8*T30 30" dual 12" european

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Marflinger
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Re: 8*T30 30" dual 12" european

#91 Post by Marflinger »

Alright, this feels like a weapon of mass production, super satisfying.

cab c and d halfway done, in around 4 hours then time was up :D
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Pre-fabricated flanges and the first two panels before putting them on the side. With the one-piece-flange(s) no problem at all.
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As spoken elsewhere, doing the blocks on two baffles at once, just by weight and let it settle while doing 1/2 on both
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Et voila :)
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Straightend the baffle to avoid past errors
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On both sides
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Next panel
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And completed to do all the braces
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marked and drilled and set the screws for all braces, but then time was up.

But this runs like a factory, very nice feeling.

I think when set of 4 is done i will have to run it fully :)
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DR250 (2 done, 2 to go)
8 T30 (in building phase)
driverack PA+
Wharfedale DP4065F
Prokustik FP14000

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Bill Fitzmaurice
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Re: 8*T30 30" dual 12" european

#92 Post by Bill Fitzmaurice »

Regarding the blocks they should be either screwed or clamped while the adhesive sets. That forces the adhesive to expand into the pores of the wood for a better bond. Without pressure on the blocks the expanding adhesive can push the blocks away from the baffle and the bond won't be as good. It's not that big a deal with the blocks, as they're not structural and once the driver screws are driven they have no shear forces working on them, but not giving Murphy's Law an opportunity to result is always a good idea.

Marflinger
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Re: 8*T30 30" dual 12" european

#93 Post by Marflinger »

Bill Fitzmaurice wrote: Sun Apr 19, 2026 1:20 pm Regarding the blocks they should be either screwed or clamped while the adhesive sets. That forces the adhesive to expand into the pores of the wood for a better bond. Without pressure on the blocks the expanding adhesive can push the blocks away from the baffle and the bond won't be as good. It's not that big a deal with the blocks, as they're not structural and once the driver screws are driven they have no shear forces working on them, but not giving Murphy's Law an opportunity to result is always a good idea.
Yeah i had the side panels for four other cabs on top, as well as all the precut braces and what was around...i think it was sufficiently pressed, but i wil try that before i don't reach there anymore.
it was not pushed away from the wood, they sit flush.
avoiding avoidable failures def a good thing yes

Edit:
This was the pressing, baffles with blocks are the first layer:
Image

It was just about pressing all at once, not clamping every block on its own.
DR250 (2 done, 2 to go)
8 T30 (in building phase)
driverack PA+
Wharfedale DP4065F
Prokustik FP14000

Marflinger
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Re: 8*T30 30" dual 12" european

#94 Post by Marflinger »

Not further on the cabs, but the shoes arrived - life is good again :)

The rest of the cabs about to come, as soon as possible
1000046117.jpg
Even two wires pretty easy compared to my previous solution.
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DR250 (2 done, 2 to go)
8 T30 (in building phase)
driverack PA+
Wharfedale DP4065F
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shawn_g
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Re: 8*T30 30" dual 12" european

#95 Post by shawn_g »

Looking good so far!

Marflinger
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Re: 8*T30 30" dual 12" european

#96 Post by Marflinger »

1000046365.jpg
Took a lunchbreak to get it a bit firther...
The left has an error on it, the front slipped while glueing a bit so there is a gap in the back now; will ad a piece there and cut it flush.

Rushing things inbetween not the ideal way, will take it slower but i think this weekend could paint come on these two :)
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DR250 (2 done, 2 to go)
8 T30 (in building phase)
driverack PA+
Wharfedale DP4065F
Prokustik FP14000

Marflinger
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Re: 8*T30 30" dual 12" european

#97 Post by Marflinger »

Ready for the paint, including the v-plates :)
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Two is kind of the limit to have on the table, so i'll keep it in pairs.

But i fear i'll have to run the first half soon as a sort of halfway snack :)
Will test around as soon as i can.
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DR250 (2 done, 2 to go)
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Wharfedale DP4065F
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Marflinger
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Re: 8*T30 30" dual 12" european

#98 Post by Marflinger »

Aaand living in a colorful life again :)
1000046644.jpg
Did a rough sum up, these 2 cabs now took around 15 hours; most elements precut saves a ton of time.
Maybe 25 without precutting.

