I just noticed these affordable units by Thomann:
the t.racks DSP 4x4 Mini – Thomann UK
DSP unit, 4 assignable outputs, low-pass / - high-pass filters, PEQ etc.
Seems very suitable for an amateur like me - 79 euros per unit, 158 euros to serve 2 speakers?
Is this the "even-poorer" man's version of MiniDSP for people who want to fool around with active crossovers?
the t.racks DSP 4x4 Mini – Thomann UK
DSP unit, 4 assignable outputs, low-pass / - high-pass filters, PEQ etc.
Seems very suitable for an amateur like me - 79 euros per unit, 158 euros to serve 2 speakers?
Is this the "even-poorer" man's version of MiniDSP for people who want to fool around with active crossovers?
Thanks for pointing this out. It's not quite a miniDSP 2x4HD, but likely has better performance than the first generation 2x4 DSP crossover box.
Here are the specs from the manual:
Both inputs and outputs are balanced, analog only. The unit can be set up via a USB connection using software but it may only be windows compatible. You might be able to download the software and try it out without having bought the unit yet.
The unit seems to have a reasonable amount of basic IIR-only filtering capabilities as shown in the attached image. The manual doesn't go into any detail about the DSP filtering capabilities but it looks like each output can get up to 7 PEQ bands as well as one HP and one LP filter from a list of preset types. This doesn't provide a huge amount of freedom to customize the crossover but it's sufficient.
I like the physical design and size - it could easily be attached to the rear of a speaker in an active speaker build.
On paper at least it's certainly not at all bad for the price. I wonder if these are also available in the US...
I noticed that Thomann also sells other units by the same manufacturer but they are more rack-style units with different numbers of inputs and outputs.
Here are the specs from the manual:
Code:
Technical specifications:
Analog Input connections:
...Type 4 × 1/4" phone socket (balanced), (max) Level +12 dBu
...Impedance 1 MΩ (stereo), 500 kΩ (mono)
Analog Output connections
...Type 4 × 1/4" phone socket (balanced), (max) Level +12 dBu
...(output) Impedance < 500 Ω
Digital signal processing
...Digital signal processor 32 bit
...A/D-D/A converter 24 bit
...Sampling rate 48 kHz
Frequency response 20 Hz … 20 kHz –0.3 dB
Total harmonic distortion (THD) < 0.008 % (1 kHz, 0 dBu)
Signal-to-noise ratio > 105 dBu
Crosstalk > 70 dBu, 20 Hz … 20 kHz
Voltage supply Plug-in power supply (12 V / 1 A , centre positive)
Dimensions (W × H × D) 160 mm × 150 mm × 40 mm
Weight 0.6 kgBoth inputs and outputs are balanced, analog only. The unit can be set up via a USB connection using software but it may only be windows compatible. You might be able to download the software and try it out without having bought the unit yet.
The unit seems to have a reasonable amount of basic IIR-only filtering capabilities as shown in the attached image. The manual doesn't go into any detail about the DSP filtering capabilities but it looks like each output can get up to 7 PEQ bands as well as one HP and one LP filter from a list of preset types. This doesn't provide a huge amount of freedom to customize the crossover but it's sufficient.
I like the physical design and size - it could easily be attached to the rear of a speaker in an active speaker build.
On paper at least it's certainly not at all bad for the price. I wonder if these are also available in the US...
I noticed that Thomann also sells other units by the same manufacturer but they are more rack-style units with different numbers of inputs and outputs.
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I found a 3-page detailed review (in German but Google Translate is your friend) of this product here:
the t.racks DSP 4X4 Mini Test :: Bonedo
The conclusion states "The t.racks DSP 4X4 Mini offers good equipment, ease of use and an unbeatable price. But the most surprising thing is the tonal performance: No noise, no artifacts". I discovered some additional blog posts by users of the unit that echoed these sentiments.
Intrigued by the review, I decided to download the software to check it out in a little more detail. I found that there is a lot more filtering (high and low pass filters) available that I realized, because any of the 7 output processing blocks can take on any one of these types:
There are three sliders in the part of the control interface underneath the text "PEQ Parameter" (bottom middle of pick in post above). These sliders control the frequency, Q, and gain of the block at left (one of the seven available). This makes it easy to "tune" the values instead of having to hand enter the values for the parameters in the boxes at left, although that can be done as well.
A phase plot is available using the "Phase" radio button in the top left corner of the black plot area. This is helpful for setting up the allpass filters for instance. Selecting "Mag" brings you back to the more familiar plot of dB gain versus frequency.
In addition to the user being able to select each of the 7 blocks to be the types above, there is one highpass and one lowpass available for each output that can be of one of the following filter types:
I might try to get my hands on one of these to check it out in person. This would work nicely with the type of active loudspeaker projects that I like to build.
the t.racks DSP 4X4 Mini Test :: Bonedo
The conclusion states "The t.racks DSP 4X4 Mini offers good equipment, ease of use and an unbeatable price. But the most surprising thing is the tonal performance: No noise, no artifacts". I discovered some additional blog posts by users of the unit that echoed these sentiments.
Intrigued by the review, I decided to download the software to check it out in a little more detail. I found that there is a lot more filtering (high and low pass filters) available that I realized, because any of the 7 output processing blocks can take on any one of these types:
- PEAK - e.g. a PEQ band
- LOW SHELF (second order shelf with user control over Q and Fc)
- HIGH SHELF (second order shelf with user control over Q and Fc)
- LOW PASS (second order with user control over Q and Fc)
- HIGH PASS (second order with user control over Q and Fc)
- ALLPASS1 - first order allpass
- ALLPASS2 - second order allpass
There are three sliders in the part of the control interface underneath the text "PEQ Parameter" (bottom middle of pick in post above). These sliders control the frequency, Q, and gain of the block at left (one of the seven available). This makes it easy to "tune" the values instead of having to hand enter the values for the parameters in the boxes at left, although that can be done as well.
A phase plot is available using the "Phase" radio button in the top left corner of the black plot area. This is helpful for setting up the allpass filters for instance. Selecting "Mag" brings you back to the more familiar plot of dB gain versus frequency.
In addition to the user being able to select each of the 7 blocks to be the types above, there is one highpass and one lowpass available for each output that can be of one of the following filter types:
- Buttwerworth 6
- Bessel 6
- Buttwerworth 12
- Bessel 12
- Linwitz-Riley 12
- Buttwerworth 18
- Bessel 18
- Buttwerworth 24
- Bessel 24
- Linwitz-Riley 24
I might try to get my hands on one of these to check it out in person. This would work nicely with the type of active loudspeaker projects that I like to build.
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