This is topic Drive-In Wifi Sound? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.


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Posted by Dustin Grush (Member # 10438) on 02-22-2019, 09:50 AM:
 
Hello,
Does anyone have any experience with the new Drive-In WiFi sound system being offered by Total Cinema Solutions? Anyone planning on trying it this season? I had a brief conversation with a salesperson and remain unconvinced that the "delay" issue has been resolved. I had been toying with a DIY solution to this, all theoretical at this point, and it seems that the additional processing for a RTP type stream would be too long. We constantly have people asking for this, and wondering why the "FM receiver" app on their iPhone doesn't pick up the sound.

Thanks in advance. I would also like to point out that I am in no way affiliated with TCS nor am I trying to cast doubt on their product. On the contrary actually, If it actually works it looks like we will be in the market for 2 of them.
 

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Posted by Barry Floyd (Member # 385) on 02-22-2019, 11:02 AM:
 
I've never seen that system before, so I can't really tell you anything about it.

I know Sennheiser makes a similar system called Cinema Connect. It does both audio and descriptive text for hearing impaired. I called once about the Sennheiser system, and was told it was not available to the US Cinema market... which I think was a load of BS. I was the perfect system to use in a drive-in setting.

One thing I've heard from others about trying to develop such a system as "streaming audio" for drive-ins was "Latency". The more customers connected to the system, the worse the latency issue became.

I would be curious as to what something like this system costs and how well it performs.

Our customers ask us constantly for wifi streaming of audio, so hopefully this system might work out IF the costs are reasonable.

EDIT: After looking over the system on-line, I called them and spoke with "Brian". He said they have sold several systems in the last week to 4 other drive-ins, the SACO in Maine, the Black River in New York State, and the Starlite in Wichita. I'd probably wait a couple of weeks and call up some of these other drive-in owners and see how it works.

For the price, it's really not that expensive. I've wasted a whole lot more money on stupid stuff over the years than what this system costs.
 

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Posted by Scott Norwood (Member # 30) on 02-22-2019, 11:17 AM:
 
What would be the advantage over FM?
 

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Posted by Carsten Kurz (Member # 5396) on 02-22-2019, 11:27 AM:
 
In general, it is not impossible to solve the latency issue in digital cinema, as technically, it is easy to shift audio back and forth in relation to the image. The only important thing is keeping latency constant and not going up and down. Also, streaming and broadcasting techniques usually can solve the issue of few vs. many devices using the service. However, you need expensive access points that are able to deal with that many clients simultaneously.

I don't know how many of the average drive in clients/cars use traditional fm radios in the US nowadays. I would think that FM is still the way to go, and probably also a lot cheaper and more solid in operation than a Wifi based solution.

But, many people may simply consider it 'cool' to use their phones instead of the old radio. They may think the sound is better because 'it's digital'...

- Carsten
 

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Posted by Marcel Birgelen (Member # 6801) on 02-22-2019, 11:45 AM:
 
The advantage could be that you can support multi-channel audio and the digital signal could boost the quality. In practice, it's not that simple.

Latency will not be your friend, there is a lot of stuff involved that will make it difficult to get the latency correct for all things involved:

- Wifi itself incurs latency, also there is a considerable challenge to get good in-car quality all over the field and also to serve all clients simultaneously.
- If you serve everybody with a unicast stream, even bandwidth can become a potential problem. Broadcast over wifi isn't all that reliable too.
- Encoding and streaming will introduce latency, although this part is the part that's the most easy to compensate for, since it can quite easily be measured. Also, by creating a "fake buffer", any large jitter in the system can be compensated.
- Your mobile phone will introduce latency in the networking stack, the decoding/processing stack and then also in the playback stack.
- You probably don't want to play it on the wacky speakers of your mobile phone, so you connect it to Bluetooth... e.g. that of the in-car Bluetooth system. This will not only incur the latency of the phone, Bluetooth itself, but also that of the car Bluetooth and stereo system.

With so many layers of unknown in between, lipsync audio will become an afterthought.

For subtitling, it will work, but subtitles are far more graceful than audio.

And besides all earlier mentioned arguments: Don't forget the extra level of customer support for telephones not working, car Bluetooth systems not pairing with the phone, people forgetting to connect to the correct Wifi network, phones not connecting to the correct wifi network, outdated phones, phones with issues, etc. etc...
 

