PQ at Sound & Recording

In the current edition (5/2017) of Sound & Recording magazine, you will find a review about our PQ Mastering Equalizer:

The German company SPL has an exeptionally diversified portfolio, which provides inexpensive entry-level devices, as well as exquisite Mastering equipment used by legends like Bob Ludwig to give the final touch to the records of the pop music elite. Now joining this state-of-the-art line-up: the PQ Mastering Equalizer, fully finished with 120V rail technology.”

First impression

Weighing 15,2 kg, the SPL PQ Mastering Equalizer is one of the heaviest devices I ever tested in my 14-year-career as an author.”

When looking through the ventilation slots you realize: this unit is packed with electronics! Of course the solid manufacturing also makes the PQ heavy: The housing is made of a thick steel sheet, the elegant front is skilfully shaped out of 8 mm aluminum.”

Technology

The current model 1540/1544 is much cheaper [ than the previous model 2050 ], but still its list price is 5.999 euros. This is a lot of money – but it is a very good price per kilo if you consider the high-quality technology that comes along with the unit, as we will see later.”

The inside of the SPL PQ is based on a modular design; each filter band is located on a board, each equipped with eight (!) discrete op-amps. When you consider that there are 2 x 5 bands, you get a total of 80!”

SPL‘s discrete op-amps are powered with a supply voltage of +/- 60 volts (120 volts in total); thus the SPL PQ reaches a maximum level of 32,5 dBu, which means that the SPL PQ is able to handle up to 10 dB more than conventional studio devices; this means there is practically no way to distort it.”

Because of the huge headroom, the SPL PQ reaches an overall dynamic which is significantly above 120 dB – as much as state-of-the-art Mastering converters!”

Also the harmonic distortions are sensationally low...”

In short: The SPL PQ defines the limits of what is possible in terms of analog technology.”

In practice and sound

In light of such great values it becomes pretty clear how this equalizer sounds: crystal clear and extremely transparent.”

...to describe the personal sound-experience, I would say that the SPL PQ sounds absolutely amazing.”

The right adjective for its sound is not colorless but colorfast. Because the PQ is a device, which does not create or falsify tone colors, but it makes the existing sound better.”

It is fascinating, how transparent and discreet the PQ operates. Even if you're doing bigger corrections, the result does not sound ‘equalized’ but simply ‘right’.”

To really put the PQ to the acid test, I did some tests with problematic material such as a few ‘audio sins’ from the late 80's … it is quiet astonishing how well you can spectrally restore such recordings with the SPL PQ and how phat and punchy these former unpleasant recordings sound afterwards.”

Conclusion

The SPL PQ is a state-of-the-art device, which demonstrates what analog technology is capable of achieving audio-wise. The PQ sounds incredibly transparent and offers, thanks to the 120V rail technology, a huge headroom. In practice it is impossible to overdrive the unit and even at extreme sound corrections no artifacts occur.”

The PQ is suitable for discreet sweetening as well as for remastering older productions or even spectral restoring.”

Considering its many application possibilities, its perfect sound quality and the extremely high-quality execution, one really have to admit that the value for money of the SPL PQ is entirely justified … finest audio technology, Made in Germany.”