Thought: I wonder how actual Cinema surround decoders measure?

[DownUnderGazza]

With the uniformly abysmal measurements we're seeing for AVR and AV Pre/pros, it got me thinking...

-- I wonder how actual Cinema surround decoders measure?

-- Is the experience we get in a Cinema measurably better then we're being served up at home?

Forgive me if professional decoders have already been measured...

 

[GXAlan]

The old Lexicon MC-12HD (last “true” Lexicon) had good specs

 

[amirm]

Datasat (DTS brand) released one of their Cinema processors (AP20) for home years ago. I got into an argument with their advocate on the forum which him claiming great performance. After much prying, he post a tiny graph from which I showed it underperformed the DAC they were using.

Here is their measurements of 1 kHz tone:

As you can (barely) see, it has a third harmonic that is around -90 dB. Here is TI's measurement for the same DAC chip they were using:

Here, the third harmonic is near -110 dB or 20 dB better.

Assuming a noise-free system, their SINAD at best would be 90 dB.

As a funny aside, that processor became popular overnight due to its very low cost. They were selling to commercial channel so had to keep prices low. They then revised it with a linear power supply and doubled the price, killing the one reason it was selling!

 

[DownUnderGazza]

Thanks @amirm.
So can we infer from this that the (pitiful) performance we're seeing in home AVRs and even in expensive dedicated AV processors is about on par with what we pay to listen to in commercial cinemas?

 

[GXAlan]

Thanks @amirm.
So can we infer from this that the (pitiful) performance we're seeing in home AVRs and even in expensive dedicated AV processors is about on par with what we pay to listen to in commercial cinemas?

The Datasat and Barco have digital outputs so it is possible that the high end commercial cinemas use a pure digital chain to the amps.

I know Cinemark uses Crown iTech5000’s

 

[direstraitsfan98]

I love movie theater audio. it's on such a different level to home audio. I interstellar in imax. saw @ the cinesphere at ontario place back in feb. this year when they were showing 5 different nolan films, plus 2001: a space odyssey. there is a very cool audio in one scene it happens where cooper and brand are slingshotting off the black hole to get back home right before they detach (track is called detach) there is very low 13-19hz organ notes and the speakers in my particular imax theater were so loud you could hear the ports chuffing. never heard imax speakers do that in any other movie. it was that loud and low. during the black hole scene where they initially roll out of the 'space bulk' there is a low pass bass tone that caused the entire room to pressurize and resonate. and keep in mind the cinesphere is a enormous dome structure made of metal. it was very intense.

of course you can only experience this if you see it in imax since the sound system is properly calibrated to the venue space. i dont think its possible to get similar experiences with home theater unless you hundreds of thousands of dollars on up to spec laser projector and sound system. i am sure a few private homes in california have such setups but they are all wealthy hollywood studio execs I reckon

Thanks @amirm.
So can we infer from this that the (pitiful) performance we're seeing in home AVRs and even in expensive dedicated AV processors is about on par with what we pay to listen to in commercial cinemas?

I think outside of seeing a movie in the theater there isn't an 'on par' home experience at least when it comes to a properly setup IMAX venue. I didn't even get into the picture quality of dual laser projector systems, and 70mm film but I guess that's not really relevant to this thread.

 

[Promit]

Remember that extremely low distortion is rarely if ever a design priority in professional sound reinforcement of any sort. It's much more important to be able to fill a large space with uniform sound at reasonable distortion levels, reliably, for massively more demanding duty cycles and longer lifetimes than any home based system. There are also very different requirements for control and maintenance. Yeah sub-optimal distortion at the DAC might be objectionable from a hypothetical and "moral" point of view, but it's inconsequential compared to the other problems that need to be solved in these spaces.

I think it'd be nice to see something like a Crown XTi measured here, as it's probably representative of the performance level of equipment in good venues.

 

[GXAlan]

I love movie theater audio. it's on such a different level to home audio.

I remember thinking to myself the opposite until I saw A Star is Born in the theaters and found the concert scenes incredible.

Some of the JBL Pro ScreenArray use the same 2414H compression driver that you find in the Studio 5 line. I quickly went from the 530 to the 590 to the S/2600 which uses the same compression driver as the Everest DD55000.

There is something about JBL compression drivers thats work well for movies, regardless of how much power you have. The Studio 530 and 590 are great gateways into JBL horns and I highly recommend it just to hear the effect for yourself. Even listening at 1W, there is a difference.

It may very well be that coloration from the horn is part of the way the movie sounds in the theater.

