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!

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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.

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.

170156-hp-pavilion-media-center-tv-m8100y-pc-remote

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!

What is Room Equalisation (EQ) and why should you care?

The Perfect Loudspeaker

Loudspeaker design nowadays is advanced to a point where loudspeakers have a pretty much flat frequency response between 20Hz to 20Khz, which are the lower and upper boundary of human hearing. In an ideal home cinema, the main speakers reproduce frequencies from 80Hz up while the subwoofer is reproducing frequencies from 80Hz down (in simplified terms). Sounds below 80Hz cannot be localised by human hearing (that is you cannot tell where the sound originated from) and because of the complexities of sound waves interacting below 80Hz in small rooms, it is best to have only one (or more) carefully placed subwoofers reproducing these lower frequencies.

Here Comes the Room

It’s great we have such advanced loudspeaker design, but once you put the speakers into a room, things get messy. The sound waves will reflect off the surfaces of the walls and furnishings and interact to create drips and peaks in the frequency response, making some frequencies louder, others quieter and yet others to echo and ring as they decay.

vergleich-absorberExample of frequency response of a loudspeaker in a room

What is even more upsetting is that this is not uniform in the room. As you move your head, sit somewhere else or walk around, the dips and peaks change. If you have just spent 100’s or 1000’s on speakers, the situation is rather unacceptable. You obviously want to get the most out of your equipment.

EQ to the Rescue

There are two main ways to combat the above: digitally using equalisation and with acoustic treatments. The former is somewhat easier to implement and a lot more wife (or for our lady enthusiasts, husband) friendly.

Digital Room Equalisation is built into most receivers nowadays. Some are more effective than others. Let’s have a look at some of what is currently on the market:

Audyssey MultiEQ XT and MultiEQ XT32: Audyssey’s technology deals with the most problematic frequencies below 200Hz very well, especially when it comes to MultiEQ XT32. At the same time, higher frequencies may not sound natural to some listeners. Some manufacturers (such as Denon) allow you to apply it to only the bass frequencies for this reason. MultiEQ XT32 was also available in standalone products as SVS AS-EQ1 and Audyssey’s own branded subwoofer equalisers. They have been discontinued, however. It’s worth picking up a used one if you have a receiver that lacks a good subwoofer equaliser.

Yamaha YPAO and YPAO R.S.C: Yamaha YPAO and YPAO R.S.C are discussed in detail here. They both do a great job with frequencies above 80Hz. Fortunately, the implementation in most recent Yamaha receivers is fully editable using Parametric EQ, which gives you enough resolution to tackle most issues. The only exception to this is ringing of the modal frequencies (see below), which is important for subjective sound quality.

Parametric EQ solutions: a fully parametric EQ solution, such as the ones from MiniDSP, allow you to target the modal frequencies in the room precisely, therefore allowing the reduction of ringing / echoing of sound in the lower frequencies. A good parametric EQ is therefore essential for frequencies below 80Hz and good to have below 200Hz.  Neither Audyssey or YPAO tackle ringing at these problematic frequencies.

Dirac Live: Dirac is at the forefront of audio equalisation research and seem to be overtaking even Audyssey. Their impulse response correction algorithms seem to be gathering great reviews. More recently, they are also available in MiniDSP NanoAVR DL product, which makes it affordable. It is also very easy to use for those with not a lot of experience in equalisation, but who want to get the most out of their equipment. The highest end home cinema kits feature Dirac Live.

How to EQ?

If you’re new to home cinema, at the very least read your receiver’s manual and run the automatic calibration routine with all its feature set. If you’re more adventurous, you can supplement your system with a fully configurable parametric EQ for your subwoofer to tackle the modal frequencies in your room. For this, you will need:

  1. A parametric EQ connected between your receiver and your subwoofer
  2. The free Room EQ Wizard (REW) software from HomeTheatreShack.com.
  3. A compatible USB microphone.

