Loudness Correction and Yamaha YPAO Volume

Here you were thinking you had it all sorted once you applied EQ to your system, hey? Not so fast… a flat EQ is not going to give you correct tonal balance after all. Meet Loudness Correction.

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What is Loudness Correction?

Human hearing is not as sensitive in the higher and lower frequency ranges as it is in the mid-range. What this means in practice is that when not listening to a recorded program – let it be music, movies or TV shows – at the volume the program was recorded at or intended to be played at, the treble and base seem to drop off quicker than the midrange as volume is decreased. This actually upsets the tonal characteristic of the program material – even though you may have a completely flat frequency response for your speakers.

Here you were thinking you had it all sorted once you applied EQ to your system, hey? Not so fast… Now you actually know why a flat frequency response for a system is only actually perceived flat if it is playing at the right volume… unless of course we apply loudness correction.

I won’t go into the biological reasons for this or the estimations of how human hearing responds to changes in sound pressure. If you want to know more about the technical ins and outs of Loudness Correction, do a search for any of the following terms on the Internet:

  • Fletcher-Munson equal loudness contours
  • Robinson-Dadson curves
  • Normal Equal-Loudness Level Contours, ISO 226:1987

Loudness correction is not something new, it has been around in stereo systems for the last 30+ years. In fact, I have a loudness control on my 12-year-old stereo system in my car. However, auto-loudness correction is relatively new in the field of Home Cinema – first introduced by Denon and Marantz and other receiver manufacturers about 8 years ago through the inclusion of Audyssey’s Dynamic Equaliser, which is still the most sophisticated to date. Since then, THX, Dolby and more recently Yamaha have come up with their own version of it.

When it comes to movies, reference level for all channels – except the subwoofer channel – is calibrated by adjusting the playback system such that a pink noise signal recorded at -20dB relative to full scale (0dB) creates 85dB sound pressure level as measured with a C weighted SPL meter at the seating locations. Volume levels are adjusted for each channel individually until they reach 85dB.

Speakerreferencelevel.gif

The premise is valid: when listening to movies below the reference level (85dB), the tonal characteristic of the movie is changed. However, since loudness correction is not an exact science – human hearing is difficult to measure precisely – the different systems implement it slightly differently.

Yamaha YPAO Volume

I took some measurements with regards to Yamaha’s YPAO Volume to see how much loudness correction is applied to the high (above 6.5Kz) and low end (between 20Hz and 400Hz). Results are below:

  • volume at -40dB : 4dB added both high and low end
  • volume at -35dB: 3dB
  • volume at -30dB: 2dB
  • volume at -25dB: 1dB
  • volume at -22dB: 0dB – originally measured this at -22dB, but actually this should be -20dB as I am looking at the graphs now.

Screen Shot 2017-08-05 at 11.40.05 AM.png

Since I don’t have a unit that has YPAO volume – Yamaha sent me a unit (RX- A3060) to test for this – I wanted to know if I could re-create the effect using simply the base and treble controls on my unit. Below are the results:

Screen Shot 2017-08-05 at 11.43.58 AM

As you can see from the graph, applying 4dB to both treble and bass at -40dB, the results very closely match the low end, but the high end is not as closely aligned between 3KHz and 8Khz. Let’s have a look at higher volume levels:

Screen Shot 2017-08-05 at 11.47.39 AM

At -30dB, adding 2dB to both the high and low end, the effect is decreased, but also the errors. Since I actually listen between -30dB and -25dB normally, I have added -1.5dB to both bass and treble permanently on my older a3020 equivalent receiver.

How does it sound in practice? I have to be honest, Yamaha’s new RX-A3060 sounds noticeably clearer than my RX-A3020, even when matching the loudness curve using bass and treble controls as closely as possible and setting them up the same. (Please note that for the graphs above, the subwoofer EQ was turned off and the Yamaha was left to its own devices when it came to EQ.)

Now was it due to YPAO Volume, which works really well when listening to both movies and music at lower volumes, or was it the difference in DACs, the new 64bit YPAO or other component changes between the units? It is hard to know, but likely a combination of all the above. In the same room, with the same speakers, the difference in clarity was noticeable.

 

 

Yamaha YPAO Configuration – The Right Way

Introduction

I have been around to a friend recently who just bought the latest and greatest Avantage Receiver from Yamaha and AU$5000 worth of speakers but didn’t bother to read the manual in how to set up the receiver correctly.

