Wednesday, November 6, 2024
Car AudioProduct Reviews

Ground Zero GZ HF693

One of the very best looking of all 13 tested sets of six by nines in this group. The chassis is simple pressed steel but it is finished in the smartest of gunmetal chromes, called Black Chrome in the manual. The magnet also has a cover over it, finished in the same sheen. The woofer is unusual in that it has an Aluminium cone said to be better for true pistonic movement without flexing or bending and with power compression free response, as long as the heat from the coil is thermally linked to the cone. It wicks away so fast that any rise in temperature that might alter impedance is obviated.
A simple 6dB per Octave passive is just a single capacitor but it is fat one mounted under the mid and there is another for the tweeter, proving that unlike some three ways that simply piff it all off to the mid and tweeter and let them sort it all out with their natural roll offs and limitations, this speaker is made to be filtered correctly. A relatively new model, not to be confused with the very similar but heavier duty cast chassis model previously in the range and to be found on the web.
– Pressed Steel chassis with Gunmetal Chrome finish
– Magnet boot with same Gunmetal Chrome finish as the chassis
– Aluminium coned woofer
– 25mm Dome super tweeter
– 25mm Polyamide midrange driver
– Power handling 125w RMS, 200w peak
– Sensitivity 91dB (2.83V, 1m)
– Frequency Response: not quoted
– Impedance 4 Ohms
– Mounting depth 71mm
– Lug connection terminals for spade-end speaker connectors
– Paper whole-range template, fixings and speaker cable included
– Steel mesh grilles
Review by Adam Rayner
The first impression of the sound of this speaker is that it is a little splashy in the high frequencies but solid in the lows. The Vibe QB69 does have an amazingly powerful full woofer motor on its back that can sound great with a ported box but the porting thing does limit the low end frequency cut off where free air or better yet a sealed box will allow the speaker to drop to the lowest frequency the wobbliness of its suspension allows. This is often deeper than the average 35-50Hz tuning that a ported box exhibits. As soon as you go below a tuned frequency in a box-and-speaker driver system, the level drops off really quickly. Its why a lot of folks prefer sealed for SQ and ported for weight. And these really play down to a low place, deeper than the Vibes if not as mayhemic.
Rich and fat and able to hold and properly play that lovely odd bass drum with the wibble-wobble, they were at least as good as the mighty Kenwoods for their bass, if not slightly better. The tweeter and midband driver are both 25mm domes but seem to play different passbands and work well, if not as exotic as the Mylar thing on the Hertzes. Sweet and dynamic when not driven hard, they give great edges to sparkly sounds and that ‘Ting!’ bit on the second SQ track. All this while holding a really luscious bass line.
Proving themselves to be a really good compromise between that urge to want to tear your face off with sound sometimes and wanting it to sound lovely when you are feeling saner, they are a good all rounder with slight hooligan propensities yet an ability to play with delicacy if not spanked. As such they earn enough to score a coveted Talk Audio Recommended flag
Overall 8.8
Sound Quality 8
Build Quality 9
Power Handling 9
Efficiency 8
Value For Money 10