Noob seeks information on implementing Equalizer APO with hybrid loudspeaker system - 3-way plus subwoofers

[Rick Womble]

Thank you for reading this post.

I am currently building a 3-way loudspeaker system. Subwoofers will be added at some later date.

The tweeters and mid-range drivers will be in one enclosure with a passive crossover and will be powered by a pair of mono-block Hypex amps.

The woofers will be in a separate enclosure and will be powered by a stereo Hypex amp.

The eventual subwoofers will also be powered by Hypex units.

All playback will originate from a Windows laptop running Foobar.

Can Equalizer APO be used to implement DSP for this system?

Please understand that this is my first attempt to build a system using multiple amps or DSP. You may have questions for me that I cannot immediately answer or that I have may to respond to you with questions of my own.

Thank you for both your patience and assistance.

[Peter Verbeek]

If I get your setup correctly it depends on the number of output jacks of your laptop. If only 2 (stereo) and you want DSP on all separate speakers (tweeters, etc.) then the answer is probably no. Of course one could do all sorts on a stereo signal, on both channels separately or together. Stuff likely EQ-ing which is something that's Equalizer APO good at. Btw. I'm using this extensively in my Peace equalizer interface for Equalizer APO. And also, Equalizer APO users use VST plugins, mainly for DSP.

[Rick Womble]

Thank you for your reply.

At present, I am looking at running the audio from the PC through a Motu interface which will be connected to the amps.

[Peter Verbeek]

I guess, on this Motu interface you have multiple output channels. Like Rex Bob is pointing out you can use these channels to create your setup. It's a bit difficult to spread a stereo signal over the channels so each channel can have its own loudspeaker but this is entirely possible. Of course the input signal should be a stereo signal not a 5.1 or 7.1. And it also depends what you want to DSP. If the Motu does this then nothing special has to be done in Equalizer APO. If the DSP is just EQ-ing then that's also quite easy with Equalizer APO. If you want to use VST plugins for DSP per (set of) loudspeakers (drivers) then you might run into a channels separation problem. But I'm not sure what the limits are if any. Perhaps it's just a matter of trying. So the re-direction can be like this:
- L(eft) and R(ight) to woofers (bass)
- S(ide)R and SL to mid-range
- R(ear)R and RL to tweeters
So that's in Equalizer APO commands:

Copy: VL=L VR=R
Channel: L R
Filter 1: ON LPQ Fc 200 Hz Q 1
Copy: SL=VL SR=VR
Channel: SL SR
Filter 1: ON HPQ Fc 200 Hz Q 1
Filter 2: ON LPQ Fc 2000 Hz Q 1
Copy: RL=VL RR=VR
Channel: RL RR
Filter 1: ON HPQ Fc 2000 Hz Q 1

The cut-off frequencies are in this example 200 Hz and 2000 Hz. Note that these aren't hard cut-offs as low and high pass filters are used. But hard cut-offs aren't a good thing generally speaking.

I can give you a Peace configuration which does exactly this. Or you can build it yourself using Peace or Equalizer APO's Configuration Editor.

[Rex Bob]

YES. With a 5.1 or 7.1 sound card, Equalizer APO can work with a virtually unlimited number of channels, but only on the same device. Limit amplification level fo mid-hi channels. To avoid burning down the speakers if filters turn off.

[Rick Womble]

Thank you for your reply.

At present, I am looking at running the audio from the PC through a Motu interface which will be connected to the amps.

[Rex Bob]

Pay attention. The EqualizerAPO works through the windows APO. ASIO, WASAPI exclusive bypass it.