BillFitzmaurice.info

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

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.

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

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 ?

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

Try both and let your ears decide .

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.