Author Topic: The M1 speaker project with ABC switch  (Read 16443 times)

Offline HAL

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The M1 speaker project with ABC switch
« on: September 11, 2024, 04:12:06 PM »
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.

Offline Nick B

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Re: The M1 speaker project with ABC switch
« Reply #1 on: September 11, 2024, 10:47:09 PM »
Rich,

That is a really good idea 👍

Nick
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Offline HAL

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Re: The M1 speaker project with ABC switch
« Reply #2 on: September 12, 2024, 05:23:46 AM »
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:

Offline HAL

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Re: The M1 speaker project with ABC switch
« Reply #3 on: September 13, 2024, 01:08:20 PM »
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.

Offline HAL

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Re: The M1 speaker project with ABC switch
« Reply #4 on: September 25, 2024, 08:23:50 AM »
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.

Offline HAL

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Re: The M1 speaker project with ABC switch
« Reply #5 on: October 01, 2024, 06:43:42 PM »
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.

Offline HAL

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Re: The M1 speaker project with ABC switch
« Reply #6 on: October 04, 2024, 12:25:03 PM »
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.


Offline HAL

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Re: The M1 speaker project with ABC switch
« Reply #7 on: October 06, 2024, 12:24:47 PM »
The ABC Switch system is operational.

Now to finish wiring the passive crossovers for the speakers.

Offline HAL

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Re: The M1 speaker project with ABC switch
« Reply #8 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! 😮

Offline Nick B

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Re: The M1 speaker project with ABC switch
« Reply #9 on: October 12, 2024, 11:35:35 AM »
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! 😮

👍 👍 😃
Orchard Starkrimson Ultra amp
Hattor Big preamp
JMR Voce Grande speakers
Holo Cyan2 dac
Holo Red streamer
Hapa Aero digital coax
WyWires Silver cables
TWL Digital American II p cord
Audio Envy p cords
Roon, Tidal, Qobuz
PI Audio UberBUSS

Offline HAL

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Re: The M1 speaker project with ABC switch
« Reply #10 on: October 12, 2024, 04:05:49 PM »
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.

Offline HAL

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Re: The M1 speaker project with ABC switch
« Reply #11 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.




Offline Nick B

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Re: The M1 speaker project with ABC switch
« Reply #12 on: October 14, 2024, 11:05:51 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
Orchard Starkrimson Ultra amp
Hattor Big preamp
JMR Voce Grande speakers
Holo Cyan2 dac
Holo Red streamer
Hapa Aero digital coax
WyWires Silver cables
TWL Digital American II p cord
Audio Envy p cords
Roon, Tidal, Qobuz
PI Audio UberBUSS

Offline HAL

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Re: The M1 speaker project with ABC switch
« Reply #13 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.

Offline Nick B

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Re: The M1 speaker project with ABC switch
« Reply #14 on: October 15, 2024, 05:50:38 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
Orchard Starkrimson Ultra amp
Hattor Big preamp
JMR Voce Grande speakers
Holo Cyan2 dac
Holo Red streamer
Hapa Aero digital coax
WyWires Silver cables
TWL Digital American II p cord
Audio Envy p cords
Roon, Tidal, Qobuz
PI Audio UberBUSS