Linux based HTPC with multi-channel DSP/crossover

jr@mac

So this thread: http://techtalk.parts-express.com/forum/tech-talk-forum/1273819-on-the-way-to-active-with-ecasound

And also this thread: http://techtalk.parts-express.com/forum/tech-talk-forum/67951-new-the-active-crossover-designer-for-ecasound-ladspa-acd-l

Have got me thinking what to do with an IBM desktop I dragged home this last summer. It has an Intel Core i3 (not sure which version) and I installed 4gb of RAM, a 120gb SSD, a GeForce 210 (fanless), and will be dropping an Asus Xonar DS with upgraded OpAmp into it. 

It currently has Linux Mint installed on it - to my great joy it natively runs Netflix on Chrome. That has been my biggest complaint about making "the switch" to Linux for my HTPC. As much as hacking a system is enjoyable to me on several levels, I find it annoying to have to hack for mundane purposes such as watching "Frasier" (or to give perspective to the Apple people - to do anything but read email or use a copy of MS Office with reduced functionality). 

Soooo.... now that I can watch Netflix on Linux, and now that I can stand on the shoulders of giants and implement a pretty kickass DSP on that same Linux box, I have determined what my winter project is going to be

For amplification, I plan on starting with a simple four channel setup using the amplifier section in my Onkyo 809. It is a pretty beefy amplifier section into two channels, somewhat less so on four channels, and like most AVR out there gets pretty tepid in five channel and above. The key, however, is that it does offer seven channels of full range amplification and dual subwoofer outputs so it is pretty flexible as far as all that goes. The video output is toast, so I can no longer take advantage of the incredible video processing but I can use the HTPC to come close. 

So yeah... winter project lineup:

1. Max Fidelity/Seas TFFC build with wife. She is going to glue the flat pack up, cut the driver and port holes, finish the cabinet however she wants, and I will hold her hand through the measurement and crossover design process. 

2. Viawave/Wavecor monitor build. These are going to be my personal monitors in the nerdery, to replace the Vifa/Audax build I did a while ago in honor of the late, great Lou Coraggio.

In addition to the passive crossover we will be designing for the MF/Seas build, it will serve as the guinea pig for the active system, which will eventually live in our bedroom. 

isaeagle4031

I've got an old pc sitting in the shop. No idea what is in it or if it even works. My plan has been to use it as my test rig. The base is there though to make it into a nice htpc located at the work/test station. I'll be watching and asking questions Jr. 

As far as amps, I'm wanting to build a couple of op amps anyway and this will be a nice way to push that idea along too.

PWRRYD

Op amps?

isaeagle4031

Stupid phone. Should just be amps lol

JasonP

Yay for amp building! I have the parts for two chip amps lying around: LM3886 and TDA7293. Now I'm assembling the parts needed to build a Pass F5 class A discrete. Mmmm, amps.

greywarden

I've always wanted to build a small AMD AM1-series fanless/SSD HTPC with Linux or Kodi on it for music, but until I have my own space for a legit music setup, I'll have to hold off on that.

greywarden

I found this, thought it might help out

https://hellbach.us/blog/tech/diy-budget-htpc-media-center-build-giveaway/

jr@mac

I want quiet, so want to discuss some basic concepts. 

For a given ACP/TDP would you consider it better to run a lower clock speed but multiple cores, or a higher clock speed but fewer cores? Not sure of the exact CPU currently installed, but it is an i3. As a general rule, are there low power Intel chips available, that will run with a heatsink only? 

I have a Geforce 210 fanless installed, and it has a 120gb SSD installed, so quiet is covered in that respect. That leaves the funky little power supply to shut the hell up. It is a smaller model, something like 220 watts, but noise suppression isn't a typical consideration on these enterprise/business class desktop models and the fan on the PSU runs pretty consistently.

I have limited time available for these projects, and hacking a PSU to install a different fan is, to me, not a good use of that time. So - idears on that as well. 

JasonP

I'll link you to tests later when I am home, but the Intel stock cooler is virtually silent: under 20db at all but the highest loads.

greywarden

jr@mac said:

I want quiet, so want to discuss some basic concepts. 

For a given ACP/TDP would you consider it better to run a lower clock speed but multiple cores, or a higher clock speed but fewer cores? Not sure of the exact CPU currently installed, but it is an i3. As a general rule, are there low power Intel chips available, that will run with a heatsink only? 

