8-30-2017, Mobile Electronics -- I hope you enjoyed last month’s article looking at the manufacture and design of loudspeakers. I also hope you reviewed the previous article where Andy provided some basics on audio for us. This month we move forward with Andy showing us the basic necessities of tuning. Hold on, though, this ride might be a little shaky. Andy goes after things that I have heard said many times, and things that I have said before. What I suggest is keeping an open mind and be willing to learn from this industry veteran.

Let’s see what Andy is sharing with us this month.

Andy Explains

I’m going to commit heresy right here at the beginning so we can get beyond it as quickly as possible. This is really easy. Understanding why it’s easy isn’t so easy and I’ve provided some of those explanations in a previous article and in countless Facebook and forum posts.
System tuning isn’t really optimizing, it’s troubleshooting. If it was about optimizing, then we’d all be able to provide pretty good performance by just hooking stuff up. Anyone who’s serious about autosound knows this isn’t the case. This isn’t about taking what you have after it’s hooked up and making it a little better in 20 minutes. This is about a realization that once the product is hooked up, the job is only partially completed. Tuning a system isn’t an add-on or an extra service we provide for our favorite customers, just like programming an alarm for a particular car isn’t an option.
I hear the following statement all the time after listening to cars when I visit shops: “Not bad for the twenty minutes I spent,” and it makes me want to drown myself in the bathtub. What if you were demoing a recent security system installation for the guy from the company that makes that system and at the end of the demo in which nothing worked properly and several features weren’t enabled, you said, “Not bad for the five minutes I spent programming it”?
This isn’t about doing a better job. This is about finishing the job.
If you only have 20 minutes to finish a job in which you’ve spent a week making panels, upholstering them, adding lighting and accents, running wires and arranging them for FB photos, you’ve spent two hours shooting, then two things need to change: 1) you need to bill more time to finish the job and 2) you need a more efficient and predictable process for tuning. That’s what this article is about.
Before we go there, I want to talk about a couple of other statements I hear too often. The first is, “sound is subjective”. This is often proffered by people who, in a discussion about audio principles and their application, are suddenly out of their comfort zone and are looking for a quick exit. The idea that some customers prefer more high frequency content or more bass, a well-defined image or more spaciousness at the expense of image definition doesn’t mean there are no rules. A stereo system is, by design, supposed to do specific things and in order for it to work, some stuff just has to be right. Once you get those things right, changing the system performance for your customer’s preference is straightforward.
The second statement is, “I listen to everyone and I use all of those tips and tricks when I tune.” This is dangerous if sound quality, speed and predictability are important. If you’re an enthusiast working on your own car, then experimentation is part of the fun. Experimentation on a customer’s car is just a money pit.
Tips and tricks are tools. Many of them work, but they don’t all work in every situation. Knowing when to deploy them is important. What if you had one of those giant Snap-On tool boxes and all that was inside was a set of screwdrivers? You know how to use screwdrivers so you bought those. You’d have a lot of other drawers to fill. What if a bunch of people from every tool manufacturer and even some DIY guys give you a new tool every time they stop by. Every time someone gives you one and says, “this one is magic, you should try it to see if it works,” you put it in the drawer. Then, when you encounter a situation in which your screwdrivers don’t do the job, you start pulling other “magic” tools you don’t understand  out of the box to try them? Is that a process designed for success? Is success even likely?

Tips and tricks, shortcuts and workarounds are good for experts. You have to know when to use them and what they do or else they’re just a barrel of monkeys likely to make a big mess. The usefulness of tools depends mostly on the user’s understanding of what they’re for and how to use them. If the guy who gives you one can’t explain why it works and when to use it and you don’t know either, then it isn’t a tool. It’s a monkey.

Read the rest of the story HERE.

9-28-2017, Mobile Electronics -- In the last segment on this topic, I suggested a process to be used in the installation bay for tuning cars that’s effective and efficient. For some readers, this process may differ greatly from what you’ve been told by numerous enthusiasts, sound quality judges and other accomplished tuners. So, before we get started here, I’d like to explain why.
There’s a big difference between tuning cars as a profession and tuning cars as a hobby. For the hobbyist, the tuning is often the end rather than the means. The tuner likes to spend hours experimenting, listening and retuning. For the professional, these extra hours spent on listening and retuning eat into our profits and our ability to move on to the next car.

Finding Balance
First, my objective in all of the tech tips I write—whether those tips are on the Audiofrog web forum, on Facebook or in articles like this one—is to provide an appropriate balance between speed, predictability and performance. In the interest of speed and predictability, I favor objective processes that don’t require us to use our ears and make a thousand subjective analyses and an endless series of adjustments. There’s a place for subjective analysis, but that’s after all objective measures have been exhausted.
There’s a temptation among many of us to see the speedy and objective process as worse than the lengthy “artisan” process of tuning primarily by ear. This is a fallacious argument if the quality of the performance that the two processes provide is the same or even similar.
Here’s an example: Every subwoofer box built for a round subwoofer needs a hole in the baffle that fits the subwoofer. What’s the appropriate tool? Most of us would immediately say it’s a router with a circle template or a circle cutting jig. For some, the answer is a CNC router. We don’t bash these processes as lacking the necessary opportunity to include our “art” or our skill in the process, even though cutting the circle freehand and with no line to follow using a jigsaw would better demonstrate our circle cutting skills.
What are the chances that we’d cut a circle with a jigsaw and no guide to follow as accurately as our CNC machine? Not good. Eventually, with a series of files and sandpaper, we might get close and after a much longer process, we could demonstrate that the outcomes are similar. What’s the difference? Cost. If we’re charging the customer $30 to cut a round hole, then it behooves us to use the most efficient method that provides an appropriate outcome.
In our circle cutting example, the objective process is not only speedier, it’s more accurate, too. Determining if the circle is correct is a simple matter; either the speaker fits or it doesn’t fit.
“Hey, there’s a difference. Sound is subjective but a circle isn’t!”
Yes, that’s true. Sound is somewhat subjective. Some customers prefer more bass. Some prefer less high frequency content. That doesn’t change what stereo systems and a stereo recordings are designed to do. That design dictates what’s correct. The system is correct when the left and right frequency responses match and the signals arrive at the listener in phase. After it is correct, we can make some adjustments for personal preference.
When we are tuning cars, our objective tools and the information they display allow us to see how far from correct we are in each step of the process. Because of the way our brains work in processing what we hear, it’s helpful for us to use analysis methods that correlate well with what we hear. Some measurement processes are better than others.
We’re all probably familiar with the situation in which the RTA curve appears to be correct, but the car sounds terrible. In some cases, tuners use this as a reason to reject the tool, rather than look deeper into the reason that what appears to be correct is not. The first question to ask in that situation is, “Does this measurement make sense?” The second question is, “What am I really measuring?” The RTA doesn’t lie, but it also doesn’t completely characterize the performance of the system. It shows us one aspect of performance.
Do tools exist that allow us to completely characterize the performance of the system? Sure. Do we all know how to use them? No. Is it necessary to completely characterize and correct everything? No.
Our next consideration should be, “Which deviations from correct are inaudible?” We don’t need to focus on those. If we don’t need to focus on them, then we don’t need to spend money and time analyzing them during a production tuning process. As a skills-building exercise to be conducted on our own time, learning those processes and how to use those tools may make us better able to identify problems and solutions, but those activities should be extracurricular. When we’ve improved those skills to the point at which we can deploy them to increase accuracy, predictability or efficiency, we should introduce them into our process.
The objective of this article is to clear up a few misunderstandings about what we measure, what it means and what’s sufficient based on audibility. 

Read the rest of the story HERE.