Upgrade Recommendations?

[ryouiki]

Is there any other locations that you can try one of the subs in? perhaps a near-field location, like right behind the seat?

Yep, I can relocate them at will... I spent like 2 hours today just moving one around the entire room trying to mark good locations. The back wall behind the seat wasn't terrible, just individually measured the current spots worked out the best (but not when combined).

Could I just take 30-40 measurements and then just go through averaging pairs until the best result is found? Moving this thing as many times as I have today is getting old I tried the opposite approach by moving the sub to MLP and just measure the locations with the UMIK, but what I got from that, and what happened when the sub was actually placed there were not very similar.

 

[shadyJ]

I would look for locations that best compliment each other's response, so look for responses that correct each others weaknesses with each other's strengths. You are lucky in one respect, the ULS-15 mk2 is not a very heavy sub. It's relatively manageable. The ULS-15 mk1 is 20 pounds heavier, but it makes a big difference, the mk1 is a PIA to move around.

 

[William Lemmerhirt]

Sorry for the hit and run earlier.
Not here to go against shady, just saying where is start at home. I'd stuff them both in the front or rear corners, set level on each, run sweep with mains and one sub, set phase to get best response. Then, use spl, or spl function in REW while running lfe test tone in avr. Turn on second sub and check spl level. Adjust second subs phase for the most output. Run measurement sweep, subs only, then one with the mains. See what the XO region looks like and see how the subs together on their own, and go from there.
This is the method I use at home to blend 3 subs, and I'm sure there is a better way but it works here. Some say run only one main when sweeping to avoid combing effects, or use the center.
Can't recall, if you have minidsp or other EQ.

 

[ryouiki]

The corners in this room just aren't sub friendly... even without measuring you can go stick your head in the corner and realize it is just not a good spot unless you like it really boomy.

I'll continue to fiddle with it, it took me 4-5 days of moving things around to to be happy with positioning of L/R speakers... going back and forth between moving speakers and moving theater chairs until it made me happy.

I may try to repeat the experiment where I put the subwoofer in the MLP and move the microphone... I realized afterwards that I putting the microphone right next to the wall, whereas the actual sub extends out over 2 feet. Its not so much related to the subs weight, its dealing with the weight plus changing outlets, tripping over the XLR cable, etc.

 

[William Lemmerhirt]

Yeah, tripping over stuff and moving it all and still tripping over it is a headache, but one that's worth it. As far as putting your head in the corner, that doesn't matter. The only thing that matters at all is the LP(or LPs). Corner loading excites all the room modes at the same time so IME their easier to deal with(EQ). If in fact it does make your room boomy, you can still do the same procedures I mentioned just in different spots. My thinking is to first align one sub with the mains, and each sub thereafter with the system. They should be easier to integrate that way.
Btw, how do they sound despite the sketchy measurements?

 

[William Lemmerhirt]

Also, if you're doing the test with the sub on the LP, and walking around with the mic. Are using the spectrograph? Or sweeping each spot? I've read the spectrometer is better as more of a real time visual. Faster...

 

[ryouiki]

Btw, how do they sound despite the sketchy measurements?

All my complaining about dialing in positioning withstanding, I think they sound really good. I had done some switching back/forth between one of Hsu vs. the Klipsch, and the difference felt quite obvious.. listening is pretty subjective so maybe its just placebo effect, but the ULS just feels like it has way more presence in the room, measurements or not.

The HSU test CD was also quite fun... its the wrong sub to do it with any authority, but still managed to let me "feel" the 16Hz tone.

I won't be sending them back...

 

[William Lemmerhirt]

Had a feeling you'd be keeping them.

 

[ryouiki]

Well put a fork in me I'm done

I took measurements in about 30 different locations, sat down and looked at them all, matched up pairs that would complement each other, tested both subs at all locations that should have worked, in every case I end up with a big null that only exists if they are both on. The only case where they seem to work together is when they are located right next to each other.

Perhaps the room doesn't like me, or perhaps this is beyond my feeble brain.

 

[William Lemmerhirt]

When you find a null. What happens if you move the phase on only one?

 

[ryouiki]

When you find a null. What happens if you move the phase on only one?

Adjusting the phase will move the null around, but not eliminate it. For example the front corner + midwall individual measurements have peaks/nulls that should even each other out. When both subs are running together those areas are nicely taken care of, but a huge (-10db) dip suddenly appears in the 30-40Hz range. Change phase on on sub, or the other sub, will move this area up further into the frequency range.

Actually even co-located, it I seem to recall that one sub has to have the phase switch opposite each other or problems arise.

