Hello folks,
I am crossing an 18Sound 12NMB420 at 800 Hz to a Coral M-100 driver on a 400Hz tractrix horn. The 12" midrange sits in a semi open baffle enclosure (semi-cardoid).
Right now they are crossed passively using a 2. order LR topology. As you can see the mid overlaps the Coral quite a lot while the breakup region is still rather pronounced (1.5 to 3 kHz).
1/6 octave smoothing - please ignore everything above 5 kHz as my soundcard exhibits weird low pass behavior above this frequency.
What I am proposing is a mixed order crossover: 3. order mid-woofer and 1. order compression driver. Why this topology? Well, I wish to retain the 2. order type central vertical lobe pattern. To me this yields a very constant and seamless sound nicely showcasing what the drivers can do. I listen from 14 feet away (4.5 meters) and the sound is very coherent over a wide sweet spot.
You are all welcome to suggest the pros and cons of mixed order XO in this particular application.
Cheers
Kris
I am crossing an 18Sound 12NMB420 at 800 Hz to a Coral M-100 driver on a 400Hz tractrix horn. The 12" midrange sits in a semi open baffle enclosure (semi-cardoid).
Right now they are crossed passively using a 2. order LR topology. As you can see the mid overlaps the Coral quite a lot while the breakup region is still rather pronounced (1.5 to 3 kHz).
1/6 octave smoothing - please ignore everything above 5 kHz as my soundcard exhibits weird low pass behavior above this frequency.
What I am proposing is a mixed order crossover: 3. order mid-woofer and 1. order compression driver. Why this topology? Well, I wish to retain the 2. order type central vertical lobe pattern. To me this yields a very constant and seamless sound nicely showcasing what the drivers can do. I listen from 14 feet away (4.5 meters) and the sound is very coherent over a wide sweet spot.
You are all welcome to suggest the pros and cons of mixed order XO in this particular application.
Cheers
Kris
Nice looking rig! The mid reminds me of Gary Pimm's mid cardioid. Works well!
At first glance, I'd say you need a lot more underlap. But I can't really see well enough. Do you have your measurement files for each driver? If you also have them in a text format (like FRD) that would be great.
Impedance sweeps will be very handy if you are going to do this passive.
If you have that info, I'd be happy to help. It can take a lot of hours and hand banging to get it right. Another set of eyes can sure help!
At first glance, I'd say you need a lot more underlap. But I can't really see well enough. Do you have your measurement files for each driver? If you also have them in a text format (like FRD) that would be great.
Impedance sweeps will be very handy if you are going to do this passive.
If you have that info, I'd be happy to help. It can take a lot of hours and hand banging to get it right. Another set of eyes can sure help!
18Sound 12NMB420 resp.
The response I've measured is virtually a dead ringer for the one on the product sheet here 12NMB420 - High Output MB Neodymium Driver.
The response I've measured is virtually a dead ringer for the one on the product sheet here 12NMB420 - High Output MB Neodymium Driver.
Good! I see that you have the WT3 plots. Can you export them as ZMD files, zip and post them here? One for the 12 and one for the horn.
Do you have the measured FR of the horn and driver? I'll go from the 18 sound FR for the 12.
BTW, how much attenuation are you now using for the horn?
Let's see what Michael and I can come up with from that.
Do you have the measured FR of the horn and driver? I'll go from the 18 sound FR for the 12.
BTW, how much attenuation are you now using for the horn?
Let's see what Michael and I can come up with from that.
Stereophile: Spica TC-60 loudspeaker
"..Spica's unique combination of a fourth-order low-pass filter for the woofer and a first-order high-pass for the tweeter.."
(4th Bessel and 1st Butterworth.)
"..Spica's unique combination of a fourth-order low-pass filter for the woofer and a first-order high-pass for the tweeter.."
(4th Bessel and 1st Butterworth.)
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I'll try to export the WT3 plots tomorrow and see if I can find the driver+horn measurements.
I've padded it 12 db to get it down to 100 db sensitivity. The tractrix horn provides more on axis power than a sectoral. Maybe as much as 7 db.
more stuffing
I made these measurements yesterday. The speakers are slightly tweaked as I added a bit more stuffing to the open backed enclosure.
1/3 octave smooth. 0 to 30 deg.
The 200 Hz hump looks better.
I'll see if I can get a measurement session going this side of christmas...
I made these measurements yesterday. The speakers are slightly tweaked as I added a bit more stuffing to the open backed enclosure.
1/3 octave smooth. 0 to 30 deg.
The 200 Hz hump looks better.
Hi Pano,
I sorry but finances do not permit such a purchase (yes, I use ARTA). I am paying two mortgages + a loan and until I sell my other apartment I'll be on a tight budget.
Now if only somebody would loan me a power amp then I could roll in my double 15" ATC sub with a passive line level XO...
I sorry but finances do not permit such a purchase (yes, I use ARTA). I am paying two mortgages + a loan and until I sell my other apartment I'll be on a tight budget.
Now if only somebody would loan me a power amp then I could roll in my double 15" ATC sub with a passive line level XO...
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