It sounds a bit like a click-bait title. However, it is not intended that way. Just as there are good and bad power supplies and there are good and bad d/a converters and phono preamplifiers, there are good and bad DSPs. In this background article, we discuss Stassen’s DSP service.
Now, we previously published an interview with Steven Samaan. He is the technician who comes – potentially – to correct things in your space. Steven actually works in the pro-audio world. He is trained to make large installations sound good in challenging acoustic environments. How he handles that, he explains in the interview.
Watch and listen to the interview
Engineering from the pro world
A brief summary of the service Stassen offers is that they have used technology from the pro-audio world to help consumers at home. This involves both solid hardware and knowledge, as each really can’t do without the other. You can put in a great high-quality DSP, but if you don’t know how to work with it, the results will still be horrible.
Now some will think, “But there are solutions that walk you through the whole process, right?” Yes: that’s right. You can think of Dirac, Trinnov, Lyngdorf, et cetera. And yes: those solutions can solve some problems without fail. But let’s be honest: if this would work so fantastically; why don’t they use it in studios or at live events? Surely a trained engineer wouldn’t be needed then? After all: run the software, place a microphone at 10 points in the venue and you’re done!
So that’s not how it works. But that’s not to say that DSPs don’t work. In the pro-audio world, especially at live events – DSP technology has been used for years to solve frequency response, time and phase challenges (they are mostly tight to each other). After all: how else do you get the Amsterdam Arena to sound right? You can’t do that (only) with a few decent arrays. Those arrays must be well placed and also work well together. The latter is done software-wise by using delays, equalizing and to some extent also beam-forming (directing sound). Only in this way can everyone in the venue – or in the open field – enjoy a concert.
To the consumer
Together with Steven Samaan, Stassen wanted to bring this technology to the consumer. After all: home enthusiasts also have to deal with sometimes particularly challenging acoustics. Think of a kitchen where in-ceiling speakers must also sound good. Or a living room where there is too little aborption. Or of course an already very good listening room where that dot on the ‘i’ needs to be added!
Together with Steven Samaan – the DSP expert employed by Stassen – Stassen has developed a DSP that Stassen and Steven say is state of the art. The DSP chip itself is lightning fast and can process 192,000 ‘taps’ in real time. That is, the DSP can process 192,000 points in the spectrum to be processed in real time. And that’s a lot, your author can guarantee you.
Stassen and Steven had this chip implemented as nicely as possible by, among other things, applying nice in- and outputs – the DSP must go somewhere in the analog signal path – and looking carefully at the device’s power supply. The result is an incredibly transparent device that allows a pro to optimally adapt a hi-fi system to the room.
Before and after?
Now, of course, the main question is: how does this DSP perform? We’ll get to that in a moment. First, let’s explain how Steven goes about his work.
Steven Samaan works primarily with white noise. This is because a frequency sweep puts a totally different load on the system and the space in which the system is located. Moreover, music consists of complex patterns in which there is almost never one signal at a time. Music does not consist of test signals, right?
By playing white noise, it is immediately visible where the problems in the reproduction are. You immediately see comb filtering as well as phase problems.
Now the baseline in our room was already pretty good. Fortunately. Still, there was a problem; on the right side we have some shelves with some decorative items on them. These shelves, in turn, are reflection points. And these are visible in the baseline measurement. The right side measures differently than the left partly because of these reflections. And that, of course, impacts the reproduction.
Now, your author is somewhat aware of this, but you get used to it. Steven heard it directly himself; he doesn’t know the room and the system and therefore hears deviations faster. And again: your author didn’t hear it anymore.
However: when this point was corrected via the DSP, more calmness was immediately audible. This is because the brain no longer has to work on this issue, and thus has more space left for relaxation and processing of music. Interesting side effect.
Tweaking to perfection
Now this session was mostly about showing the possibilities and showing what it can do. In the scant thirty minutes that we tweaked, the result was: more calmness, more tonal balance and more relaxation while listening due to balanced phase behavior.
Of course, Steven was still not completely satisfied: “normally I do spend longer and go for perfection for the client.” That makes sense. But we must say: even in this short time, the positive impact of this DSP service is well audible. Alpha Approved…!