Audio output options for HTPC

With a HTPC, audio output can be a little confusing with so many types of sound output ports. Firstly, there are the regular analog speaker output ( Left, Right, Central/Subwoofer/Rear Left & Rear Right ). We usually only use the audio out to PC speakers. With a HTPC, there are a few more options to choose from..

There are the S/PDIF compressed digital audio ports that comes in two flavors, optical TOSLINK and copper version in RCA connector ( usually orange in colour ). S/PDIF is a method for DVD players to send compressed audio like DTS or Dolby Digital  to your AV receiver to decode them.

Since HTPC are usually placed in the living room together with an AV Receiver, the best method to output the audio would be S/PDIF to the AV receiver similar like a DVD/BD player.

There is new method to output BOTH audio & video called HDMI. This is somehow electrical compatible with the DVI video signal. That is why you see some graphic cards some with DVI ports with HDMI converter. HDMI carry high bandwidth and only requires 1 cable to do the job.

Now with three methods to output the sound from the HTPC, it would be a little confusing especially to the software running in the operating system. Some software will use the default method from Windows Control Panel and some software can be configured directly where to output the sound to.

Price Distribution in % for all the components

With a limited budget for the HTPC rig, I have to decide on which components should I spend more money on and which components I should keep the pricing down.

Main components - 42% of the total price

Motherboard - ASUS M4A785TD-V EVO ( 13% )
CPU - AMD Phenom II X3 720 BE 2.8Ghz ( 15%  )
Memory - 4GB DDR3 PC1333 Corsair XMS3 ( 13% )

This is what I consider the main components and technology investment for my HTPC rig. I have decided to go with a newer AMD 785G chipsets with a DDR3 motherboard. The flexibility for AMD CPU platform is that since the memory controller is built into the CPU, for budget constrain considerations, you can also go with DDR2 motherboard and ram and cut down the price significantly. I have also chosen a X3 Black Edition with unlocked multiplier but for a purely HTPC rig, a X2 or X3 non Black Edition would be sufficient.

Secondary components - 37% of total price

XQBOX HTPC800 chassis ( 11% )
Xigmatek NRP-PC501 Power Supply ( 8% )
Zalman CNPS 7800 LED CPU cooler ( 7% )
Hauppauge WinTV150 TV Input Card ( 11% )

For the HTPC chassis, the HTPC800 is considered low price compared to some full aluminum chassis. The front panel looks pretty decent with 2 temp sensors and 1 CPU fan sensors.

Initially I thought that I can save on the CPU Cooler by using the stock AMD cooler but once the heat built-up in the chassis, the stock CPU cooler was spinning at 6000 rpm and it is really noisy. I had to invest in the Zalman CNPS 7800 LED CPU cooler to keep the noise and heat at bay.

For the power supply, I believe a lower power rating could also be used and save up some money for others like a bigger hard disk or some.


Other components and accessories - 21% of total price

500Gb hard disk ( 6% )
Lite-ON DVD-RW ( 3% )
Bluetooth Keyboard with touchpad + Bluetooth dongle ( 9% )
Other accessories ( HDMI cables, extra silent fans, RCA splitters ) ( 4% )

For my case, I decide to go with only a 500GB of hard disk as I have an existing 500Gb on my NAS. I will upgrade to Blueray Drive later when the prices start to come down.

The keyboard and mouse pricing threw me over budget as initially I had chosen those Cordless keyboard and mouse combo but later found out that they do NOT work with HTPC setup as the wireless range is only like 2 to 3 feet only. I had to returned it and exchange for a Logitech PS3 Bluetooth keyboard with built-in touchpad and buy a bluetooth dongle to power up the Bluetooth keyboard. For choosing wireless keyboard, please do not use those cheap cordless ones and buy a good Bluetooth keyboard with built-in touchpad or trackball type. You can also have an option to buy a Bluetooth mouse if you do not fancy those touchpad or trackball mouse.


Summary :

Main components - 42% of the total price
Secondary components - 37% of total price
Other components and accessories - 21% of total price

This is my HTPC rig price distribution with a premium on DDR3 4Gb ram, Black Edition CPU and 500W power supply. The two components that I unexpectedly spend more was the CPU Cooler and Bluetooth keyboard + touchpad. If I choose a DDR2 2Gb, X2 CPU and 400W power supply, I might still be within my overall budget for this rig.

