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Digital Source(s) for LX521.4

August 2nd, 2023, 12:21 pm

The assembly of the LX521.4 is almost complete (I have to complete one subwoofer channel) -

lx521.4.jpg


For the electronics I will initially use an Emotiva Basx A6 (tweeter, mid-range, and bass), Emotive Basx A4 (each subwoofer driven separately), and a miniDSP Flex 8 dsp/dac for the crossovers (Madisound includes a Flex 8 configuration file with the LX521.4 assembly instructions).

For a digital source I have a htpc that can dual boot Ubuntu 22.04 or Windows 11 (Ryzen CPU). I have been digitizing my CD's with Ruby Ripper. The Flex 8 has for inputs WiFi, usb, spdif optical and coax. I would prefer to use Ubuntu for my htpc. What I have used in the past for my htpc digital output is the spdif optical output. I am looking for suggestions as to what ripping and playback software to use (Audacious on linux can output directly to ALSA). Also comments on using the optical input of the Flex 8 would be welcome.

Note that with Ubuntu 22.10 Pipewire will supersede Pulse Audio (in 22.04 both are installed but Pulse Audio is still the default).

Finally any suggests for going from analog (records) to digital in real time (hardware) would be welcome (I don't feel like digitizing all my records). Initially I would use the line input to a ASUS Xonar sound card.

Re: Digital Source(s) for LX521.4

August 2nd, 2023, 12:43 pm

Tell us about the subs.

Re: Digital Source(s) for LX521.4

August 2nd, 2023, 1:41 pm

Each subwoofer has two SEAS L26RO4Y 10" subwoofers -

https://www.madisoundspeakerstore.com/approx-10-subwoofers/seas-l26ro4y-10-subwoofer-4-layer-vc-d1004-04/?gclid=CjwKCAjw_aemBhBLEiwAT98FMkD50nCUT_CvYRcVsHr1nvNgbbc_jieQhw-4P1INbEWAPs0DEjp9KxoCdZwQAvD_BwE

They were designed by SEAS in collaboration with Linkwitz. I don't know why they are in a back to back configuration (the wiring in one is reversed so that the reinforce each other in the dipole configuration), perhaps to allow assembly in a more compact space. The cabinet is just a baffle (no back). If I had an appropriate (one that could drive a 2 Ohm load) amplifier the speakers would be wired in parallel (electrical connections reversed to compensate for the fact they are geometrically reversed). Since I have a 4 channel amplifier each driver will be driven from an independent output (I am just splitting the right and left subwoofer outputs from the Flex 8).

Re: Digital Source(s) for LX521.4

August 2nd, 2023, 2:35 pm

The opposed firing sub drivers in the W frame is for distortion reduction according to the theory.

Channel D Audio offers phono to ADC units for use with their software.

The dspNexus 2x8 has phono preamp capability as well as DSP crossover and HiRez DAC's. You just wire the phone cartridge outputs as balanced to the XLR inputs on pins 2 and 3 with the table ground on pin 1. The system just needs power amps and the crossover design to run.

Re: Digital Source(s) for LX521.4

August 2nd, 2023, 3:25 pm

After I get everything working with the hardware I have I am considering upgrading to the dspNexus.

Re: Digital Source(s) for LX521.4

August 2nd, 2023, 5:12 pm

HAL wrote:The opposed firing sub drivers in the W frame is for distortion reduction according to the theory.

Channel D Audio offers phono to ADC units for use with their software.

The dspNexus 2x8 has phono preamp capability as well as DSP crossover and HiRez DAC's. You just wire the phone cartridge outputs as balanced to the XLR inputs on pins 2 and 3 with the table ground on pin 1. The system just needs power amps and the crossover design to run.


The opposing subs wired antiphase will reduce even order harmonic distortion but will not affect odd order harmonics.

Re: Digital Source(s) for LX521.4

August 10th, 2023, 7:10 pm

The wiring from the amplifiers to the speakers is complete. Now I have to read the manual on how to program the miniDSP Flex 8 and I can do first sound.

WiredLX521.4.jpg

Re: Digital Source(s) for LX521.4

August 18th, 2023, 7:35 pm

First Sound and Music. DSP, amps, and HTPC wired up. Using REW to fine tune DSP -

FirstSound.jpg


Do anyone have comments on whether or not DIRAC would improve a system link mine?
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