Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Riley Casey]

Lots of reasons to use dedicated sub processing most important of which is things like limiter settings and brand &  model specific slopes and EQ that the generic console EQ can't match That said if the OP wants to get a handle on running subs as an effect ( essentially what this set up is for ) this configuration provide that option quickly and for free. Once questions have been answered about the value of subs as a console output then it's time to drill down to the nuts and bolts of what is the best way.  Given the OPs application description and gear list I'd imagine the console output EQ option would be all he needs.

As already mentioned a few times. I like system processing outside of the mixer.
Think if you need to swap in another mixer at some point, no need to worry about
a an unexpected scene glitch taking out the processing, ect.

The DBX 360 has three inputs, two can be set up as AES inputs.

[Russell Ault]

Lots of reasons to use dedicated sub processing most important of which is things like limiter settings and brand &  model specific slopes and EQ that the generic console EQ can't match {...}

Perhaps I've spent too much time using Meyer products, but surely the 828SP (i.e. a subwoofer with a DSP amplifier so powerful that it has an LCD screen and a network jack) has all that built in, no?

Hi passing subs keeps the ultra low frequencies out of the sub that it can't reproduce anyway. {...}

Per my "too much time using Meyer" comment above, I guess I tend to ASSume that if a DSP-powered subwoofer would benefit from an HPF that the manufacturer would build that in for me.

-Russ

[Tim McCulloch]

Perhaps I've spent too much time using Meyer products, but surely the 828SP (i.e. a subwoofer with a DSP amplifier so powerful that it has an LCD screen and a network jack) has all that built in, no?

Per my "too much time using Meyer" comment above, I guess I tend to ASSume that if a DSP-powered subwoofer would benefit from an HPF that the manufacturer would build that in for me.

-Russ

Like the picture on the food package, perhaps Riley should have overlaid the words "SERVING SUGGESTION."

When I'm willing to sacrifice some ELF extension for extra LF output, I'll do what Riley shows.

[Riley Casey]

When I'm not opining on the inter webs I'm a full time Old Guy ™ so when I read JBL sub I just skip to needing amps and processing to make them work and ignore the important details. All that stuff about processing ? Fageddatoutit. Just roll with the subs as an effect from the console surface idea with the small caveat that having EQ / low pass available on the console surface would allow you to offset the crossover shift issue with running up the sub level IF you combined that with sliding the low pass filter down at the same time. Pretty fiddly thing to have to play with in real time and again given the kinds of things that make subs as effects something worth using it's not something I'd wring hands over.

https://www.youtube.com/watch?v=OjYoNL4g5Vg

Perhaps I've spent too much time using Meyer products, but surely the 828SP (i.e. a subwoofer with a DSP amplifier so powerful that it has an LCD screen and a network jack) has all that built in, no?

Per my "too much time using Meyer" comment above, I guess I tend to ASSume that if a DSP-powered subwoofer would benefit from an HPF that the manufacturer would build that in for me.

-Russ

[Russell Ault]

{...} When I'm willing to sacrifice some ELF extension for extra LF output, I'll do what Riley shows.

I think it says a lot about the kinds of shows that I tend to mix (or, perhaps, the kinds of venues that I tend to work for) that I'm more likely to find myself doing the opposite (i.e. sacrificing headroom for ELF extension by putting in a small-ish parametric boost around 30-35Hz).

-Russ

[John Schalk]

Since the OP's system is fully powered and being used for the same band on a regular basis, I can't see a reason to add an external DSP unit just to add a HP filter to the mains.  The SRX 828SP has four options for the LPF when not being used with a JBL SRX main speaker, which is the case here.  The OP can choose from 60Hz, 80Hz, 100Hz, or 120Hz on the control panel of the SRX 828SP.  FWIW, the manual kind of sort of implies that the subs are crossed over at 80Hz when used with JBL main speakers.  Annoyingly, the manual doesn't specify the filter type and slope for the crossover options.  Does anyone know if JBL uses 24dB/octave Linkwitz Riley filters on the LPF?

Once the OP chooses a LPF frequency for the subs, it's a pretty simple process to setup a matching HPF on the main eq for the L+R output in the X32.  You can even leave a small gap between the subs and tops if you want to allow for running the subs hotter than the mains.  For example, set the subs LPF at 80Hz and then add a 90Hz high pass on the main bus in the X32.  From there the "go the extra mile" step would be to use a dual channel FFT measurement app to see if the system needs any delay to align the RCF & JBL components.  The only risk to using the main eq to high-pass the RCF mains is that the eq filter needs to be added every scene/preset that the band uses. 

[David Morison]

FWIW, the manual kind of sort of implies that the subs are crossed over at 80Hz when used with JBL main speakers.  Annoyingly, the manual doesn't specify the filter type and slope for the crossover options.  Does anyone know if JBL uses 24dB/octave Linkwitz Riley filters on the LPF?

The spec sheet shows this:


Which shows the nominal crossover frequencies at more or less 6dB down from flat, so closer to LR than any other standard topology.
It also shows the "Top" setting is definitely the same as the 80Hz.
However, it looks like the Low Pass slopes are a lot steeper, around 40db/Octave, not 24.

FWIW,
David.

[Mike Caldwell]

Since the OP's system is fully powered and being used for the same band on a regular basis, I can't see a reason to add an external DSP unit just to add a HP filter to the mains.  The SRX 828SP has four options for the LPF when not being used with a JBL SRX main speaker, which is the case here.  The OP can choose from 60Hz, 80Hz, 100Hz, or 120Hz on the control panel of the SRX 828SP.  FWIW, the manual kind of sort of implies that the subs are crossed over at 80Hz when used with JBL main speakers.  Annoyingly, the manual doesn't specify the filter type and slope for the crossover options.  Does anyone know if JBL uses 24dB/octave Linkwitz Riley filters on the LPF?

Once the OP chooses a LPF frequency for the subs, it's a pretty simple process to setup a matching HPF on the main eq for the L+R output in the X32.  You can even leave a small gap between the subs and tops if you want to allow for running the subs hotter than the mains.  For example, set the subs LPF at 80Hz and then add a 90Hz high pass on the main bus in the X32.  From there the "go the extra mile" step would be to use a dual channel FFT measurement app to see if the system needs any delay to align the RCF & JBL components.  The only risk to using the main eq to high-pass the RCF mains is that the eq filter needs to be added every scene/preset that the band uses.

Yea for just a simple high pass on the top boxes doing that in the mixer would be fine. Good suggestion on under lapping the crossover.

[ProSoundWeb Community]