TV Input Card - Hauppauge WinTV PVR-150 Media Center Kit

One of an important part of a HTPC is the TV input card to received tv / satellite or cable signal from the content provider. As my case in Malaysia, the obvious choice is Astro, a tv satellite provider that have all the tv channels onto one source.


For my case, after doing some research and what most other HTPC users are using, I decided to get the Hauppauge WinTV PVR-150 Media Center Kit, with PCI video input card, a Media Center remote controller and and best of all, an InfraRed (IR) Blaster that can send IR signal directly to the Astro decoder to change the channels. This is very important to be able to do scheduled tv recording.

Setting up the WinTV-PVR 150 is pretty straight forward, just install the software and detect the tv input signal. For my case, I use S-Video for video input ( better picture quality ) and RCA left & right for audio input.

On the Astro decoder output, I have multiple options for audio and video out. For digital audio, I connected the SPDIF optical cable directly to my AV receiver. For analog audio, I use a pair of Y-RCA splitter to split the L+R audio RCA connectors, one pair to the HTPC as mention above and another pair directly to my plasma tv.

As for the video output, I use the RCA video connector to my plasma tv and S-Video into the WinTV card. My HTPC connection to the plasma tv is via a HDMI connection.

CPU Cooler and heat issues

When I started budgeting for a HTPC, I left out the budget for a CPU cooler as all CPU includes a heatsink fan. With stock CPU cooler, the heat transfer are at best low to moderate performance. As HTPC need to be as silent as possible so that when watching a movie or listen to music without hearing the CPU fan noise, the stock CPU cooler just isn't suitable for this requirement.

When running at full CPU load during video conversion/encoding, the stock CPU fan speed was running at max speed of 6300 rpm. This create a lot of noise and is pretty annoying, I tried many method to disperse the heat away from the chassis but due to limited space in an enclose cabinet, most of my attempts  are not effective. There was even one time that the chassis was so hot that the CPU temp reading was almost 60C with a motherboard temp reading of 58C. The fan was spinning at full speed but the hot air was recirculated inside the chassis which makes the matter worst.

With recommendations from a vendor that sold me the HTPC chassis, I decide to invest in a CPU cooler to solve this heat issue. I was still concern that the hot air would still be re-circulated inside the chassis but this top performance low profile CPU cooler managed to solve all my problems at one go - the fan runs silent, blow the air downwards to cool down the CPU heatsink plus all the surrounding components like chipsets and memory. Best of all, this CPU cooler height is very low and can even be fitted into  small form factor (SFF) chassis.

This is the Zalman CNPS 8700 LED CPU cooler with a nice blue led. It have 2 heatpipe connected to a full copper heatsink. The installation was a bit challenging as the nice ASUS designed chipsets heatsink was blocking the clip from going down all the way to lock in the CPU cooler. Luckily the chipset heatsink are adjustable with small springs on the screws so that I can lift it up a little to allow the clip to lock in the CPU cooler.  I would not want to repeat this process again in such small space to work with.

This is how it looks like with the Zalman CNPS 8700 LED installed taken with flash and CPU cooler running. The CNPS 8700 LED being a low height cooler, is design to fit all motherboard as mine had only a 5mm space between the copper heatsink to the side chassis fans.

Here is another picture with camera flash turn off to show the cool blue LED.

Overall, I was very satisfied with this Zalman CNPS 8700 LED as it was able to lower BOTH fan noise  ( the max RPM is only 2400 ) and both the CPU & motherboard temp. With full load, the CPU temp is at 52-54C with motherboard temp at around 37-40C depending on the ambient temp.

I made the air flow in the following directions, cool air comes in from the black 80mm fan near the hard disk bracket ( with another 120mm fan blowing cool air from behind the tv cabinet ), cool down the hard disk and flow towards the CPU cooler blowing air downwards to copper heatsink and all surrounding components and finally hot air is blown out by the two orange fin fans. From the front of the HTPC chassis near the DVD drive, I can feel hot air being push out from the tv cabinet.

With the current setup, I should be able to run this HTPC 24 hours without worrying about noisy and heat issues.

