Hi everyone
I'm new to this forum and hope I can get a little help or building suggestions from you. 🙂
I would like to build a midbass enclosure for my Eminence Kappa 12A. The only requirement is that te driver has to be direct-radiating to produce also some mid sound.
Is it possible to build a horn or should I use a vented enclosure? The size does not matter much, but it should be no more than 100 cm high, 50 cm wide and 40 cm deep. Something like a like a floor standing box maybe?
The mid driver on this box will be a Fostex FD600 to play the mids and highs, or maybe a seperate tweeter for that.
My goal is to use this enclosure from about 80 to at least 650 Hz. I tried a simulation with Hornresp but I'm not there yet.
Thanks for any help in advance!
Jay
I'm new to this forum and hope I can get a little help or building suggestions from you. 🙂
I would like to build a midbass enclosure for my Eminence Kappa 12A. The only requirement is that te driver has to be direct-radiating to produce also some mid sound.
Is it possible to build a horn or should I use a vented enclosure? The size does not matter much, but it should be no more than 100 cm high, 50 cm wide and 40 cm deep. Something like a like a floor standing box maybe?
The mid driver on this box will be a Fostex FD600 to play the mids and highs, or maybe a seperate tweeter for that.
My goal is to use this enclosure from about 80 to at least 650 Hz. I tried a simulation with Hornresp but I'm not there yet.
Thanks for any help in advance!
Jay
Eminence suggests drivers with qt <0.4 are not suitable for sealed enclosures. Must be vented.
Eminence.com has a suggested cabinet design https://www.eminence.com/pdf/Kappa_12A_cab.pdf
fs 45 hz qt .27 vas 112.1 L useable frequency range 62-4200 hz rms power 450 w sensitivity 99.3 db 1w1m
They are suggesting a 1.7 cu ft box Vb 1.6 cu ft Fb 65 hz F3 73 hz 2 vents 3" ID length 2.3" 28.3 l/cuft 45.3 L
That f3 is just about what you wanted, 80 hz. You subtract off the volume of the panels, braces, and any other drivers in the box to get internal volume.
I would prefer a f3 of 62 hz. You would have to limit the wattage to not blow xmax. f3/f0 =1.38 Vb factor from David Weems 4th ed fig 5.8 0.7 .7*112 L = 78.4 L Port length for single 4" port per chart 5-8 ~1"
Two smaller ports of same area as 4" port can be used.
That 78 l box size is bigger than eminence suggests for the maximum. You can always cut a box down if it measures badly but you can't make it bigger. I intend to use coarse thread machine screws in my initial assembly of my box. I'm using MDF. Screw holes will be tapped. No glue until I'm happy with the sound measurements. You can also fill a too big box with felt, foam, or braces, which also serves to break up standing waves at the higher frequencies. Eminence said their design volume was for minimal fill.
Eminence.com has a suggested cabinet design https://www.eminence.com/pdf/Kappa_12A_cab.pdf
fs 45 hz qt .27 vas 112.1 L useable frequency range 62-4200 hz rms power 450 w sensitivity 99.3 db 1w1m
They are suggesting a 1.7 cu ft box Vb 1.6 cu ft Fb 65 hz F3 73 hz 2 vents 3" ID length 2.3" 28.3 l/cuft 45.3 L
That f3 is just about what you wanted, 80 hz. You subtract off the volume of the panels, braces, and any other drivers in the box to get internal volume.
I would prefer a f3 of 62 hz. You would have to limit the wattage to not blow xmax. f3/f0 =1.38 Vb factor from David Weems 4th ed fig 5.8 0.7 .7*112 L = 78.4 L Port length for single 4" port per chart 5-8 ~1"
Two smaller ports of same area as 4" port can be used.
That 78 l box size is bigger than eminence suggests for the maximum. You can always cut a box down if it measures badly but you can't make it bigger. I intend to use coarse thread machine screws in my initial assembly of my box. I'm using MDF. Screw holes will be tapped. No glue until I'm happy with the sound measurements. You can also fill a too big box with felt, foam, or braces, which also serves to break up standing waves at the higher frequencies. Eminence said their design volume was for minimal fill.
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Hey
Thank you so much for your answer and sorry for the late reply. I had to wait for several months now until I finally got the speakers. I will try to build the enclosures this month. I used WinISD to simulate.
It will be a 60 L vented cabinet. We'll see how it goes.
I will let you know when I finished my project. 🙂
Cheers!