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
Nov 23, 2022
The current challenge in custom/mixed-signal design is to have a fast and silicon-accurate methodology. In this blog series, we are exploring the Custom IC Design Flow and Methodology stages. This methodology directly addresses the primary challenge of predictability in creat...
Nov 22, 2022
Learn how analog and mixed-signal (AMS) verification technology, which we developed as part of DARPA's POSH and ERI programs, emulates analog designs. The post What's Driving the World's First Analog and Mixed-Signal Emulation Technology? appeared first on From Silicon To So...
Nov 21, 2022
By Hossam Sarhan With the growing complexity of system-on-chip designs and technology scaling, multiple power domains are needed to optimize… ...
Nov 18, 2022
This bodacious beauty is better equipped than my car, with 360-degree collision avoidance sensors, party lights, and a backup camera, to name but a few....

featured video

How to Harness the Massive Amounts of Design Data Generated with Every Project

Sponsored by Cadence Design Systems

Long gone are the days where engineers imported text-based reports into spreadsheets and sorted the columns to extract useful information. Introducing the Cadence Joint Enterprise Data and AI (JedAI) platform created from the ground up for EDA data such as waveforms, workflows, RTL netlists, and more. Using Cadence JedAI, engineering teams can visualize the data and trends and implement practical design strategies across the entire SoC design for improved productivity and quality of results.

Learn More

featured paper

Algorithm Verification with FPGAs and ASICs

Sponsored by MathWorks

Developing new FPGA and ASIC designs involves implementing new algorithms, which presents challenges for verification for algorithm developers, hardware designers, and verification engineers. This eBook explores different aspects of hardware design verification and how you can use MATLAB and Simulink to reduce development effort and improve the quality of end products.

Click here to read more

featured chalk talk

Designing with GaN? Ask the Right Questions about Reliability

Sponsored by Mouser Electronics and Texas Instruments

As demands for high-performance and low-cost power conversion increases, gallium nitride offers several intriguing benefits for next generation power supply design. In this episode of Chalk Talk, Amelia Dalton and Sandeep Bahl from Texas Instruments investigate the what, why and how of gallium nitride power technology. They take a closer look at the component level and in-system reliability for TI’s gallium nitride power solutions and why GaN might just be the perfect solution for your next power supply design.

Click here for more information about Texas Instruments Gallium Nitride (GaN)