He's got a point, but anyone not looking to show off and who cares about the audio experience probably is already smart enough to figure out that a high spl achievement doesn't equate to balanced response. The first thing people describe when they ask about audio [especially car audio it seems] is whether they're looking for spl or sq, so as a whole it's already widely seen that the two aren't wholly or innately compatible.

Not that they can't be melded well, but that's always up for debate...

I would think that article is aimed directly at cars and subs, Yes it is cool that you can hit high spl numbers, but in reality it sounds like crap.

Soydeedo is right. when anyone asks for help in any of the car audio forums i visit the first question is SPL or SQ. Im not totally convinced they know what good sq is (there are exceptions) but they help out allot in choosing components.

From what i have heard Hexibase builds some amazingly good boxes and is a top knotch guy. I bet he got tired of everyone wanting top spl boxes and wanted to clear a few things up.

Humorously enough, even after extensive consulting sessions with many of my clients, I feel like there were still some "gray areas"... For instance, a client who'd request a loud sounding design would write back complimenting me on it being the loudest design he's ever heard but wondering why, simultaneously, it didn't meter equally impressively. Conversely, a client who'd request a design to achieve high numeric pressure would write back complimenting me on having won first places at various competitions but wondering why, simultaneously, it didn't sound equally impressive. I've essentially begun having to differentiate between audible loudness (as it is perceived by the ear) and numeric loudness (as it is perceived by a pressure sensor). Furthermore, many of my designs would fall under the erroneous scrutiny that I've described in this article. Many of the enclosures that I didn't design as "pressure builders" would get metered anyway, scores would get posted (out of context) on various forums, and some resident guru would invariably chime in with a higher score, concluding that my designs aren't so hot after all. I'm hoping that this article will constitute a tactful reference to help some of these folks out.

Honestly Pete...we've had this disagreement before.

The reason why they sound different is because there is a difference between a score at the headrest and a score at the dash. Just because a certain vehicle scores higher on the dash doesn't mean they score higher at the dash. It is just that simple and 100% verifiable.

If that was your worry, why didn't you cover any of the differences between how you believe it is perceived by the ear and how it is perceived by the pressure sensor? Why not explain why there is a difference. Instead, you went on a long, wordy, unnecessary diatribe that amounts to wide vs narrow bandwidth.

The ear is sensitive to pressure in the same way that any of the sensors are. The only difference is the physical mechanism through which sound is gathered and amplified. However, this mechanism is constant as long as the set of ears are constant, thus a vehicle that is louder at the headrest will be louder to the meter and to the ear. This is easily verifiable. What other factors do you think are at play here? Do you have supporting sources?

By all means...please prove me wrong.

I'm not entirely certain as to what this challenge is intended to accomplish for you, the readers, or for me. I will, however, entertain your inquiry as sincere curiosity. Above all else, I'm not here to submit anything radically contrary to the established science of sound, just my personal findings.

Bandwidth aside, there is a number of different ways that any given frequency can sound while registering the exact same decibel reading on a piece of sound pressure measuring equipment, even if the microphone is located at the exact spot where the listener sits.

I first demonstrated this about three years ago with an AudioControl SA3055 when I played a 60Hz tone through a door speaker, adjusting the volume to achieve a flat reading of 100dB. I then switched over to the subwoofer and adjusted the amplifier gain so it too would achieve a flat reading of 100dB (same measuring point). Then, I begin switching back and forth between the 100dB 60Hz tone coming from the door speaker and the 100dB 60Hz tone coming from the subwoofer in the rear.

Suffice it to say, even though the meter was none the wiser (with a consistent reading of 100dB at 60Hz), my ears perceived a tremendous difference between the two sources, and not just in tonality but also loudness. A difference that everyone whom I demonstrated this experiment to was also able to acknowledge.

From there, I went on to experiment with different sound sources making the location of the sound source a constant from one to the next small-scale test enclosure. I experienced a very similar phenomenon; after being adjusted to a flat numeric baseline reading, different types of waveguides and acoustic filters would still yield varying audible results.

You ask for supporting sources; as I've already mentioned in the article, I can't summarize a physical listening experience to a numerical figure. Would you use an RTA as an aide to better appreciate listening to a thunder storm or to somehow verify it's consistency with the numeric figures? Absolutely not. In fact this may sound like an absurd premise but that's just it - it is absurd. Appreciate sound with your ears - that's the underlying premise of what I'm trying to get across.

I have seen time and time again a vehicle "sound" louder to a person and then wonder why it doesn't meter as well as the next guy who's stereo doesn't "sound" louder.

Good writeup Pete.

Great article.

Neil

I guess the burden of proof is on you and not Pete. Youre basically telling us that were not hearing what we think were hearing because a number on your meter tells you so. Im an big SQ guy and i always measure my scores at the headrest and I can tell you right now that my L7 box is flat from 30Hz to 70Hz +/- 3DB and in that range it hangs at about 138DB. I also have a Type-R box thats flat in the same range and it hangs at about 141DB but my L7 box sounds louder than the Type-R box---no question about it. Are you telling me that I;'m "hearing things"???

Pete.....great article! I realy think youre onto something here that is worth a whole article of its own. But I do agree SPL meters are just secondary tools. Like if you listen to a song and something doesn't sound right to your ears then you can go back around with a meter and say "aha! there's a 10DB dip around the midbass" and so you adjust your EQ and you listen again.