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Posted by Dustin Grush (Member # 10438) on 02-22-2019, 01:35 PM:
 
Thanks for all of the replies. Good to see I'm not alone in my skepticism.

This is in no way going to replace FM.

For the "why" question:
We get some walk-ins who don't think to bring a radio. We also get people who rarely use their FM radio in their car and only discover its broken when they try to listen to the movie. Others want to "walk around and see their friends" and still listen to the movie. There is also probably the "cool factor."

This unit is getting its audio from the 8-channel output that would be timed with the FM modulator. We use a JSD-60 and I don't believe that there is a way to delay channels individually, but could be wrong about this. They do make "delay boxes" for placing speakers in a large room and having them all sync, but that isn't offered in their package.

Latency is the word that I was trying to use before but couldn't think of.

As far as troubleshooting the system this would have to be treated as a "if it works then great, if not use something else for tonight" because I rarely have time to troubleshoot things that aren't mission critical for the night, and I hate to do things that way.

Thanks again for the replies.
 

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Posted by Carsten Kurz (Member # 5396) on 02-22-2019, 02:22 PM:
 
I guess it's better (though not 'cooler'...) to hand out portable fm radios. Maybe you can buy some from china that look like an iPhone ;-)

I also remember that there are cheap mobile phone headsets that include a simple fm radio.

- Carsten
 

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Posted by Monte L Fullmer (Member # 2797) on 02-22-2019, 02:31 PM:
 
I work part time on occasion at our local ozoner and I get people coming in if there is an app available for the sound, and do get asked if we have WiFi.

I tell them that using WiFi is impossible due to the delay issues.
 

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Posted by Dustin Grush (Member # 10438) on 02-22-2019, 02:52 PM:
 
Carsten,
We do have a few radios that we hand out, free of charge, with a drivers license as collateral. This has worked rather well over the past few years that we have done it, and I have yet to have one go missing. At one point I even had out local screen print shop look into getting personalized ones with our logo, but the minimum order was ridiculous.

Monte,
Up until now that has been my answer as well. Of course I occasionally get the "well it works at so-and-so drive-in..." Its even funnier when they tell me that it works at our other location, not realizing that the two are under the same ownership, just with a different name.
 

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Posted by Leo Enticknap (Member # 534) on 02-22-2019, 04:17 PM:
 

quote: Scott Norwood

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What would be the advantage over FM?

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quote: Terry Monohan

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I have a question was or is the FM sound system stereo multi channel?

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quote: Terry Monohan

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Wow Wi Fi STEREOPHONIC SOUND for the drive inn.
The trailer trash crowd will love It with their cracked loud rattled boom box speakers in their old cars.
The neighbor houses may not like all the extra bass sound coming from the lot late at night If the theatre is close in town and not way out in the boondocks.

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quote: Frank Angel

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I would consider it a much better marketing strategy and investment to spend a few extra $$ incorporating Dolby's Virtual Surround circuitry, encoding a surround channel in the two channel FM transmission signal. It's simple, it's cheap and it gives the DI a great marketing hook

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The question is how you make it work in your average car, that doesn't have the matrix decoder available to demux the surround and potential center channel?

Or you upgrade Carsten's idea and hand-out soundbars, a separate sub woofer and a speaker for your surround channel. Doesn't sound (sorry) all that practical...

I think the only real benefit of digital transmission is that it can potentially increase the playback quality, but ever so slightly. Internationally, DAB+ is becoming the standard for digital radio transmission, but in the US it's mostly "HD Radio". Potential problems are spectrum licensing issues and very expensive equipment, compared to plain analog FM transmitters.

The quality boost going from a good analog system to a digital system will be negligible. In my car, with a "premium" sound system, I can hardly distinguish between compressed DAB+ and good FM. It's only very apparent when the signal goes out of reach. While digital will induce hard drops, analog FM will either slowly fade away into the background noise or be overpowered by an interfering radio station.

Keep in mind that digital radio might also introduce extra latency due to internal buffers, both at the encoding but also at the decoding end.

While "HD Radio" and DAB+ both support some forms of surround sound, I doubt many in-car system are capable of extracting and rendering it accordingly.

The surround part feels to be the only compelling reason for me, to even try to implement a digital solution, but it fails at a potential very low adoption rate of in-car sound systems.
 