To know more about how to measure your room and configure a Parametric EQ, the MiniDSP or HomeTheatreShack websites offers some good guides, but in essence you will have to:

  1. Install all the software
  2. Measure the room response (in this case for the subwoofer)
  3. Calculate the EQ filters automatically or manually in REW
  4. Input the filters into your choice of EQ
  5. Re-measure the altered frequency response
  6. Repeat until you get satisfactory results

Modal Frequencies and What to Do with Them

Modal frequencies in effect are frequencies excited or affected by the size of a room. The modal region is the region below which modal excitation happens. This is normally somewhere below 250Hz for medium to large home cinema rooms. What happens in the modal region is that certain frequencies – very accurately predicted by room dimensions – will combine and re-enforce each other or cancel each other out in a way that creates big differences in loudness and decay time of the frequency. This will make the rest of the frequency spectrum – especially frequencies close to the mode – smeared, masking detail and transparency of the sound reproduction. To resolve this, the modes need to be calculated and measured using REW using the Room Simulation module, then checked using a frequency sweep and waterfall diagram. Once the offending frequencies are found, Parametric EQ filters need to be designed to EXACTLY match the mode’s frequency and Q to rob the mode of its energy. This will help reduce decay time also and make the waterfall diagram more even.

waterfall - beforeWaterfall plot showing increased decay time in the modal region. The most offending modal frequencies are clearly visible at 29.6Hz and 71Hz. Interestingly, speech intelligibility is affected by a modal at 83Hz, even though it is not as visible on the diagram.

We have really only touched on some basic concepts when it comes to equalisation. Nevertheless, the topic deserves the attention of anyone serious about home cinema. Learn it or get a friend or consultant who has the knowledge. It makes more of a difference to the perceived sound quality than your choice of speakers or amplifier. This is because the tonal quality that you like in your speakers is a lot to do with the above graphs. Even cheaper speakers can sound fantastic with the right equalisation and a good quality subwoofer.

How to build a $300 screen that performs like a $2000 one

Now you can order pre-mixed paint from us. Please contact us for more.

The difference a screen makes

You can project onto a white wall and get a really great picture, but if you’ve spent more than $500 on a projector, you will notice a marked difference with a purpose built screen. The benefits of projecting onto a great screen include the following:

  1. Increased sharpness / perceived resolution of the image
  2. Increased contrast
  3. Better ambient light rejection (when using a grey or silver screen as below) which means you can watch TV, movies or Sports with some ambient light on without completely distorting contrast

Enter Projection Paint

There are some – may I say – rather expensive paints on the market that you can use to build a DIY screen. In this article, I will show you how to get the materials yourself, mix the paint, paint the screen and hang it.

Please note that this is a fixed frame projection screen, which means it is not really possible to paint a roll-up screen with the below method.

Getting the screen

There are a few options on where to paint the screen.

  1. If you have the wall-space you can paint the screen on the wall with a black frame or even paint the whole wall with the paint mix below to create an invisible screen… until the projector is turned on that is.
  2. If you cannot paint the wall, you have the option of getting an MDF sheet to paint or even better…
  3. Paint on 3-5mm foamex / forex PVC sheets. These sheets are really light and easy to work with. You can nail them to a wooden frame for hanging or even nail them to the back of some bookshelves.
  4. Any other rigid material that is paintable.

imagesForex Sheet

You can calculate the screen size you need at http://www.projectorcentral.com/projection-calculator-pro.cfm and get the materials cut to size, leaving enough outer rims for nailing and hanging.

Getting the paint

The paint mix is called Black Widow. I will show you how to mix and variate the colour shade of this paint mix to get the desired results. For now, let’s look at the base, no frills mix, for which you will need the following:

  1. A matt white water based paint. Any will do such as the Dulux Wash and Wear Matt white. The most important thing is that it is water based and matt. 2L is plenty for upto 140″ screen.
  2. You will need to ask the paint to be tinted using black paint to a grey to a shade of N7.8. If this is not possible an N8 will provide the right shade of grey also. If your trade centre doesn’t know how to tint paint using the N tint codes, ask them to call Dulux or a Dulux Trade Centre.
  3. You will need Auto-Air Colors 4101-16 Aluminum Base Fine paint, which is a water-based silver paint formula. You will need 4 parts white paint to 1 part Auto Air Colors. If you’re using 2L of white paint, this will mean 480ML of Auto Air Colors. Be sure to buy the “fine” coarseness.
  4. A short nap roller
  5. Fine sandpaper