Good sound is dependent just as much on doing the setup correctly, than it is on buying great gear. I was shocked and horrified to learn that after spending almost AU$10K on his setup, he didn’t bother to go through the expert setup procedure, he simply placed the mic on the couch (a big no no), measured one microphone position and off he went. Then he complained to me that the system sounded like $h1t, pardon my French! Of course it did…

However, after fixing his setup, I realised many people do the same, so it’s time for showing you how to do Yamaha YPAO – and actually most other home cinema receiver – setup correctly. Some of the advice below can be applied generally to all receivers. I will highlight Yamaha YPAO only advice here.

General Setup

Before anything else, you should go into the Manual Setup section under Speaker Setup and set the amp assignment correctly, dependent on which speaker terminals you used for which speakers and whether you used external amplification. You will need to refer to your receiver’s user manual as it does differ dependent on the the make and model of your receiver, even if we only look at Yamaha Receivers.

Microphone Placement

Firstly, auto setup should be configured as follows:

  • Multi-position: this is true even if you are only using one chair in one position to listen to the system. Although manufacturers include a single placement setup procedure, it is nearly impossible to get great sound using only one sample. They will either over-correct or under-correct for variations in frequency response. ALWAYS select multi-position measurement.
  • Angle Measurement (YPAO only): this will ensure that CinemaDSP will be configured correctly and if you have an ATMOS or DTS X enabled receiver, the height information will be used to ensure sounds are steered correctly to the different speakers. I would recommend to always select this option as well.

Ok, now with regards to Microphone placement:

  • DO NOT place the microphone on a hard surface like a table or even your couch (either on the seat or head rest) by itself. This will allow it to absorb reflections from the couch or hard surface in a way that is not natural. Unless you plan on listening to your system by putting your ear where your @$$ is or by placing your head on the coffee table and resting your foot on the couch (sounds rather uncomfortable if you ask me!), do not do this.
  • DO place the microphone on a tripod. The microphone has a grove that goes into your standard camera tripod. If you don’t have one of those, elevate the microphone by taping it to an upside down glass (the kind you drink out of). I usually use a plastic cup that has a slim bottom so it doesn’t act as a hard surface for reflections. Make sure you only tape the bottom of the mic. When I do this, I elevate the glass or cup using soft pillows to ear height, and not some other hard surface like a box or – as my friend did – a metal hollow side table.
  • DO make sure that the microphone has a “line of sight” view of all the speakers in the room if possible – at all microphone positions. The only exception to this is the subwoofer which does not need to have a line of sight view from the mic. I sometimes make some exceptions to this when it is totally unavoidable. For example, I have the back surrounds on a bookshelf which the back seats don’t have a line of sight view of. When I switch to the calibration which includes all seating positions in my home cinema, there were some mic positions at the back that did not have a line of sight view. However, all the front seats did. Not a huge deal but I don’t listen with that calibration when we only sit in the front row as it’s not ideal.

Have a look at the diagram below which you can find variations of in Yamaha documentation. The below is the correct version with number 1 position being in the centre of the couch (or chair). Some versions of this diagram were incorrectly putting number 1 on the side of the couch.

i361_070815

However, this is where it ends for me. I usually do the following, which seems to work with YPAO and other receivers as well:

  • Position 1: in the centre of the couch with microphone at ear height, away from the  headrest of the couch. Basically, this is right in the centre of where your bum will be but at ear height. The reason this needs to be in the centre is that the delay / distance measurements are taken from the first position. If you were to place this first measurement off centre, some seats would get better distance measurements while others a lot worse. We want to even this out and have every seat experience the most ideal sound the room allows.
  • Position 2: Same position as number 1 but to the seat to the right of the centre seat. On a 3-seater couch, this will be the right-most seat.
  • Position 3: same as position 1 and 2 but to the left. In case you’re wondering, it doesn’t matter if you go left or right.
  • Positions 4-6: Now I repeat the same measurements I did in Positions 1 to 3 but with the microphone placed much closer to the headrest where your ears would be, but at just enough height that it clears the back of the couch by a cm but also that it is getting some of the reflections off the back of the couch. Why? Because this is the position your ears will be AND there will be reflections that will muffle the sound that originate from the headrest of the couch.
  • Positions 7 and 8: I normally do these positions just between positions 1-2 and 1-3 (just a little off-centre) but in the same elevation and distance from the back of the couch as positions 1 – 3. This is to ensure we give the receiver enough variation for the room acoustics and don’t overwhelm it with having to compensate for that particular couch.

