Velodyne DD18 Owners - Tips and Guidance?

I recently acquired a Velodyne DD18 in perfect condition and I wanted to see if I could get input from fellow owners on how to get the most out of the subwoofer.

Should I take advantage of the low-pass filter? I'm currently doing that, sending just 80hz+ to my speakers (Audio Physic Avanti III) and letting the subwoofer handle the rest. However, I'm wondering if I'm losing any detail or quality by adding that step. Do others use this approach?

Placement: I find I have to place the sub far awayfrom my turntable because at high volumes I seem to get a lound shuddering effect, likely because the sound pressure or vibrations are somehow jiving with some natural frequency in the tt setup. Playing digital there is no problem.

I have the sub setup behind my speakes, about 6 inches from the front wall placed on a Sistrum 101 stand.

I have the volume at about 12 as I don't want it making its presence too obvious. I find the software/alignment quite quirky and not so user friendly. I can't seem to get any sound test frequency to measure the room response, so I just do the standard 1-2-3 alignment holding the mic roughly where my head is in the listening chair.

Anyways, I know the above doesn't include many specific questions but overall am just looking for some best-practices tips on getting the most from this subwoofer. I listen to a broad selection of music and this system is also for movies.
If you have clean bass you might get away with the low pass filter. I use the speaker inputs on my sub and let the speakers have full range. Just be careful not to over set your crossover. If you hear a bloated sound, lower your crossover until it goes away.
If your speakers go down to 50hz, start at 60hz on the sub and see if it works out.
Good luck.
Did you cancel the setup from the prior owner?
Thanks for the tips so far.

Yes, the sub was re-defaulted and aligned for my room based on the auto-calibration I did.

I am getting some bloat, or at least i find I have to adjust volume downward sometimes as movies in particular seem to make the bass a bit more noticeable than I would like. I'll try and connect the sub direclty and let the speakers go full range and will see if things get a little better.
What do mean by "can't seem to get any sound test frequency to measure the room response,"? Are you not hearing the test sine wave?. If not, how is auto calibration even working?. Is there something wrong with the dd18?. I might be misunderstanding here. Let's assume I am.

Went through something very similar a couple years ago, when adding my dd12. To make a very long story short, try the low pass and get comfy/familare with the software controls. I tried coutless adjustments while running all low frequencies to the dd12. Must have spent 20+ hours trying to get it right. Eventually got it to sound "ok" but not what I had hoped. Had always believed that letting a sub handle *all* the base was
the obvious/correct route. Turns out I was wrong for my setup and gear.
Just like you, i wanted minimal slam and zero noticablity. Using the
lowpass let my aerial 7b's jump back in down low. This changed
everything. Found that to a certain cutoff, the aerials sounded better

down low then the dd12. Especially mid bass as it was night and day. Below 50hz is where they needed a little help, so that's where i ended up.
Still had to spend many more hours getting it dialed in. Auto adjustment
didn't cut it for me. Software seems complex at first but really gets a lot
easier as you use it. Trick is to make single adjustments and listen before
moving on. Keep it simple regarding the eq part (shoot for a smooth line,
not straight). I kept the setup stuff out over a two week period and slowly
dialed it in. Ended up having 3 saved setups for different types of music.
Can easily switch between them with the remote. You could/should add a
movie specific setup as well (my ht system is completely separate). Am
currently running my dd12 cut off at 56hz with the volume set at 12.
Sounds great and you can barely tell it's there.

Again, try the low pass with full range to your mains. It could be the ticket
You need to have the sub connected to a video display if you don't. Then you can easily see the settings and adjust the crossover frequency. I would also remove the stand from underneath. I would also let the mains run full range as Levy suggests. If your mains go down to 50hz and you have the sub set to 80 it will sound bloated. How is the sub connected?
Hi Guys:
Thanks for the extra input. Yes, I have video connected to the sub (strangely enough, via a bit CRT front projector) so I can see the visual cues for calibration.

However, I do not seem to get any sine wave sound. I can play music, and i can see the wave drift from left to right and it's clear that the microphone is picking up the music and reflecting the frequencies etc., but I can't seem to get any calibration sine wave sound.

If I press the standard 1-2-3 for general room calibration, I get about 20 or so pulses which shake the room, and that lasts about 1 minute, so I that seems to be working fine.

Just to clarify then, the recommendation seems to be to run my speakers full range, and connect the sub to my pream seperately, but focus the sub on lower frequencies only. I should start the sub where approximately my mains cutoff?

thanks again for the tips. I wish this calibration stuff was easier
Just to clarify then, the recommendation seems to be to run my speakers full range, and connect the sub to my pream seperately, but focus the sub on lower frequencies only. I should start the sub where approximately my mains cutoff?
That's what I do in my system. I have a DD-15. There is no sine wave only the pulses.
Do you have the manual? If not go to Velodyne's site and download one.
I use a pair of HGS-15s with an SMS-1 (precursor to DD15) balanced (XLR) lines from the pre/pro to the SMS-1 and then to the subs. The subs are located behind the main LR speakers, crossover is set at the pre/pro to 60 Hz (the crossover at the subs is set to off), and the level of the subs is set using white noise generated by the pre/pro to match the level of the other 7 speakers. Even experienced listeners are unaware of the subs, except, of course, when they do something you know the mains couldn't be doing like shaking the room when there is an explosion in a movie or providing that more felt than heard subtle vibration when a low pedal note is invoked on a pipe organ. Setting the subs to too high a level is major inhibitor to good integration; you really don't want to be aware of the sub as a sound source.