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Posted by Jack Ondracek (Member # 1466) on 03-01-2019, 06:54 AM:
 
Install soundbars... I like that!

As Marcel suggests, HD radio does indeed introduce latency... a lot of it. Depending on how it's set up, I've seen everything from a few seconds to over 40.

In the US, the term "HD Radio", for both AM and FM, refers to a process that one company holds the monopoly on. "Ibiquity" won out over other digital processes after lawsuits were threatened when the FCC tried to dictate (like FM stereo) the winning method. AC-Delco decided it was too expensive to put decoders for the 3 or 4 competing methods in their radios and, after heavy investments into Ibiquity by Disney and, I think, NBC/Universal, "decided" to support only the Ibiquity method.

To-date, the installed base continues to be spotty and, due to lack of interest by the car-buying public, does not seem to be growing, like FM did in the 70's or color TV did in the '60s. There are only a couple of desktop options, and you have to look around to find them. So long as that continues to be the case, HD will be a "chicken and egg" situation. Broadcasters won't really want to invest in something that few will actually hear, and the public won't see much value in investing in the few available receiver options.

For broadcasters and certainly smaller economies, like the drive-in business, the transmission equipment is horrendously expensive, is generally available only to licensed broadcasters and, if you're using more than the first (HD-1) channel, you have to pay licensing royalties to Ibiquity to have the extra subchannels unlocked.

I don't believe there will ever be an HD-type solution aimed directly toward drive-ins. The numbers simply are not there. Beyond current analog FM broadcast technology, any options will continue to be adapted from products intended for other industries.

The other issue is user penetration. Because of the cost and (in mildly rugged terrain) reception issues, HD has only taken a foothold in larger communities, and even then, a small one.

In the Seattle market, nearly all of the major commercial FM stations are HD equipped and, though they've tried, none of them claim to be making any kind of financial return on their investments. For the most part it's been an image thing... keeping up with the competition, so to speak.

Because of interference, cost and nearly zero interest from listeners, there are no remaining Seattle-area AM stations broadcasting in stereo. I turned off the last operating AM stereo exciter last Summer. Ironically, the other three (also now off) were news and sports-talk stations... voice-centric formats that sounded much better in stereo!

We're basically back to the same given... for now. Analog FM, done right, is comparable to anything else you could economically send out of your booth.

As for the ongoing desire to somehow get real surround to your car.... our customers have a nagging habit of messing up our extraordinarily well-engineered stereo transmission by merely turning their cars around and viewing the movie from the back end. Just by doing that, right becomes left and left becomes right. It almost makes you want to turn the stereo off and mix it all into one channel.

One owner found a way to inject the 19kHz pilot into his transmitter, even though he had no stereo generator on it. For anyone who cared, their stereo light came on, and most of them believed he was really broadcasting that way.
 

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Posted by Sean McKinnon (Member # 612) on 03-01-2019, 07:45 AM:
 
Psycho acoustically our brains are forgiving of sound that reaches us after the picture because in the real world there is a wide range of delay based on many factors including distance and temperature but we don't notice it. All you would have to do is make sure that the possible latency range is always enough to put the audio behind the picture and that the maximum latency isn't enough to noticeable. I know easier said than done. My point is just that a constantly changing latency isn't as big of a problem as long as it's enough to always keep the audio after the picture.
 

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Posted by Frank Angel (Member # 248) on 03-01-2019, 09:24 AM:
 

quote: Marcel Birgelen

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The question is how you make it work in your average car, that doesn't have the matrix decoder available to demux the surround and potential center channel?

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That's the beauty of Dolby's Virtual Surround system, Marcel. You supply it with 5 channels, say from a DVD or BluRay, or in this case, outputs from the Cinema Processor and it manipulates the phasing so that the surround channels are folded into the Left Right channels of say a stereo TV set or two channels of a computer audio card, and the phase manipulation causes the two channel playback of the device to create a phantom, illusional surround channel just from two speakers. In order for it to work, the listener needs to be in the sweet spot or near equidistant between the Left and Right speakers.

Beauty of this is that coincidentally, that's pretty much where the occupants of the car (or TV set, at a computer or listening on a headphones) are sitting.

