editor's blog
Subscribe Now

Bad Speakers Cast a Bigger Shadow

Let’s face it: a lot of the speakers we have these days are crappy. I know how my laptop sounds; I used to attribute that partly to what I assumed was a cheap sound card (since, why would you put an expensive one in something with crappy speakers?). Later, I retired that laptop for use as a “gateway” for things like Netflix and Pandora, driving into a monitor that also had speakers. And those speakers also sucked.

But when I connected the laptop audio to real speakers, suddenly I got rich sound like I had never heard from a computer (although I’m sure it would have sucked for an audiophile…). In other words, it wasn’t the sound card at all: it was the speakers that transformed music into a tinny mishmash.

I had a conversation the other day about this with Les Tyler, president of THAT Corp., which has a division dedicated to dbx technology for TV audio. They’re trying to address this issue, since no one who makes monitors or TVs (in particular) seems to want to use decent speakers – they’re often not even willing to have the speakers face the audience (what a concept!). It’s a cost thing; video is king; audio is… well, perhaps it’s a throwback to Warner Brothers’ Harry Warner in the ‘20s: “Who the hell wants to hear actors talk?”

In case you think they’re going to find a way to get 12”-woofer base out of a 1” speaker, they will assure you that “we can’t change the laws of physics.” But they say that they make bad speakers sound better, essentially by measuring the transfer function of the speakers and then applying the inverse to the sound in a DSP software algorithm.

It’s not quite that simple –the actual inverse transfer function would apparently be huge, so it’s a good approximation. The function is also a function of loudness, and, hence, must operate dynamically to keep the signal from overdriving the speaker.

The solution is split into two pieces: the TotalSonics piece is what ends up in the TV itself, adjusting the sound in real time. Their TotalCal product is used by developers to calibrate the solution to the specific system and speakers. It’s a microphone that measures the sound quality of unassisted sound; those measurements are used to determine the corrections.

There’s one other TV sound problem they’re trying to correct: that of varying loudness levels. This has actually been addressed legislatively through the CALM law that says that ads can’t scream any louder than the rest of the programming. But that only applies to a given channel. Different channels may have different loudness levels. Their TotalVolume solution is aimed at “equalizing” the volume of different channels.

That last bit actually has another application of interest to me. Because my sound goes through an oldish amplifier with a manual volume knob, I find I’m constantly getting up to adjust when changing from one or another movie on Netflix or between audio channels like Pandora, soma-fm, or my local radio station’s stream. I suppose I would be thankful if that getting-up process were the only exercise that got me off the couch, but it’s not, so I’d love some equalization in the laptop. And it is something dbx-TV could do, perhaps in the future. But there’s no specific plan for it yet. Oh well… I can hope…

Leave a Reply

featured blogs
Dec 19, 2024
Explore Concurrent Multiprotocol and examine the distinctions between CMP single channel, CMP with concurrent listening, and CMP with BLE Dynamic Multiprotocol....
Dec 24, 2024
Going to the supermarket? If so, you need to watch this video on 'Why the Other Line is Likely to Move Faster' (a.k.a. 'Queuing Theory for the Holiday Season')....

Libby's Lab

Libby's Lab - Scopes Out Silicon Labs EFRxG22 Development Tools

Sponsored by Mouser Electronics and Silicon Labs

Join Libby in this episode of “Libby’s Lab” as she explores the Silicon Labs EFR32xG22 Development Tools, available at Mouser.com! These versatile tools are perfect for engineers developing wireless applications with Bluetooth®, Zigbee®, or proprietary protocols. Designed for energy efficiency and ease of use, the starter kit simplifies development for IoT, smart home, and industrial devices. From low-power IoT projects to fitness trackers and medical devices, these tools offer multi-protocol support, reliable performance, and hassle-free setup. Watch as Libby and Demo dive into how these tools can bring wireless projects to life. Keep your circuits charged and your ideas sparking!

Click here for more information about Silicon Labs xG22 Development Tools

featured chalk talk

Shift Left Block/Chip Design with Calibre
In this episode of Chalk Talk, Amelia Dalton and David Abercrombie from Siemens EDA explore the multitude of benefits that shifting left with Calibre can bring to chip and block design. They investigate how Calibre can impact DRC verification, early design error debug, and optimize the configuration and management of multiple jobs for run time improvement.
Jun 18, 2024
46,571 views