4-way / 8-out DSP?

The hows and whys of running sound.
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monekh
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Joined: Mon Mar 31, 2014 5:56 pm
Location: London / York, UK

Re: 4-way / 8-out DSP?

#16 Post by monekh » Fri Oct 30, 2015 12:28 pm

all really helpful information on crossovers guys, definitely need to do more study before steaming into another build! :)

will play with BW/LR filters, & lower sub crossover point to compensate for higher sub output and report back. we've already cut panels to build more of both, so that should improve things. have been considering DRs... scared of the build but hopefully will get there one day!

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BrentEvans
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Location: Salisbury, NC

Re: 4-way / 8-out DSP?

#17 Post by BrentEvans » Fri Oct 30, 2015 12:45 pm

CoronaOperator wrote: Consider this 80 hz DSP crossover setting:
Image

Now we do nothing but turn the gains up on the subwoofer channel (DSP still at 80hz):
Image
Now the acoustic crossover has jumped up to ~135 Hz even though the DSP says 80hz. The actual acoustic crossover may be very different than what your DSP says depending on the output of your tops vs subs.

This is a very good point. However... remember that it applies to system response, not gain settings. You may have to adjust gain going to one section or another to make system response flat so that the crossover will work as designed. This is where an RTA is helpful... you bring up one section at a time until the levels match. From there, the above advice applies.

I REALLY need to do the gain structure video I've been planning. This is a great addition to my outline.
99% of the time, things that aren't already being done aren't being done because they don't work. The other 1% is split evenly between fools and geniuses.

CoronaOperator
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Re: 4-way / 8-out DSP?

#18 Post by CoronaOperator » Sat Oct 31, 2015 8:13 pm

BrentEvans wrote:[ You may have to adjust gain going to one section or another to make system response flat so that the crossover will work as designed.
Dubstep systems are never flat, that graph I posted where the subs are ~20dB's higher than the tops are typical. For headliners ~30dB's higher are pretty normal. ~138 dBC is where we usually run our subs for Dub shows and only around ~112 dBA for the tops.
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

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