A lot has already been said about this amazing EQ, as there are currently ten reviews already here on KVR. For me, it's not a surprise so many people are raving about this plugin, as I believe this one is unique in both sound and handling.
Let's start with some basic information. SplineEQ is a linear phase equalizer plugin. This means that it does not change the phase of a sound, and as a result, gives a more natural sound. All this comes with a price however, because a little bit of latency will be introduced. As I'm using this EQ mostly as a master EQ and a few instances during mixing, I'm not complaining about this latency, I'm more than happy to pay this "price" and get an amazingly good and natural sounding EQ for it in return.
An unique approach
When we look at EQ plugins like Sonnox EQ, DMG Audio EQuality or Duende X-EQ, we talk about parametric EQ's. This type of EQ is what most people are very familiar with. They often have a fixed amount of bands that include high and low pass filters, high and low shelving filters and bell filters. When you take a look at EQ plugin like the Waves API 560 or Voxengo Marvel GEQ, you will easily see they are different, and these are known as graphic EQ's.
When we take a look at SplineEQ, we will find it's not exactly a parametric or graphic EQ as we have come to known in the last few decades. So what is it? Well, it's more a parametric EQ than it's a graphic EQ, that's for sure, but you won't find the high and low pass filters, shelving filters or bell filters in this plugin. SplinEQ uses a very unique approach to making curves and it's called Bézier splines. SplineEQ gives you the ability to design your own curves. The retail version ships with up to 60 bands so your imagination is the limiting factor here. This way of shaping a sound might take a few minutes to grasp, but once you understand how it works, you will probably love it as much as I do.
An unique sound
This EQ being unique in the way it's working, that is something that we have established so far, but I have not said anything about the sound. Ladies and Gentleman, that's because I wanted to save the best for last. This EQ sounds amazingly transparent. You will not find any analog buttons, hidden tube emulations or anything like that in this plugin. The only thing this EQ is doing for you, is shaping the sound with a transparency that is breathtaking. Adding a few db's and cutting a few db's with a standard digital EQ often result in a sound that somehow sounds like it's been altered. It's like you hear that there is an EQ on top of the sound. With SplineEQ, it's like the sound has been changed from within, and the result sounds as natural as it sounded before. Of course there is a limit to this transparency and we hopefully all understand that boosting 30dB around 5Khz on a full mix will most likely give a very unpleasing result, but this has nothing to do with the EQ plugin, and all to do with the person behind the knobs doing something very weird.
SplineEQ in use
During the mixing process I do use SplineEQ when a sound needs fixing, or in other words, when my normal go-to mixing eq's don't have the precision to fix a problem. For example, a kick drum that is recorded without a lot of body/low energy. With SplineEQ I have managed to make a kick sound powerful and punchy again by adding and cutting more than a handful of dB's at some critical frequencies while sounding totally natural at the same time. The difference between the kick drum with and without EQ was nothing short of a miracle. I asked some friends to listen to the difference and they couldn't believe at first that this was the same recording with just some help from an EQ. Countless of times I used the help of a transient designer and compressor together with different eq's to fix this type of bad, lifeless recordings, but with SplineEQ, I managed to fix it quicker and better without the need for other tools.
Another example of a recording that needed to be fixed was a lead vocal that was recorded in a very tiny room with a crappy microphone and no room treatment at all. I was able to remove a lot of the resonating (boxy) sound of the room without destroying the rest of the sound. Again, the end result sounded very natural and the difference compared to the original sound was stunning. I tried a lot of other EQ's to do the same, and although I was able to get very pleasing results with another one of my favorite clean EQ's, in the end, I preferred SplineEQ. I don't like mixing bad recorded songs, but SplineEQ makes my life a bit easier when the client has no intention of delivering a better recording.
When mastering, I love clean/transparent EQ's and this is where SplineEQ shines! It's probably not a surprise that it has become my favorite mastering EQ. When I'm mastering a track I always (try to) respect the mixer engineer, so I always try to keep the character of the track the same, while at the same time, making it translate as good as possible on many different devices. With SplineEQ, I can fix certain frequencies with an incredible precision. I have been able to master tracks with this plugin that normally would have needed a new mix. Having said that, I still prefer a new mix that doesn't need this kind of fixing, but sometimes there is no money/time and SplineEQ can really save the day.
In my opinion, SplineEQ is an amazing plugin. The way you can shape the curves and the way it stays transparent even when boosting or cutting a pretty high amount of dB's, is both unique and impressive. I'm confident that this EQ will find it's way to most of my future mixing projects and all my future mastering projects, just like it has done for the last couple of months.
For $19 this EQ is a steal. To be totally honest, I don't know what the developer must have been thinking when deciding to sell this plugin for so little money. In my opinion, it's on par with the very best there is on offer in the digital domain.