AVS Forum banner
Status
Not open for further replies.
1 - 20 of 82 Posts

·
Administrator
Joined
·
1,496 Posts
Discussion Starter · #1 · (Edited)
Light Chair Purple Entertainment Interior design


Hello AVS!

Welcome to the Ask Me Anything with Peter Aylett!

An integrator of over 30 years and now a partner at HTE Acoustic Interior Design, Peter currently chairs the CTA/CEDIA R10 Standards Committee as well as one of its workgroups currently re-writing best practice for entertainment space/cinema/theatre audio design.

If you have any questions concerning industry standards for designing and setting up home theaters, or want the perspective of an experienced engineer then Peter is your guy to ask for robust answers that are highly detailed and product-agnostic.

This thread is now open, and will run until Sunday, Nov. 28th! We can't guarantee that every question will be answered, but even if not, you'll still be seeing some interesting responses.

Looking forward to seeing your questions!

Welcome Peter!

All the best,
Dan
 

·
Registered
Joined
·
88 Posts
Why aren't manufacturers in this industry held to higher standards? There's no excuse for making TVs with only 1 full speed HDMI port in the 21st century. Yet, most manufacturers did it with HDMI 2.0, and now they're doing it again with 2.1. It's ridiculous.

Second. Why does the industry refuse to move on from IR remotes? Nobody offers BT or RF all these years even on premium models of HT equipment.
 

·
Administrator
, TBD, Ascendo Immersive SMG-15, Seymour Screen Excellence
Joined
·
585 Posts
Why aren't manufacturers in this industry held to higher standards? There's no excuse for making TVs with only 1 full speed HDMI port in the 21st century. Yet, most manufacturers did it with HDMI 2.0, and now they're doing it again with 2.1. It's ridiculous.

Second. Why does the industry refuse to move on from IR remotes? Nobody offers BT or RF all these years even on premium models of HT equipment.
You understand he is an Acoustics expert right? CEDIA standards for acoustics.
 

·
Registered
Joined
·
30 Posts
You understand he is an Acoustics expert right? CEDIA standards for acoustics.
No worries. I'll play!

1. Cost. In a REALLY competitive market, it costs manufacturers far more money to implement that latest tech as the silicon is more expensive. By the time that silicon cost comes through the supply chain, even $10 extra at retail can send a marketing department into a spin
2. 'Higher Standards' - Interesting phrase. As a professional, I will choose the equipment that best meeds the needs of my customer, and what I promised them. Generally, all my sources are connected to an AVR/processor so a single HDMI socket is enough! Different scenarios need different levels of functionality. Why pay for something you don't need...
3. We're beginning to see a shift towards RF remotes in all their different flavours. AppleTV, Amazon Fire TV Stick already use BT. Many TV remotes that use gyro motion sensing to move a cursor around the screen use RF remotes. Agin, it comes down to cost. IR is cheap, simple and zero config for most people.
 

·
Registered
Joined
·
65 Posts
From an acoustically point of view, in home cinemas that are normal rooms and not dedicated spaces, is it better to have a lot of stuff (like shelves with books, furniture, etc) or it's usually better to keep the room less crowded?

Does a room filled with stuff makes audio calibration tougher?
 

·
Registered
Joined
·
2 Posts
I have questions regarding construction of riser. I am trying to build a bass trap and have some questions. Room is The platform is 10'3" wide by 6 with a 2" landing. I am constructing it with 2x6 (10x8). On top I am running 2x8 for the 6' platform. I am either going with sandwich of roofing paper with 1/2 inch, or just 3/4 osb subfloor. Fill with pink or rockwool.???

The basement flooring is laminated flooring with moisture barrier underneath. I was planning on building the platform on top of a piece of carpet padding that I had laying around. Note back of riser goes to wall. It was a very quick sketch!

Ceiling is low (7'6") but need platform to be approx 14" up to see over front chair.
Not really clear by my "drawing" , but there will be an approx 2' landing behind front row as a step and path to riser chairs. That makes platform approx 10x8 (6x8 where top chairs will be located). Platform will overhang by 2" and will be carpeted.
Handwriting Rectangle Font Parallel Slope


Questions: Thank you in advance!

