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DIY Speakers and Subs

kgveteran's Avatar kgveteran
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Is it possible to use full range drivers and avoid a XO ?
SteveCallas's Avatar SteveCallas
01:33 PM Liked: 43
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You wouldn't need a crossover, but you would need passive EQ if you want a flat FR, as I don't know of any single driver that can cover say 80hz - 20khz +/3db.

A line array of coax drivers could be interesting.
LTD02's Avatar LTD02
01:35 PM Liked: 1170
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there may be some very high efficiency drivers that can play up toward 10khz and play some bass. lowther, maybe a few others?
Erich H's Avatar Erich H
04:21 PM Liked: 733
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Just out of curiosity, I know using more than one tweeter is considered bad for most speakers. But why isn't it an issue with line arrays? If it is an issue, would a narrow cabinet with an almost circular shaped baffle help out?
tvrgeek's Avatar tvrgeek
05:10 PM Liked: 26
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You might visit the forums on the WEB for full range drivers. Quite a following. I believe the attraction is that your brain is very good at adjusting frequency response, but does not like all the time/phase nasties in multi-way systems.

My personal feeling is that line arrays are a very good tool for certain sound reinforcement problems, but not the best for living rooms.
Looneybomber's Avatar Looneybomber
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The downside to a line array of full range drivers is the center to center spacing issue. Using 4" drivers, that'd start becoming problematic at around 3300hz.

Check out PE. They have a box of 200 tweeters for 10 bucks! I want to buy a box just for the hell of it.
tvrgeek's Avatar tvrgeek
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I always wondered what 100 or so of them as a panel would work like. Say a 5 x 20 array?
kgveteran's Avatar kgveteran
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Yes, this would be for my living room. I could live with 14khz top end. I would ues a pair of PE kit 15" subs XO@100hz via the subs xo.

Mostly for MP3 files from my computer, party music.

Would a 1/3rd octave EQ help what ever space issues of the 4" would cause. I like the lack of a XO myself.

I would like (16) 4" full range in a very narrow cabinet. Cool project.

What are spacing issues ?


KG
kgveteran's Avatar kgveteran
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Quote:
Originally Posted by SteveCallas View Post

You wouldn't need a crossover, but you would need passive EQ if you want a flat FR, as I don't know of any single driver that can cover say 80hz - 20khz +/3db.

A line array of coax drivers could be interesting.


Would a line array of cheap coax drivers work ??
tvrgeek's Avatar tvrgeek
06:01 PM Liked: 26
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Look in past issues of Speaker Builder. There were projects not dissimilar to this. One of the ideas was to vary how they were wired to reduce output progressively to the top and bottom. Some have tried curved baffles to reduce the deviation from driver to listener. I have some built in a helix. I have seen even driver spacing, and odd driver spacing.
I still think building a very good 2 way monitor with electronic crossover will be a far better system for a living room for less cost. My bias.
Looneybomber's Avatar Looneybomber
06:03 PM Liked: 23
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Quote:
Originally Posted by kgveteran View Post

What are spacing issues ?

Comb filtering.
mayhem13's Avatar mayhem13
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On the cheap, take a look at these Kg....



http://www.parts-express.com/pe/show...number=299-271

These would need a pair of 8's or 10's on the bottom for 150hz on down....kinda what McIntosh does on their array speakers. Functional as a stable base for an otherwise top-heavy design. BTW PE has some buyout 10's that Erich turned me onto this morning......



http://www.parts-express.com/pe/show...number=299-245

Most line array builders overcome the effect of comb filtering by power tapering the wiring.

Hey KG, hows about takin a crack at an AVS Line Array project!
gpmbc's Avatar gpmbc
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http://www.audience-av.com/parts/A3.php Response is flat from 40hz-22khz.
penngray's Avatar penngray
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Quote:
Originally Posted by gpmbc View Post

http://www.audience-av.com/parts/A3.php Response is flat from 40hz-22khz.

I like that driver! Nice find.
vasyachkin's Avatar vasyachkin
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Quote:
Originally Posted by Erich H View Post

Just out of curiosity, I know using more than one tweeter is considered bad for most speakers. But why isn't it an issue with line arrays? If it is an issue, would a narrow cabinet with an almost circular shaped baffle help out?

very good question. fortunately i am a genius so i can answer it.