If you were configuring one seating position, a chair or arm chair, do the above exactly but divide up the chair equally or do some positions to the left and right of the chair at ear height as well as just a bit in front and above ear height.

If you have multiple couches, I recommend, doing more positions on the couch that will be your primary listening position and doing the rest on the other couch(es) following the above principles.

Angle Measurement (YPAO only)

YPAO in higher end Yamaha receivers will allow you to do something called an angle measurement. You will have to do this in Position 1 above, but use the little boomerang that came with your receiver like the one below.

YPAO mic

The positions are marked. Position 1 on the boomerang must face towards your front speakers, while 2 and 3 towards the back. The boomerang can be fixed onto a tripod as well. I really recommend this. Otherwise the taping method works here as well.

Measure each position by following the on-screen guidance. Please note that the height position is only available on Atmos and DTS X receivers.

Manual Configuration

Cabling and Crossover

Once YPAO (or other Receiver config) has finished, check the following:

  1. Speaker cabling is normal in all positions.
  2. Check what the crossover frequency was set to on your speakers.

Even though your speakers may be able to do frequencies below 80hz, it is not recommended to go below this cross over for movies as those frequencies are hard to control even from the subwoofer alone. However, your milage may vary. If you don’t have a separate subwoofer EQ, but only using the Yamaha, you may want to leave crossovers below 80Hz or leave speakers as “large” so no crossover is applied to them. As a rule of thumb, if Yamaha configured your speakers with a high crossover, you should not lower it (e.g. from 100Hz to 80hz), you can however up the crossover frequency (e.g. from 60hz to 80hz).

The reason you should not lower crossover frequencies is because the setup routine determined that anything lower than the crossover frequency doesn’t reach the seating positions without major dips (-3dB which is 1/2 of the percieved volume) in frequency response. If you lower the crossover, you may still get an uneven response or may not hear certain frequencies at all as now the subwoofer is not playing them back either.

If the crossover set is much higher than you know the speakers can reproduce, you may want to repeat the setup routine paying attention to mic placement. If they still come up short, think about aiming the speakers with the woofers pointing at the main listening positions.

Equalisation Curve

The equaliser on Yamaha receivers can be set to the following:

  • FLAT: this is the default. You should set this if you listen to a lot of TV, not just movies or you listen below reference level (around -17 volume on Yamaha receivers, 0 volume on THX and Audyssey enabled receivers) and your room has lots of soft furnishings.
  • NATURAL: this is the old CinemaEQ curve. It tames the high end to make sure that movie soundtracks don’t sound too bright if you have a normal living room with lots of hard surfaces like floors and walls without carpet or other soft coverings. Also use this if you are listening to movies LOUD as otherwise even without hard surfaces, just being much closer to the speakers than in the cinema will elevate the high frequencies beyond what was intended. Please note that some DVDs and Blu Rays had EQ applied during mastering to lower the high frequencies for playback in the home. If a movie sounds too muffled with this, you have two options: up the treble 2dB which may work or switch to the flat curve.
  • FRONT: this leaves your front left and right speakers alone and will timbre match all the other speakers to them. Unless you like how your front speakers sound because they are some ultra-expensive supersonic beasts, do not set this. Leave this alone. This is there to please a special few who spent $50K+ on their front two speakers.
  • THROUGH: no EQ is applied. Why would you do this unless you sit inside an anaphoric chamber? Seriously! Don’t!

Other settings

  1. Adaptive DSP should be switched on. It variates the DSP strength based on volume.
  2. Adaptive DRC (Dynamic Range Control) should be switched on if you’re listening at lower volume levels (below -25). Anything above -25 I would recommend switching it off as it can introduce a harshness to certain sounds on any receiver without YPAO Volume.
  3. YPAO Volume should be switched on. I am going to do a review of it in June 2017, at which point I’ll make further recommendations and check if it needs to be switched off for reference listening (anything above -25 really).

Surround and Surround Back Speakers Volume Levels

The only major issue I see with Yamaha receivers – or most receivers that don’t have Audyssey – is that they don’t variate surround speaker volume levels dependent on volume. When listening to surround programs at lower volume levels, the surround and surround back speaker volumes might need to be increased in certain setups to maintain the same surround envelopment. I have heard different views on this but it seems to me like those that have their surround speakers at ear height seem to have less trouble with this than those who have them somewhat higher than ear height or further away than the front speakers.

