Working on a demo for CAF2024 room 702.
Had feedback that folks want to hear what the dspNexus 2x8 can do for normal box speakers, so have a plan to retrofit a 2-way speaker I will call the M1 with an ABC Switch to allow the room to hear the difference between the original passive crossover, upgraded passive crossover and the dspNexus 2x8. This was a production speaker that is an 8in acoustic suspension woofer and sealed tweeter.
Been working on the switching system to go between the 3 crossovers and using relays with a RPi5 as a controller driving power MOSFET's driving the12VDC relays. All the wiring and connectors are the same for all 3 channels.
The RPi5 control system works, so now to try and house the system for use. To prototype, just using cardboard boxes big enough to hold the parts.
There will be one box behind each speaker with a separate control box with keyboard and monitor for switching control. The Neutrik 4-pole connectors are the drive signals to the replays with protection diodes.
Here are the relay boxes with parts just being test fit before cutting holes and installation.
Rich,
That is a really good idea 👍
Nick
Nick,
Thanks!
This should be very revealing of the differences for anyone that has not heard all styles of crossovers on one speaker.
The upgraded passive parts are also better matched channel to channel compared to the original crossover. :thumb:
The first ABC Switch relay box #1 prototype is done. The Neutrik connectors are relay switching signals on the front with the outputs to the speaker drivers.
Rear connectors are the ABC inputs from the different crossovers.
Now to build relay box #2.
The new passive crossover boxes are nearing completion.
Once done, just need to build the pc board with the power MOSFET's for the relay control and then wire up the system.
Built the two relay driver pc boards and wired them to the output connections.
Next is to wire the RPi5 GPIO wiring to the driver pc boards.
The time to test the relay switching.
The ABC Switch RPi5 and Relay control boards are now connected.
Time for some relay testing for channel #1 then swap to channel #2. Then onto both.
The ABC Switch system is operational.
Now to finish wiring the passive crossovers for the speakers.
The M1 speakers ABC Switch System is ready for testing.
This is the original passive crossovers, upgraded component passive crossovers and inputs for the dspNexus 2/8 DSP crossover system.
Now for system connection and listening trials. Need to level match the 3 crossovers. Cable lengths for each channel are 8ft of Belden 1309A 14awg speaker cable without the PVC jacket.
Then, let the games begin! 😮
Quote from: HAL on October 11, 2024, 02:47:08 PM
The M1 speakers ABC Switch System is ready for testing.
This is the original passive crossovers, upgraded component passive crossovers and inputs for the dspNexus 2/8 DSP crossover system.
Now for system connection and listening trials. Need to level match the 3 crossovers. Cable lengths for each channel are 8ft of Belden 1309A 14awg speaker cable without the PVC jacket.
Then, let the games begin! 😮
👍 👍 😃
Getting close Nick!
For the upgraded M1 speaker crossover, the original value of two inductors used is not a stock value. Had a matched pair of aircore inductors made for the new passive crossover for the ABC Switch box system.
I will install these and ready for system installation and ABC crossover trials.
The M1 speaker ABC Switch is getting installed for testing and listening.
Will be using a new dspNexus 2/8 with AK4499EX DAC's arriving today for the setup for CAF2024. My other systems are setup and wired, so time for a travel unit.
Quote from: HAL on October 14, 2024, 06:19:52 AM
The M1 speaker ABC Switch is getting installed for testing and listening.
Will be using a new dspNexus 2/8 with AK4499EX DAC's arriving today for the setup for CAF2024. My other systems are setup and wired, so time for a travel unit.
Rich,
Can you transport the blue speakers in a van or do you need something bigger?
Nick
Nick,
Yes, the AGN II speakers can go in a large van. A minivan might work. I have used an E350 or Transit style to move them.
These are not going to CAF2024. The demo room available are to small to set them up.
Quote from: HAL on October 14, 2024, 02:30:18 PM
Nick,
Yes, the AGN II speakers can go in a large van. A minivan might work. I have used an E350 or Transit style to move them.
These are not going to CAF2024. The demo room available are to small to set them up.
Ok. Thx Rich
The M1 box speaker ABC switch is operational. First using the original passive crossover for reference.
Will startup the logic box tomorrow to switch to the upgraded passive crossover for some run time. The crossovers are always getting signal from the amp channel they are connected to for extra run time.
Once that is running can then try the dspNexus 2/8 DSP crossover for the M1.
To have a fair comparison, each amp being used is getting signal from an AK4499EX DAC channel in the dspNexus 2/8 and pink noise will be used to check level matching.
Fun stuff!
The AB is now setup for both the original and upgraded component passive crossovers.
All good, so waiting on the arrival of the other set of 4 XLR cables that match the first set of 4 to setup the dspNexus 2/8 as the DSP crossover instead of the passive crossovers for the C capability. The ABC switching just needs the 4 amps outputs to run the speakers.
Last set of 4 amp to speaker cables to connect the amps via the switches to direct drive the tweeter and woofer. This is for the dspNexus 2/8 channels to amps acting as the new DSP crossover for the M1 speakers.
Quote from: HAL on October 18, 2024, 06:51:12 PM
Last set of 4 amp to speaker cables to connect the amps via the switches to direct drive the tweeter and woofer. This is for the dspNexus 2/8 channels to amps acting as the new DSP crossover for the M1 speakers.
Hi Rich,
Don't recall if you mentioned it before, but what wire are you using on those speaker cables?
Nick
Nick,
It is Belden 1309A 14awg Stranded wire with the PVC outer covering removed.
I remove the PVC makes it a lot easier to handle. The inner dielectric is polyethylene, so good for audio.
Quote from: HAL on October 21, 2024, 04:45:59 AM
Nick,
It is Belden 1309A 14awg Stranded wire with the PVC outer covering removed.
I remove the PVC makes it a lot easier to handle. The inner dielectric is polyethylene, so good for audio.
Thanks, Rich.
The M1 Acoustic Suspension speakers ABC Switch System is operational and playing music.
Now to get it packed up for CAF2024 and work with the Magnepan LRS speakers.