Quick, What Makes You Angry?

[Patrick Bateman]

Are there any design trends in commercial speakers that make you ANGRY?

Whenever I attend CES I see dozens of newbie MISTAKES exhibited by commercial speakers. It blows me away that companies sell products with flaws that are easy and inexpensive to fix.

Here's an example of this - a commercial speaker that uses a woofer which is not recessed into the baffle.

http://www.sonicflare.com/archives/d...ndy-greene.php

Anyone who's measured a speaker knows that failing to recess the baffle will introduce a nasty peak and a notch into the midrange response.

This is Loudspeakers 101 guys! What a dumb mistake to make.

[Jay_WJ]

Surface mounting a woofer is okay in most cases. What is problematic is surface mounting a tweeter.

In addition, the above design is a unique omni-directional design. We cannot simply say it's a bad design because the woofer is not flush mounted.

[Patrick Bateman]

Originally posted by Jay_WJ
Surface mounting a woofer is okay in most cases. What is problematic is surface mounting a tweeter.

In addition, the above design is a unique omni-directional design. We cannot simply say it's a bad design because the woofer is not flush mounted.

Yes, the effect will be there with a midrange too. The frequency is predicatable based on the diameter of the frame, and the height of the edge. The bottom line is that it's a noob mistake that anyone who's measured their speakers would catch.

A lot of consumers would be shocked to find out how many manufacturers barely put any effort into measuring their speakers, and designing a proper crossover. 75% of the time the appearance of the speaker is the highest priority.

[Jay_WJ]

I didn't mean to argue against your general statement---bad mistakes often found in commercial speakers.

As for the issue of surface mounting vs flush mounting, take a look at:
http://www.zaphaudio.com/mtg-surface.html

And here's his observation about surface mounting a woofer:

Surface mounting a woofer however is not so bad. Some woofers are designed for it by having rounded over flanges, but the one above is a squared off flange. The real issues to consider are 1)looks and 2)changes in acoustic center. Bringing the woofer forward on a flat baffle may help with some crossovers, depending on the order and phase connection of the tweeter among other things.

[Lynn Olson]

Manufacturers and reviewers of highly priced, highly promoted speakers that never reveal any measurements (FR curves, anything) of the system or any technical info about the drivers. I can think of many examples here, most notoriously by a former cable company.

I mean, what's the big secret? Car companies brag endlessly about the many techno-features of the latest models, and so do reviewers. What's the deal with high-end loudspeakers?

Maybe they should just be more honest and talk about the one thing that matters, the margin that goes to the dealer and the current SPIF programs for the salesmen.

[AKN]

Hi,

Are there any design trends in commercial speakers that make you ANGRY?

Yep..

Small speakers.
Excursion instead of surface.
Big heavy surrounds.
Low Qm, well not always.

[fpara]

-Using active signal correction to overcome ignorance in passive design.
-Using huge subwoofers (15"-18") in small enclosures (~2-3 cuft)
-Always going for bass SPL at the expense of bass extension.
-Using $5K amps with $500 speakers.

[Scottmoose]

-Mediocre crossovers (and most are) slap-bang in the middle of the vocal region. Even if the XO is good, putting it right in the telephone band isn't exactly a great idea.

-Massive treble lift. I can think of one example which is +20db at 20KHz. If I wanted a headache, I'd listen to a dentist drill.

-The regularly repeated nonsense that FR drivers a) cannot do anything under about 100Hz, and b) require a horn as a matter of course. Most of the people who repeat these things a) have never heard a pair of FR drivers, and b) don't know anything about horns, though they might occasionally have heard of the Lowther Acousta (hardly a shining example of horn design at the best of times) and mention it in passing, as if it were the only example ever made.

[nunayafb]

The frequency is predictable based on the diameter of the frame, and the height of the edge. The bottom line is that it's a noob mistake that anyone who's measured their speakers would catch.

Another noob mistake is applying a general rule to all designs: You are referring to edge diffraction of a forward firing woofer/speaker. First you are right about front firing speakers, with a surface mount you get two baffle step scenarios, one is the round "baffle" aka the frame and the other is the actual baffle. The lower the cutoff point for the speaker the less important the surface mount becomes.

In this case the speaker fires up and the spheres radiate the sound in a 360 degree pattern, I'm not certain but I imagine the effect is minimized/reduced by this arrangement. (The edge diffraction fires towards the ceiling, mostly, and the sphere mostly radiates just the sound immediately beneath it ie. the the cones direct energy.)

In addition, you'll notice that the speaker frame is on the edge of the baffle in some spots, this arrangement look like it produces a complex baffle response. By complex I mean that the frame of the woofer and the baffle are one at spots and all of the different edge distances vary from small to zero yielding mostly high frequency baffle effects( they may be above the cutoff point of the woofer) there is no simple equation to predict the final response. It is possible to achieve a good FR with this arrangement.
Did they take the time to model/prototype and get that good response, I don't know but without testing I am not going to assume it is a problem.

Thanks

[owdi]

Surface mounting a woofer can be a design decision. You trade a small ripple in the FR for better alignment of acoustic centers. I'm not defending the speakers you linked to, but the woofer and tweeter seem to line up pretty well. Not that it matters, since the intended listening axis is 90 degrees off.

Dan (/noob)

EDIT: an interesting twist to the speaker you linked to would be to mount the tweeter inside the metal sphere above the woofer, pointing up. Then you could mount the tweeter sphere above it, and get a pretty cool looking speaker. Replacing the rectangular enclosure with a cylinder would complete the effect.