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Auto Air Colors

You will mix the above together using a drill and paint mixer head for 2-4 minutes

Painting the screen

  1. Using the paint mix, you will paint the surface with the roller in one direction only (vertical or horizontal) using quick movements. Go over it once quickly.
  2. Do NOT go over the surface again until it has dried.
  3. Once the first layer has dried, use the fine sandpaper to remove any imperfections from the surface.
  4. Remove any dust created by the sanding using a duster or a dry cloth.
  5. Repeat until you have at least 4-6 coats and a smooth even surface.
  6. Let the screen dry out completely before using it.
  7. Enjoy!

Variations on the above mix

The mix above comes out to a light to medium grey that is perfect for rooms with light coloured walls and bright projectors. It rejects ambient light well and has great contrast characteristics with the lights off as it rejects reflection from the light coloured walls.

If however, you are building a dedicated home cinema room with dark or black walls and you don’t intend on using the projector in ambient light, and you have a projector with great contrast (such as a JVC), you will want to mix a slightly lighter mix.

For a lighter mix, simply tint the white paint closer to N8.5, N9 or even N9.5. For 3D projection, which needs a lot of light, you could even try mixing with only a white base, as opposed to grey.

Recreating the cinema experience: Yamaha’s Cinema DSP

Cinema versus Home

Movies are designed for the big screen and movie soundtracks for the big auditoriums of cinema multiplexes. When played back through a home cinema system in a smaller room, the perceived tonal balance of the soundtrack changes.

Tonal Balance: in simple terms, it is the amount of perceived bass, mid-range and treble present in a soundtrack.

All modern receivers have a way to combat this through equalisation of the speakers / room and filtering of the high frequencies which removes the perceived treble push of smaller, undampened spaces like your living room. However, you may notice that even after such equalisation, something is missing no matter how loud you play your equipment. This is because the big cinema auditoriums have different reflection and reverberation of the sound as it bounces around the room than in a smaller room.

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This is what Yamaha went on to solve using their expertise in musical instruments and sound recording. Enter Yamaha Cinema Digital Soundfield Processing (DSP),

Yamaha Cinema DSP

Yamaha knew about this issue before all other manufacturers and they went onto recording and analysing the real-world behaviour of sound in cinema (and other) spaces. The extensive amount of data collected allowed them to digitally recreate the spaces using digital signal processing and in 1985 they released the Yamaha DSP-1, a standalone processor that could re-create cinema soundtracks as if they were being played back in a cinema.

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Fast-forward almost 30 years and Yamaha’s Cinema DSP is in all Yamaha Home Cinema Receivers and have advanced to a point where it requires serious attention from anyone interested in home cinema.

What you need

You will need

  1. A recent Yamaha Surround Receiver with at least 7.1 channel capability. Although Yamaha’s lower end units can do virtual Cinema DSP through a 5.1 set-up, it is not nearly as effective as having separate speakers.
  2. An additional two speakers that will be used for the Front Presence speakers. They can have lower power handling and efficiency than your main speakers. Small bookshelves or satellite speakers will do with a frequency response from 100Hz to 20Khz.
  3. More wires

Speaker Configurations

In essence, Yamaha’s Cinema DSP reproduces the reflections and reverberations of the cinema spaces through 2 height speakers at the front called Front Presence Speakers. Although you can use the front left and right speakers to reproduce the soundfield (called Virtual Cinema DSP), it produces a muddy and indistinct sound and does not compare well to the real set-up.

Yamaha’s more advanced Cinema DSP called Cinema DSP HD3 uses an additional set of speakers for the back soundfield called Rear Presence Speakers. When using DSP HD3, the Front Presence Speakers are more important to install than the Back Presence Speakers. Please see the full configuration below:

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Cinema DSP 3D and Cinema DSP HD3

Cinema DSP 3D only has the capability to use Front Presence Speakers. Yamaha’s lower and mid-range receivers have this version. The rear soundfield data is mixed into the surround speakers. For this reason, it works better if the surround speakers are not at ear height but at least half a meter or more above the listening plane.

