First Build. Titan 48 w Lab 12.

Post your build odyssey here.
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jmanso
Posts: 134
Joined: Wed Feb 05, 2014 6:33 am
Location: Lisbon, Portugal

Re: First Build. Titan 48 w Lab 12.

#106 Post by jmanso »

I don't think I ever posted the endresult of my "odyssey".

It's finally finished (for now at least, might be building a couple more now)

https://i.imgur.com/6vNPLSk.jpg

Full rig is now:
2xOT12 loaded with Deltalite II 2512 and 12horn array
4xTitan48 loaded with 18Sound 12NLW9300

I don't have a picture of my rack setup but i have it as such:
the t.racks DS2418 2 in 4 audio splitter
dbx 231s equalizer
dbx DriveRack PX speaker manager

Subwoofers amp - the t.amp TSA 4-1300 running 4x8ohm
Tops Amp - dap palladium 1200 - either running both tops on one channel if monostacked as in picture, or full stereo when not stacked.

I've only gotten the amp last week and have yet to test everything but already ran some tests at home and it easily reaches past 80v.

I have a question as well.
these drivers limit is at 70v
I want to setup my limiter as stated in the plans,
I set both HF and LF and ran a sine wave of 40hz from my computer. Then I set the limiter at 1db reading 69.4v on my multimeter which was perfect.

After that, I played a very bass heavy music that goes waay below 40hz while having the amplifier still hooked up to the multimeter.

I had peaks that went as high as 73.4v which made me lower the limiter to 0db which is now at around 62v.

Is this caused from me using the wrong frequency sine to limit the signal or is it more likely from a faulty voltmeter ?

also, each db in the limiter makes for a very big change voltwise. I'm running an input signal at around -24db headroom. Should I have an higher input so to have better sensitivity on the limiter?

Thanks

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DJPhatman
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Location: Warren, MI
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Re: First Build. Titan 48 w Lab 12.

#107 Post by DJPhatman »

You should be using a fairly steep Low Frequency cut-off, aka high pass filter, at 35Hz using 4 T48 stacked together, or 40Hz with 2 stacked together. Minimum of 24dB/oct, preferably 48dB/oct. If you don't have a steep enough filter, you will need to raise the cut-off frequency to compensate. I don't know if the dBx Driverack PX is capable of this.
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

jmanso
Posts: 134
Joined: Wed Feb 05, 2014 6:33 am
Location: Lisbon, Portugal

Re: First Build. Titan 48 w Lab 12.

#108 Post by jmanso »

First of all sorry but I am nothing but a leyman here, so I'm trying to understand everything you said so I don't reply something silly

I'm setting up the driverack with 2 similar setups, one running 35hz, one 40hz so I can have both choices at a simple switch.


I get a lot of different cutoffs when I'm setting the crossover, I get, BW 6, 12, 18, 24 and LR12, 24 so I don't think I can archieve the 48db/oct setting you mentioned.

I honestly don't know the meaning of BW or LR so I just had the steepest setting which is LR24. that is maybe a mistake.

also I have a gain setting that is set at 0.0db.

I have LR24 on both the LF and HF

jmanso
Posts: 134
Joined: Wed Feb 05, 2014 6:33 am
Location: Lisbon, Portugal

Re: First Build. Titan 48 w Lab 12.

#109 Post by jmanso »

ok, I found this online

Butterworth for odd filters, Linkwitz for even. A Linkwitz is just cascaded butterworth filters. Bessel filters are for keeping an even phase/group delay.

Each of the filters has a different Q value, which give different amplitude responses. BW is Q or 0.49, LR is 0.71 (which is 0.49^2), which is because it's just a double BW filter.

LR filters are -6 dB at crossover, so they sum to flat (0 dB). BW are -3 dB, so they sum to +3 dB.


maybe I should use the BW one for that +3db sum ?

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

Re: First Build. Titan 48 w Lab 12.

#110 Post by CoronaOperator »

jmanso wrote: maybe I should use the BW one for that +3db sum ?
Try both and let your ears decide :wink: .
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

jmanso
Posts: 134
Joined: Wed Feb 05, 2014 6:33 am
Location: Lisbon, Portugal

Re: First Build. Titan 48 w Lab 12.

#111 Post by jmanso »

I think that was it.

After changing to LR24 ran the 50hz sine again, same meter read 82v instead of the 70v It had.

Lowered the limiter to 0db and now runs at a smoothly 69.4v

Also, ran some bass heavy music (that was spiking at 73v) and now it never goes over 68v.

Quite happy now.

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