I saw this hawked at a computer show decades ago and it worked surprisingly well. It actually did sound like stuff was coming from behind my head. If you are not setting perfectly centered between the two speakers, the surround audio will shift somewhat, but the illusion is still there until you are at or beyond one side or another of the speakers.

Not sure what happens in cars that put speakers all over the place, but it should still cause some sort of anomaly in the location of sounds in the stereo field since all those speakers in the car still are placed in a way that you hear correct Left and Right stereo location/separation, and that's all Dolby Virtual Surround requires. Sony at one time made a Virtual Surround process for headsets. Feed it 5.1 audio in, and it will give you virtual surround sound in the headset or any two channel playback device.

But that's not the point -- whatever it is that the Dolby Surround encoder does to psychoacoustically manipulate sounds to create even a slight illusion that patrons are hearing stuff from behind their heads, that's enough of a marketing advantage that will allow the DI to use a very powerful phrase in their ads -- Dolby and Surround Sound. It will help to dispel the notion that DIs have terrible audio, stemming historically from those 4 inch Eprad or Symplex window-hanging speakers. And nowadays, car owners like to brag about their vehicle sound systems, the higher end cars boasting sound systems like Bose or Sony or Bang & Olufsen, etc. They already believe their car audio system delivers great sound. Now the DI is just adding surround to it.
 

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Posted by Scott Norwood (Member # 30) on 03-01-2019, 02:32 PM:
 

quote: Frank Angel

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In order for it to work, the listener needs to be in the sweet spot or near equidistant between the Left and Right speakers.

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quote: Frank Angel

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That's the beauty of Dolby's Virtual Surround system, Marcel.

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quote: Scott Norwood

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I had to laugh about Jack's comment about people who park backwards. I'd never thought of that, but it is pretty common for people with minivans.

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Yeah, I also had a good laugh, but it makes somewhat sense for certain car configurations. I doubt your sound will be any good though.

Maybe, you could offer the backwards channel for them, where left and right are reversed.
 

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Posted by Frank Angel (Member # 248) on 03-01-2019, 05:14 PM:
 
Thing is, in today's cars, seems they are able to use multiple speaker placement so that both the driver and the passenger (at least in the front seats) do get a fairly distinguishable stereo soundfield; if I didn't hear stereo in my new car, I would give the car back. I almost gave it back when I found out 1) it didn't have a CD player and 2) the bluetooth receiver (which SHOULD have been able to pair with a neat little CD player, DOESN'T seems they somehow configured it to pair only with effin cellphone...not other Bluetooth stuff.

With this psychoacoustic trickery, it will work as long as you can hear some stereo separation. I've actually never sat in the back seat of my car so I don't know what they hear, but in the end, it's really more about marketing and bragging rights to say you have 360° surround sound at the DI rather than if it actually presents a perfect placement of what's in the surround channels. Let's face it, when you sit in a theatre, depending on your seat location, what you hear in the way of sound location is never going to be exactly where the mixing engineer placed them.
 

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Posted by Marcel Birgelen (Member # 6801) on 03-01-2019, 05:34 PM:
 
Hearing somewhat balanced stereo in a car shouldn't be that difficult, even without speakers directly pointed at your ears. It's a small room with sufficient reflective surfaces. You'll notice that's harder to hear stereo if you open your adjacent window for example.

Isn't the problem that the phase-shift "phantom sound" trickery only works if left and right are almost exactly in-phase at the listening position?

Now, I don't know how much leeway there is and a car might be sufficiently small to not be a problem in that regard.
 

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Posted by Carsten Kurz (Member # 5396) on 03-01-2019, 09:04 PM:
 
I remember me biasing the stereo balance towards my driver seat, at least on my personal car.

Setting the car backwards for DI watching - that means, they have rear surrounds...only...

- Carsten
 

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Posted by Jack Ondracek (Member # 1466) on 03-01-2019, 11:53 PM:
 
At the outset, I'm not sure an effects adapter is something I'd be interested in putting in here. It's enough that we butcher the director's intent by mixing everything down to 2 channels, reducing the dynamic range by about half by using a mixture of AGC, multiband compression and FM "distortion-canceled" clipping , adding some stereo enhancement to widen the field, then sending the result out to a few hundred cars, each of which has different acoustic characteristics... none of which was properly equalized to standards. Wait! Most of them have equalization controls on the front panel. Gad!

