Eminence Alpha 15" has bass in OB? - Page 2 - diyAudio
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Old 27th September 2012, 08:36 PM   #11
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Quote:
Originally Posted by sreten View Post
Hi,

Its best to assume all Eminence measurements below say 100Hz are inaccurate.

rgds, sreten.
Eminence measurements are accurate for the specified measurement condition:

The microphone is mounted 1m from a 2 ft. X 2 ft. baffle built into the wall with the speaker mounted flush against a steel ring for minimum diffraction, in a 2700 cu.ft. chamber with fiberglass on all six surfaces (three with custom-made wedges) driven by a Hafler P1500 Trans-Nova amplifier.

Whether that measurement has any correlation to a usual environment is certainly open to discussion, but it allows for comparison of their different drivers under the same test conditions.

That said, anyone concerned about having enough low bass should not be considering OB as a solution.
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Old 28th September 2012, 09:03 AM   #12
sreten is offline sreten  United Kingdom
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Hi,

None of the Eminence measurements show bass responses
that agree with the published parameters of the drivers,
ergo the measurements are inaccurate in the bass.

rgds, sreten.
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Old 28th September 2012, 11:37 AM   #13
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On a personal note i believe the measurements are real but need not agree with the t/s parameter. T/s parameters is just an attempt to model the behaviour of the driver based on a mass and a spring with a dampener, does not take into consideration the acoustical properties of the cone, flexing of the cone etc.

I believe the t/s parameters will bring us closer to understanding the properties of the speaker but is no a substitute for the real measurement. There is more to play. After all you can get all the t/s parameter without having a microphone. You can even get a t/s parameter of a loudspeaker without a cone. I see you try to get that to sound....

Oon
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Old 28th September 2012, 11:55 AM   #14
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On a different note, do you guys think that eminence is measuring their speakers differently from other manufacturers, and hence they disadvantage themselves? Kinda strange.... if it was done by one of us i would sincerely doubt the result, but since it is done by a manufacturer i am sure he did it properly.

One discrepancy between their measuring technique and our living room is their measurement is done in an acoustically dead room, anechoic chamber. Our living room will definitely have more reflections off the walls, and bass is certainly more reflective, and less likely to be absorb, the bass response should certainly be better....

Oon

Oon
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Old 28th September 2012, 12:31 PM   #15
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Quote:
Originally Posted by oon_the_kid View Post
Before we get any further on this topic, do most people introduce a bass boost to the speaker either by passive means or active means by biamping?


Oon
Yes, I do with OB.
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Old 28th September 2012, 12:37 PM   #16
sreten is offline sreten  United Kingdom
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Quote:
Originally Posted by oon_the_kid View Post
On a personal note i believe the measurements are real but need not agree with the t/s parameter. T/s parameters is just an attempt to model the behaviour of the driver based on a mass and a spring with a dampener, does not take into consideration the acoustical properties of the cone, flexing of the cone etc.

I believe the t/s parameters will bring us closer to understanding the properties of the speaker but is no a substitute for the real measurement. There is more to play. After all you can get all the t/s parameter without having a microphone. You can even get a t/s parameter of a loudspeaker without a cone. I see you try to get that to sound....

Oon
Hi,

Beliefs based on personal opinion with no technical basis are just that.

Technically you don't have a leg to stand on, and your making no
attempt to answer the OP's question, just muddying the water.

rgds, sreten.
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Last edited by sreten; 28th September 2012 at 12:46 PM.
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Old 28th September 2012, 12:38 PM   #17
tinitus is offline tinitus  Europe
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guys, you should have look at Fane Sovereign series
several OB drivers to choose from there
and one them a big 12" fullrange
even I could be tempted
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Old 28th September 2012, 12:42 PM   #18
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Quote:
Originally Posted by sreten View Post
Hi,

Beliefs based on personal opinion with no technical basis are just that.

Technically you don't have a leg to stand on, and your making no
attempt to answer the OP's question, just muddying the water.

rgds, sreten.
Just maybe your taking my response out of context. Lighten up!
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Old 28th September 2012, 12:49 PM   #19
sreten is offline sreten  United Kingdom
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Just maybe your taking my response out of context. Lighten up!
Hi, Sorry, I wasn't replying to your post, rgds, sreten.
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Old 28th September 2012, 01:11 PM   #20
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Another thought comes to mind. This is a high effienciey speaker with fairly low x-max. So there is a possibility the coil that is moving out of the magnetic gap and the experiencing poor linearity. In other words. It might be experiencing soft clipping at 1w. So it might have a response much close to its t/s parameter at 0.1W. Which is still pretty loud....

Oon
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