I believe both Audyssey and Dolby researched this and found it to be true, however. I find the same when listening in my home cinema where the surround speakers are somewhat higher than my front speakers while my presence speakers are on a third plane altogether near the ceilings. I normally increase surround and surround back channels by 1-2 dB dependent on how loud someone is listening to the system in general. You could even design a reference setting and a low volume setting turning this and other features on and off. On Yamaha you can do this using something called “Scenes”.

Give me feedback in the comments below and let me know how you go! Happy Listening!

UHD 4K Blu Ray – a year on

Reflecting on UHD Blu Ray as a format a year after its introduction…

Any video disc standard of past has taken time to shine. Both DVD and Blu Ray in fact took a year to start producing content that was better than the previous standards – VHS and DVD respectively. I remember the first round of Blu Ray discs: barely better than DVDs when the DVDs were played on top of the range hardware having the best chips for cleaning, filtering and sharpening the image. What I have seen with UHD Blu Ray is déjà vu all over again.

UHD Blu Ray – the Theoretical Benefits

There are three major benefits of the new UHD standard that should theoretically overshoot Blu Ray by a large margin:

  1. 4K Resolution: 4x the pixel density of Blu Ray resulting in a much sharper image.
  2. Wide Colour Gamut (BT.2020): a much wider range of colours that can be displayed on screen resulting in more realistic colours when used correctly.
  3. High Dynamic Range (HDR): giving the image more contrast, more depth, and a much higher range of brightness variations depending on the display the disc is played on. The brightness variation is not only in the highlights – for those in the know – as that is only the recommendation for use. However, HDR is already being used in more creative ways.

The Reality Today

Unfortunately, a year on we are still waiting to be amazed by the new standard and here is why:

  1. Standard Blu Ray is a very mature technology. In fact, the video compression technology (AVC or H.264) for standard Blu Ray has had more than 10 years to mature to ensure image quality, integrity and sharpness are at their optimum. The compression technology for UHD Blu Ray (HEVC or H.265) on the other hand is still in its infancy by comparison. It has not reached the same level of efficiency in its ability to keep all the detail in the picture as AVC has, nowhere near in fact. [note: HEVC is more efficient than AVC but comparatively looking at its own life-cycle it isn’t at the same maturity!] There is a lot more to come from HEVC in the coming years. However, we are now at a point where HEVC is starting to shine.
  2. The Blu Ray players, upscaling chips and upscaling technologies we have for standard Blu Ray have also had 10 years to mature and have they matured alright! We have image enhancement technologies using contrast enhancement (Darbee) as well as Super Resolution algorithms (e.g. JVC’s Eshift, Sony’s Reality Creation) that when used together easily rival UHD 4K images by analysing information on pixel by pixel and frame by frame basis to fill in the missing pixels.
  3. The data-rate used for the first round of UHD Blu Rays is still only at just above standard Blu Ray levels. This is because only the 50GB and 66GB UHD Blu Rays have been efficient enough to manufacture. The promised 100GB discs are not yet standard. This is a huge drawback.
  4. The compression (or authoring) software used to make UHD Blu Rays is nowhere near as mature as it is for Blu Ray. This means compressionists have had less control over where bits are allocated for the most optimal picture quality for these first year discs.
  5. However, even if they used the new 100GB discs, the images wouldn’t be sharper. In fact, around 95% of movies released on UHD Blu Ray in the first year were sourced from 2K masters upscaled to 4K as opposed to proper 4K images. This is partly because most films – especially that need heavy CGI – upto now have been finished at 2K resolution. To go back and re-do the CGI at 4K would be very costly. However, the trend is now changing due to the 4K push.
  6. Even if a movie is finished at 4K, we know from working with standard 1080p Blu Ray that the best examples of the format are those discs that have been sourced from imagery 4x the resolution: in this case 4K. This is because there is more information to work with when cleaning up the picture for digital storage. Also, more high-frequency information – and therefore finer detail – can be captured by downscaling an image from a higher resolution digital source. So it stands to conclude that the best UHD discs will come from digital intermediates (DIs) that are at least 6K or higher resolution. In fact this is what we see as the best examples of the format. More on that in a moment.

