In my experience the effect of the allpass of a LR4 crossover at ~1.5kHz is almost impossible to hear on musical signals.
But that does not mean FIR is useless...
Actually it is not about semantic, this is fundamental to the topic at hand.
A driver corrected with minimum-phase corrections stays minimum-phase.
A driver corrected with non minimum-phase corrections becomes non minimum-phase.
A multi-way non-coincident loudspeaker corrected with minimum-phase corrections is not minimum-phase.
A multi-way non-coincident loudspeaker corrected with non minimum-phase corrections *can* become minimum-phase.
A driver corrected with minimum-phase corrections stays minimum-phase.
A driver corrected with non minimum-phase corrections becomes non minimum-phase.
A multi-way non-coincident loudspeaker corrected with minimum-phase corrections is not minimum-phase.
A multi-way non-coincident loudspeaker corrected with non minimum-phase corrections *can* become minimum-phase.
The semantics of minimum-phase term are very well defined. And they are different to phase coherency.
Also summing outputs from several filters is not the same as applying a filter to the input. Summing outputs of two minimum-phase filters is *not* minimum phase. If frequency response is flat, but phase response isn't - it is *not* minimum-phase. It doesn't matter in this case if individual drivers are in phase (coherent) with each other or not.I ordered the hardware for my project and got it (DLCP with SMPS and more).
Let me first describe what I want to do:
I am building a 6-channel amplifier using 6 UCD180 amplifiers from Hypex powered by a SMPS400A180.
Instead of implementing a conventional crossover board in the 2 speakers containig
a low- , mid- and high-driver i want to use the DLCP from Hypex as an active loudspeaker filter
to drive the speaker-chassis' via the 6 amps in a Stereo configuration.
I will not use the optional input-/control board for the DLPC because I don't want to use
the DLCP as preamplifier.
The preamplifier I have has balanced outputs that will be connected via balanced XLR cable connections to
the analog inputs of the DLCP directly to J2 pin 1 to 6 as defined in the DLCP manual.
The first thing I did was to connect the Hypex DCLP-SMPS to the DLCP and a USB connection to J3 of the DLCP.
Due to the manual I have to connect:
- USB data positive (green wire) to pin 5 of J3
- USB data negative (white wire) to pin 6 of J3
- USB Ground (black wire) to pin 8 of J3
After powering on the SMPS the DLCP did some blinking of the LEDs and after about 2 seconds all the 9 red LEDs on the DLCP board were on and the green LED near J6 as well.
I did not change any jumpers on the board !
Gain adjust was 15dB on both channels and both jumpers on JP5 were in the normal position.
Then I connected the USB cable to my PC.
Disappointing result:
The PC recognized a device on the USB port and tried to install some kind of driver(s) and at the end I got a message that the device connected to this USB port was not known to Windows. In the device manager I can see a 'unknown device' entry in the USB section.
Disconnected the USB cable for a minute and retried the procedure with same results.
My PC runs Windows7 64bit SP1 and all updates installed, so I tried to do the same things with my Notebook with 32bit WIN7: same result ! Any help appreciated
Let me first describe what I want to do:
I am building a 6-channel amplifier using 6 UCD180 amplifiers from Hypex powered by a SMPS400A180.
Instead of implementing a conventional crossover board in the 2 speakers containig
a low- , mid- and high-driver i want to use the DLCP from Hypex as an active loudspeaker filter
to drive the speaker-chassis' via the 6 amps in a Stereo configuration.
I will not use the optional input-/control board for the DLPC because I don't want to use
the DLCP as preamplifier.
The preamplifier I have has balanced outputs that will be connected via balanced XLR cable connections to
the analog inputs of the DLCP directly to J2 pin 1 to 6 as defined in the DLCP manual.
The first thing I did was to connect the Hypex DCLP-SMPS to the DLCP and a USB connection to J3 of the DLCP.
Due to the manual I have to connect:
- USB data positive (green wire) to pin 5 of J3
- USB data negative (white wire) to pin 6 of J3
- USB Ground (black wire) to pin 8 of J3
After powering on the SMPS the DLCP did some blinking of the LEDs and after about 2 seconds all the 9 red LEDs on the DLCP board were on and the green LED near J6 as well.
I did not change any jumpers on the board !
Gain adjust was 15dB on both channels and both jumpers on JP5 were in the normal position.
Then I connected the USB cable to my PC.
Disappointing result:
The PC recognized a device on the USB port and tried to install some kind of driver(s) and at the end I got a message that the device connected to this USB port was not known to Windows. In the device manager I can see a 'unknown device' entry in the USB section.
Disconnected the USB cable for a minute and retried the procedure with same results.
My PC runs Windows7 64bit SP1 and all updates installed, so I tried to do the same things with my Notebook with 32bit WIN7: same result ! Any help appreciated
Oh, and I forgot to mention, of course the Hypex Filter Design program cannot connect
to this device.
to this device.
While it's nice to know the limit of taps, it stil doesn't answer my original question.
Will FIR be available in the upcoming software?
448 taps is ok. Somewhat limited but still useful.
The dlcp should show up as a USB audio device and as a HID device. Standard windows drivers. Did you try powering up the dlcp first and then connect the usb?
That is exactly what I did.
As I understand it , the green LED shows that the DLCP passed a successful
booting. But it does not matter if the DLCP is connected before it's power on/boot sequence or after it. Windows does in both cases the same thing.
Windows recognizes a USB device at the port where I connect the DLCP
and says 'unknown device'.
As I understand it , the green LED shows that the DLCP passed a successful
booting. But it does not matter if the DLCP is connected before it's power on/boot sequence or after it. Windows does in both cases the same thing.
Windows recognizes a USB device at the port where I connect the DLCP
and says 'unknown device'.
I think I don't need to connect the 5 Volt line to pin 7 but nevertheless did it in one of my tests but it did not help, same symptoms as before.
I assume that implies FIR will be available now in the new software. Your answer isn't very clear.
It's not decided yet. To use FIR in the DLCP the firmware has to be changed first.
To connect 5 Volt pin 7 did not help either, tried it.
I bought the DLCP and the other Hypex hardware through a german dealer,
it was originally Hypex boxed and is latest level hardware with QC-label so
I think it was tested before they sent it to me.
I have no idea what I can do wrong connecting just 4 wires to the USB port
of the DLCP as described in the manual.
And Windows recognizes the device but after the negotiation decides not to
accept the device (don't know why). Windows is not very conversational to the
user and does not tell me why.
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Took a picture of the USB cabling I am using.
Just straight wiring from a USB plug to J3 of the DLCP.
Picture attached.
