Sanity check: Bad Sub ? (REW Sweep results)

[TLS Guy]

Unless I'm misremembering Erin's measurements, the Q 11 Meta's port tuning is 35 hz or so. Their response is dropping like a stone below 30 hz. Feeding them the lfe channel seems pointless and potentially risky.

It could be for movies, but in music there is little content below 30 Hz. I run my rig with all speakers except the ceiling speakers full range. I have never had a problem. I highly doubt his left and right speakers will be damaged though. Minimizing the crossover settings improves the transient response. When I use crossover to all the speakers, it is unquestionably a downgrade. The crossover from the mid lines to the bass lines is acoustic, and the LFE added. After all before this bass management craze we always ran our speakers full range, and I never had a problem, which is most of my life. I run my family room speakers full range and push them hard at times. Mind you, KEF B 139s are really robust and capable speakers. Falcon acoustics are producing them again, and reporting brisk sales. That driver goes back to 1969. I don't think a modern driver of that size, and many that are larger, can compete with them.

 

[Linwood]

...common sense is a much better starting point. Just because it is a fancy program with a name given by an ad. exec, it does not mean it is right by a long shot. So don't slavishly trust them ever.

Thanks. My current mode is first I have to figure out what it is doing before I start undoing anything.

 

[Linwood]

Crossovers:

So I've listened to hours or videos and read a bunch of writeups and I honestly do not know how crossovers work.

Some (and google's AI) say that you set them in the manual section of speaker setup before using Dirac Art, but other indications are the closest you get is using the F Support Low which is a cutoff at which that speaker does not provide "support" (which is the cancellation of standing waves as I understand it), but it is not clear that's the traditional crossover point, and certainly it doesn't indicate it matters where you start.

I listened to one Direct Engineer discuss some related things, like subwoofer phase, and his reaction was "doesn't matter, it will figure it out and do the right thing". Though he did say the support cutoffs needed some attention.

So to the original question: I have no idea how it's set, and whether the setting before you start matters (because it's painful otherwise as I don't know how you get back into that setting if you wanted to change it shot of some kind of reset).

I am starting to understand ART's philosophy, though there's so much contradictory advice out there (e.g. whether or not to let the center support other speakers; the Dirac Engineer seemed to say for all speakers they should provide support unless the speaker is already too close to running out of capacity just to play).

And another mystery to me is that ART is supposed to understand the acoustic structure of the space in the room, where standing waves will interfer or re-inforce so it can act on them at different frequencies, and to do this at different locations -- but there's nothing in the measurements that provide precise location information. Is the space to the left at 2', 3', 1.5'... the system doesn't know. All the measurements seem relative locations, not quantitative distances.

 

[Kingnoob]

It could be for movies, but in music there is little content below 30 Hz. I run my rig with all speakers except the ceiling speakers full range. I have never had a problem. I highly doubt his left and right speakers will be damaged though. Minimizing the crossover settings improves the transient response. When I use crossover to all the speakers, it is unquestionably a downgrade. The crossover from the mid lines to the bass lines is acoustic, and the LFE added. After all before this bass management craze we always ran our speakers full range, and I never had a problem, which is most of my life. I run my family room speakers full range and push them hard at times. Mind you, KEF B 139s are really robust and capable speakers. Falcon acoustics are producing them again, and reporting brisk sales. That driver goes back to 1969. I don't think a modern driver of that size, and many that are larger, can compete with them.

With my avr to to run mains full range, I think I have to select double bass or the sub won’t get that lfe channel the mains are doing ? My icons only go down to 35hz or so I run them at 60. Ancient onkyo.
Dirac Art cost a lot you need a new avr that supports it and multiple subs ?

 

[Linwood]

Dirac Art cost a lot you need a new avr that supports it and multiple subs ?

The Denon x3800h supports it, and getting two SVS PB-1000's, second coming tomorrow.

From a lot of reading and watching I'm convinced (a) I have a terrible room setup but don't intend to fix it, and (b) it does the most to fixing bad rooms. Not that it can be a complete fix.

