JBL GTO1214BP

A slightly trapezoid enclosure with a gentle taper to the upper dimension. This is a bandpass enclosure, such that the rear of the GTO 1214 subwoofer can be seen firing from a sealed section of the enclosure behind a clear window (with white internal illumination from two LEDs) into the ‘front’ part of the enclosure. This is the only way that the driver’s output can reach the car’s cabin via the single ‘Slipstream’ port. The front is finished in half black shiny laminate and half clear plastic window. The front panels are held in place by a set of black plastic moulded edging pieces, all secured with attractive Allen headed fixings. The box is tightly covered in tough grey carpeting (and I know, as the first bass reflex one was severely tested by cats’ claws this one was re-wrapped in polythene between tests) and has two connection cups on the right hand end as you look at it. One is a twelve volt plus and earth supply for the lighting, the other is a conventional set of binding posts for the watts of bass. The box we had was the four Ohm version, it can be bought as a two Ohm if you wish.
– Frequency response: 30Hz to 150Hz
– Three-quarter inch MDF construction
– Power Handling: 350w RMS (1,400w peak)
– GTO 1202D vented pole piece subwoofer driver used
– Large top rubber roll surround and progressive lower spider
– Cone has raised forms, including JBL logo (hidden within)
– Large front firing gas flowed port (internal end as well)
– 4 Ohm voice coil
– Gold plated 4mm binding post terminals
– Separate 12V DC connection for illumination (2x white LED)
– JBL GTO SERIES badge on front
– Efficiency: 93dB 1w/1M
– Dimensions: 420(h) x 626(w) x 423(d) mm
Review by Adam Rayner
What a difference a deci-Monkey makes! For fifty quid more than the ported version, the Bandpass box here is a big fat slice of bass better in some crucial ways. The first thing to grasp is the difference between the kinds of boxes. A sealed box allows a woofer to drop way down to the limit of the wobbliness of its suspension. A ported box allows the speaker to sing like you do in the bathroom, with a cavity ‘tuned’ to resonate at the same frequencies as the bass the speaker is making and fling huge gouts of air out of a port, or hole in the enclosure. This is also called bass reflex and allows the back wave of the speaker cone to couple up with the front and all that means that a well designed ported enclosure can be up to 3dB louder than a sealed one.
That said, the sealed will drop deeper, while the ported will get quieter much quicker as the depth goes down, or frequency drops, as the tuned frequency of the enclosure is left behind.
However, bandpass as this design is described, gives you a slice of both, with great sealed box acoustic suspension of the driver itself, meaning it can be given fifty watts more power for one, and the ported front box being able to really go for it. Only minor drawback is that it has a closely delineated ‘slice’ of frequencies it wants to play best. You can eff about with the bandpass design to make it louder, or deeper, or tighter, but as you approach one end goal of the ‘design triangle’ then one or both of the other desirable qualities goes away in proportion.
So, designing a bandpass box to work brilliantly is the work of the true acoustic alchemist. I nominate a certain forum user called ‘micb’ as the Reader Most Likely To Grasp Concept. It can go up to a multi-chamber, multi-driver lunancy and as each level of complexity is added, you add another ‘order’ to its description. So you can get seventh and eighth order bandpass boxes etc.
It can get really techy and physics-of-sound-in-air really fast and I love it.
What is all you need to know is that JBL are Audio Gods and have more years of expertise on their side than most other makers can only have masturbatory fantasies about. The GTO1214BP is thus a minor work of genius exhibiting tightness, depth and great SPL.
It does of course exhibit some bandpass limitations but the compromise is incredible.
I gave it a slice of ‘My Bass Hits Hard’ with lyrics like ‘StreetWires 140 Amp alternator, harder to kill than a Terminator’ from Power Supply’s ‘More Bass, More Boom, More Bottom’ and let it have it. I gave it a good bit more than the 350w it is rated for, I’m sure. All courtesy of the JBL GTO24001 monoblock. This’ll do over 1,500 watts onto four Ohms, so I was careful.
Well a bit.
As the drops and mad bass lines wobbled and crescendoed, I could tell that some of the notes were just too silly way down below normal music for the box and thus the true Bass CD-only nutter may not be the right buyer for this item, but then it’d hit a note it did like and it was absolutely astonishing. The power and weight and might that came poohing out of that port had to be felt to be believed.
Yes, it is a good bit bigger than the ported job and yes, it is fifty Nicker more and I know I was pretty impressed with the output of the ported GTO1214BR but this BP version is outstanding.
It will track low as hell, to at least as deep as you’ll find on pretty much anything bar slow jams and big air-shifting tracks (like I used) and it will severely pressurise your cabin, with that fat weighty feel-it-in-your-chest pressure so beloved of the hooligan.
It happens to be lovely to look at as well, and while the extra fifty quid has been spent on woodwork really, I’d love to have seen this as a more capable blingy lighting system. Mind you, you could customise it like mad as the wires and connections for 12V are all fitted and the Allen headed fixings are all top class. But don’t mess, in a dark boot, all you see is the speaker chassis itself, lit in white light and very horny it doth look as well.
So all in all a very desirable and high performance product, scoring sufficient for to earn itself a coveted Talk Audio Best Buy Award.
Sound Quality 9.0
Build Quality 9.0
Power Handling 9.0
Efficiency 10.0
Value For Money 10.0
Overall rating 9.4