If the difficulty of getting the imagery captured, prepared and compressed wasn’t enough, there are a few design and few teething issues with the format as well:

  1. HDR as designed for UHD Blu Ray only takes into consideration flat panel TVs and not projection. This is an oversight of massive proportions. It isn’t even that the cinema HDR standard wasn’t ready, as Dolby Vision (one of the HDR standards) is used for Cinema HDR in the US. Even Dolby didn’t push for this to be in the standard, as Dolby Vision for UHD Blu Ray and in the cinema are two different standards. Having said that, a year on we have ways to calibrate projectors that emulate Dolby Vision or HDR10 (the most commonly used HDR standard), but it is not fully accurate to what the director intended. In fact, we have no way of getting fully accurate imagery for projection for HDR at this point.
  2. HDR10, the most commonly used standard, has had no dynamic meta-data until recently. Dynamic meta-data is required for HDR as the mastering displays that UHD Blu Rays are created on have vastly different performance characteristics than our TVs and projectors in the home. Our TVs and projectors have a fraction of the colour palette or brightness to play with when displaying the images, therefore we need a way to tell the display how to interpret the data to be accurate to what the director intended. Dolby Vision has this information but HDR10 is now catching up, slowly.
  3. The Wide Colour Gamut should be something that allows a more accurate representation of what we see in the cinema. The cinema standard colour gamut, DCI P3, fits into the colour gamut of UHD Blu Ray (Bt.2020). However, instead what has been happening in some cases is movie studios thinking they should differentiate the UHD Blu Rays by “turning colour up to 10” and using a palette that at times does not look natural, or faithful to the cinema presentation. They do this to give you more of a “thrill”, however, this is where immaturity of using the format shows. It destroys the original creative intent.

The Future Starts Now

I believe the future is here. We are now starting to see UHD Blu Rays that are in fact bettering Blu Rays by a wide margin due to some of the above issues having been addressed. I will mention two that have just come out, almost exactly a year after launching the first round of UHD Blu Rays:

  1. Planet Earth II: this BBC series was captured at mostly 6K resolution using some of the best cameras and downscaled to UHD Blu Ray. It really shows what the format can do today.
  2. Passengers (2016): this heart-warming Sci Fi was also captured at over 6K resolution and downscaled for capture onto UHD Blu Ray. What’s more, the movie’s colour palette is faithful to the original cinema presentation. This is how UHD Blu Ray should be done, ladies and gentlemen. The presentation is a nice cut above Blu Ray.

What’s Next for the Format?

As we have seen with Blu Ray and with DVD before it, UHD Blu Ray is just coming into its teenage years. The format still has a lot of road to travel and we can expect the following as it matures:

  1. Compression technology, HEVC, will improve further over the next couple of years to be more efficient and also to produce sharper and more nuanced images.
  2. Authoring software will improve to provide optimal bitrate to the right places in the bitstream.
  3. 100GB discs will become the norm providing almost twice the bitrate of today’s disks.
  4. Image enhancement technologies such as Darbee and Super Resolution algorithms will be adopted for 4K images, bringing out even more detail in the picture.
  5. The majority of movies will be scanned and then finished at 6K and even 8K resolutions, providing the best starting point for retaining high-frequency detail and therefore image sharpness.
  6. HDR technology will continue to mature both in its implementation and in its use by movie studios.
  7. Movie studios will stop playing with Wide Colour Gamut as a new toy and will respect the creative intent and integrity of the original works.

So in conclusion, we haven’t yet seen the best this format will be able to do. The format has a lot of headroom to improve – in fact more than previous technologies – and we will see some phenomenal picture quality from this format over time.

Yamaha YPAO R.S.C – Take Two

Introduction

In a previous blog post, I introduced YPAO R.S.C. (Reflection Sound Control), which is Yamaha’s room equalisation system. If you’re new to room equalisation, please read this post first. I will present some measurements below to show what R.S.C. is doing exactly.

Function of R.S.C.

According to Yamaha, the pure function of R.S.C. is to remove unwanted first order reflections from the sound. This should improve stereo imaging and intelligibility. As we will see there are other added benefits.

R.S.C. filters are applied before any Parametric Equalisation. In fact, all further measurements were taken using the following method on an RX-V3073 (the equivalent of the RX-A3020.

