• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

THE Boutique Bass Cab Shootout

#241
DukeLeJeune said:
Imo you are absolutely correct.

It can SOUND LIKE the room becomes "overloaded" at a certain SPL, and that is an accurate description of our PERCEPTION, but what's really happening is this: The ear is having a NON-LINEAR response to what is actually a LINEAR acoustic effect. So it sounds like a distortion sets in at a certain volume level, but really it was there all along, in the same proportion, but it was simply below our detection and/or objection threshold.
Click to expand...

So you'll hear the distortion on the recorded track when playback volume rises?
 
  • Like
Reactions: MDBass and smeet
#242
DukeLeJeune said:
Imo you are absolutely correct.

It can SOUND LIKE the room becomes "overloaded" at a certain SPL, and that is an accurate description of our PERCEPTION, but what's really happening is this: The ear is having a NON-LINEAR response to what is actually a LINEAR acoustic effect. So it sounds like a distortion sets in at a certain volume level, but really it was there all along, in the same proportion, but it was simply below our detection and/or objection threshold.
Click to expand...
Very nice explafication, Duke. That makes it clear, and seems to explain many other perceptual issues too.
 
  • Like
Reactions: ekfritz and MDBass
#243
DukeLeJeune said:
Imo you are absolutely correct.

It can SOUND LIKE the room becomes "overloaded" at a certain SPL, and that is an accurate description of our PERCEPTION, but what's really happening is this: The ear is having a NON-LINEAR response to what is actually a LINEAR acoustic effect. So it sounds like a distortion sets in at a certain volume level, but really it was there all along, in the same proportion, but it was simply below our detection and/or objection threshold.
Click to expand...

What he said! :thumbsup:
 
  • Like
Reactions: MDBass
#244
DukeLeJeune said:
Imo you are absolutely correct.

It can SOUND LIKE the room becomes "overloaded" at a certain SPL, and that is an accurate description of our PERCEPTION, but what's really happening is this: The ear is having a NON-LINEAR response to what is actually a LINEAR acoustic effect. So it sounds like a distortion sets in at a certain volume level, but really it was there all along, in the same proportion, but it was simply below our detection and/or objection threshold.
Click to expand...

Well yeah that is true as far as the linear effects that are present at low volumes are concerned. But in real life spaces, as opposed to a bona fide acoustic lab, there are significant acoustic artifacts that can occur at higher volumes that are mechanically constrained by the springiness of the some fixture, or simply the mass [rest inertia] of some structure when volume is low. Thus, because there is some non-trivial constraint to responding to vibration [or constraing the mode of induced vibration] there can be artifacts at higher volumes that are simply not present at low volumes [not demonstrably extant as opposed to merely not noticeable to human ears].

Without getting totally insane you could end up making signals loud enough to create artifacts not present at modest volumes that are powerful enough to not just make your measurements wonky but be starkly noticeable to the listeners = for example high amplitude signals impinging on: loose bits in spring loaded door hardware, sheet metal parts of light fixtures, wall panels that then flex to the point that they actually rattle against the studs at a loose spot, the cat which then tries to hide in the piano... et cetera.
 
  • Like
Reactions: dukeorock, MDBass, agedhorse and 1 other person
#245
Foz said:
Well yeah that is true as far as the linear effects that are present at low volumes are concerned. But in real life spaces, as opposed to a bona fide acoustic lab, there are significant acoustic artifacts that can occur at higher volumes that are mechanically constrained by the springiness of the some fixture, or simply the mass [rest inertia] of some structure when volume is low. Thus, because there is some non-trivial constraint to responding to vibration [or constraing the mode of induced vibration] there can be artifacts at higher volumes that are simply not present at low volumes [not demonstrably extant as opposed to merely not noticeable to human ears].

Without getting totally insane you could end up making signals loud enough to create artifacts not present at modest volumes that are powerful enough to not just make your measurements wonky but be starkly noticeable to the listeners = for example high amplitude signals impinging on: loose bits in spring loaded door hardware, sheet metal parts of light fixtures, wall panels that then flex to the point that they actually rattle against the studs at a loose spot, the cat which then tries to hide in the piano... et cetera.
Click to expand...
When something sounds off......... Always blame the cat.
 
  • Like
Reactions: ekfritz, Nofrets2, John D Harris and 3 others
#247
Maybe something like this with the mic centered on the drivers as Tom suggests [this was a woofer measurement thus the mic placement ignores the mid and tweet].

testrig2_zps028b544b.jpg
 
  • Like
Reactions: dukeorock, MDBass, monsterthompson and 1 other person
#248
Foz said:
Maybe something like this with the mic centered on the drivers as Tom suggests [this was a woofer measurement thus the mic placement ignores the mid and tweet].

View attachment 2885610
Click to expand...

I had considered doing something like that, but it's easier to do vertical measurements when we do our 15-30-45 degree off-axis measurements.
 
  • Like
Reactions: MDBass and Foz
#253
Foz said:
Is that [off axis data collection] happening here?

If so, this thing is off the chain = I'm impressed.
Click to expand...

I hadn't originally planned on it for my own edification, but I would be willing to do so if enough people are interested.

Dependant, of course, on the folks loaning me the cabs (which is both players and builders at this point) being ammendable to letting me keep the cabs awhile longer.

No possible way to quadruple the workload before NAMM this weekend.
 
  • Like
Reactions: ahc
#255
Foz said:
Maybe something like this with the mic centered on the drivers as Tom suggests [this was a woofer measurement thus the mic placement ignores the mid and tweet].

View attachment 2885610
Click to expand...

Never would have even thought to set it up this way, but I do have barstools and boom stands on hand...we'll see how it shakes out
 
#257
Foz said:
Maybe something like this with the mic centered on the drivers as Tom suggests [this was a woofer measurement thus the mic placement ignores the mid and tweet].

View attachment 2885610
Click to expand...

Look up, look down... unless this is a ceiling-less room you will have a standing wave situation between the floor and ceiling. Even without a ceiling, the floor boundary will insert a response artifact (especially sitting that high off of the floor boundary). No way will the response analysis be accurate, and the coherency values should indicate this.
 
  • Like
Reactions: ekfritz, murphy and MDBass
#259
Foz said:
Are you doing windowed frequency response data collection or just sound sample files?

Cause if you're just doing sound samples there aint much point in off axis stuff IMO.

My $0.02
Click to expand...

I was just planning on sound samples, but if enough people were interested I was going to make the stems downloadable for anyone who wanted to dive head first down the rabbit hole.
 
#260
Dave Hill said:
13 pages without a single sound clip or impression. WTH?! Lol
Click to expand...

Took awhile to get all of the cabs on-hand + an out of state funeral.

I've been specifically avoiding giving any impressions before posting the samples, but I'd be happy to respond via PM if you're interested in hearing them beforehand.
 
  • Like
Reactions: MHT75 and Lowendtech

Latest posts

Top Bottom
Back