Use Balanced Pro 1 as a 2nd sub channel

[blownrx7]

I have two subs that I want to connect using balanced outputs. I can use the normal subwoofer channel and wanted to use the Programmable Pro 1 channel as identical to the other sub channel. Going through the "Mix Levels" menu, there is no choice for "Subwoofer", just LFE. I set the LFE to 100% add in a Low Pass filter crossed over at 80 hz and NOTHING comes out of the Pro 1 sub. I called Parasound and they said I have to experiment with mixing in a combination of the front channels to get the correct level along with using the Low Pass filter (BTW I was educated that LFE is only 20hz and below information).
I still did not get anything out of the sub unless I added in some CENTER speaker to the Mix Level. I think this was because I had the front (and center) speakers set to LARGE and may have contributed to no output on the Pro 1 channel. I guess I could change them to SMALL too but all I really want is a 2nd balanced SUB channel...
I thought I could just get a Second Subwoofer channel coming out of the Pro 1 channel (just like the Unblanced Pro2) - but no.
Comments?

[goldear]

I no longer have my Halo to refer to so I don't know how they implimented the LFE on this unit WRT the programmable channels...but, LFE generally refers to the dedicated .1 channel on a discrete soundtrack. If there is no .1 in a discrete (or stereo) track, than there will most likely be no sound.

Also, depending on the processor and soundtrack, LFE can encompass anything from below 20hz to above depending on what the mixer wants to put in that channel. For this reason, you may have to mix in these other channels and cross them over appropriately if you want that sub to work.

[Brian]

I had been running my subs this way until last week when I sold them. I had set everything to 100% in the mix levels, for all speakers, and then used the filter to match my other settings. If you only do the LFE, you will only get sound during certain tracks or from certain sources that have LFE.

Also, if you have your speakers set to large, that changes how it plays. Although I don't recall exactly how it affects things. And if they are set to small and you are listening to an analog source, I think only the main sub would play, not the one on the Pro 1 input.

I've also tried using an XLR Y adapter to simply split the sub signal and that works as well.

[Chris D]

Yes, I'm using a similar concept to power Clark Synthesis tactile transducers from the Pro 1 channel. If you set LFE and ALL other mix levels to 100%, and then set your filter at the same place your main subwoofer is set at in the Halo setup crossover setting, Pro 1 should act just like your main subwoofer.

Now here's the interesting thing--I would imagine that the one difference you would see between Pro 1 and your main subwoofer would be this: Your C1/C2 processor should take all bass tones contained in any speaker set to "Large" and send it to the speaker, not the subwoofer. Similarly, all base tones contained in speaker channels set to "Small" will go to the subwoofer. That's how the Large/Small settings work; you're defining whether your speakers can handle the bass or whether the sub should do the job.

However, when you configure Pro 1 with the mixes, you are telling it to act like a SPEAKER, not just a subwoofer. So Pro 1 containing all LFE--yes, that's the same as a sub. But if you have your center channel set to "Large", and you have a bass tone contained in the center channel, it will come out your center channel speaker, not your main sub. But I would think that it WOULD come out Pro 1 as well, since you're telling it to output 100% of the center channel, filtered below some cutoff freq.

Make sense? I would make sure you have the right filter settings, like not mixing up high and low pass, for one.

[blownrx7]

After experimentation of numerous permutations of the Programmable channel (100% all channels; 100% front 3 channels; 75% all channels, etc etc), I have not succeeded in obtaining an output identical to the Balanced Sub output. I even tried just going with the unbalanced Sub output but, curiously, that was not at the same level as the Balanced output.
So I am going to go with the simple solution of using a Y-connector. Technically, this should not be an issue since the ouput is going into an A51 which can (should) handle the impedance. Philosophically, I don't like it but I'll get over it.

Time to make a DIY deluxe Balanced Y-connector
Thanks everyone for all the comments and suggestions.

[blownrx7]

I did try different permutations with the Large and Small speaker settings.

[goldear]

"I even tried just going with the unbalanced Sub output but, curiously, that was not at the same level as the Balanced output."
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Actually, this is quite normal. I'm not familiar with all the technical details, but the impedance characteristics of balanced vs unbalanced cables can vary from -10db/B to a +4db/U (which, if I undestand correctly, is due to the different voltage characteristics in pro vs consumer gear). While I've heard that some consumer manufacturers make allowances for this difference...they can still vary by 6db or so.

[Chris D]

As a side note, yes, Parasound has told us that the balanced outputs have increased levels from the unbalanced outputs, which is why some people with highly efficient speakers like Klipsch have mentioned a "hiss" present with balanced outputs, and have gone to unbalanced instead to fix the problem.