  1. Running a multi-position YPAO with all 8 speaker positions.
  2. Copying the flat curve over to the manual curve. This also copies the R.S.C filters as we will later see.
  3. Zeroing out the PEQ filters manually (to 0dB on all) as this will keep the R.S.C. filters but remove any parametric equalisation. This has also been confirmed by Yamaha Japan – and the measurements that follow.

Measurements

YPAO succeeds in its goals – with some speakers and seating positions better than with others. I will show an example below with a centre speaker measurement. The centre speaker is located underneath a tensioned screen. The speaker is tilted upwards towards the listening positions. However, because of the room dimensions and multiple hard surfaces between the speaker and the listening positions on the sofa, the 70Hz to 250Hz region is a real issue with room modes – peaks and dips galore – that reduce intelligibility and are hard to deal with using PEQ alone.

Frequency Sweep

The below frequency sweep has 1/6 octave smoothing so all that is visible that R.S.C. cut some reflections in the 60Hz to 200Hz region. The green line was measured in the “through” position, while the pink line in the manual setting with no PEQs applied. Please note that R.S.C. is applying some attenuation to the signal output. The attenuation is dependent on the filters applied by the system, so it varies from channel to channel. The graph below has been adjusted to take this into consideration.

It is interesting to note that there is some activity going on above the modal region (above 250Hz). This isn’t necessarily bad as long as the robustness of the correction is taken into consideration. For example, Dirac Live does this across the whole spectrum also, but the higher frequencies are corrected, the more correlation needs to be between samples.

center rsc v no

Now let’s have a look at the modal region with less smoothing to see what’s really going on there. Now this is more interesting. R.S.C. actually dealt with a dip in the 70Hz to 80Hz region, where the subwoofer crosses over to the centre speaker and removed some frequency build-up because of the back and side walls between the 80Hz to 200Hz.

center rsc v no v2

So what is actually going on in the 70Hz to 80Hz region? Obviously no PEQ filter would be able to fill that region in since waves are cancelling each other out – as that has been tried before on this set-up. Let’s have a look at what is going on in the phase of the signal to answer that question.

Phase Measurements

As can be seen in the below measurement without any R.S.C. filters applied, there is a phase shift in the crossover region. This is quite common.

center phase no eq

As can be seen in the below measurement with R.S.C. applied, the subwoofer and centre speaker phase are better aligned in the crossover region, therefore removing the dip in the frequency measurement. So far so good.

center phase rsc

Ringing

Finally, let’s look at the spectrogram to see whether ringing has been improved. To be honest, ringing wasn’t much of an issue for this speaker / seating position. But as we can see in the after diagram, the crossover region looks a lot smoother and overall sound pressure levels have been better equalised in the modal region.

center spect no eq

center spect rsc

Subjective Listening Tests

After the above measurements were made, the PEQ filters got re-applied that smoothed the frequency response out, now having a much easier job of doing so.

Having the same PEQ applied over R.S.C. and no R.S.C. filters, though not a perfect test, the sound with R.S.C. filters applied just seemed more 3 dimensional with a better stereo image from the front and surround channel pairs. The sound of the centre channel is also improved in terms of smoothness.

What’s also clear is that the bass region is improved in terms of tightness. Even though amplitude was corrected with PEQ filters, the bass still sounded boomy in some listening positions without R.S.C. applied.

Tips and Tricks

The above does pose a challenge for those that like to have the Yamaha presence channels going along with the base 5.1 or 7.1 set-up and want to do a “full manual” configuration with R.S.C. applied. How do you measure the frequency response of these speakers after R.S.C. has been applied? Here’s a neat trick:

The easiest is to feed the left, right or surround left and right speakers with the frequency sweep signal while having the receiver in 9 channel / 11 channel stereo mode.

To hear the signal only come through the corresponding presence speaker, configure the 9 channel stereo to maximum high balance, maximum strength and maximum front / rare – left / right balance as needed. This will channel around 80% of the energy through the measured speaker, which is good enough to get an accurate measurement.

Happy Listening!

The Home Cinema PC – Simply!

Introduction

I love packaged media such as DVD – in the old days – and now Blu Ray. Packaged media will always have the upper hand when it comes to quality of picture and sound so let’s hope it’s here to stay. Nevertheless, there are so many of us who download TV shows or even want to have easy access to a library of movies without having to lift our back sides off that comfortable couch.

Since this problem is not new, many options are now available to do just what we want from Microsoft Media Centre PCs and appliances to games consoles like the Xbox One. In the following pages, I will show you my favourite solution that delivers the best balance of usability, features and quality.

