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Discussion Starter #181
First measurement, with no correction applied (AVR EQ off)
This is at MLP

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once things settle down -LOL
interesting to see how that suck-out is resolved . . .
starting to look like MBM territory . . .?
time for an epic ET redesign . . ?
 
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Congrats on finishing. So you wired the speakers to a 1ohm load to the amp??

The suckout is may be a placement, happens when you can't move things around. It's quite large and is a fairly typical problem area. Sometimes moving MLP a foot will fix it or at least improve it

.Adjusting phase/delay may or may not help. If I remember you cant build another anywhere so a sealed sub in another spot would be the last resort if it cant be sorted.

Eq them as 1 sub, that's what it is.
 

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Discussion Starter #186
I’d guess that is a front to back room node. Try standing 2’ closer and try measuring again. If still there, try standing 2’ to the left and try measuring again.
You must be some sort of wizard... 2 feet in front of MLP:
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Discussion Starter #187
Congrats on finishing. So you wired the speakers to a 1ohm load to the amp??

The suckout is may be a placement, happens when you can't move things around. It's quite large and is a fairly typical problem area. Sometimes moving MLP a foot will fix it or at least improve it

.Adjusting phase/delay may or may not help. If I remember you cant build another anywhere so a sealed sub in another spot would be the last resort if it cant be sorted.

Eq them as 1 sub, that's what it is.
Yessir, 0.9ohm technically. They're dual 3.6ohm vc. I'll see what I can do with the phase and delay. Honestly I can't believe how unfortunate it is that it only really appears right there! Dang! We'll get it sorted out. Oh darn I need to build another supplemental sub... haha love it. Let's see what else I can do first though.
 

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Discussion Starter #189
Ok, so unfortunately no amount of EQ will be able to fix the null in your current seat, it would be a futile experiment. Is it possible to move your seat forward or back a bit? If not a full 2’, even just 1’?
Unfortunately, moving the large L sofa forward or back may be just as futile of a task. It's already in the optimal position for room layout really. I mean moving backward would put us further from the TV and close off the traffic area so I don't like that. Moving the whole thing closer seems like an OK idea to me with the exception of the very front seat of the couch will be looking almost 90 degrees to the TV. Honestly, nobody ever sits there. I'll see what I can do!

I have a lot of OC 703 for what it's worth. I was planning on making a really large frame/trap for the back wall anyway.
 

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Discussion Starter #190
Alright, I moved it one foot forward.
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short version . .
that equipment / EC stand looks like a prime candidate for a make-over
Santa just called so I need to take this . . .
 
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This is where I need to learn more about REW and tuning for room acoustics. I do know that you can treat peaks but you can't treat dips as you're asking the amp/sub to perform against a room and you run the risk of damaging the equipment.
Maybe others can provide some additional help but it appears that moving the MLP two feet closer would be the easiest outcome. Or working to flatten the curve from wherever the best (most agreeable) position is for the MLP.
 

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OK- suck with limited options-
you're not done yet- you have plenty of untapped cranial horsepower thinking about this
however
2 years ago, I had a 30" thtlp in the front right corner, pointed at the ceiling
a 24' thtlp on the floor pointed into the rear left corner- both BASH 300's, not too fancy with options
all i had to work with was distance, as a delay factor
didn't have my 2x4 yet (god- i'm so dumb sometimes . .)
6 sub tweak sweeps.jpg
2018 1 1 13 jpeg to post.jpg
2018 1 1 13 jpeg to post.jpg

so with REW and using sub distance tweak
in this 10-ish x 10-ish room i was able to get this change
so maybe some MBM work in a new build / configured stand there,
even some PE 10's with PR's due to size constraints
 
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with re-doing the EC thing,
the depth could allow for a pair of something like this,
maybe just 1, tuned into MBM- it depends
the PR's allow for ported response without a really huge box ,
could stillget a good tuing, maybe only 2 PR's
this one is 13 xc 21 x 12 but I went "big' it was for my Honda van> 400 w. plenty
it'll do 25 hz just fine so . . . filling in seems feasible
"something" built into the redesigned DIY stand could easily (?) pick up MBM boom-boom and be well integrated
and take care of the suck out
 
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Well done. Thank you for sharing your results. It looks great!

