JBL GTO24001

Product Details
Manufacturer: JBL
Distributor: Car Audio & Security
Website: link
Typical Selling price: (CAS) £599.99

Monophonic bass amplifier for high power systems. Created by design to cope with low impedance loads down to two Ohms but not less. It doesn’t need to as it is rated to deliver very high power at sensible impedances. At four Ohms it is delivering over one and a half kilowatts! The amplifier is made from a brushed black anodised Aluminium extrusion with end plates bearing the connections in classic fashion: Power and speaker connections at one end, signal connections and controls on the other. The power connections are by dual sets of four gauge terminals, so you have to connect two four gauge power wires and two four gauge earth cables to run it. One set of power terminals also has a third remote switch-on wire connection point. There are two sets of speaker wire connections, fit to take up to eight gauge wires and they are parallel so as to be able to cope with no lower than a two Ohm load altogether. The amp has RCA stereo input and a throughput or Aux out on RCA. No high level input. There is another system called the DBO or Dynamic Bass Optimization (sic). This is extra to the regular bass crossover, (which allows the lows to go by or pass as in lowpass) and is a ‘highpass’ crossover that operates in the deep bass zone only. It is effectively a subsonic filter to keep the really too deep stuff from wastefully straining in your box and it can go all the way down to 20Hz. The DBO Booster can then be applied but has its frequency determined by the setting of the DBO’s filter. It can give you a fat or else more subtle hump in output just above where your tuned frequency is if you like it. And you probably will. The amp is very low profile, too, which is unusual in this power bracket. Usually it’d be a suitcase. The amp is decorated with silvery trim pieces that also house translucent panels that are lit from within by white LEDs and look very attractive indeed when lit. There is a JBL sticker included in the carton with the remote knob and phone cable to control output.
– Class D
– Mono operation
– 1 x 1,700w RMS @ 4 Ohms @ 1%THD
– 1 x 2,400w RMS @ 2 Ohms @ <1% THD given 14.4V DC
– Aluminium heatsink with brushed black finish and silvery embellishments and white illumination
– Dual paired 4Ga. Power Terminals with cross headed grub screw bare wire socket connection
– Dual speaker 8Ga. Connections (minimum impedance 2 Ohms)
– Low pass crossover settable between 32Hz and 320Hz
– DBO Dynamic Bass Optimisation system of subsonic filter and boost circuit
– DBO subsonic filter settable between 20Hz and 100Hz
– Up to 12dB of boost available just above DBO frequency
– Max input signal 6V
– Frequency response 20Hz to 330Hz -3dB
– Remote level controller supplied with RJ-11 cable
– Signal to Noise Ratio 65dBA (ref 1W into 4 Ohms)
– Signal to Noise Ratio 97dBA (ref rated power into 4 Ohms)
– Fuse Rating 300A x1 (supplied in branded holder)
– Supplied with Remote Level Control and RJ-11 cable
– Fixings supplied for RLC and amplifier’s attachment
– HxWxD(mm) 53 x 630 x 263mm
Review by Adam Rayner
This is a bass monster! The GTO24001 is rated to be CEA compliant which means that not only are the figures true, they are actually a bit understated if anything. I had a bit of a moment with the PowerBass XA3000D previously as I was a bit scornful of the voltages in speaker leads but this baby is even naughtier as she doesn’t rely on driving into a fragment of an Ohm to make the kilowatts. So I took more care and didn’t flap my own self this time around!
This behemothic nutter put out more than one thousand seven hundred watts into a ‘normal’ four Ohm load and is rated at 2,400w into an easily available two Ohms. I could have been supplied with two Ohm bass enclosures as the first test on this amp was a brace of JBL bass boxes, one bass reflex and one bandpass and both come in four or two Ohm variants. At the time of writing I have had a go on the bass reflex job and nearly killed the ruddy thing by stupid use of the amp’s DBO circuit. This is a brilliantly simple idea and tracks a boost circuit just ahead of the filter circuit. You set the bottom frequency and the booster then applies at frequencies just above that. So you can have a box that gives up around 35Hz and boost it hard at 45Hz which it’ll love or custom tune the amp’s output to be deeper if you are using a real deep-tuned ported enclosure like some of the real big bass lads out there.
I found the manual excellent and simple and it shows you the terminals dual four gauge power inputs with one having the remote turn on terminal and also that you get a really superb looking fuseholder for going near the battery with the JBL logo on it. It does fail to mention that you will have to split this 1/0 gauge wire into two four gauge ones to fit the amplifier correctly. I did this split very close to the amplifier’s terminals with an Autoleads terminal system from a power kit recently tried. It was also the donor for the earth side 2x4ga to 1×1/0 Ga conversion.
This keeps the need for extra accessories up. However these can be cheap when compared to paying for the huge 1/0 gauge terminals to be fitted to the amp’s arse end. It keeps the whole product’s price down to an absurd level for what is a very savage bit of kit.
I suppose when your big brother is a six kilowatt Crown-derived nuclear explosion, no one’s going to get over excited about 2,700watts.
I do.
Holy Basserator Batman! It lights up like a sexy Christmas tree and yet takes up a very low slung look. It has a solid and clunky relay inside to turn on and off as you can hear a click of great solidity as you power up and down. This is a Good Thing, what with all the juice it wants to suck and blow.
The good looking bass knobber accessory is a simple attenuator and won’t affect how much the boost level is set. So you can play with it in confidence if you set it carefully in the first place as all-the-way-on in set up. That way it’s used as an attenuator as per design.
I loved the effortless power. I loved that I could NOT make it warm up in my level of use and I loved they way it sounded. There may be more expensive and more flashily equipped bass amps but the DBO is so bloody clever and the build is so nice to look at and the amount asked for all this is so low in real terms that it earns itself a seriously rare Talk Audio State of the Art award.
Looking for a seriously meaty one-less-thing-to-worry-about BIG bass provider and still want to be able to buy some woofers after you have bought it? Then this is the beast.
Frankly to get it off me, they will have to beg and in the meanwhile I declare it Talk Audio Magazine’s new Test Bass Amp.
Just Bloody Loud.
Overall 9.6
Sound Quality 9
Power Output 10
Features 9
Build Quality 10
Value For Money 10