1- Does this build make sense? Should platform extend wider than 10 feet wide?
2- Where should bass trap vents go? How many vents and what size? I understand they should be back against wall and on side. However, platform is approx 2 feet from one side wall (and 4 feet on other side). So unsure about side locations.
3- Room is in basement and planning on using black,lined curtains on sides and to just next to screen. This will help cover the side alcove where a future snack bar may go. Not sure if will curtain the rear as there are 2 AC vents. If no curtains in rear would consider acoustical panels. However, don't use ac in basement too often and can open curtains to allow air prior to watching (or have cutouts made in the curtains. There is currently no door to room. May add a hidden bookcase door in future.
4- Should rear sub go on platform next to chair or on floor between platform and wall?
 

Attachments

·
ABSOLUTE ULTIMATE AV
Joined
·
6,286 Posts
Hello Peter,
First and foremost I want to say thank you for taking the time to do this and answer peoples questions and for all of your hard work regarding industry standards.

For the benefit of those who are not in the know please can you kindly explain what is the CTA/CEDIA R10 Standards Committee, and what is RP23, RP22, and RP1, why these matter, and how will these affect the home theater market moving forwards?
 

·
Registered
Joined
·
30 Posts
From an acoustically point of view, in home cinemas that are normal rooms and not dedicated spaces, is it better to have a lot of stuff (like shelves with books, furniture, etc) or it's usually better to keep the room less crowded?

Does a room filled with stuff makes audio calibration tougher?
Great question.

A reply detailing all the facets of the way speakers, rooms, stuff in rooms and listeners interact would take a year. Probably the most important aspect, and one that's quite straightforward to explain and measure is RdT - Reflection decay Time. You'll usually see this stated as 'RT60', and one of the great acoustics myths is that it is a single number. RdT is usually stated over an octave band (an octave being a doubling of frequency). The most common octave band to see it stated is 500Hz to 1KHz. The RT60 time is how long it takes for sound to decay by 60dB and is a measure of how reverberant a space is (an echo is a discrete sound, reverberation is a combination of all the decaying echos). Sound is absorbed by stuff to different degrees and dependent on frequency. High frequencies (Above 4KHz) are REALLY easy to absorb. Carpet and its underlay do an excellent job. Midrange frequencies (Around 400Hz to 4KHz) are easy to absorb at the top end of the frequency range getting increasingly harder as the frequency goes down. Bass (Below 400Hz) is REALLY hard to absorb.

The 'correct' RdT time is hotly debated. Around 0.3s to 0.35s is a good number to aim for without doing a complex calculation. Others may disagree (-:
The trick is to consider all frequencies, and to have your absorption as linear and even as possible across the audible frequency spectrum (With a pragmatic, but not massive allowable rise in the RdT below around 150Hz in most room sizes). So, use some inexpensive software, an inexpensive measurement microphone, and a free tone generator to measure the RdT time of your room from 62.5Hz up to 8KHz. That will then tell you where you are and what you may need to do next. The mistake most people make is to over absorb high frequencies (Using lots of 25mm / 1" Absorption material), but barely touch low frequencies. This ends up in a dead and boomy room -YUK!

The great Floyd Toole talks about 'The acoustical treatments of life' such as carpet, curtains, sofas, people, chairs, beanbags etc. You may well find that in a normally furnished room, you don't need much extra material at all to achieve good and linear RdT times at high/mid frequencies. At bass frequencies, however, you may need to do some work.

To answer your calibration question - A room with lots of broadband bass absorption is far easier to calibrate as the room mode and null extremes are flattened, thus leading to a far more even bass frequency response across the room. Having stuff in a room is generally much better than having a bare room.
 

·
Registered
Joined
·
30 Posts
Hello Peter,
First and foremost I want to say thank you for taking the time to do this and answer peoples questions and for all of your hard work regarding industry standards.

For the benefit of those who are not in the know please can you kindly explain what is the CTA/CEDIA R10 Standards Committee, and what is RP23, RP22, and RP1, why these matter, and how will these affect the home theater market moving forwards?
Great questions, and very close to my heart...

The CTA (Consumer Technology Association) has long been a standards development organisation. Since most of their members are manufacturers, their standards focus on product and component level ones. Around 15 years ago, CEDIA (Custom Electronic Design and Installation Association) created the R10 Standards Committee with The CTA (The CTA already had 1 to 9...) to focus on standards and recommended practices related to the installation of technology into residential environments. Last year, CEDIA itself became an ANSI Accredited Standards Organisation and has now taken over the running of R10 though it absolutely remains a joint CEDIA/CTA effort.
The key with R10 (and all the other CTA 'R' committees) is industry consensus. R10 is the only totally product and commercially agnostic standards committee within the installed residential technology space. Any member of either The CTA or CEDIA has the right to participate - The working groups are not, and cannot be selective so to ensure there is no bias. There are rules for conducting meetings with respect, and 'lurkers' may be asked to either contribute occasionally or withdraw from the workgroup. Prices, products and brands are NEVER discussed and the Chairs ensure that everyone can have their say, and their position debated.