If you're willing to go thick, or build bass traps, AND devote a good chunk of surface area on the front/rear walls that apparently causing your cancellation, you might be able to damp a bunch of that null out.

if you haven't already checked out Ethan Winer's home made bass traps, that might be worth doing. You could probably do it with a WHOLE LOT of OC 703, but that might not be cost or volume effective. If you look at the absorption coefficients and extrapolate with thickness, you might do alright if you're willing to make it 12"-18" thick, (better than R-19, but still a whole lot of volume) and you'd still likely need to have a lot of surface area covered, but who knows? I once 'fixed' a weird problem in about that range by accident by putting a fat dresser in a corner behind me, effectively partially changing the room dimensions on the bottom half of the room. If you're willing to play around, and keep building stuff, I think you've still got a decent shot at finding some kind of acceptable resolution without resorting to an auxiliary 'fill' subwoofer.
 

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I've been to Mikes HT, "The Event Horizon" several times
for the inaugural opening for the LA HT group, big doings-

this relates to BM and effectiveness of bass trapping and what is really needed
He spent a LOT of time & $ planning and the journey is a great read
the results truly OTT
but it was the people and resources of info that made it work
just like you were the guy who didn't think IB was the way to go
just to inspire you and your ability to get into the real nitty gritty
"The Truth is out there"
 
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Discussion Starter #198
Hey Guys,

I've been doing quite a lot of reading/testing...EQ-ing!

First off, I followed the guides/videos as suggested and tuned the subwoofer response using REW and the minidsp 2x4HD. After I got that as flat as I could, I ran everything through Dirac live, again EQing the sub as suggested. Again, it feels like you're not supposed to stack filters on filters, but what do I know? I've learned a lot here I didn't know before. Actually come to think of it, I haven't measured the corrected sub response to see how it's all doing after Dirac. Obviously I know how it looked when it was measured through Dirac, which would have been with the first EQ applied (just REW EQ). I'll have to see what the response looks like after both minidsp/rew EQ and dirac EQ and post it back here.

Next, I realized I'm not going to get rid of that cancellation null. It is what it is, and cannot be fixed except by repositioning either the subwoofer (lol) or moving the listening position (which I already did). So now I know of only two other options to fix this--a ****load of absorption/Helmholtz resonator OR another subwoofer to fill in the Hz.... I'm not dealing with a Helmholtz resonator, although the science behind it is very neat! Almost like a black hole tuned to a specific frequency. I'm not going to put 12" of OC 703 across my entire back wall. It should be known that I did stack 24" or so of it in various 6 foot sections on the back wall to see what it did (and off the back wall, 3 ft off the back wall, etc) and it really didn't do anything for these bass frequencies. They're really my favorite nuisance to be honest!

So, I'm going to add another sub(s)... BUT I'm not so stoked about it. Reason being, I want it to fill in a gap of between 39 and 41Hz and stay quiet the rest of the time. That's really goofy but it's what I'd want ideally. The obvious problem here is the integration. Am I overthinking it? I don't want to ruin the sweet sweet infinite baffle sound by having some inferior garbage playing as well. Which brings me to my next point/question: In an ideal world, the subwoofers are all the same. This is pretty common knowledge and what is accomplished most of the time when we see multi-sub setups. I can't do another HS-24. I don't know where I'd put it. I am worried that mixing subwoofers will yield less than desirable results. I just can't spend another 12 or 13 hundred for this hobby right now... maybe 1000 but certainly no more hahaha (jk)

Kind of reminds me of kids who purchase luxury used cars because they're the same price as 'regular' brand new cars. It's too late by the time they realize the error of their ways- the luxury car sits unused because it is too expensive to fix.

At least in my case, the subwoofers certainly aren't sitting unused!
 

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Room nodes are a prick. I have almost the exact same monster hole at that frequency at my back row of seats. I am running multiple subs, but unfortunately I have a null at a frequency in the front row; so the rear subs are helping fill that gap. I can't eq both so the back row gets stiffed lol.
 

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Discussion Starter #200
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