 

[lovinthehd]

Crossovers:

So I've listened to hours or videos and read a bunch of writeups and I honestly do not know how crossovers work.

Some (and google's AI) say that you set them in the manual section of speaker setup before using Dirac Art, but other indications are the closest you get is using the F Support Low which is a cutoff at which that speaker does not provide "support" (which is the cancellation of standing waves as I understand it), but it is not clear that's the traditional crossover point, and certainly it doesn't indicate it matters where you start.

I listened to one Direct Engineer discuss some related things, like subwoofer phase, and his reaction was "doesn't matter, it will figure it out and do the right thing". Though he did say the support cutoffs needed some attention.

So to the original question: I have no idea how it's set, and whether the setting before you start matters (because it's painful otherwise as I don't know how you get back into that setting if you wanted to change it shot of some kind of reset).

I am starting to understand ART's philosophy, though there's so much contradictory advice out there (e.g. whether or not to let the center support other speakers; the Dirac Engineer seemed to say for all speakers they should provide support unless the speaker is already too close to running out of capacity just to play).

And another mystery to me is that ART is supposed to understand the acoustic structure of the space in the room, where standing waves will interfer or re-inforce so it can act on them at different frequencies, and to do this at different locations -- but there's nothing in the measurements that provide precise location information. Is the space to the left at 2', 3', 1.5'... the system doesn't know. All the measurements seem relative locations, not quantitative distances.

It's a fairly simple concept, just where high pass filter and low pass filter slopes "cross" so as to create a relatively flat response. Then there are different slopes and approaches to automated setting of ideal crossover (even if slope is limited, so....).

 

[Kingnoob]

The Denon x3800h supports it, and getting two SVS PB-1000's, second coming tomorrow.

From a lot of reading and watching I'm convinced (a) I have a terrible room setup but don't intend to fix it, and (b) it does the most to fixing bad rooms. Not that it can be a complete fix.

yeah I meant it’s not cheap for Dirac Art I can probably get my room sounding good without fancy eq and measurements. Can’t afford a $1500 receiver right now.
Ahh I wish I could get better subs but only able to afford a single if I got one. Not happening til something breaks.

 

[ski2xblack]

Happy turkey day! @Linwood It seems you're beginning to appreciate the challenges.

Think about your initial impressions when your speakers arrived, when you first noticed how good the bass was, when your sub was not even plugged in! That's because your speakers are pretty much full range, with the bass integrated into a cohesive whole, courtesy of the engineers at KEF.

Now think about what you're faced with by adding subs. You're in the unenviable position of donning your own speaker engineer hat, to add subs while maintaining/preserving that integrated, cohesive whole (no small task). Or let Dirac tackle it for you-always verify using REW.

High passing your mains will have some benefits, mainly reduced modulation distortion, and allow a bit more dynamic wiggle room. But that also means the pressure is on to get the crossover correct, lest it result in less than integrated, cohesive results and audible tells.

We've already mentioned some of the options to you, some which sidestep having to conjure the perfect crossover, at least somewhat.
-You should probably let the Q 11s run full range.
-Let the SVS subs handle the lfe (leave the lfe channel lpf at 120 hz)
-Experiment with the sub's lpf settings and see how it measures. Try 40-60 hz or so, measure, tweak, remeasure... Follow the procedure from the video you posted, it had some great calibration advice.

So under this scenario, rather than a textbook crossover (e.g. LR4 implemented at 80 hz, the most typically recommended target), your subs and L and R speakers will overlap, providing four sources of bass which should aid with modal smoothing.

After that you can decide whether or not to high pass your center and surrounds. They're all ported designs, so the inherent phase shifts could be an issue, so experiment as needed.

You could always try high passing all your speakers, as is typically done, and who knows, it might end up working better in your situation. It would be a bit safer, if you're blasting it at disturb-the-neighbors spls. Just realize, higher crossover settings means dividing the fundamentals and harmonics of recorded instruments and divvying them out to separate speakers, which is ripe ground for errors, so you (or Dirac) need to match the competence of those KEF engineers to arrive at that integrated, cohesive result.