HTPC Chassis

To have a PC in the living room means that it needs to looks like more like a HiFi components than a regular PC chassis. Since most HiFi component are horizontal instead of the regular vertical orientation of a PC chassis, most if not all HTPC chassis are horizontally oriented.

There are many choices for HTPC chassis with some really really cool but also very expensive. Some Korean brands even have a mini vga display in front of the HTPC chassis. I was searching around and found a very nice but not too expensive chassis offered by an online forum.  It have a large power switch that looks like a volume control knob with a blue ring, a blue LCD panel that displayed 2 temperature sensors for case and cpu with a middle display for CPU fan speed.

This chassis is large enough for better air circulation but small enough to fit inside my 4 slots tv cabinet. The front panel have 2 USB ports and a HD Audio connectors for mic and line out.

The placement of the power supply was a bit weird as it was just behind the power knob and the power supply fan is blowing down towards the chassis.

One of the biggest issue of having a PC inside a tv cabinet is the heat dissipation , and heat creates a lot of fan noise as the CPU fan needs to spin faster to cool down the CPU. With a stock CPU cooler, the annoying thing is that the CPU fan was spinning more than 6000 rpm when running on full CPU load and does not cool down later as the heat does not escape from the tv cabinet.

This is a photo of the chasis with a stock CPU cooler.

I had to cut a hole behind the tv cabinet and installed a 120mm silent CoolerMaster fan that will blow air towards the rear o f the HTPC chassis. I also swap one of the chassis fan to blow cool inside the chassis instead of sucking hot air from the chassis.

Power Supply Selection

Selecting power supply is a tough choice as there are like so many power ratings to choose from, 350W - 1000W, PFC ( Power Factor Corrections ) and so many brands.  I always believe that if the company is good in one line of products (for example a PC maker) I would not buy a LCD monitor from them as I know that they would just OEM it from some major LCD maker and put their sticker on it. I would also buy a power supply from a company that specialized in making power supply or other factor that caught my attention.

For this case, it was both the higher specs, nicer design and "GREEN" factor that the company supports.

The Xigmatek power supply caught my attention as being a company that support GREEN initiative by using a recycled cardboard. The NRP-PC501, is a 500W power supply with all the necessary extra connectors to connect up to 2 power hungry x16 3D graphic cards, support both 4 or 8 pins EPS12V connector. All the cables comes with nice sleeve to keep all the cables in place with a nice 140mm quiet fan.

This is the picture of the power supply with a large 140mm transparent fan with a nice quality finish. 500W is way too much for HTPC power requirements but since power supply is one of the components that does not go obsolete as fast as the rest of the technologies,  I choose to invest in a higher power rating power supply as I can still reuse it in other chassis if needed to.

Memory Selection - DDR3

After deciding on the main components, the rest of the HTPC components was quite easy. With the motherboard only support DDR3 ram, choosing memory types was an easier task. I decided to use 4GBytes of Corsair XMS3 DDR3 PC-10666 ( 1333Mhz running in pairs of 2GBytes ).

Why did I choose Corsair over the other brands like Kingston or Muskhin, I do not know, perhaps I find them to be a reputable memory chip maker or they did an excellent marketing to position their brand ahead of others.

I use 4GB ram because with only 128M DDR3 of sideport memory (additional memory specially dedicated to the 3d graphic card), the integrated graphic card can have the options use the main memory as video ram once the 128M of sideport is fill up.

CPU Requirements

Since I have decided to use the AMD Phenom II processor, I have a wide choice to choose between 2, 4 or 4 cores.  From my readings, all AMD Phenom II are 4 cores but during manufacturing, some of the cores or cache might be faulty, instead of throwing it away, they sold them as X2 or X3 with different cache sizes.

After much comparison between price vs budget vs number of cores, I went for the middle one, an AMD Phenom II 2.8Ghz X3 720 Black Edition. I took the Black Edition just in case I want to have some fun to overclocking the processor as the multiplier is unlocked.

As a Home Theater PC is different from a desktop or gaming PC, the main issue is keeping the noise to the lowest level and keeping the chassis as cool as possible to prevent the CPU fan RPM from spinning too fast. I will explain in more details about chassis and cpu cooling later.