We don't even have a volume control here. Where else do you give every customer the ability to decide for themselves where "7" is?

The kids want to hear the sound on their Beats, and Dad is sitting on a lawn chair with a DeWalt speaker in front of him. It's not the "Voice of the Theatre", but if it falls out of his truck on the way home, it'll probably still work.

For us, I'm pretty sure THX certification is out of the question.

The point is that every customer is bringing his own auditorium and infinitely-variable, customized sound system with him... none of which we can exert any kind of individual influence over. Technically, it's a hot mess... but everyone seems thrilled to have it.
 

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Posted by Brad Miller (Member # 2) on 03-02-2019, 12:15 AM:
 

quote: Jack Ondracek

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... our customers have a nagging habit of messing up our extraordinarily well-engineered stereo transmission by merely turning their cars around and viewing the movie from the back end. Just by doing that, right becomes left and left becomes right.

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Well Jack, you could always setup 2 transmitters!

Forward facing cars please tune to 102.9
Reverse facing cars please tune to 104.5
 

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Posted by Jack Ondracek (Member # 1466) on 03-02-2019, 12:21 AM:
 
That's true, Brad. We've also considered putting in a general information channel that people could listen to on their way up the line to the boxoffice.

Unfortunately, we live in the shadow of Seattle, where just about every available channel has some kind of full-power, LPFM, non-com or translator on it. We were lucky to find 3 quiet places to put our main channels on. Finding 3 more for reverse-polarity and maybe another 3 for descriptive audio would be unlikely.
 

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Posted by Carsten Kurz (Member # 5396) on 03-02-2019, 06:18 AM:
 
So, Wifi streaming audio could be your friend ;-)

'For those placing their cars in reverse, please download our reverse audio app'.

- Carsten
 

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Posted by Rick Cohen (Member # 6140) on 03-03-2019, 03:23 PM:
 
My opinion on the WiFi Sound option is, why bother? Other than the "cool" factor, I see more liabilities than benefits. FM sound is widely available, and simple. Just park, turn on the accessory, and tune in the frequency. Fast, simple, mostly pain free. Asking people to download an app, set up their bluetooth speaker, and then hope their phone battery or bloutooth battery doesn't die over the course of two movies, that's asking a lot. Factor in the latency issue, some cars using FM Radio parking next to other cars using WiFi Radio, blasting their systems at all different rates of delays, it would be a nightmare. If people don't want to use their car radio for some reason, they can always bring a portable, or borrow one of our 24 loaner radios for a $3 fee.
 

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Posted by Marcel Birgelen (Member # 6801) on 03-04-2019, 03:43 AM:
 
Instead of using precious FM space for your reverse-parkers, maybe you could offer headsets with FM tuners.

quote: Carsten Kurz

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I remember me biasing the stereo balance towards my driver seat, at least on my personal car.

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Car stereo systems should have a button called EGO mode for this.

But shifting balance usually only manipulates the amplitude, but not the phase.
 

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Posted by Carsten Kurz (Member # 5396) on 03-04-2019, 07:29 AM:
 
Nana, germany here, of course there is a seat sensor for deactivating the passenger airbag that controls ego mode automatically...

Then of course for those gentlemen drivers, there must be an 'ego mode override' button. I think it is called 'Auto Ego Mode Enable/Disable'

- Carsten
 

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Posted by Dave Bird (Member # 490) on 03-04-2019, 09:04 AM:
 
I find it kind of fun explaining to younger folk that their phone actually doesn't "do everything" and that the "radio stations" on their apps aren't really radio......then again, we don't provide wifi either.

Brad's idea is simple enough, though most people don't seem to care, I'm not sure what you'd call it, but when I walk around the theatre at night, there's a sort of "surround sound" that seems to hang in the air, with the ground serving as your "sub".

I've often wondered why one of our neighbors over in French-speaking Quebec run one screen in English and the other French. It would seem to me fairly simple to broadcast both on each screen. We actually get a fair number of their French patrons who come to us because they prefer the non-dubbed English version.

The other solution to "backwards" patrons would be to fire up the old AM transmitters!
 

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Posted by Jack Ondracek (Member # 1466) on 03-04-2019, 10:41 AM:
 

quote:

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The other solution to "backwards" patrons would be to fire up the old AM transmitters!

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