Ok, why offset mids and tweets?

jbeckva

jbeckva

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Here's a good question I think for all ya's out there..

Why do we have speakers where the mids and tweeters are offset, and not placed in the center of the cabinet like the woofer? I think it has something to do with proper phase and imaging, right?

But... shouldn't they be offset in a mirrored fashion between left and right speakers? That's one thing that bugs me about these CV's I have - the drivers on the left are closer to my ear than the right side because both of them have the drivers offset to the right of center.

Hmmm.. might be some fun creating new cabinets. There would be an interesting project, eh?
 
You build your boxes to match the woofer. It has to move a certain amount of air. Sealed cabs are bigger than ported. So when you design a speaker you try to make them stand out. So you put the others in different positions if you want. Some do it to set them in phase and all kind of things.

Larry
 
Listen to an Altec 604 or EV coaxial or Utah Celesta and tell me. Unless there's a bit of power to the mids or tweeter inline, I don't know if the woofer performance can be addressed as well and that's why large cabinets are often used to add bottom to the lower frequencies with co/triaxiala.

6x9s used to do just fine in cars, or oblong in the rear and round in the doors of smaller cars...these are giving way to separates as well. Some car makers place a tweeter in the A pillars, some type of midrange or midwoofer in the dashtop and maybe a 2 or 3 way in the back but a lot of that gets taken out or redone with a new amp and a sub.

Now don't get me wrong, I like banda but I came across a car where I couldn't even appreciate that tubalike bass line and that was my sign. Good grief! Please learn to go deaf correctly.

To finally answer you, keeping the bass and mid, treble apart should keep then from having phasing and harmonics errors.

They look pretty too. That should be enough.
 
More importantly, the drivers should be offset in the Z direction to keep the front face of the driver diaphragm directly in front of the voice coil aligned in the same plane. Hardly any speaker manufacturers do this (a few do). This minimizes phase distortion, especially at the crossover points when 2 drivers are producing the same audio signal. Keeping the component drivers (woofer, mid, tweet) in separate cabinets allows this to be easily achieved.
 
Sometimes drivers can be offset horizontally to compensate for a smoother baffle step in the frequency response. That is at the transition point where frequency goes from being very directional (high), to become wider to more omnidirectional (low). This step in frequency response is affected by the size of the wavelength and how wide the front baffle is. Offsetting a driver will create two small points of transition rather then one big one. There are different ways to attack that problem, but if they are offset for that purpose specifically, then the speaker pairs will generally be sold in mirror imaged pairs.
 
Left.....
 

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Right...
 

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Yah.. that's what I'd expect from any set of speaker with them offset like that - mirrored. But of course these CV's aren't like that.. dem cheap bassids...
 
I'd say they are offset because they look good that way, and it doesn't much matter if they are. The mids and highs usually radiate right to you ears, while the lower frequencies are less directional and actually get sound reinforcement from not going straight to your ears. Probably why it doesn't matter where in the room you place your subwoofer, or woofer for that matter. :cyclops:
 
jbeckva said:
Yah.. that's what I'd expect from any set of speaker with them offset like that - mirrored. But of course these CV's aren't like that.. dem cheap bassids...
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Because Cerwin is GOD. No further explanation is required.
 
orange said:
jbeckva said:
Yah.. that's what I'd expect from any set of speaker with them offset like that - mirrored. But of course these CV's aren't like that.. dem cheap bassids...
Click to expand...

Because Cerwin is GOD. No further explanation is required.
Click to expand...

**Cough**, Doc let go of my nut!!! :o

Cerwin is a cheap company with very nice speakers, I've had some, and many others that are not mirror image in the tweet/mids, some of us can hear the diff, some can't, get ye to a Martin Logan dealer dude, a nice curved piece of mylar will change your life baby!!!
 
It's the nice draft on his cheeks.
 
laatsch55 said:
SLAB LOVER!!!
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Till the day they put me in a 'hopefully, M-L box', yeah baby, I'ma fiend for a nice pair a of Slab's :mrgreen:

Pullin' some serious loads, draggin' the A and B rails into the ditch, makin' them sing for their supper.....


Waaay OT, sorry...kinda.....hehehehe!!
 
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