Under R10, there are a number of workgroups. The current active ones are -
WG1 - Audio
WG3 - Video

WG1 is currently working on -
RP22 - Recommended Practice for Multichannel Audio Room Design (Though this title will likely change). This will be the definitive recommended practice on the design of the room and system for private cinema/theatre/screening room/media room design. We hope to finish by February next year.
RP1 - Performance Facts. A recommended practice for manufacturers to give us engineers the objective facts we need to make informed specification decisions. As an example, we are likely removing Watts as a recommendation for both amplifier and speaker specifications, and replacing it with short and long term voltage capacity (At 2,4,6 & 8 Ohms for amps, and with an impedance curve for speakers).
RP??? - When RP22 is done, we'll move onto a recommended practice for the measurement and verification of audio systems.
WG3 is currently working on -
RP23 - Recommended Practice for Video System Design. Both projection and flat panel.

As part of RP22 and RP23 we are introducing four different levels of overall objective system performance. The metrics will be predictable at the design stage, and measurable/veifable at commissioning. Level one is the baseline for what we feel reproduces a basic level of artistic intent. Level four is at the bleeding edge of what is achievable and is draconian in its requirements.

PLEASE don't ask me any more specifics about performance levels as we've not yet finished and I can't share the information as it's not mine to share (-:

My belief is that these works, when complete and looked at as a whole, will shift the conversation away from 'what brand or product do you recommend', and towards performing engineering design to ensure consistency of performance BEFORE then specifying the correct product to meet the engineering need.
 

·
Registered
Joined
·
1,648 Posts
If you live in an area with a stable electric grid and very low danger of lightning strikes, how much should you worry about power? Just get whole-house surge suppression and call it day? Or should one look into isolation transformers, power conditioning, balanced power, additional surge suppression at the rack, etc?
 

·
Registered
Joined
·
312 Posts
How do I know if a speaker has SBIR issues, particularly my LCR front stage?

I was thinking of making 6” thick safe n sound acoustic panels and put them right behind each tower since there will be a small gap I can’t remove and even though this would push them out more, it should absorb reflections right?
 

·
Registered
Joined
·
6,505 Posts
Why cant i change my tvs screen aspect ratio when watching 4K ??
For example if im watching something thats 2.35 2K i can switch it to 16x9 to fill the screen.
Yea yea i like it that way sometimes. :)
But if im watching something thats 2.35 4K i cant switch it to 16x9.
Tried on amazon 4K fire stick & 4K bluray....no dice.
 

·
Registered
Joined
·
1,018 Posts
To answer your calibration question - A room with lots of broadband bass absorption is far easier to calibrate as the room mode and null extremes are flattened, thus leading to a far more even bass frequency response across the room. Having stuff in a room is generally much better than having a bare room.
A follow up question here:

In more and more newer designs, I see much less use of the typical bass traps (either OC703 triangles in the corner or various pressure based absorbers in high-pressure zones). Instead the bass is optimized by placing seats and multiple subs accordingly and seat-to-seat variation and modes are close to being eliminated. (<80-100hz only though)

What is your treatment design principles when it comes to managing the bass in a home theater?
 

·
Registered
Joined
·
14,023 Posts
How do I know if a speaker has SBIR issues, particularly my LCR front stage?
Every speaker in a room unless the walls are far away has SBIR....

I am curious where Peter prioritizes dealing with SBIR versus room modes, decay time, etc. and whether he subscribes to the approach of using in wall speakers (baffle wall design) as a way to remove SBIR from that direction?
 

·
Registered
Joined
·
14,023 Posts
Why cant i change my tvs screen aspect ratio when watching 4K ??
For example if im watching something thats 2.35 2K i can switch it to 16x9 to fill the screen.
Yea yea i like it that way sometimes. :)
But if im watching something thats 2.35 4K i cant switch it to 16x9.
Tried on amazon 4K fire stick & 4K bluray....no dice.
Typically this ability to ZOOM is a feature of the TV/display, and not the source (though some video processors can do it, too) -- though of course some TV's these days don't include this feature, either.

I am curious about Peter's view on constant image height setups, though I understand he is more on the acoustics side than the display side.