Will test stack the 4 to see what happens and if everything fits within the next few days, thursday night they'll get used and maybe abused to reach to the limits :)

Now i've completed half the plan, 4 t30 and 2 dr250 for each side. In theory, doubling the cab count should double the volume again...this will be interesting :D

Will do pictures and measurements.
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Seth
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Re: 8*T30 30" dual 12" european

#99 Post by Seth »

This is exciting news! Wow, that was quick. Great job!

For what it's worth, doubling cab count, assuming they're in one stack, will result in +6dB.

Doubling of perceived volume, while subjective, is commonly stated as +10dB.

Tripling cab count, again, sonically coupled in a single stack or stacks right next to each other will get you +9.5dB... not quite double the output, but subjectively close enough to consider it as such since 0.5dB is all but imperceptible.

Quadrupling cab count... +12dB. So, your four cabs will sound just a tad louder than twice that of a single cab.

When splitting subs left and right like you're planning on doing, you don't get the benefit of mutual coupling... where the cabs combine and act as a single source. You won't get the +6dB from doubling the cab count with split stacks. But, you do get wider coverage at the cost of comb filtering and a "power alley" up the middle with dead zones left and right of the power alley. A benefit when used intentionally, an unfortunate side effect when just setting up the system the way it "should" look instead of setting it up to sound how it should sound. Splitting them with at least 2 wavelengths of distance of the lowest frequency you want to produce helps minimize the effects of comb filtering, but it wont completely eliminate it.

Here's a reliable reference read:
prosoundweb.com - The “Power Alley” – AKA, The Troubling Interaction Of Subwoofers

Can't wait to hear how it goes on Thursday!
Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Marflinger
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Re: 8*T30 30" dual 12" european

#100 Post by Marflinger »

Yeah the doubling was just written without precise thoughts to it. Sure not really doubling, but it will exceed what the first four can do.
And i think the first 4 will already be super loud :)

I will report on this experience, today only the wiring on the cab left and mounting the drivers and wheels and i'm done :)

Depending on the spare time i'll try to measure here and pre-eq before setting up fully and testing everything at war volume.
Will need some stands for the dr's for now, as my t30-stand is only one available for now.

The frame on the v-plate above is made to carry the still to do dolly for the dr's, so the wheels hang in there well hidden.

I'm now at a height of roughly 180 cm for the bottom of the dolly for the dr's, perspectively i'd add another rising of 10 or 15 cm with the bottom of the dr.
I thought about the front of that dolly, would it benefit in any way if i extend the angle of the compression horn flange downwards? Or just take it straight down?

Will do a drawing somewhen, about the dolly thought in general and including that front angle idea in both options that came to my mind.
DR250 (2 done, 2 to go)
8 T30 (in building phase)
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Marflinger
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Re: 8*T30 30" dual 12" european

#101 Post by Marflinger »

Oh and to the spread stacks, yes aware of that effects.
Will test around what works best when all cabs are done.

The end would give me many options to stack, i thought about doing both plated sets of 4 t30 next to each other, and placing the dr's on the outer edges of the t30-row for instance. Will have to test if that gives a reasonable stere image, but this would add the coupling back in again.

The other end of the possible setups would just be two t30 on top of each other and one dr sitting above it, kind of the minimal solution.
Everything in between should work as well :)
DR250 (2 done, 2 to go)
8 T30 (in building phase)
driverack PA+
Wharfedale DP4065F
Prokustik FP14000

Marflinger
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Re: 8*T30 30" dual 12" european

#102 Post by Marflinger »

Aand the little one is ready for her first trip :)
1000046764.jpg
Except the cases, all of this will be doubled :))
Really like it and really excited to run it fully :)
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88h88
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Re: 8*T30 30" dual 12" european

#103 Post by 88h88 »

Looking good, let us know how it goes when you get it all set up!
4xOT12s, 2xT39s@22", TTLS@18", 2xT60@18"

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Seth
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Re: 8*T30 30" dual 12" european

#104 Post by Seth »

Just a cautionary note for today, when setting your limiter, you must use a sinewave signal and it must be either a frequency that's not effected by the highpass or lowpass filter (the filter setting isn't when the filter starts working, it's the point where the signal is already -3dB or -6dB, depending on the filter used) or with the highpass and lowpass filter's completely disabled (my preference). 50-60Hz is usually good in either case. Multimeters will not accurately measure voltage of music. It must be a sinewave. Hope all goes well and everyone has a great time today.

If you have to do it with the T30's connected, start with the limiter threshold all the way down and slowly increase it until you get to your target voltage. Amplifier gains all the way up for the T30 channels when you do this.
Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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