Few years back I reviewed the APL software and APL1 hardware unit. I already concluded that the APL had a great algorithm to calculate the system sound power response. The APL1 unit is a two channel equalizer which connects in series before the DSP unit in a typical car audio system. You can read the full review of it here (it's a bit related to this, the measurement part is discussed in detail there...):
With that said, here's the review of the 1012 DSP:
Before I installed the 1012, I used a MiniDSP C-DSP and an APL1 for input EQ. It worked fine but it's always a bit tedious to setup two different processors. For years now I've tried to create a perfect coherent stage in my car but to pull some of things off, like correcting subwoofer delays - you require a lot of processing power with FIR-based filtering. Getting the acoustic crossovers right is also a challenge, often there's cancellations in the stopband of the HP/LP filter and this does affect the stage more or less depending on setup. To attain a "perfect" acoustic crossover, you need two set of speakers (midrange/tweeters for example) that both operate in their optimum sound power range and got a flat response in each respective area before equalization. For a 3" driver the sound power response is optimal to slightly above 3kHz (the driver got a frequency response that's omnidirectional into all axis).
You can attain an optimal power response in the crossover stopband in two ways basically, one is to lower the crossover frequency and the other is to use steep slopes (tall order filters). The drawback of lowering the crossover frequency is that you need a tweeter (in this example) that goes lower without audible distortion. The drawback of using tall order filters with conventional filters is that you get massive phase distortion (group delay). If you got a setup like mine with tweeters that doesn't like to go very low using tall order filtering is the preferable option. Now to the point... The APL 1012 gives us tall order filtering with the option to completely eliminate the delay caused by the crossover. With this we can perform pre-equalization of every speaker in the system and then place the crossovers on top of the equalized response to attain a near perfect controlled rolloff into every axis. This is very important since the majority of the sound we hear in an automotive environment comes from reflections that cannot be equalized individually (of course).
That's the theory and I must say that it really does work in practice as well. Even though I had put a lot of time into setting up my old system, this processor did wonders when it came to staging. Most likely due to more powerful equalization and optimized crossovers. Within half an hour I managed to get a better sounding setup than the one I had before with little effort and I haven't even made the post-corrections yet. The idea is that you can setup EQ and crossovers/delays then run the measurements once more to get a more accurate response. A quick TDA measurement showed that multiple small issues had disappeared, primarily in the midbass/midrange region. After the first listening session I noticed that the stage both jumped upwards, got some improved depth and that midbass/sub integration was as good as I've ever had in my car. With a balanced subwoofer volume the upfront bass is amazing now, stage stays stable with most content.
Having said that - A processor, no matter how good cannot be a substitute for a good install. (Just felt obliged to clarify that fact).
Anyways, the APL1012 in comparison to the APL1 is complete DSP with EQ, crossovers and time alignment which eliminates the need for an external DSP as you required with the APL1 unit. The version I have features ten output channels, two analogue inputs and a SPDIF input but there's a version available that also got TOSlink. With 10 channels you could either run a 5-way setup or a common 4-way with rear channels for ambiance etc. The unit got more processing power than most DSPs on the market with cascadable FIR-filters for each channel with 4096 taps available at the moment (it's the firmware that's the actual limitation in the current version). Crossovers are 4th or 8th order and both linear phase and minimum phase filters with group delay compensation are available. You can use the built in equalization function to generate target curves (global EQ) or EQ individual channels. You can also use up to 45ms of delay for each channel which is really good for rear channel experimentation or subwoofer GD compensation. Since the DSP is FIR-based you can also experiment with linear phase filtering. For instance, you could basically make a zero delay vented subwoofer output, I would wait until there are more taps available on the subwoofer channels for increased accuracy though.
The process is pretty simple. If you are familiar with the APL1 unit, you know how the filters are generated in APL Workshop or TDA EQ. For the APL1 unit, the filters are stored in left and right channels to be used as input EQ for each side respectably. In APL1012 unit, each of the filters are instead used per channel (per speaker) and the crossovers are applied on top of these filters. The big advantage of this is that you actually EQ each channel individually before you cascade the crossover on top the filter, this way the stopband will be perfectly equalized with no phase nulls in the actual acoustic crossover region. You can either invert the IR or use the built-in group delay compensation function to cancel out the substantial delay of the tall order filters.
(To clarify, it runs the full APL equalization on EACH speaker)
While working in the C5 software you don't need to upload filters manually as you got the option to directly control the units from the software just like any other DSP software. The software is pretty straightforward to use once you get the hang of it. The software caters both to the less experienced and the advanced user with the cascadable filter option.
The actual hardware are high quality as usual with respectable brand components internally. You can connect volume, sub gain, balance pots and an input selection switch from the two external mini XLR ports which are an improvement over the previous units where you had to open up the chassis. Volume and subwoofer pots are smooth and work really good in a 'linear' fashion from 0-100% output, I believe you get around 6m (~18ft) length of cable. The EQ mode switch work just the APL1 with the exception that modes 1 through 5 are reserved for each set of output filters, still you got 16 modes in total so there's plenty available if you wanna swap between different EQ curves or filters. It also got balanced RCAs which eliminates ground loops if you ever should run into that problem.
All in all I highly recommend this unit, used right it offers (in my opinion) the most processing power available among any of the readily available DSPs. It's a sizable unit compared to many other DSPs but I like the simple and clean design of the unit but it shouldn't be too much of an issue to find a spot for it. I don't think anyone would be disappointed with this unit and it will probably take a while before you feel the need to upgrade to anything else...
A manual is included this time around, it describes what the various functions in the software does so don't worry too much about setting it up
For price, please contact Raimonds Skuruls. As far as I understand the price is different as units are built with somewhat different features and some accessories like the external controls are optional.
Here's some pictures of the packaging (I let that speak for itself) and the included C5 software:
Here's how the C5 software looks:
(Main window where you upload all your filters, manage delays, muting etc.)
It accepts *.fir / *.wave files (Workshop, TDA EQ format or an IR as wave). Details about workshop is in the APL1 review <<
Crossover section, you choose your crossover points and the lowpass/highpass are placed at the same place. No need to mess around with different crossover settings/slopes in this type of setup. Here's a standard 4-way setup with minimum phase crossovers (you can also choose linear crossovers in the dropdown menu).
Every time you upload a filter you get to see the frequency response, phase, group delay of the actual measurement. You can also view all curves of the different speakers in a separate graph window.
Here's an example how you can use the volume, sub and EQ mode switch. I simply set my headunit on a fairly high output (below clipping of course) and use the controls directly connected to the DSP.
Even though it's in the manual, I will write it here as well. When using the C5 software, do not, I repeat not use space or any special symbols in any of the filenames, project folders etc. It kept me busy for a while when setting up my system, safe to say... I will do a separate little video how to measure and how to use the software in the how-to section later!
At the time of writing this, the unit isn't included on the website. Here's a link to the official APL website: http://aplaudio.com/conc2/
Raimonds is also active on this forum, so you could PM him directly.