T24 Build

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jimbo7
Posts: 849
Joined: Fri Dec 28, 2012 10:45 am
Location: St. Louis

Re: T24 Build

#16 Post by jimbo7 »

I've PL'd wires out the side of my ATs before and it was fine. Messy and not pretty looking, but it worked. It was temporary till the speakons and binding post arrived.
BFM builds:
XF212
T24 BP102 24"
2x SLA's 6-5" mids, 9- gt-302's
2x AT 14" MCM 55-2421
TrT 5" MCM 55-2421
AT 18" JBL GTO804
2x OT12 flat array
2x SLA Pro 2-Alpha 6's 2-Goldwoods
2x T39 24" 3012lf
Simplex 10 BP102

Bruce Weldy
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Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T24 Build

#17 Post by Bruce Weldy »

Ok, now I need some help....

Got the crossover wired inside the cab. Hooked everything up just to test and ran some music through it. Speaker was just sitting in the sub and it's still missing one side.....I noticed that I was hearing a lot of higher end material out of the sub driver.

So, I unplugged the top box to check it out.....ran a 1k test tone through it and was hearing it....ran a 4k tone through it....hearing that too. When I plugged the top box back in, of course that box reproduced both tones much louder.

I've always run my subs through a 24db/octave slope crossover, so I've never experienced hearing the higher stuff though a sub. The T24 passive crossover is as per the plans. The plans say the high pass is 6db/octave slope, but it doesn't address the slope on the low pass.

Does it have a really low db/octave slope on the low pass? Is that why I'm hearing 1k and 4 k out of it?

I don't see how it could be wired wrong.....it's very simple. Just put the inductor in series with the driver....not much to screw up there.

Bill or Leland.....any ideas? Should it be like this since it's passive?

Need to figure it out before I button it up.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Chris_Allen
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Joined: Wed Jul 11, 2007 2:43 pm
Location: Huddersfield, UK

Re: T24 Build

#18 Post by Chris_Allen »

Even if you are getting hi end frequencies through, will they not be filtered out by the horn?
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

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LelandCrooks
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Re: T24 Build

#19 Post by LelandCrooks »

It's a first order 6db. You will stilll hear higher frequencies , albeit at lower and lower volumes. The xover point is 150hz iirc, so 1k will only be about 4-5 db down.
If it's too loud, you're even older than me! Like me.
http://www.speakerhardware.com

Bruce Weldy
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Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T24 Build

#20 Post by Bruce Weldy »

LelandCrooks wrote:It's a first order 6db. You will stilll hear higher frequencies , albeit at lower and lower volumes. The xover point is 150hz iirc, so 1k will only be about 4-5 db down.
Thanks Leland. I kinda' figured that was the case. So, I guess I'm gonna' be pulling a wide swath of EQ centered around 150 to clean out the mud in that area....with two sources playing there.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Bruce Weldy
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Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T24 Build

#21 Post by Bruce Weldy »

LelandCrooks wrote:It's a first order 6db. You will stilll hear higher frequencies , albeit at lower and lower volumes. The xover point is 150hz iirc, so 1k will only be about 4-5 db down.
Ok....so, what's the reasoning in using such a shallow slope for the crossover? I'm sure it would require more components to go steeper....what would that look like?

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T24 Build

#22 Post by Bruce Weldy »

I wonder if surgeons feel a little reluctant about closing after working on somebody's plumbing......I mean, why are we closing up the cool stuff where nobody can see it?

Last look before the side goes on.
T24 2015 09 small.jpg

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Tom Smit
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Location: Sarnia, Ont. Canada

Re: T24 Build

#23 Post by Tom Smit »

Looking good, Bruce.
What are the four plates for?
TomS

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: T24 Build

#24 Post by CoronaOperator »

Bruce Weldy wrote:
Ok....so, what's the reasoning in using such a shallow slope for the crossover?
$$$$$$
Bruce Weldy wrote:I'm sure it would require more components to go steeper....what would that look like?
You would need 2 of these:

and then 2 of these:

that's over $130 for a 12 dB/octave x-over @ 120hz.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

Bruce Weldy
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Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T24 Build

#25 Post by Bruce Weldy »

CoronaOperator wrote:
Bruce Weldy wrote:
Ok....so, what's the reasoning in using such a shallow slope for the crossover?
$$$$$$
Bruce Weldy wrote:I'm sure it would require more components to go steeper....what would that look like?
You would need 2 of these:

and then 2 of these:

that's over $130 for a 12 dB/octave x-over @ 120hz.

Yikes!

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T24 Build

#26 Post by Bruce Weldy »

Ok, I guess the crossover does indeed fit in the driver chamber....but it was way easier to get it in before putting on the other side.
T24 2015 10 small.jpg

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T24 Build

#27 Post by Bruce Weldy »

Chris_Allen wrote:Even if you are getting hi end frequencies through, will they not be filtered out by the horn?
Those with more knowledge can correct me if I'm wrong, but the horn doesn't filter high frequencies per se, but rather harmonics of the root. In this case, it's the root that's coming through, not harmonics.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T24 Build

#28 Post by Bruce Weldy »

Tom Smit wrote:Looking good, Bruce.
What are the four plates for?
As I stand over six feet tall and bending over isn't one of my favorite activities, the idea of tilt-back casters on a two foot tall cabinet is far from appealing.

So, I'm putting four casters on the bottom and I will roll the little darlin' to her proper position.....I may even sit on her to rest my aching back.

If this experiment works out the way I want, it will reside in my garage as my stereo...(albeit in mono) when it's not pounding unsuspecting drummers into sonic nirvana. Most drummers around here don't get any kind of monitor - now they will have the best one on the stage.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Bill Fitzmaurice
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Re: T24 Build

#29 Post by Bill Fitzmaurice »

Bruce Weldy wrote: Ok....so, what's the reasoning in using such a shallow slope for the crossover? I'm sure it would require more components to go steeper....what would that look like?
$$$$$. A high quality 18dB 2-way passive crossover at 150Hz or lower would cost more than an active crossover. That's why they're not used. The 6dB crossover in the plans is a better than nothing option.
Those with more knowledge can correct me if I'm wrong, but the horn doesn't filter high frequencies per se, but rather harmonics of the root. In this case, it's the root that's coming through, not harmonics.
The horn filters high frequencies. It neither knows nor cares if they're fundamentals or harmonics.

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T24 Build

#30 Post by Bruce Weldy »

Bill Fitzmaurice wrote:The horn filters high frequencies. It neither knows nor cares if they're fundamentals or harmonics.
Then I learned something. So, I'm assuming that the 4k I heard coming out of the speaker itself will be greatly attenuated when coming out of the horn?

That would indeed be a good thing.

Thanks for another lesson.

And mea culpa to Chris - you were right.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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