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Receivers of this class are capable of 7.1 or 9.1 channel output. For 7.1 channel receivers, the back surrounds will not output sound when the Front Presence Speakers are being used by Cinema DSP. The 9.1 channel receivers have the capability to power all 9.1 speakers at the same time.

Cinema DSP HD3 improves on 3D with two things:

  1. An additional two channels at the back (Rear Presence Speakers) that only reproduce the CinemaDSP effects for additional clarity. This expands the speaker configuration to 11.1.
  2. Double the processing power to calculate more precise soundfield data both in the frequency and the time domain. For example, this means that sound reflections are tracked in space for double the time than with DSP 3D providing even more clarity.

From Adventure to Sci Fi

When Cinema DSP is configured well, you will experience your walls literally melting away and your home cinema opening up to sounding like a big movie theatre. To configure it, do the following:

  1. Ensure that the Front Presence Speakers are placed wider and higher than your front left and right speakers.
  2. Run the YPAO automatic calibration even if you will not use the EQ function of your receiver. This is because higher end Yamaha receivers will adjust the Cinema DSP parameters dependent on the already existing acoustic characteristics of your room.
  3. Select a Cinema DSP program (called movie) on your Yamaha Receiver.

There are 6 movie soundfields on all modern Yamaha receivers. Read your Yamaha manual to understand the differences between them. As a guide:

  1. Select Sci Fi for any action or Sci Fi movie or where the soundtrack has lots of precisely steered effects.
  2. Select Drama for movies with lots of dialog or for TV programs.
  3. Select Adventure or Spectacle for older movies or movies with big musical scores.
  4. Mono movie for – you guessed it – mono movies.
  5. Select Standard when no other soundfield sounds right for the movie or when you want to leave the front soundstage intact.

In addition there are many parameters you can adjust for each soundfield to make it sound less or more spacious. It is rather difficult to configure these manually, so download the Yamaha iPhone and Android app to your phone that allows you to configure them easily.

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I recommend this even if you have an older receiver that doesn’t allow you to configure soundfield data using your phone. You can simply use the app in demo mode and copy in the parameters using your remote manually.

What about other manufacturers?

Even though other manufacturers have started using DSP soundfield programs, they don’t have the sophisticated algorithms Yamaha uses. Most simply add echo or reverb to the soundtracks to create some kind of effect as opposed to precisely measured soundfield data. I recommend auditioning the difference between them.

How to choose the right display?

There are so many brands, makes and types of displays on the market today that it is rather difficult to choose one for your living or home cinema room. In effect, there are 3 major things you need to look for when evaluating the quality of a display:

Black Level & Shadow Detail Performance

One of the most important aspect of perceived image quality is not resolution, as display manufacturers would like you to believe, but black level performance. A great proof of this is the switch from old CRT TVs with great black level to the then top of the range flat panel displays, which had rather poor black levels in comparison. Normal low-resolution TV broadcast looked better on the CRTs, while the new higher resolution flat panels needed specialised DVD players and trickery in signal processing to make images watchable.

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The difference between poor and great black level performance.

Black Level: how dark or deep the blacks look on the screen.

Because of how displays work, black level needs to be evaluated on dark as well as bright images and in moving from dark to bright images. The better the black level performance of the display, the more three-dimensional the images will look on the screen.

Shadow detail: how good a display is at resolving detail in darker areas (shadow) of the image.

If a display has dark inky blacks but it fails to resolve the subtle details in the darker areas of the image, the image will look flat especially on dark images or movie scenes. It is important that great black levels are married with great shadow detail performance to give a three-dimensional image regardless of the material.

Did you know that the brightness setting on your TV affects the black levels while the contrast setting affects the bright areas of the image? Just test the controls and notice what areas of the image change.

Brightness Performance

Even before resolution, how bright a display can go while maintaining its black levels contributes greatly to perceived image quality. The brighter the image can go, the more contrast your eyes will perceive – the contrast between the black and light areas of the image. The human eye will even perceive an image as higher-resolution simply because of the brightness of the image.

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In flat panel televisions, brightness is usually pretty average from display to display, but in projectors brightness plays an important part dependent on what kind of light control you have in a room.