XBMC – now Kodi

The-new-home-screen-of-XBMC-OpenELEC

XBMC – or Kodi by its new name – is an open source, free application that anyone can download from the net. It has been around for years and it is my favourite choice for the following reasons:

  1. The audio and video quality when using an HDMI connection is excellent, regardless of the platform used: from Windows to Apple OS X to Linux.
  2. It is fully configurable to how you want it.
  3. It integrates with online movie and TV databases and downloads art, trailers and everything in between to store locally in your media library.
  4. It just works.

Choosing the hardware

having A dedicated PC

After much research, I chose to use an Intel NUC. Intel NUCs are small – actually tiny – form factor PCs that come with a processor, but not RAM. You will need to buy that separately. What is great about them is that they are cheap, don’t require a lot of effort to build, look great and have all the connections you need – including an infrared sensor for your remote.

If you’re only after 1080p (full HD) playback, any of the NUCs will do, even the celeron based ones. If you have a new 4K TV and want to future-proof your media playback device, you should buy one of the top performing NUCs as 4K is very CPU intensive: it uses a new codec (HEVC) that cannot be hardware decoded on current graphics processors.

414033-intel-nuc-kit-d54250wyk

Now you may find other off the shelf PCs for a similar price, so do have a look around.

The other option – if you’re adventurous, don’t have a lot of money and want to build your own PC – is to use a Raspberry Pi. There are many guides on how to build one on the Internet. Google is your friend!

openelec – turn your pc into an appliance

If you’re using a dedicated PC for your home cinema and you want to use XBMC, there is no better option than Openelec. Openelec is a stripped down Linux distribution that boots straight into XBMC without any other hassles. While you could make Windows or Linux boot straight into the desktop and then open XBMC, Openelec starts up faster, is more stable and can be upgraded with a remote control. The same cannot be said for Windows, but especially Linux. Plus with Openelec you remove all the added distraction that Windows brings with itself.

There are also many guides on the net on how to install Openelec so we won’t go into that here. Again, Google is your friend!

Installing xbmc / kodi on your current computer or other device

It is also possible to install XBMC on your current Windows, Apple or Linux computer and even on the Apple TV and android device. It is great to do this to try our XBMC and see if you like it first. You simply download the relevant installed from the Internet and off you go.

Choosing a remote control

Pretty much any remote control that’s been built for Microsoft Media Centre will work. The one pictured below can be had for as little as AU$15 on Ebay and has been tested to work. In fact I use one of these in my Home Cinema.

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Configuring XBMC / Kodi

audio / video configuration

To get the most out of XBMC, pay extra attention to the following configuration aspects under settings. You may need to switch the settings pane to “Expert” to get access to some of the settings.

  1. For maximum picture quality, XBMC allows you to match the refresh rate of your display to your video OR match the refresh rate of your video to your display by speeding it up or down as necessary. These settings are under System –> Video and should be enabled. One or the other should work on all systems.
  2. For maximum sound quality, especially if you’re using an external receiver or amp that has Dolby D and DTS decoding, set the audio to bitstream in settings and tick which formats your receiver supports. These settings are under System –> audio.

VideoPlaybacksettings_1

LIBRARY CONFIGURATION

It is best to store files on a NAS – such as a QNAP – or alternatively using external HDDs. Whatever the case, XBMC allows you to add new folders to your library under the file menu for movies and TV shows.

Once you have added the folders, XBMC will ask you what the folder contains and what (online or local) service to use to download movie / TV show information and art.

SPICE IT UP – SKINS

XBMC comes with a default skin called Confluence. It is functional. But XBMC can do a whole lot more. You can download and install new skins within XBMC or by downloading them from the Internet. One of my favourite is Aeon MQ (3/4/5 or 6). The skin is highly configurable and very functional and pretty.

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I hope that wetted your appetite for building an easy to use media playback device easily and cheaply. Enjoy!

Uncompressed Sound and Video are NOT Better than Compressed

The Marketing Machine

Everyone was rejoicing when Blu Ray’s standard allowed manufacturers to include uncompressed sound on disks. Most certainly Blu Ray’s provide much improved sound but did you know that even DVDs allowed sound with more precision than some of today’s Blu Ray’s have? Let me explain…

Perceptual Coding

Perceptual coding in terms of audio and video means removal of information that cannot be perceived or distinguished by the human visual or auditory systems (your eyes and your ears). In even simpler terms, it is removal of stuff that you would not actually notice if it was removed. Why is this important? Well, it allows us to cram a 3 hour movie on a disk at a quality that would normally take about 25 Blu Ray disks.