For really low frequencies, If the wavelength is larger than the home theater, that could also account for the differences in sound experience

 

[GXAlan]

@direstraitsfan98
Actually, I recall that you have a nice JBL setup too. Don’t you find that you approximate the Cinemark XD or IMAX movie experience with your setup too?

You could try a Sub18 which is intended to match the 2216-Nd. But from deep clean bass, I still think the JL Audio Fathoms are the ones to beat, ignoring cost.

 

[direstraitsfan98]

Yeah, @GXAlan I have JBL Synthesis 4367. I am very happy with movie performance in my home system but it's a far cry from a proper 'home theater' setup with acoustic room treatments and EQ being applied. I've actually gotten a lot of enjoyment using the 9 band EQ on my new preamp to tweak the 25hz and 100hz regions to get a little extra oomph in movies. I don't think any of the Synthesis line floorstanders are mean't to be used in reference home theater setups without a proper sub. I don't get much bass under 25hz where it rolls off significantly in my room. I'm too lazy to bother with subs and honestly I just haven't felt the need to get them. I know I can get significant gains if I did but I have other priorities right now. I watch a lot of movies still but I listen and care about music a lot more nowadays.

The best thing about the JBL Synthesis speakers is their crystal clear audio clarity. I was watching the first x-men movie the other night and it struck me how crystal clear the JBL made Patrick Stewart's narration sound at the opening was. No center channel and the phantom center was like I had an actual center channel in room.

 

[Senior NEET Engineer]

You could try a Sub18 which is intended to match the 2216-Nd. But from deep clean bass, I still think the JL Audio Fathoms are the ones to beat, ignoring cost.

JL Audio subs are weak for home theater. There are several other brands with much deeper, cleaner, and higher output bass.

 

[GXAlan]

JL Audio subs are weak for home theater. There are several other brands with much deeper, cleaner, and higher output bass.

Genelec subs are great, as are exotics like Procella or maybe even the horn loaded Klipsch Cinema.

But I am surprised you find the Fathom line weak for home theater. (Ignoring price, since you do pay for maintaining musicality). What would you recommend to augment the 4367?

 

[QMuse]

Thanks @amirm.
So can we infer from this that the (pitiful) performance we're seeing in home AVRs and even in expensive dedicated AV processors is about on par with what we pay to listen to in commercial cinemas?

And I don't remember ever hearing noise in any cinema I've been.

 

[TimoJ]

The Datasat and Barco have digital outputs so it is possible that the high end commercial cinemas use a pure digital chain to the amps.
I know Cinemark uses Crown iTech5000’s

This one? https://www.crownaudio.com/en/products/i-tech-5000hd
THD < 0.1%
Intermodulation Distortion < 0.2%

 

[QMuse]

This one? https://www.crownaudio.com/en/products/i-tech-5000hd
THD < 0.1%
Intermodulation Distortion < 0.2%

THD is rarely a problem, what you might hear is noise.

 

[Senior NEET Engineer]

Genelec subs are great, as are exotics like Procella or maybe even the horn loaded Klipsch Cinema.

But I am surprised you find the Fathom line weak for home theater. (Ignoring price, since you do pay for maintaining musicality). What would you recommend to augment the 4367?

I don't care much for descriptors like "musicality" or "pace rhythm and timing". I discuss subwoofers in terms of harmonic distortion, group delay, cabinet resonances, etc. Those measurements characterize most of how a subwoofer sounds, much like spinorama measurements for speakers.

Here is JL Audio E112 ($2100) compared to Rythmik F18 ($1600). More detailed measurements are available at data-bass.com

 

[bluefuzz]

And I don't remember ever hearing noise in any cinema I've been.

Well, a big room full of several hundred people rustling their bags of popcorn and noshing jelly babies while slurping smoothies and cinnamon lattes is not exactly silent ...

 

[QMuse]

Well, a big room full of several hundred people rustling their bags of popcorn and noshing jelly babies while slurping smoothies and cinnamon lattes is not exactly silent ...

In dramatic scenes when there are extremely large dynamics public is usualy quiet and noise from the speakers could be easilly heard when audio suddenly gets quiet.

 

[Blumlein 88]

The old Lexicon MC-12HD (last “true” Lexicon) had good specsView attachment 63204

This looks okay, but SINAD (inverse of THD+Noise) here is only 90.45 db. About like the better pre/pros and far below good DACs. Nothing in these specs is anything to write home about.

Excellent idea for a thread topic btw.

 

[Koeitje]

The cinema experience isn't high fidelity if you measure THD and such, but the big advantage a cinema has is that its such a big room.