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Multi-Way Conventional loudspeakers with crossovers

baffle step compensation methods
baffle step compensation methods
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Old 19th February 2013, 08:21 AM   #1
soundnovice is offline soundnovice
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Default baffle step compensation methods

if my understanding about BSC is correct, is it possible to implement BSC by choosing a woofer with 3-6dB more sensitivity than tweeter? something similar approach is taken in case of 2.5way speakers. My requirement is to implement BSC without including extra passive components? any other such techniques or methods to avoid BS?

Last edited by soundnovice; 19th February 2013 at 08:25 AM.
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Old 19th February 2013, 10:24 AM   #2
planet10 is offline planet10  Canada
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baffle step compensation methods
Baffle Diffraction Step

dave
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Old 19th February 2013, 10:38 AM   #3
chris661 is offline chris661  United Kingdom
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The problem with what you describe is that baffle step tends to happen at hundreds of Hz. Tweeters will not reach down there, so you'll have to crossover higher. That means the typical baffle step response will show up in the response of the woofer, and needs to be compensated for.

One work-around is using a small full-range (or two-way, making a 3-way system) with a woofer, and crossing at the baffle step frequency.

I do this. Works rather well: you get the midrange "magic" of a FR driver, but take the stress of LF away, giving cleaner midrange.

Note that the woofer ought to be 3-6dB more sensitive than the FR driver. In my case, its about 10dB less sensitive. I use the brute-force solution of two amplifiers, of ~15w and 120w/ch for the FR and bass drivers, respectively.

Chris
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Old 19th February 2013, 11:00 AM   #4
soundnovice is offline soundnovice
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Quote:
Originally Posted by chris661 View Post

One work-around is using a small full-range (or two-way, making a 3-way system) with a woofer, and crossing at the baffle step frequency.

I do this. Works rather well: you get the midrange "magic" of a FR driver, but take the stress of LF away, giving cleaner midrange.

Note that the woofer ought to be 3-6dB more sensitive than the FR driver. In my case, its about 10dB less sensitive. I use the brute-force solution of two amplifiers, of ~15w and 120w/ch for the FR and bass drivers, respectively.

Chris
something similar is what in my mind. i am planning to use below sub/woofer with ff85wk.
Iwai Electronics Pvt. Ltd.

ff85wk has published SPL of 86.5dB and this sub has 90dB. using two of them in series will give extra boost at low end(may be around 3dB).
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Old 19th February 2013, 11:22 AM   #5
Kjeldsen is offline Kjeldsen  Denmark
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A wide baffle is also a good solution.
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Old 19th February 2013, 11:34 AM   #6
chris661 is offline chris661  United Kingdom
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Using two in series and driving with a voltage source will give exactly zero gain, IIRC.
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Old 19th February 2013, 11:46 AM   #7
soundnovice is offline soundnovice
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Quote:
Originally Posted by chris661 View Post
Using two in series and driving with a voltage source will give exactly zero gain, IIRC.
what if connected in parallel? then the SPLs add? (assuming 8ohm woofer)
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Old 19th February 2013, 09:15 PM   #8
tvrgeek is offline tvrgeek  United States
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Quote:
Originally Posted by soundnovice View Post
what if connected in parallel? then the SPLs add? (assuming 8ohm woofer)
Woofers tend to be far less efficient than tweeters, so best learn how to implement this correctly, or any of the cheating ways. If that is not your cup of tea, build flush with the walls.
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Old 19th February 2013, 09:31 PM   #9
sreten is offline sreten  United Kingdom
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Hi,

For two bass drivers efficiency increases by 3dB.

2 4 ohm drivers in series the SPL remains the same
due to doubling the impedance cancelling the gain.
In parallel the SPL goes up 6dB due to halving the
impedance adding 3dB to the 3dB efficiency gain.

6dB is what you'd expect comparing 2 ohms to 8 ohms.

rgds, sreten.
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Old 20th February 2013, 12:21 AM   #10
PeteMcK is offline PeteMcK
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line level: Baffle Step Compensation

best method is to simply oversize the woofer inductor in a passive xover
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Impedance varies with frequency, use impedance plots of your drivers and make crossover calculations using the actual impedance of the driver at the crossover frequency
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