Table Tuba build!!

[digital_chris]

What about when I run test tones from 30hz up to 100hz ( 5hz increments ) and they are all directional, would that mean it's just a location problem? If I have my receiver LPF / HPF settings and my amp filter both set at 60hz, wouldn't that create the steep slope you mention?

[Bill Fitzmaurice]

What about when I run test tones from 30hz up to 100hz ( 5hz increments ) and they are all directional, would that mean it's just a location problem? If I have my receiver LPF / HPF settings and my amp filter both set at 60hz, wouldn't that create the steep slope you mention?

There's no way you can directionally locate a 30 Hz tone. If you can what you're hearing isn't 30Hz, it's harmonics at 120 Hz and above. That indicates a serious THD problem with the electronics.

[petegt]

What about when I run test tones from 30hz up to 100hz ( 5hz increments ) and they are all directional, would that mean it's just a location problem? If I have my receiver LPF / HPF settings and my amp filter both set at 60hz, wouldn't that create the steep slope you mention?

There's no way you can directionally locate a 30 Hz tone. If you can what you're hearing isn't 30Hz, it's harmonics at 120 Hz and above. That indicates a serious THD problem with the electronics.

+1

Is that with the mains disconnected? if not I would recommend you disconnect them so you can focus on the sub

Could it be that a panel/s is vibrating? (could be the issue you heard while watching the matrix)
A panel on one of my tat's rattled before and made it very directional no matter what frequency and did sound similar to a driver bottoming out.

[digital_chris]

Well, I decided to do a replay of those test tones, my windows and blinds do rattle in the corner when playing around 40-55hz so it's easy to know where the bass is but I can still localize tones from 40-45hz and up, but maybe not so much below 40hz. Although, throughout the whole range, never does it sound like the bass is coming from "everywhere" or even the front of the room for that matter. My mains were disconnected for this test as well.

Man, I just wish some of you could come over and hear this to either tell me something is in fact wrong with my setting/setup or that my expectations are just to high..

[tdogg]

Well, I decided to do a replay of those test tones, my windows and blinds do rattle in the corner when playing around 40-55hz so it's easy to know where the bass is but I can still localize tones from 40-45hz and up, but maybe not so much below 40hz. Although, throughout the whole range, never does it sound like the bass is coming from "everywhere" or even the front of the room for that matter. My mains were disconnected for this test as well.

Man, I just wish some of you could come over and hear this to either tell me something is in fact wrong with my setting/setup or that my expectations are just to high..

whats your location?

[digital_chris]

CT

[DJPhatman]

My mains were disconnected for this test as well.

This is a bit of your "problem". Hook the whole system up and test. Then, disconnect the sub. You should not really "notice" the bass, until it's not there anymore.

Although, throughout the whole range, never does it sound like the bass is coming from "everywhere" or even the front of the room for that matter.

This is the room, not the sub. Put the sub in the normal listening position, and search the room for the most bass. That is where to put the sub. But, some rooms will need more than one sub to tame room nodes. These are physics that can't be beaten. Except like a

[digital_chris]

I understand the basics on sub placement, but like I've already said, I can't/won't put the cab anywhere else because of the way I built it, just not going to happen.

[DJPhatman]

I understand the basics on sub placement, but like I've already said, I can't/won't put the cab anywhere else because of the way I built it, just not going to happen.

Then you will not be able to resolve your room node issues. Placement is key to the best results. Your unwillingness to properly place a sub results in the peaks and valleys of coverage. Laws of physics are a bummer.

[digital_chris]

I understand about peaks and nulls but I'm pretty sure that isn't what I'm dealing with. When the sub is in that corner, yes, the bass is very directional, but vs all of the other feasible places in the room, it's also where the bass sounds the best or loudest/strongest.

I just did a test and moved the cab up front with my mains, no room for it to stay there but I aimed the mouth at the right side of the TV wall and my problem went away. The bass was a little weaker but of course the sound was mush less directional, and that's what I'm looking for.

So, I guess placement is the problem, oh well, that just means another build will be in the near future for me

[Bill Fitzmaurice]

Bad placement doesn't result in the sub being locatable, that's purely a matter of midbass signal content that shouldn't be there.

[SeisTres]

Could it be that the lack of access cover and the close listening position might the cause of the problem? I know one time i was playing around with my t18 and removed the cover, it sounded "louder" up close, but the more further i moved, the less difference between with and without cover.

[Bill Fitzmaurice]

Could it be that the lack of access cover and the close listening position might the cause of the problem? .

Not if the access hole is facing the wall or floor as it's supposed to be.

[digital_chris]

Bad placement doesn't result in the sub being locatable, that's purely a matter of midbass signal content that shouldn't be there.

That's what I've been thinking all along but how come the bass is less localizable if I put the cab up front and very localizable when in the rear corner to my right? Both locations were being tested with the same movie.

[Bill Fitzmaurice]

Bad placement doesn't result in the sub being locatable, that's purely a matter of midbass signal content that shouldn't be there.

That's what I've been thinking all along but how come the bass is less localizable if I put the cab up front and very localizable when in the rear corner to my right? Both locations were being tested with the same movie.

If located closer to the mains they'll mask any midbass coming from the sub.