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Time For a New Sub?

Zing

Retired Admin
Famous
#1
Let's talk about the severe lack of output I have below 40Hz.

Green=Flat Purple=EQ



As you can see, I was able to EQ the subwoofer to increase output at 25Hz and below so that suggests to me, this isn't a null issue. However, whether flat or EQ'd, you can also see I have a real problem below 40Hz. Both drivers are working and I didn't have this problem in my old room. So the logical process of elimination tells me it's the new room. What can be done about it?

Remember, that I have two large openings into other rooms, all of which are open to others, including the stairs to the second floor. So basically, my ENTIRE house is my "room", at least as far as bass is concerned.

Does this make me the exception that proves the rule? Do I need a second sub or do I simply need a better performing sub? Or am I just f***ed until I choose a new room or seal my current off from the rest of the house?
 

Flint

"Do you know who I am?"
Superstar
#2
Measure the response with the mic in a corner. Chances are the low bass will suddenly appear. You cannot solve acoustics issues with a new sub.
 

Zing

Retired Admin
Famous
#3
Flint said:
Measure the response with the mic in a corner. Chances are the low bass will suddenly appear.
And if it does, what will it mean? I should look for a new location for the sub, seating, both??? Something else entirely?
 

Zing

Retired Admin
Famous
#6
Look what I fixed today. :dance:



OK, OK, fixed is a relative term in this case and used very, very loosely. :(
 

Zing

Retired Admin
Famous
#8
Maximo said:
Fixed how? You moved it? Could you HEAR the difference?
Yes, I moved it - from the left rear corner to the left front corner. And yes, I can hear (and feel) the improvement. It looks like absolute ass up there but it gets the job done. Alright, that's kind of relative too. Let's say it's gets the job done better.

And for you technical purists, you should probably subtract 3dB from 90Hz on down because I've since recalibrated and set the sub channel 3dB lower.
 

PaulyT

Behind the Curtain
Staff member
Administrator
Moderator
Superstar
#10
Cool, any improvement is good! That's a weird curve, though - why the dropoff @ 3k?
 

Flint

"Do you know who I am?"
Superstar
#11
Dang! Them acoustics stuffs are mighty and awe-inspiring! One cannot adjust knobs or buy new gear to solve acoustics issues.
 

Zing

Retired Admin
Famous
#12
PaulyT said:
Cool, any improvement is good! That's a weird curve, though - why the dropoff @ 3k?
I was not trying to plot a full-bandwidth in-room response. I was only interested in correcting the plummet below 50Hz so I changed the input sampling frequency to 8kHz since I was doing - wait for it - low frequency work.

When I first started, I disconnected my speaker so I was only seeing the sub's output. It wasn't until I started experimenting with crossover points and phase settings that I reconnected the speaker.
 

Zing

Retired Admin
Famous
#13
Flint said:
Dang! Them acoustics stuffs are mighty and awe-inspiring! One cannot adjust knobs or buy new gear to solve acoustics issues.
Flint - that was the most verbose version of "Told ya!" I've ever seen. :eek:bscene-buttred:
 

Flint

"Do you know who I am?"
Superstar
#14
Thanks for noticing.

By the way, I've been telling everyone for 7 long years and most still don't believe me.
 

Batman

Well-Known Member
Staff member
Moderator
Famous
#15
Acoustics?! :angry-banghead: Zing was just dragging the sub around the room 'til he got lucky...
 

Zing

Retired Admin
Famous
#16
Batman said:
Acoustics?! :angry-banghead: Zing was just dragging the sub around the room 'til he got lucky...
Actually, that's precisely what I intended to do and - to a certain degree - what I did.
 

Maximo

Well-Known Member
#17
:text-threadjacked: So, I have my sub where I think will be a good spot asthetically. I KNOW this isn't the way to do it. But is there protocol for getting the most out of it in it's current location? It's an older infinity that has rabos, that, by my acount is some kind of parametric equalizer thingamadoodle. Can I use that to tweek it to get some good response in the listening area? Or should I just turn it off and drag my sub around? :text-threadjacked:
 

Flint

"Do you know who I am?"
Superstar
#18
Maximo said:
So, I have my sub where I think will be a good spot asthetically. I KNOW this isn't the way to do it. But is there protocol for getting the most out of it in it's current location? It's an older infinity that has rabos, that, by my acount is some kind of parametric equalizer thingamadoodle. Can I use that to tweek it to get some good response in the listening area? Or should I just turn it off and drag my sub around?
Really, there is nothing you can do to eliminate performance issues caused by bad acoustics other than fixing the acoustic problems. There are no electrical tricks to make a node go away and still hear content at that frequency. You cannot make a true null in the response audible by using an EQ. What you can do is reduce the impact of those acoustic problems in the frequency amplitude domaon at the cost of reducing the peak SPL of the sub and also effectively removing the output at certain frequencies.

More effective, if you cannot move the sub and listener to get better sound, is to install acoustic treatments, spcifically bass traps. The proper application of bass traps can reduce the negative impact of acoustic issues in both the static amplitude domain (frequency response) and in the dynamic time domain (RT60, or ringing).
 

Maximo

Well-Known Member
#19
Ok. I have no idea how it will sound where it is at. Still waiting on other pieces before I can set it up. I will use the rabos mic to set a curve and see what I get and report back.
 

DIYer

Well-Known Member
Famous
#20
Zing said:
Yes, I moved it - from the left rear corner to the left front corner. And yes, I can hear (and feel) the improvement. It looks like absolute ass up there but it gets the job done. Alright, that's kind of relative too. Let's say it's gets the job done better.
So, will you be sending the fund that was to go to "second sub or better performing sub" to Flint now? :doh:
 
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