Rasberry Pi and active crossover revolution

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This is the same system I'm building! I'm using an old Onkyo for DAC/amp duties.

Multichannel HDMI amp seems the most cost effective way to build an active crossover system right now, as most high-quality RPi DACs are only 2ch.

I've been trying to use Jack between M PD and BruteFIR, but maybe I should just pipe it straight from MPD.
 
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keylimesoda wrote "Multichannel HDMI amp seems the most cost effective way to build an active crossover system right now, as most high-quality RPi DACs are only 2ch."

I have placed an order of this Decoder HDMI to 7 1 Analog Audio Converter HDMI Digital Audio Amplifier Machines | eBay
in ebay ,I will check if this is good for our application,
And probably I will use this with Parallel World amplifier(OP amp only
power amp).
on high , TPA3116D2 PBTL version on low, mid might be TPA3116D2.
 
Hi Isabido
"assi's" crossover filter uses FIR filter.
And it has also EQ part implemented in IIR filter.
And from my experiences room compensation sounded less smooth
than using high end drivers, as room acoustic correction is varies
by position in the room.
For example , you can see the measurement result of the drivers
I have demonstrated Dec.,27 ,2015.

at facebook
https://www.facebook.com/yutaka.iida.aedio/posts/970597729673982?pnref=story
In this configuration , there was no need to compensate if the room acoustics is smooth.
 
By taking a look at the source i found that this Software uses openmax (omxplayer), i think the same way kodi uses it. This is something I was looking for a long time. Whenever it comes to multichannel audio via Hdmi, it comes to this closed source thing but it is never explained how to do it. Hdmi-play makes it possible to pipe into openmax. (There is no alsa-sink for openmax).

I will try it later this weekend.

Regards

PS: Using google translate makes things funny but it is hard to understand :)
 
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3type programs can be downloaded as binary form at Index of /software
this system is working on Raspi2 with Raspbian OS.
About explanation,
From "assi" I have received 3 programs, I have here trasnlated his e-mail to English.

==== Start of "assi" comments====
This program modified from demonstration software /opt/vc/src/hello_pi/hello_audio/audio.c

This demo software was not working as 8 channels outputs
on newly purchased YAMAHA AV amp.

That might be partially my fault because I did not understand OpenMX
features and know-hows.So I have to struggle to let it work with various
AV amp and OpenMX.
My program is NOT the standard-like software , but I like to make them work
even the code is dirty.

In the page there are 3 programs,

hdmi_play.bin2: originally written and tested for Marantz NR1501 after trials and errors I could make them work as 8 channel output.

The follwing 2 programs are not verified on Marantz NR-1501 (Yutaka IIDA will have to verify).

hdmi_play.bin2A:LFE channel is mapped to CS(Center / Sub?) , this worked well on Yamaha RX-A1040 AV amp.

hdmi_play2B.bin channel mapping was changed to "1" to "8". this worked well in Yamaha RX-A1040.

(1) copy programs into /usr/bin
sudo cp hdmi_play2?.bin /usr/bin/

(2) then you have to edit pipe out section of /etc/mpd.conf
audio_output {
type "pipe"
name "amafir"
; followings are sample for hdmi_play2A.bin
; command "amafir /home/pi/amafir | nice -n -20 hdmi_play2.bin 96000"
command "amafir /home/pi/amafir | nice -n -20 hdmi_play2A.bin 96000"
; command "amafir /home/pi/amafir | nice -n -20 hdmi_play2B.bin 96000"
format "96000:32:2"
}

====end of "assi" comments====
 
I have tried hard, but i can not get any sound using an Onkyo SR606

I am able to pipe a test wav from sox to amafir and hdmi_play2.bin, but i can not pipe from mpd into amafir|hdmi_play2 and not even from mpd to hdmi_play2.bin.

I think there must be some other changes in the mpd.conf.

Could you please post the whole mpd.conf?

Regards
 
skyunlimited,
"assi" answered as below in Japanese
===Start of "assi"'s comment===
[original J]
soxで再生できるのにmpdで再生できないのはおそらくmpd.confのなかの
hdmi_play2.bin呼び出しのところでniceを設定しているせいです。

[If you cannot play with mpd even though played with sox output , it may be caused 'nice' command preceeding 'hdmi_play2.bin' .]

[The followings are work-around for this problem.]

1.mpd.confのuserの項目をrootに変更する。 または
[1. change user in mpd.conf to 'root' (this was NOT recommended by security reason,
but you may check by this what is the root cause.]

2./etc/security/limits.confを編集してuser mpdにnice値を設定する権限を与える。
[2. set enable user 'mpd' to be able to set "nice" command and its value.]
3.nice値の設定を辞める。
[3. Discard "nice" priority setting though you may listen the breath pause of playing music.But you know what is the root cause.]
===End of "assi"'s comment===
He had sent me default user = "root" generated system, but it was not not recommended , so I did not experience any problem like this.

(a) remove "nice" in mpd.conf pipe output
or
(b) temporarily set "mpd" user as root.(my case)
 
I am testing as mpd user "root" and "hdmi_play2A.bin", I can map 8 channels and it seemed to work well on SONY TA-DA3200ES.

I checked ,
Front => Low / Surround => Mid / Surround Back => High as 3way FIR filter.

I guess SONY TA-DA3200ES was older one (it was released at 2006) and designed as compatible with PS-3 output. hdmi_play2A.bin was now verified with old SONY and newer YAMAHA, so most of AV amplifier which is HDMI linear PCM multi-channel compatibility.

So if you donot mind or can be responsible for risk of "root" user, you may use hdmi_pla2A.bin and "root" user.
 
I have added in the directory Index of /software

- mpd.conf for Raspberry pi/HDMI multi-channel (mpd.conf.rpi2multi)
- some of configuration file for amafir program (BruteFIR)

# ls -la
合計 2408
drwxrwxrwx 2 root root 4096 1月 3 12:47 .
drwxrwxrwx 7 root root 4096 1月 2 20:52 ..
-rw-r--r-- 1 root root 1822720 1月 3 12:46 amafir_para.tar
-rw-r--r-- 1 root root 170269 1月 2 20:53 hdmi_play.tar.gz
-rwxr-xr-x 1 pi pi 142392 1月 2 04:13 hdmi_play2.bin
-rwxr-xr-x 1 pi pi 142392 1月 2 04:13 hdmi_play2A.bin
-rwxr-xr-x 1 pi pi 142392 1月 2 04:13 hdmi_play2B.bin
-rwxr-xr-x 1 root root 14273 1月 3 02:33 mpd.conf.new
-rw-r----- 1 root root 14226 1月 3 12:47 mpd.conf.rpi2multi
 
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