I have a Geforce 210 fanless installed, and it has a 120gb SSD installed, so quiet is covered in that respect. That leaves the funky little power supply to shut the hell up. It is a smaller model, something like 220 watts, but noise suppression isn't a typical consideration on these enterprise/business class desktop models and the fan on the PSU runs pretty consistently.

I have limited time available for these projects, and hacking a PSU to install a different fan is, to me, not a good use of that time. So - idears on that as well. 

I have used everything from the Pentium G3258 (overclockable anniversary edition), to an i3-4370 (3.8GHz 2c/4t) to an i5-4690K (OC'd to 4.6GHz, 4c/4t) and even a Xeon X5650 (OC'd to 4.5GHz 6c/12t) in the past couple years, my next upgrade will be at least an i7, possibly a 6-core. 

I had the i3 passively cooled with a Supermicro passive cooler (server-grade) with a Noctua 140mm 3krpm fan (sounded like a server room, lol) and with the fan at a silent rpm, my CPU was sitting around 30C idle and shot up to 50-60C with any load, so I soon installed an "AIO" water cooler, the H60 (60 has copper, 50 uses aluminum for heat transfer). 

There are coolers made specifically for passive cpu cooling, and as you'd expect, they're massive like the Silverstone HE02, Thermalright Macho Zero, and the most enormous NoFan coolers, which look pretty cool. As far as TDP for passive cooling, I would keep it 45W or under for one of the large heatsinks and 35W and under for a smaller heatsink like the Supermicro unit.

So, in my opinion, most any PC should have at least 4 threads, like your i3 does, the Pentium G3258 stutters quite a bit with normal PC operations like web browsing, music, video, etc. I feel like something with a boost or turbo clock speed of about 2.7-3.3GHz can be sufficient for media PC operations.

One day when I finally build a small music PC, I'll probably use one of the AM1 processors, passively cooled, with an 1TB SSD (<$200 nowadays!). But when I decide to build a media PC, it'll be an i3/i5 35W model and use Displayport for 4K@60Hz@4:4:4(which is leaps and bounds, technologically speaking, over HDMI 2.0, which I couldn't get to work for the life of me) from a passively-cooled <75W GPU like the GTX950 and an SSD raid array. I'll probably have to end up building a custom case for this, which I've been threatening to do for the past few years anyway.

JasonP

Data on Intel's stock cooler as promised: http://www.silentpcreview.com/article1503-page4.html

jr@mac

Hmmm... I run primarily older hardware and have not experienced "stuttering" on anything but certain "modern design" websites - and that is usually due to excessive content loading and/or waiting on plugins to load, such as the vast majority of Parts Express, for example. Not sure constantly upgrading hardware will fix shit programming. 

I run a Geforce 610 and Athlon II X2 on the HTPC currently and have zero issues with 1080P, hirez audio, or any of the audio/engineering software I have loaded on it. The only stuttering I experience is waiting for certain types of web pages to load - and that is high likelyhood due to shit programming, not hardware capability. I once downloaded over 30mb of data on a PE page, for example. 

On the other hand, my work PC runs Windows 10, an i5-5200 and 8gb of RAM, and an SSD - and I have constant performance complaints. That is likely due to Explorer being optimized for stupid touchscreen and/or mobile applications - I don't know. Office 2015 loads quick, runs quick, and closes quick on  my nerdery PC at home (Athlon FX-4130/8gb RAM/SSD) but offers pretty poor performance here at work. Maybe implementation increases overhead or maybe the real world is different from benchmarks when it comes to Intel processors, I can't say for sure - but based on personal experience I do know I will be sticking with AMD processors for the foreseeable future.

greywarden

Ok, I forgot to mention I was also running F@H at the time, which uses a lot of CPU as well as 100% GPU usage, and the CPU was sitting at 80+% load when the stuttering and audio issues were happening.

As far as the PSU is concerned (missed that, my bad) there are PSUs that will run fanless until they reach a certain temperature/load, namely the Corsair RM-series, there's a 450W version that should run fanless for whatever you're doing on that i3/210 machine, plus they're fully modular and will help clean up unnecessary cabling in the case. And for about $20 more you can get the Silverstone fanless PSUs as well.