If you have limited space or bandwidth, perceptual coding is ALWAYS going to give you better quality than lossless / uncompressed data. This is true for both video and audio. For example, if we were to take the data rate of uncompressed audio on Blu Ray today and we were to use perceptual coding using the same bitrate, we would be able to allocate more bits and more precision to data that we can actually perceive which would give higher perceived quality. In the same space, we could have movie soundtracks running at 96Khz sampling rate (96 samples a second) and 32bit precision of the individual samples, which would give audio a completely lifelike sound.

The Reality of Movie Soundtracks

Unfortunately, when it comes to movie soundtracks – unlike music – very few have been recorded and mixed at the higher sampling rate. This means that uncompressed sound at the current sampling rate (48Khz) and bit precision (16 to 24bits) is as good as it gets until studios decide otherwise. But it is good to know nevertheless that you don’t necessarily want lossless coding, especially when you have limited bandwidth. Lossy coding – if done correctly – will give better sound and picture at the same bandwidth.

While We Wait

While we wait, there are ways that sound can be much improved in a Home Cinema. I will be talking about these in the coming weeks.

How to connect up your new Home Cinema Receiver?

3 easy steps

You will need to follow 3 easy steps after you have unboxed and placed the receiver in your AV rack or other well-ventillated area of your home cinema.

  1. Connect your speaker wires
  2. Connect your audio cables
  3. Connect your video cables including monitor out

Only then should you plug the receiver into the wall and switch it on. Let’s go through these steps in detail.

Connecting your speakers

Luckly, we have a guide for you that describes this in detail. Please head over there now.

Connecting Audio Cables

Audio cables come in the following forms:

  1. HDMI cables carry both audio and video signals. In this case, the HDMI cable is the only one you need to use. All Blu Ray players use this type of connection. OLYMPUS DIGITAL CAMERA
  2. Older DVD players, audio players and even some more recent set-top boxes may use optical digital output (called toslink) to connect devices. Toslink can carry 2 channel PCM or compressed multi-channel audio such as Dolby Digital and DTS Surround Sound.toslink-stecker
  3. Even older DVD and Laserdisc players used digital coaxial audio cables to carry digital audio (2 channel PCM, Dolby Digital and DTS audio).10140546
  4. Two channel analogue RCA connections are used on some devices as a primary or secondary audio output. This is also true of high-end audio players which will include expensive digital to analogue converters.xbox-hdmi-audio7
  5. Some high-end Blu ray, SACD and DVD-Audio players use multichannel analogue RCA connections to connect to the multi-channel analogue input on your medium to high end receiver. Lower-end devices will not have such outputs.120724-Multichannel

Is it better to connect digital or analogue cables? Well, that depends on your equipment. In most cases digital audio will deliver the best quality because most receiver’s advanced DSP circuitry for correcting room response (see this article) only engages with a digital connection. On the other hand, some very high-end audio players will include a lot better digital to analogue converters which will deliver a smoother and more detailed sound. You may find, though, that you prefer a room-corrected response more. I would suggest trying both and seeing which sounds better.

Connecting video cables

Video cables also come in digital and analogue varieties. We will list them below from highest to lowest quality:

  1. HDMI: this is the gold standard. Connect this when available!OLYMPUS DIGITAL CAMERA
  2. Component: this connection type requires 3 RCA cables and they are normally colour-coded red, green and blue. Component can carry high-definition video like HDMI.Component-cables
  3. S-Video: this type of connector was only popular in Europe and was mainly used for S-VHS tape recorders and some other video equipment. It is no longer popular.Svideo
  4. Composite: this can be found as a fall back on some TVs and video players as well as popular on camcorders for a quick playback. It appears as a single yellow RCA connection labelled “video”.SONY DSC

Others:

  1. VGA: can be found on computer monitors. This is compatible with component, you just need a converter.750px-Vga-cable
  2. (Mini) Display port: can be found on some computers including those from apple. This is compatible with HDMI, you just need an adapter.100167

Power Up

Now you are ready to plug the receiver into the power, switch it on and configure it on your monitor display according to the manual.