Some might think that a HTPC does not need a powerful CPU / multicores but from my experience since the HTPC also function as a central storage for all your multimedia (photos, audio & video) , you will need to do lots of video format conversion & encoding, video editing and also to rip some audio or DVD into the hard disk.  All the above mentioned requires a lot of CPU power and a faster CPU with multi core will complete these task a lot faster with multi core supported software.

As for video playback, ATI Radeon HD4200 support UVD 2.0 to offload the main CPU from decoding high definitions video format.

Components of a HTPC

I did a lot of research on what type of components are suitable to built a HTPC for my living room. It have been a while since I last built my own PC as the previous one was since 2002 using an AMD Anthon XP system with PC133 memory.

I have decided on to narrow down the components to the below items :-

• AMD motherboard with built-in ATI Radeon graphic card
• AMD Phenom II
• CPU HeatSink Fan (HSF) Cooler
• DDR3 memory, 4Gb
• 450-500W Power Supply
• Hauppauge Win-TV-PVR-150 Median Center Kit
• Wireless keyboard and mouse
• Large SATA-II hard disk
• DVD-RW 
• HTPC Chassis

AMD Motherboard and chipsets

The most important components is the motherboard, so I was choosing between Asus and Gigabyte. With the new release of the AMD 785G chipsets, I decide to use this as it have a newer ATI Radeon HD 4200 integrated 3D graphic card with 500Mhz clockspeed. Most of the brands comes with a 128Mb DDR3 sideport memory ( additional memory dedicated to the graphic card instead of using the main memory as video frame buffer ).

After doing my research, I have chosen Asus M4A785TD-V EVO, a full ATX board over the Gigabyte models. These two boards are quite similar but the Asus board is a full ATX board with more expansion slots ( 2 x PCIe x16,  1 x PCIe x1 & 3 PCI ).

And with the following back panel needed for a HTPC requirements, HDMI, DVI and VGA connectors for video and SPDIF for digital audio to the AV Receiver.

Nice thing about HDMI is that both digital video and audio are combined into a single cable to new Plasma or LCD tv with HDMI connectors. Newer Plasma / LCD models even have more than one HDMI input connectors. The AMD 785G chipsets support HDMI 1.3.

How it all started.... DVR + Media Center

A HTPC was nothing new as it been around for quite some time and most of my requirements are met with other options like Astro MAX and XBOX, a dedicated media center with large hard disk storage.

Astro MAX

As most Malaysian have Astro digital satellite broadcast, I was the early adopters for Astro Digital Video Recorder with recording and playback functionality called Astro MAX.

I felt it was worth it for 2 reasons, first, there are 2 receiver inside the Astro MAX so that you can record 1 channel while watching another... much cheaper than paying for 2 Astro decoder that many homes have. This reason saves money, pay for 1 decoder, get 2 decoder simultaneously.

Secondly, this is the power of the Tivo concept, with our complex daily routines, we do not expect tv station to control our daily schedules by telling us when to watch what channel. With a scheduled recording functions, we just schedule the recording and watch it whenever we are free to watch, stop and continue another time and the best of all, we save time by fast forwarding all the long and mind washing advertisements. This reason saves time.

Electronic Programming Guide (EPG) was integrated but only have less than one week ahead schedule.

So most of the decision was based on the 2 basic needs, save time & money!!!

XBOX - XBox Media Center

Not to be mistaken with the Xbox 360, this is the original XBOX that I purchase many years ago for gaming with an upgraded 100Gb hard disk but currently it was used mainly as a storage for my daughter videos and photos. Just upload or convert all the video into mpeg or avi format and no more changing disc anymore.

I also purchase a remote controller and upgraded the Xbox HD kit with component cables and digital optical output (SPDIF) for a much better quality video and audio output.

With the popular XBMC ( XBox Media Center ) software loaded, this media center can play all types of video format ( no need to hunt for codec ), play music, play DVDs and a backup storage for all my digital photos since 2001.

There you have it, Astro MAX + XBMC = a Home Theater PC without a PC. With this combo solution, there are a few things still missing, firstly, 2 appliance means 2 remote controllers and no integration between both of them. The Astro MAX recorded video CANNOT be copied out, as it does not have a LAN port and all the recorded video does not have a timestamp on when it was recorded.

Just like all other electrical appliance at home, single functionality, stand alone and disconnected from each other.