If I want to get really creative, I can set one sub into EQ1 (flat to 20db), and one to EQ2 (pretty steep rolloff), and this will help minimize this null in this area... but the downside then is it creates a very lopsided response where you essentially have one sub dealing with below 40, and then above 40 you have an extra 5db gain from them working together.

 

[ryouiki]

I may have gotten this sorted, but unfortunately I can't know for sure until tomorrow because I'm off to work. Seems to be a phase problem, but its not being introduced by the phase settings on the subs themselves...

 

[William Lemmerhirt]

Since you noticed even when colocated, one of the phase switches needs to be reversed, you may want to see if the driver is wired right. If for no other reason than consistency.

 

[ryouiki]

So yes, got this sorted... was reading some notes on multi-sub setup from a fairly well know sub designer, which led me to the "fix". Pre-Pro/Audyssey seems to be having some issues related distances/phase in my setup, so I sat down and manually adjusted distance settings which cleared the problem up for the most part.

I have what appears to be an unavoidable dip just before 80hz, but the rest is relatively good down to about 19ishHz. Actually seems like there is room for additional cuts to take out a few peaks, but I don't have miniDSP yet, and for now I'm going to take a break and just enjoy what I've already managed.

Considering how measurements look if I would have just plopped them down into some spots that "sound" good, the difference is unbelievable.

 

[William Lemmerhirt]

Lol! I actually typed and deleted a suggestion to move the distance setting, but I thought I read your issues were in the 30-40ish range. Glad you're getting somewhere though. There's nothing like graduating to real subs. You can tell someone a thousand times, but until you get, ya just don't get it.

 

[ryouiki]

Lol! I actually typed and deleted a suggestion to move the distance setting, but I thought I read your issues were in the 30-40ish range. Glad you're getting somewhere though. There's nothing like graduating to real subs. You can tell someone a thousand times, but until you get, ya just don't get it.

Assuming I'm doing the math right (which is quite possibly not the case) the 2nd sub needed 2.4ms delay to correct the problem.

What is not clear to me is how all this impacts Audyssey's sub EQ... if it starts from the point of the original distances it set, then it would be trying to EQ something that has a 10db dip in it, vs. removing that by tweaking the distances after the fact.

With miniDSP involved, I have to wonder if there is just some way to make Audyssey completely leave the subs alone... maybe turn them off during calibration and then manually add them back afterwards.

 

[William Lemmerhirt]

With miniDSP involved, I have to wonder if there is just some way to make Audyssey completely leave the subs alone... maybe turn them off during calibration and then manually add them back afterwards.

Never tried that before. If I understand what you're saying you'd basically run audyssey as if there are no subs in the system. This is an interesting idea, within the point being since audyssey has no reference point of sub data it won't EQ anything even when you later tell it "yes" to subwoofer. I'd be curious to see what happens. I know for example, in speakers if you lower XO points after calibration, audyssey can't do anything in the newly added extension range. But if you raise XO points it doesn't matter since that range has been calculated for. You should get one and see! Lol

 

[ryouiki]

You should get one and see! Lol

Yeah I have one sitting in my cart for a few days, just haven't decided on what I want to do about the wiring situation... order the parts to make custom cables all the way, or just go the easy route right now and just buy their Phoenix to XLR converters. I also need to get another DMM to check actual voltages on the outputs of the Pre-Pro to figure out how to properly match input/output voltage.

I have to wonder if Audyssey is having difficulties with the subs because it thinks all of my speakers are out of phase (they are not, wiring is all correct, etc.), so it is making some goofy decision based on that... don't know.

 

[ryouiki]

Bah I went ahead and just ordered it. Is loveinthehd still around (or did I run him off)?

Trying to make sure I understand the gain structure involved here... while I would have to measure it myself to be sure, someone else with same/similar pre-pro posted values coming out of this thing.

XLR's at reference level signal/volume with 0 trims was putting out 3.9V on the subwoofer output, so I assume the miniDSP should be jumpered to 4V at input to prevent from over driving it.

 

[shadyJ]

Bah I went ahead and just ordered it. Is loveinthehd still around (or did I run him off)?

Trying to make sure I understand the gain structure involved here... while I would have to measure it myself to be sure, someone else with same/similar pre-pro posted values coming out of this thing.

XLR's at reference level signal/volume with 0 trims was putting out 3.9V on the subwoofer output, so I assume the miniDSP should be jumpered to 4V at input to prevent from over driving it.

That sounds about right. I wouldn't worry too much about exact matching unless you are planning on reference level listening, but you do want some parity between output and input ranges. Why do you want XLR cables though? They won't help anything unless you are doing long cable runs.