Ground Zero GZCT 3500

This is only a medium sized competition tweeter in Ground Zero’s books but is about as heavy duty a high frequency transducer as many other makers would even dare to reach. It is a large driver with a magnet bigger than is used on some four inch devices and has a horn-shaped depression to its front plate, at the bottom of which is suspended a short phase plug shaped item. This effectively loads the tweeter diaphragm beneath it to offer some acoustic support and to compress the output of the wider-than-the-circular-aperture driven surface beneath.
The front plate has the Ground Zero branding on it by way of decal rather than engraving and the finish is matt like the Bullet GZCT 2200 product rather than turned shiny like the stubby-horn GZCT 0500.
Using normal spade lugs for connection, they are clearly polarity marked by one being coloured red and you get a single capacitor included in with each individually boxed and sold unit. Fixings are included and the rear decal is plastic protected for removal last thing before installation, which it has in common with all the competition tweeters, yet only seems to make sense for woofers to me. I reckon this is about the decals for all being made from the same sheet material-with-clear-backing that is used for the woofers and those can be mounted magnet out or seen behind clear windows in competition grade installs. They do seem to be very low in price for the sheer amount of driver you get.
– Diameter 102mm
– Magnet assembly 70mm diameter x 15mm deep
– Impedance: 3 Ohms
– Resonant Frequency: 3000Hz
– Frequency Response: 3.5kHz to 20kHz
– Power Handling: 25w RMS, 100w peak
– Efficiency: 104dB 1w/1m
– Mounting Depth: 36mm
– Simple lug type terminals
– Front Aluminium cast plate with integral supported phase plug held above diaphragm
– Horn front piece with approx 30mm throat
– Aluminium-Magnesium tweeter diaphragm estimated at 45mm including suspension
– Rear decal has protective film to be removed after installation.
Review by Adam Rayner
Of all of the four Competition tweeters offered in this bonkers range by Ground Zero, these are the closest to usable by ‘normal’ people! Yes, they are able to slice the ears clean off the side of your head if you are not careful but they are not as seriously dangerous as the two compression horns in the range. They are shallow enough to mount in much more real-world locations than the huge 2200 bullets or 0500 slicey stub-horns and yet offer a degree more high frequency outrageousness than the rather posh looking GZCT 2500 that was reviewed with the GZCW 6-4Y midbass drivers. Again, they use Aluminium-Magnesium alloy domes and while these can go incredibly loud, I’m not convinced that they sound as sweet as say a silk dome can, or even a mad-price paper-pulp near-field three inch dome is able to.
It is another that can be used for adding-in when parked at shows by a simple switch or if you are being posh, a relay. Alternatively, if you are a bonkers SPL head and want to use a tweeter that has the wonderful combination of ridiculous potency for cutting through your bass yet is cheap enough to fix or replace if your arrant hooliganism fails to notice you are sending 300 watts of square waves to it in a fit of pique, then this may well be your puppy.
Having said that, one of the better things about bullet compression drivers is that unlike so many tweeters, they are repairable by simply unscrewing them and replacing the diaphragm. I’m asking UK Ground Zero HQ to check this for me for the others but for this one, at £15 each it means that even if you pop one you don’t have to order a pair!
Again the good build, very high sound output per watt injected, together with the low price make for this to scrape into the Talk Audio Recommended zone. In this case it is isn’t with a big caveat, just that the GZCT 3500 is best for high SPL installs rather than day to day use.
And remember if it makes your ears ring, It’s your maker telling you to turn it down.
Overall 8.8
Sound Quality 7
Build Quality 9
Power Handling 9
Efficiency 10
Value For Money 9