In a normal living room with imperfect light control and light walls, projector brightness is more important than black level performance. While in a completely light-controlled room with black walls, black level performance becomes more important than brightness. Ideally you want a display that can do both.

For 3D performance, you will want high brightness again.

In flat panel displays, black level performance is more variable than brightness performance, therefore you should be paying more attention to that.

Resolution

There are three things under resolution you need to look our for.

Native Resolution

Native Resolution: the actual number of pixels available on the display.

Please refer to the diagram below regarding the type of resolutions currently available on displays.

resolutions-ultra-hd-4k-1080p-720p-dvdResolutions of modern displays

The amount of pixels you need to keep the image looking great depends on your viewing distance from the screen. As a guide, at the average viewing distance of 3 meters, you will notice the benefit of:

1080p / Full HD panel for any display above 30″ (display size is measured in inches diagonally).
4K for anything larger than 70″.

This means there is no actual benefit of buying a display with a resolution below those sizes at the distance of 3 meters for the average person.

Scaling Performance

Another area you need to look out for is how the display handles scaling.

Scaling: the transformation of an image from one resolution to another. For example, a DVD or TV image which has a maximum native resolution of 576p to 1080p.

Although most new material is now on Blu Ray and therefore 1080p natively, we still watch content on lower-resolution formats such as DVD and broadcast TV. The display needs to be tested regarding how well it handles this scaling. Some displays do this poorly but otherwise they perform well. In that case, you can still buy playback devices such as DVD players or set top boxes that do the scaling to the display’s native resolution to improve the image to bypass the internal scaling of the display.

Motion Handling / Motion Resolution

The last aspect of resolution is motion handling. It is also called “motion resolution”.

Motion Resolution: how well a display maintains image sharpness with moving images.

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Display manufacturers understand how important motion resolution is, so much so that they employ digital trickery  called frame interpolation – to reduce motion blur to keep image sharpness. You will want to turn any such trickery off and evaluate the display’s native ability to switch its pixels on and off using the same source device, such as Blu Ray player.

How to correctly evaluate a display?

This is the tricky part: as much as the above areas can highlight a display’s native performance, it is actually an interplay of the source device AND the display that will give you the end result. What does that mean? You need to evaluate the display’s ability using similar playback devices that you will be using at home, such as DVD players, Blu Ray players, TiVo, Gaming Consoles, etc.

Also, you need to set these devices up correctly to get the best performance out of the display: settings such as output resolution, output frame-rate, colour system, etc.

Which display technology?

So which display technology excels at all areas? It turns out some do better in some areas than others and it depends on your preference and situation as to what’s going to serve you best. The best thing to do is look out for the three areas above and trust your own eyes.

Flat panels:

Normal LCD Displays:

  1. Great native resolution, brightness and colour reproduction
  2. Below average black levels
  3. Below average motion resolution

LED and OLED Displays:

  1. Great black levels
  2. Great brightness
  3. Great all-around resolution
  4. Motion-resolution dependent on manufacturer and product

Plasma Displays:

Yes, they are still around, although in small numbers.

  1. Great black level performance
  2. Good brightness
  3. Below average motion resolution

Projectors

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DLP Projectors

  1. Class-leading brightness performance and motion resolution
  2. Great Colour reproduction – especially for 3-chip varieties
  3. Black level and shadow detail performance depends on manufacturer and product – goes from average to class-leading.

Recommended for brighter home cinema rooms as the high brightness will create a better perceived contrast. Also recommended for high-frame-rate material such as sports and 3D.

LCD Projectors

  1. Generally challenged black levels and shadow detail performance, although some manufacturers are better than others.
  2. Great brightness and colour reproduction
  3. Good but not great motion resolution.

Recommended when DLP projector is not suitable for viewers because of the DLP Rainbow effect.

XSDR – IDLA – LCOS

  1. Class-leading black level and shadow detail performance bettering even the best cinemas in the World.
  2. Historically low brightness over their lifetime more suited for dark home cinema rooms
  3. Motion-resolution has considerably improved but DLP still betters it.

Recommended for dedicated, light controlled home cinema rooms. The best cinemas use this technology for 2D viewing. DLP is still better for 3D.