So perhaps Peter can share his view about angles of spread for left and right speakers -- such as "behind the screen" in a constant image height setup, and "aside the screen" for a 16x9 screen?
 

·
Registered
Joined
·
2 Posts
I have questions regarding construction of riser. I am trying to build a bass trap and have some questions. Room is The platform is 10'3" wide by 6 with a 2" landing. I am constructing it with 2x6 (10x8). On top I am running 2x8 for the 6' platform. I am either going with sandwich of roofing paper with 1/2 inch, or just 3/4 osb subfloor. Fill with pink or rockwool.???

The basement flooring is laminated flooring with moisture barrier underneath. I was planning on building the platform on top of a piece of carpet padding that I had laying around. Note back of riser goes to wall. It was a very quick sketch!

Ceiling is low (7'6") but need platform to be approx 14" up to see over front chair.
Not really clear by my "drawing" , but there will be an approx 2' landing behind front row as a step and path to riser chairs. That makes platform approx 10x8 (6x8 where top chairs will be located). Platform will overhang by 2" and will be carpeted.
View attachment 3200731

Questions: Thank you in advance!

1- Does this build make sense? Should platform extend wider than 10 feet wide?
2- Where should bass trap vents go? How many vents and what size? I understand they should be back against wall and on side. However, platform is approx 2 feet from one side wall (and 4 feet on other side). So unsure about side locations.
3- Room is in basement and planning on using black,lined curtains on sides and to just next to screen. This will help cover the side alcove where a future snack bar may go. Not sure if will curtain the rear as there are 2 AC vents. If no curtains in rear would consider acoustical panels. However, don't use ac in basement too often and can open curtains to allow air prior to watching (or have cutouts made in the curtains. There is currently no door to room. May add a hidden bookcase door in future.
4- Should rear sub go on platform next to chair or on floor between platform and wall?
Follow up... my ceiling is Ceilume ceiling tiles with fiberglass ins in the joists above. Is this going to be an issue? ...especially if using Atmos??? If so, do you have an acoustical suggestion to remediate?
 

·
Registered
Joined
·
65 Posts
We read a lot about the benefits of dual subwoofer vs one subwoofer in home cinema. Most modern AV receivers and audio processors have two sub outputs, for using dual subwoofer.

But I have seen a lot of guys that are using more than two, 3, 4, 5 even 6 subwoofers and not in large rooms but in regular size rooms. Moreover, they also buy the largest and most powerfull subwoofers they can afford.

My question is, when it comes to number and size of subwoofer, when do we stop? Is it too many and too big something that is not only unnecesary but it is actualy detrimental?
 

·
Photographer
I have a nice display and a good sound system
Joined
·
17,833 Posts
Hi @Peter Aylett

AVS Forum is, of course, full of members who worship at the altar of deep bass, done right. I count myself among them.

I am curious about the whole topic of infrasonic bass and seek your opinion on a couple of things:

1. If cost is no object, what's roughly the lowest frequency (in Hz) that's worth chasing after for home theater, in your opinion?

2. While there are lists that cover deep bass in movies, so we know where to find it, I am wondering how much content below 16 Hz is truly intentional? How about single-digit Hz content, already very rarefied, how much of that is intentional? And if it is intentional, under what conditions are frequencies like that being mixed and monitored? How does the viewer know they are honoring "artist's intent"?
 

·
Premium Member
Joined
·
4,417 Posts
How much space should be between my compression loaded horn speakers and my .8 gain AT weave screen? Right now I’m at about 6 inches of space between the front of speaker and back of screen material roughly. Thanks.
 

·
Registered
Joined
·
3,450 Posts
I have a simple question related to the first - why isn't there a standard for RF remotes? IR remotes are great because they all adopted the NEC protocol so it's easy to design a remote to do it all. But with the annoying shift to RF remotes, it means I back to having a half dozen devices on my table and a ream of paper explaining how to configure the settings on every device. Back when the Harmony remote was a thing, this was easy, but now it's back to being an annoyance.

How in the world is this moving forward? Going from a mess of remotes down to one programmed to do it all and now back to a million remotes again. What does an installer do - surely you don't tell your customer that they have to live with a table full of remotes? Is there a potential standard in the works to make it so it's possible to consolidate?

Also, we generally know things like CEC are flaky - are there plans to improve and standardize things so it becomes more reliable? In many cases it works, until it doesn't, and in other cases it just doesn't work at all.
 
1 - 20 of 82 Posts
Status
Not open for further replies.
Top