AgreeMsg

Calvin

Henno: In a car, however, I find [equalizers] unavoidable

Well, yes and no.

I have what might be considered a distributed equalizer -- no equalizer per se, but enough individual controls to do a pretty good simulation of an equalizer. That is, my bass is on its own amplifier -- so I can adjust bass response separately from the rest of the system. My mid-range speakers each have a separate L-pad (resistor pot) on them so I can adjust both the amount and location of mid-bass. My treble speakers can be adjusted by the gain on the head unit. And then there are the coarse bass/treble and loudness settings on the head unit itself. So, while I have no equalizer in the car, I can in actuality do quite a lot of equalizing.

John: The fact that a perfectly flat response sounds terrible means that recording studios aren't using speakers with flat responses.

Well, maybe... I was referring specifically to a pink noise track in competition, in which the object of the game is to divide the 20Hz -- 20KHz spectrum up into 1/3 octave intervals, giving 32 separate bands, and then make each one play at exactly the same decibel level as all the others. That gives a straight (flat) line across the spectrum analyzer, and it is pretty impressive when a competitor has the kind of control of his system that allows him to tune like that. But listen to music with that equalization, and it sounds terrible--not enough bass response, not enough treble response, it seems like it's all mid-range.

I kind of think we're not talking about the same things here when I refer to "flat" on a pink-noise competition, and you refer to flat equalization of music.

tanstaafl.



"There Ain't No Such Thing As A Free Lunch"

I kind of think we're not talking about the same things here when I refer to "flat" on a pink-noise competition, and you refer to flat equalization of music.

I'm pretty sure that a flat spectrum test (the pink noise calibration you refer to) is actually not very flat in terms of the EQ settings required to pass that test.

Most stereo equipment is designed to sound good to the ear rather than to a calibration test. So most of the stuff you buy off-the-shelf is going to have far from flat response. So when you (Doug) say "flat", you're referring to the pink noise test. But when your average consumer says "flat" he means "whatever my stereo sounds like natively with all the tone and EQ controls set to zero".

Tony Fabris
Empeg #144

I kind of think we're not talking about the same things here when I refer to "flat" on a pink-noise competition, and you refer to flat equalization of music.

A "flat" response is the audio equivalent of wysiwyg for graphics. What goes in comes out exactly as the recorded medium asked. No matter how you do your equalisation curve you should get the same result. It doesn't matter whether you use pink noise, white noise, or plain music - you're trying to fit the output curve to the input curve.

The ugly truth is that if you have a perfect wysiwyg (and no distortion, intermodulation etc) system and it sounds awful - then it's telling you the recording you have is awful. Because what you're hearing IS the recording, unaltered. The problem may be that the recording studio decided to equalise for the average speaker system.


- John (from empeg)

(The above may not represent the views of empeg :)

if you have a perfect wysiwyg (and no distortion, intermodulation etc) system and it sounds awful - then it's telling you the recording ( . . ) is awful.

Makes sense. Thanks for clarifying

Henno
# 00120 (6GB+18)

I am now sufficiently interested to look deeper at this; I originally went for the open speaker approach based on Doug's descriptions and experiences, and yes, when I tried it, it appeared to make a difference. It was also due to the fact that there are no real locations inside the cabin of a Mini to place an enclosed bass unit of sufficient volume.

I've seen a product which takes advantage of one of those 'unused' spaces in a car - beneath the front seats. I can't remember what its called, but it functions basically as an enclosed speaker transmitting (pretty much) directly into your - spinal column.

What I don't know is anything more than the manufacturer's hype - like whether they actually work, or whether they're too big to fit under the seats of a Mini, or whether they just give thump and no tones.

All questions for someone else.

Save the whales. Feed the hungry. Free the mallocs.

They work ... well in fact. They're expensive, I'm told. I know someone who has a pair under the seats in his Corvette -- we checked his to see if they'd fit under the seats in my MR2. I've got about 5cm of clearance beneath my seats and it does not appear to be enough space.

I can get make/model information if you're still interested...

-- Bleys

"If you would judge, understand." -- Seneca

In the UK, Maplin Electronics sell these things, or at least they used to. A few years ago Patrick (empeg hardware designer) and myself worked with a company developing immersive simulators and we tried these little subs under the seats (which were fibreglass Sega seats at the time). They didn't work very well - "rattled" a lot I seem to recall.

The last time I saw the project they had uprated to 10" drivers in a ported enclosure right behind the player's back (and replaced the horrible Sega seat with a proper rally car seat). I don't think they need hydraulics to make the thing shake now :-)

Rob

It was a 450W 12" driver, actually, in a 45L enclosure. Driving right into the kidneys of the person sitting in the seat. Go in for a game, come out with a nosebleed and backache :) One of my better efforts, shame they scrapped it.

Patrick.

Opinions expressed in this email may contain up to 42% water by weight, and are mine. All mine.

Warning: pre-historic thread.

For the measurement mic, www.linearx.com's M31 microphone ($150) comes with a floppy disk with all the calibration data (frequency response measured in anechoic room with known speakers). If I aligned my speakers to that, I'd have response as good as the microphone, which is +/-1dB. Has anyone had any experience with measurement microphones, speaker measurement or anything related? In theory, I can get some absolutely superb sounding speakers simply by applying the inverse of their response. No idea how it'll turn out in practice, but I'm sure I'll have fun trying :)

Have you tried this yet? I'm very interested in this too.

For the M31, what would you connect it to to do the actual measurement? It seems designed for use with Linearx's boards and software and those are expensive.

How about the Radio Shack sound-level meter (cat# 33-2050)? People have good things to say about it on the net and there are published corrections that compensate for its response curve. I'll probably give it a try.

Borislav