20-40hz problem in room. Pease help :(

[nathan_h]

Not bad. Change your crossover from 80 down to 60. May help.

 

[Pogre]

After a run of Audysssey, these were the results. however any slight adjustment to levels afterwards and I get a HUGE null between 80-100hz which is another problem I've been battling with. I assume it's some kind of phase issue with the mains. I'll do a few more runs tomorrow and get the graphs up

That looks more reasonable. It doesn't just drop off a cliff and looks more like a curve. There's a narrow dip at 80-ish hz but it doesn't look "huge" to me. I definitely can see a second sub helping out the bottom end.

 

[Pogre]

Not bad. Change your crossover from 80 down to 60. May help.

I'm actually thinking the opposite. When I had a dip in the same 75-80 hz range a higher crossover fixed it. A dip that narrow isn't too bad tho.

 

[TLS Guy]

After a run of Audysssey, these were the results. however any slight adjustment to levels afterwards and I get a HUGE null between 80-100hz which is another problem I've been battling with. I assume it's some kind of phase issue with the mains. I'll do a few more runs tomorrow and get the graphs up

That looks better. That low Q null just above 80 Hz, is of no practical significance and will not be audible.

I can tell you, you will not get to -3db at 20 Hz with that sub. You need at least five to six times the power at 20 Hz to do that. That will take two beefy subs I think.

 

[William Lemmerhirt]

This is my suspicion as well, which is why I asked if he has better bass in the north or south sides of the room. I didn't consider the open stairway because it looks like there are doors he can close for that, right?

I thought of the staircase too. But my whole right side is open and I’m pretty flat to the 14-16hz range.
Wonder where that 115 rolls off at?

 

[Pogre]

That looks better. That low Q null just above 80 Hz, is of no practical significance and will not be audible.

I can tell you, you will not get to -3db at 20 Hz with that sub. You need at least five to six times the power at 20 Hz to do that. That will take two beefy subs I think.

I agree. Normally when I see "Klipsch subwoofer" I cringe, but that specific model is actually not a terrible performer for what it is. A little lean on power and their published fr shows 18 hz on the low end but they don't specify any +/- so hard to say for sure. A pair of PB4000s would rock that room for sure tho!

 

[Pogre]

I thought of the staircase too. But my whole right side is open and I’m pretty flat to the 14-16hz range.
Wonder where that 115 rolls off at?

They give fr but don't specify +/-. I think KEW is who said it's actually a pretty good sub for a Klipsch sub tho.

 

[Darren-s-88]

That looks better. That low Q null just above 80 Hz, is of no practical significance and will not be audible.

I can tell you, you will not get to -3db at 20 Hz with that sub. You need at least five to six times the power at 20 Hz to do that. That will take two beefy subs I think.

The dip on the last graph I posted is definitely reasonable, it's the second I seem to adjust sub levels that there's a huge dip. I'll get measurements tomorrow and post them up to how what I mean. think I've bored her enough with it for today haha

 

[lovinthehd]

They give fr but don't specify +/-. I think KEW is who said it's actually a pretty good sub for a Klipsch sub tho.

View attachment 44247

Had a pretty good review with measurements from Brent Butterworth from what I remember....

 

[nathan_h]

I'm actually thinking the opposite. When I had a dip in the same 75-80 hz range a higher crossover fixed it. A dip that narrow isn't too bad tho.

True.

Not too bad and it is possible a higher crossover might be better as well.

I should have suggested experimenting in both directions.

After a run of Audysssey, these were the results. however any slight adjustment to levels afterwards and I get a HUGE null between 80-100hz which is another problem I've been battling with. I assume it's some kind of phase issue with the mains. I'll do a few more runs tomorrow and get the graphs up

The more I look at this the more I think this is excellent results given your room size, this particular sub, etc.

 

[William Lemmerhirt]

True.

Not too bad and it is possible a higher crossover might be better as well.

I should have suggested experimenting in both directions.



The more I look at this the more I think this is excellent results given your room size, this particular sub, etc.

What are dims(feeling stoopid) of this room? From the drawing, it looks like about the size of a one car garage stall. I can’t believe that 115sw wouldn’t be solid to at LEAST 22hz.

 

[William Lemmerhirt]

They give fr but don't specify +/-. I think KEW is who said it's actually a pretty good sub for a Klipsch sub tho.

View attachment 44247

Imo it’s Klipsch’ best sub.
Doesn’t probably matter, but here’s a shot I lifted from “somewhere else”. It’s the same sub, but it’s good down to about 22 where it has a little bump from the room. My gut still says, don’t trust that mic.

 

[nathan_h]

Given the open areas it looks like about 20x30 feet, maybe larger because the stairs are open and we don’t know what’s up there.

 

[PENG]

After a run of Audysssey, these were the results. however any slight adjustment to levels afterwards and I get a HUGE null between 80-100hz which is another problem I've been battling with. I assume it's some kind of phase issue with the mains. I'll do a few more runs tomorrow and get the graphs up

Which Audyssey version are you using? It it is XT32 and can use the Editor App them I am sure you can do much better yet, and it isn't too bad the way it is already.

The level seems a little low, you probably should try turning the volume up to get at least 65 dB average, for better accuracy.

 

[Darren-s-88]

sorry guys been a bit busy and haven't had chance to post, I have a few home made subs kicking around and decided to turn a small sealed sub in to a ported mid bass module using a kappa pro 12a driver. crossed the mains over at 250hz and stuck the MBM behind the TV.. After a lot of trial and error I got a decent result, the only issue is my sweet spot is pretty narrow and if I adjust one sub even a decibel or 2 higher without the other it throws the whole thing off which I don't understand.

The graph with the best response was how I've left it, the second showing what happens if I turn up one sub slightly. Still overall not happy and going to order miniDSP, but things are certainly looking a lot better. Also that tight fast tactile bass feel you get from pro drivers (kappa pro) is a very welcomed addition

what I don't understand is when measuring subs separately, there's no dip in mid bass with the MBM. However play them both together and it can create nulls that weren't previously there? (like adjusting the volume on one sub too) adjusting the phase can help but creates a null somewhere else.. can speakers be in phase at some frequencies and out of phase at others?

 

[Pogre]

By null, do you mean that narrow dip at 92 hz? That's not much of a null and I think would virtually disappear with some smoothing (assuming you didn't already). Really, both measurements look more similar than different, tho "latest" is a bit better. That said, I think a Mini will help you dial that in even better. It's not a horrible response, tho you should change your vertical scale to 5 dB instead of 10. Doesn't look as nice, but it will give you a more accurate picture. It helps when you're tweaking with a Mini.

 

[nathan_h]

Agree that the newest measurements are looking quite good.

And about nulls: Yes, dual subs can create horrific nulls where there wasn't one before. That is why careful placement and calibration/adjust of each one is critical to getting the advantages of dual subs.

(If all you want it more output, just stack them together. If you want more even bass across multiple seats, place them separately, correctly.)

REW actually has a very cool modeling program. It uses a rectangular sealed room so it won't tell you where to put your subs, but you can see the impact or good placement versus bad placement by moving subs and listeners around the room.