Pro-Speakers - I just need to hear it again

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It’s been 25 years since I last built any pro use speakers. Now back then the word was you can’t use “hi-fi” speakers because you’ll blow them out. So after all these years, I just need to hear it again. Is this basically still true?

I found the specs on the Adire Extremis 6 and think it’d make a wonderful small set of speaker boxes for my car that I could pull out and use for small club gigs. (Dinner Jazz). I can’t find pro speakers with specks anywhere near this.

Extremis 6 are rated 100W – but at 100w of an upright bass are they going to blow?

Thanks,
 
Yep, things have changed.
Here's a link to a group of guys doing small gigs.
Scroll down to the middle of the page and check out their speaker placement:
http://www.bottlehead.com/straight 8/straight_8.htm

You could also build their smaller version:
http://www.bottlehead.com/valve/whamodyne files/page2.html

The reasoning behind these array type speakers is the wattage for each speaker is doubled. In your case 4 - 100 Watt units will handle 400 Watts. The sensitivity also goes up - anywhere from 3 to 6 db. Depending on the number of speakers used. The more speakers the higher the sensitivity.

One speaker in a little box for a jazz club won't do. The people in front will get blasted and the people in the back won't even hear it.
You could download Jim Griffins paper on line arrays to get a better handle on their uses:
http://www.audiodiycentral.com/awpapers.shtml
 
Thanks all.

The bottlehead array definitely looks interesting, but a bit much for me to carry around. I’m already using a point source amp and have to do things like point it towards the wall to spread the sound.

Anybody invent a fresnel lens yet to disperse sound.
 
Array power tapering.

After thinking about RJ's suggestion, I am leaning towards a line array solution. In thinking about this I put together a utility that lets me play with the power tapering. (If I decide to use tapering). It probably duplicates some other tool out there, but in case anybody else wants to play with it.

First look at the various diagrams at:
http://www.zalytron.com/ -> Line arrays

So how this utility works is to pass in rows of drivers to it like:
C:\temp>ohm.exe -r 8,8 -r 8,8,8,8 -r 8,8,8,8,8,8
Total ohms: 8.72727272727273
% of Power per line:
1: %27.27, %27.27,
2: %6.82, %6.82, %6.82, %6.82,
3: %3.03, %3.03, %3.03, %3.03, %3.03, %3.03,

So given a row with two 8ohm drivers, another row with 4 and another with 8, the impedance is 8.72 ohms. And if you put in a 100watts, the percent shows how much power would be going to each driver.

Here's an example mixing 6 and 12 ohm drivers like partsexpress 269-685 and 269-680 (No - I won't be using these, I'm just playing)

C:\temp>ohm.exe -r 12 -r 6,6 -r 12,12 -r 6,6,6,6
Total ohms: 4
% of Power per line:
1: %33.33,
2: %16.67, %16.67,
3: %8.33, %8.33,
4: %4.17, %4.17, %4.17, %4.17,


Attached is a zip of the perl source. It works with activestate perl. I don't know that the equations are right, but feel free the fix them. Sorry - no comments - it's whipped together
I have an .exe version also but it's too big to attached to this forum. I could mail it to someone and they could host it.


I should sure like to find some drivers like Phil Jones uses:
http://www.philjonesbass.com/Products page.htm
 

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Mounting muiltiple drivers horizontally is an audio faux pas of the first degree; I'd highly recommend against anything along the lines of the Phil Jones speakers for that reason. Comb filtering on the horizontal plane with that driver configuration will give an off-axis response that looks like a siesmic chart of a 7.9 earthquake. As for the power tapering, probably more trouble than it's worth for what you're intent is. Check out the line array drivers at the Eminence site, see if they have any recommended box configurations.

I'd suspect you can find drivers that are quite similar to if not the same as the Jones models at Parts Express for less than $15 each.
 
The 802 is a sonic nightmare, for the reasons noted above. The four driver Bose (401? I don't remember.) arranged vertically is OK as far as that goes, but way too inefficient for real pro-sound use.
To the untrained eye (which must include the designer in this case) the Jones cabs look quite formidable, but an audio engineering student submitting those boxes as their design thesis would get a failing grade.
 
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