge advantage for players moving their own gear, though. We had no trouble fitting this cabinet in car trunks and hatchbacks, something we couldn’t always accomplish with traditional 4x12 cabinets.

Comparison of the size difference between 3rd Power SB312 and Marshall 1960-style cabinet.

Just watch out for the house sound guy when he mikes your cabinet… if he’s thinking “top left side” (or right) for his mic placement, he’s going to be baffled (pun intended) by the lack of response he gets from that mic position. 


4 Stars

The sound from the SB312 cabinet (and presumably the same-on-the-inside HLH312) is nothing short of revolutionary.

The triangular speaker array is a real innovation that delivers huge on its promise. 3rd Power founder Jamie Scott describes the sound as that of a 36” speaker with the immediate response of 12” speakers, and this is a very accurate description. The cabinet sounds just as big as a 4x12 cabinet, but what makes it really stand apart is the reduction in directional sound.

Sound from the triangular speaker array really disburses across a noticeably wider sound field, and this has some tremendous advantages over traditional 4x12 enclosures. First, if you’ve ever found that you had to stand in just the right sweet spot in front of your rig to hear your tone in its finest glory, this design solves that problem. We found that we could move great distances around our rehearsal studio space or stage area and hear our tone clearly — and at a consistent volume. This design made a real difference.

The other obvious advantage is that other band members can more easily hear your tone without relying upon a monitor mix —it will sound bigger and richer to them. And, fans in the front row won’t suffer from the directional sound of typical 4x12 cabinets when you’ve got this on stage behind you.

The Celestion G12H is a classic rock speaker with a British flavor (that is to say polite and creamy), widely used in many styles of rock, pop, country, and metal. We played the SB312 not only with a 3rd Power HD100 head, but also with an ENGL e580/850 rig and a Mesa/Boogie Road King II.

In all cases, we loved the sound, which was bold, tight, and smooth — never shrill. Some speaker cabinets are tuned so specifically to one particular line of amps that they don’t always sound uniformly strong when paired with different amps, even when the cabinets feature the same speakers (at the same ohm rating) as another manufacturer’s cabinet. Obviously, differences in the quality of construction, the choice of wood, the size of the cabinet, and even the method of mounting the speakers all contribute to differences in sound. The SB312 cabinet sounded universally strong, a testament to all of the factors being considered, and we never once found our tone sounding different enough from our usual 2x12 and 4x12 cabinets that we needed to make a trip to our amps’ EQ controls for minor tweaking.

We easily recommend pairing the SB312 speaker cabinet with your favorite amp if you’re not tied to an all-from-one-manufacturer rig. You’ll get the familiar tone you have come to rely upon from your amp, but with a huge sweet spot in which to bask in the glory of your tone. To continue this tennis analogy, using one of the 3rd Power speaker cabinets is like going from a midsized racquet head to an oversized head, but with the performance characteristic and attack profile of the more nimble, pro model. Sweet (spot)!

Documentation and Product Support

2.5 Stars

There was no documentation included with the speaker cabinet, but the 3rd Power website has a great FAQ document and other technical papers explaining the unique properties of the speaker cabinet design.


3 Stars

The 3rd Power SB312 speaker sells for $1,099, and is offered with a choice of speakers including the Celestion G12H, V30, Alnico Gold, or a 3rd Power designed British 75, a ceramic magnet 75w version of a G12M manufactured by WGS.

The pricing is competitive with other professional 4x12 speaker cabinets. Sonically, you’ll never notice that you’re one speaker short, and the slightly smaller cabinet size could make all the difference between taking this cabinet to a gig in your car vs. leaving it home in favor of your compact 1x12 or 2x12.

Contact Information

3rd Power Amplification


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