Earthquake EQ7000PXi 7-Band Pre-Amp/EQ

Product Details
Manufacturer: Earthquake Sound
Distributor: Earthquake Sound UK
Website: link
Typical Selling price: £189.99
A half DIN Equaliser with the classic array of controls: Seven fixed frequency knobs, a subwoofer crossover and an auxiliary input. The subwoofer control has gain and crossover point knobs mounted as a dual concentric potentiometer-inside-another-potentiometer. A very sexy tech that is a sweet and old fashioned thing, designed to save space in tight places. Like the input-output modules of a busy mixing desk. Another of these ‘˜twofer’ pots is used to control volume and fader functions. Next along is the aux/radio button, although the manual calls this the CD/Main button (as it is labelled on the smaller EQ4000PXi product) and then goes off into some oddness about the ‘˜CD Changer or Radio’ which must come from fifteen years or more ago, when the CD changers of this world would have a separate line out, rather than feeding through the headunit! So this bit of the manual is out of the ark! Also, the unit quite clearly was once fitted with the flimsy retractable-button type of potentiometer and is labelled as having ‘fully retractable controls’ on the box in four places which is piffle as they are not. However the ‘˜retractable’ type are toys and you can feel the quality and smooth running of the knobs that are used.
Finally, although the unit is superbly well made and labelled, the actual EQ adjusters have odd labelling. One end of travel is marked 0dB and the other is marked 18dB. Yet these knobs clearly have an easy to feel ‘˜detent’ or slightly locking point, at the top of their travel, due North as it were. This is usually used for an EQ boost/cut control with an equal number of decibels of adjustment up or down on each side of travel. In truth, that is exactly what these are, with up to 9dB of cut or 9dB of boost, based somewhat fatly around the frequency points labelled for each of the seven knobs. i.e. There’s quite a wide ‘˜Q’ or Quality factor for these knobs’ adjustment being the bandwidth and slope of the boost or cut and shown as a stack of curves on the unit’s top printed surface.
What’s normal on lesser units is 12dB each way but that makes the controls very blunt and more for playing around with for taste reasons, rather than serious EQ use. Keeping to +/-9dB makes for a much easier to fine-tune control and yet by labelling with the bigger numbers and using a weaselly-worded line in the manual like this; ‘Control range: 18dB (12 O clock is the bypass position) to get around it, you can have the better unit and still label it like something out of Spinal Tap.
But it’s bloody odd and really should be labelled ‘˜-9dB’ and’ +9dB’ under each of the seven knobs rather than simply ‘˜0dB and ‘˜18dB’ as it misleadingly states now
Lastly and nice and up-to-datedly is the front Aux input on a 3.5mm tip/ring/sleeve stereo microjack. The main input selector button on the front chooses between your headunit (labelled ‘˜Radio’) and ‘˜Aux’ being the rear Aux RCA input. But when you plug an iPod or MP3 player’s analogue stereo output into this plughole, the rear Aux is overridden, automatically switched by the act of plugging-in, like headphones and you hear the ‘˜front socket input’.
– Pre-amplifier with Three Input sources
– 12 Volt RMS output
– Front, Rear and Subwoofer RCA outputs
– Quick-plug system for power, earth and remote connection
– Subwoofer gain and crossover point dual concentric potentiometer
– Volume and front/rear fader dual concentric potentiometer
– Seven fixed frequency adjustment potentiometers fixed at: 48Hz, 120Hz, 275Hz, 700Hz, 2kHz, 5kHz and 14kHz
– Front 3.5mm microjack input
– Lit by blue LEDs
– 5mm thick Aluminium front plate, coated and printed steel casing
– Top-mounted input gain control (via a screwdriver hole)
– Input sensitivity: 100mV RMS to 14V RMS
– Input Impedance: 3.8 to 10.2k Ohm
– Output Impedance: Sub channel 510 Ohm; Front & Rear Channels 2.2kOhm
– Output Level: Sub channel 11V RMS @ 0.1% THD; Front & Rear Channels 7V RMS @ 0.1% THD
– Total Harmonic Distortion (THD): 0.003% @ 3 Volts Output
– Frequency Response: 15Hz to 34kHz @ -3B
– Subwoofer Frequency Control Range: 60 to 160Hz
– Channel Separation: 68dB
– Signal To Noise Ratio: 96dB
– Dimensions: (WxHxD) 177 x 30 x 114mm
Editor review : Earthquake EQ7000PXi 7-Band Pre-Amp/EQ
At this point, I will freely admit my bias. I LOVE half-DIN and it is as rare nowadays as hen’s teeth. It really was only ever the Americans who really got into the half-a-car-radio size. We had some EQs from Kenwood and others and there was once a full DIN 36 Band fader EQ from Coustic that I have never seen in the flesh that I wanted so bad I could taste it. But Half DIN has always held some delights. Crossovers and equalisers you can mess about with from the driver’s seat? Joy! (Even when driving I confess, with the EQs.)
But while these half-DIN EQ units have been made and sold by all sorts of US outfits, as far as I am aware, there are none currently on sale in the UK from any other makers. Which makes this an unusual beast in the UK indeed. I plugged it into the system as the last thing tested with the Clarion APX1301E bass amp (here:link) and the Infinity Kappa Four (here:link) along with the Ground Zero GZRW 12XD-AL subwoofer in an Acoustic Wood enclosure (here: link) and then plugged the unit in using the mains socketty thing as used by the MB1 bass doubler also tested on the same rig. Of course, in most serious Earthquake cars, a real fan would be using both in tandem and be having a real balancing act to achieve with EQ versus bass doubling to get the best out of the system without blowing it all to hell. Which of course you can, as EQ can really suck a bass amplifier inside out if applied injudiciously.
I fired it up and had a play. It was a little challenging to get wired in as it only needs a single RCA feed and yet needs a slew of RCA outputs to feed four channels and stereo bass. At first I had problems but then moved the power draw to a place closer to the battery by re-wiring my shoddy workmanship. IT worked well, then.
I can report that the potentiometers on this unit are lovely. Analogue-smooth and sweet. Even the dual concentric pots were smooth and even and linear in effect. I played with the many bands and found that indeed, adjustment could be done with delicacy as well as to change the flavour. The crossover function at the front is effective and the aux button a useful mute if you have no the source plugged in.
I liked the frequency points chosen and they go nice and high as well as nice and low from 48Hz to 14kHz, which is a little further out than many makers. There’s a wide soft Quality Factor or ‘Q’ to these controls, so it doesn’t sound all notchy. A powerful device, I reckon if I owned it, I would arse about with the subwoofer level; and the EQ pots all the time as I drove, but then I am a live sound engineer by trade initially, so we tend to piss about with controls.
So, a powerful, sweet and clean EQ that adds mess-with-it-on-the-fly operability, making it either easy to mess up, or great fun, depending upon your usage. Serious owners will be careful to set it up then not mess with it. Either way a great piece of kit with character, from its lovely Blue LED internal lighting to that cute input trim pot you can get at before you install it. Supplied with Molex connector for power/earth and side ears to mount where you want.
What’s not to like?
Overall 9.6
Sound Quality 10
HMI/Ease of Use 10
Flexibility 9
EQ Effectiveness 10
Value For Money 9

If you want to get hold of one of these deliciously retro devices, then e-mail [email protected] or call him on 01634 263786 to order.