Sound Performance Lab, better known as SPL, is a German company specializing in the making of high quality studio equipment since 1983.
We remember their commitment in the creation of products that have rightfully entered the category of hardware most used in recording and mastering studios, tools that in the transition period between full analog and digital studios, gave a great hand to sound engineers. example of Vitalizer and Transient Designer, now in its fourth revision; over the years it has developed hi-end equipment used in mastering studios, such as the Passeq, while in the preamp and channel strip range, models such as the series have become hugely popular GoldMike with an excellent quality / price ratio.
Regarding the preamplifiers range, we received a new product, theSPL Crescendo Duo, younger brother of the Growing up, a high-end 8-channel preamplifier from which the two-channel version renamed "DUO".
One might think that the difference between the two products consists only in having taken two channels of the Crescendo, inserting them in another chassis, but as we are going to find out, things are not completely in this way, in fact, there are three substantial characteristics that differ between the two products.
Difference SPL Crescendo 8 ch and SPL DUO
First, the gain pot on the Crescendo Duo is a step, so you can match perfectly the two channels in a stereo recording, while on the 8-channel version the potentiometer travel is continuous.
There is a high pass filter, which is not present on the older brother and finally there is an additional output control via a potentiometer that can be activated separately.
In terms of sound, the two products are almost identical. This series of SPL preamps is based on a 120 volt technology specially developed, which aims to ensure a particularly neutral sound with low distortion. SPL clearly explains this technology in this video available on their channel Youtube.
A look at the SPL Crescendo Duo
At first glance this DUO series presents itself with the same design as the 8-channel version, with a nice modern black and silver look. THE two channels they are contained within two rack units (unlike the three of the other version) and the weight is approximately 6kg.
Sulla frontal all control switches are present, i.e. six small metal switches used to activate functions such as phantom power, phase inversion, the -20 dB and the high pass filter, which produces an attenuation of 3 dB per octave a 120 Hz.
There are also two knobs, one for gain control and one for output, of which that of the gain of considerable size and as already mentioned above, with step control, so as to surgically adjust the gain stage from 18 to at 70db, while the output one, smaller, allows you to adjust the output signal by + \ - 10db, with the possibility of being deactivated. Even the VU Meter it is generously sized and glows yellow when activated. There is a small slot under the VU Meter, where there is a screw for calibrating the display. In addition, the display of the VU meter can be reduced by 10 dB. To fine-tune the degree of pre-amplification, an output control potentiometer with a range of +/- 10 dB is also available, but this function can also be deactivated if it is not necessary.
Sul back panel, in addition to the power socket and the ground lift button, there are inputs and outputs. We are very surprised to find two outputs for each channel, so as to have the possibility to send the microphone signal to two different recorders, without the need for an external splitter. Another feature, decidedly less important, but equally curious, is the presence of the writing on the "mirror" connections, so that you can read them well even when you look down from the top of the preamplifier.
An technical note not specified by the company, but present in some product reviews, is that the Crescendo Duo can also be used as line preamplifier.
SPL Crescendo Duo on trial
As the description of this product states, the Crescendo series has been designed to give us a sound as neutral as possible, with excellent dynamics and low distortion. As for me, the review could end here too, because the German company has fully achieved its goal. We tested the SPL in the studio by comparing it with some scattered material, such as the preamps Heritage Audio 73jr, the preamps Midas XL3 series and the preamps ISA of Focusrite Red 8 and it must be said that the most transparent of all were the signals that passed through the SPL.
Obviously this feature has a lot of pros, but it also has some cons. Wanting to flea for a product like this (which we reiterate, it has already fully passed the test), in a jazz recording, of classical music, the product is absolutely valid, but probably on some other type of material, especially if used in a home studio that needs a strong character for its productions, the Crescendo Duo may not be the perfect choice. But what for some might seem like a minus for many of the audio pro is actually a real one ?. In fact, having a preamp so linear and with an impressive headroom allows you to acquire real instruments, such as items, guitars, strings e car's battery performance, without having to compromise is a rare resource. After such a real acquisition, the post-production work is on velvet. Applying Eq, compression, or better still, saturation in parallel to such a precise signal is the solution to have quality and color of the highest level by taking advantage of the pre mastering grade and dozens of hardware or software tools available on the market.
Conclusions
SPL with the Crescendo series has made a clear leap forward, compared to the old GoldMike series, while still keeping faith with its values, namely those of creating hardware that is never out of the box and ready for intensive use in any recording studio. Another point in favor are the many features present in the product, the attention paid to the user on which many other companies sin that simply continue to do what has always been done for several years without any kind of upgrade. I speak from little things like the reverse writing on the back panel, up to the step controls for the gain, up to the possibility of having two outputs for each channel. Often far more expensive preamps have half the possibilities offered by the Crescendo series.
For testing they were used
Henry of Marino
Voice - Neumann u87 - Heritage Audio 73jr
Voice - Neumann u87 - SPL Crescendo Duo
Useful Information
Producer: Sound Performance Lab
Product: Growing Duo
Italian distributor: Midimusic SRL
Price: 1.990 Euro