2 tweeters are bad because it can be avoided.

in line array it can't be avoided therefore its OK.

makes sense ?

for example work is bad because we dont like to work.

but we have to work therefore work is good.

got it ?
kgveteran's Avatar kgveteran
07:26 PM Liked: 40
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Power tapering the wiring ? I'll google it in the mean time.
Erich H's Avatar Erich H
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Quote:
Originally Posted by kgveteran View Post

Power tapering the wiring ? I'll google it in the mean time.

http://www.greenie512.net/greenie512..._tapering.html
tvrgeek's Avatar tvrgeek
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Quote:
Originally Posted by kgveteran View Post

Power tapering the wiring ? I'll google it in the mean time.

Also look at Zaletron
mayhem13's Avatar mayhem13
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Quote:

Great Link Erich!
Erich H's Avatar Erich H
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Quote:
Originally Posted by mayhem13 View Post

Great Link Erich!

Looking around through that side will lead to tons of different designs he has done or by others that he knows.
kgveteran's Avatar kgveteran
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I may be limited to one sub, but that should be ok. Great link. Grouping seems to be encouraged.

Now drivers.

http://www.parts-express.com/pe/show...number=269-482

http://www.parts-express.com/pe/show...number=269-480


What about the coax driver thing ? Seems like the tweeters being far apart could be an issue ? Just a guess on my part.... I'm trying to keep cost down as you can see. I really don't need them , it just looks like a cool project to do.
kgveteran's Avatar kgveteran
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Quote:

By the looks of the diagram, it looks like the drivers (if 8ohms) are grouped in parallel and then the four groups are paralleled for 8.7ohms.

If not, I would need a little wiring help. Odd numbers seem to add up to three in the center group.

Alot more than meets the eye with line arrays.
catapult's Avatar catapult
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Jim Griffin's line array white paper: http://www.audioroundtable.com/misc/nflawp.pdf

John Murphy's full-range-driver array: http://www.trueaudio.com/array/
Looneybomber's Avatar Looneybomber
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Quote:

Power tapering reduces the effects of comb filtering, but it also reduces the effect of the line array. The more you taper, the closer it gets to a point source.

One of the strengths of a line array is that a person is kept in the "near field" for much farther away from a speaker than a point source. That means sound drops off at 3db/doubling of distance vs. 6db. The more you taper, the more that column of sound is reduced so you lose that near field advantage.

No free lunch.
tvrgeek's Avatar tvrgeek
04:35 PM Liked: 26
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Quote:
Originally Posted by Looneybomber View Post

Power tapering reduces the effects of comb filtering, but it also reduces the effect of the line array. The more you taper, the closer it gets to a point source.

One of the strengths of a line array is that a person is kept in the "near field" for much farther away from a speaker than a point source. That means sound drops off at 3db/doubling of distance vs. 6db. The more you taper, the more that column of sound is reduced so you lose that near field advantage.

No free lunch.

Exactly why they work so well as PA systems in small clubs.
I was not aware of the side effect of power taper. Thanks for the tip. It makes sense when I think about it.
lennon_68's Avatar lennon_68
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Quote:
Originally Posted by gpmbc View Post

http://www.audience-av.com/parts/A3.php Response is flat from 40hz-22khz.

Looks like something Vas would build. 3" full range driver with extremely light cone, huge neo motor, and 12mm xmax... Only $170 each:

http://www.parts-express.com/pe/show...number=296-220
LTD02's Avatar LTD02
04:56 PM Liked: 1170
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not sure about those daytons. where are the specs?

if you can beat down the resonant peak, these may work well, especially for $15 a pop:

http://www.parts-express.com/pdf/297-433.pdf
LTD02's Avatar LTD02
05:08 PM Liked: 1170
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Quote:
Originally Posted by gpmbc View Post

http://www.audience-av.com/parts/A3.php Response is flat from 40hz-22khz.

lol. "less than 1db power compression up to 95db."

lol. "exceptionally flat response from 40hz up." check the graph. 20db spread.

no doubt it kills bose acousticrap, but that's not saying much.

xbl makes it interesting. the p-p xmax spec is horse poo. divide by 2.

this driver doesn't seem to be worth the money.
lennon_68's Avatar lennon_68
06:48 PM Liked: 20
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Man, we're in the wrong business... we should all be eBay entrepreneurs:

1400% markup
kgveteran's Avatar kgveteran
07:31 PM Liked: 40
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(40) per side http://www.parts-express.com/pe/show...number=289-124

PE wholesale for $1.40 each.

I think the wiring harness will cost more than the drivers !

The sub will have to be 150hz. I wonder how the 15" kit sub will handle that.

I think sealed with insulation would work fine. I'll use a hole saw, heck with a router for 80 total holes.

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