Good morning!
Been busy climbing in and out of the roof this weekend - started building my IB at last.
Climbed into and out of the roof about 900 times over the past two days. Managed to get 3 sheets of plywood in there so far, but that will be increasing quite a bit before the project is done.
I am going with two manifolds, each with 2x 15" drivers. Amplifier is a crown XTI 1000. The amp can do 700w RMS per channel into 2Ohms, and has a USB port at the back with which you can set crossover points, DSP, parametric EQ, phase, gain, delay, etc. Very nice.
I had quite a nightmare trying to find drivers that would work for the IB. I looked at FiCar in LasVegas as well as Acoutic Elegance (AE). Both companies were willing to ship drivers to me but the cost would have been insane. These things are seriously heavy...
I started doing some homework on local drivers, measuring just about everything I could get my hands on. I eventually found a driver that would work, and it was in the most unlikely candidate (in my mind) of them all:
Starsound 15" SVC from autostyle (SSW 381 SVC). Free air specs (run in) measured by my as follows:
* Qts - 0.445
* Qms - 5.299
* Qes - 0.485
* Re - 3.401 Ohm
* Fs - 21.53 Hz
* BL - 13.3 N/A
* Le - 3.59 mH
* Mms - 186.7 grams
* Vas - 282.9 lit
* SPL - 89.54 dB
* SD - 825.4 cm^2
Compare to AE's IB15 specs (from their website):
* Fs: 16Hz
* Qms: 6.8
* Vas: 439L
* Cms: .45mm/N
* Mms: 220g
* Rms: 3.239
* Xmax: 18.5mm
* Xmech: 25mm
* Sd: 830sqcm
* Vd: 3.07L (p-p)
* Qes: .78
* Re: 5.5ohm
* Le: .33mH
* Bl:12.49
* Pe: 500W
* Qts: .7
* PL: 86dB
There is quite a difference between the two in terms of Fs. I am sure this has to do with the Mms however. 186.7g vs 220g should drop the Fs from 21.53 to about 16Hz if need be. Not sure this will be necessary, but the microphone will show the truth when the time comes.
The SSW 381 has higher sensitivity, lower Qts (I can increase this electronically if need be), similar BL strength, lower Vas. I am sure the IB15 will have higher XMax, and surely has a better motor and basket as well as lower distortion. That being said, the Starsound only costs R650 inc. VAT and is easily available here.
Some pictures of the build progress so far:
Been busy climbing in and out of the roof this weekend - started building my IB at last.
Climbed into and out of the roof about 900 times over the past two days. Managed to get 3 sheets of plywood in there so far, but that will be increasing quite a bit before the project is done.
I am going with two manifolds, each with 2x 15" drivers. Amplifier is a crown XTI 1000. The amp can do 700w RMS per channel into 2Ohms, and has a USB port at the back with which you can set crossover points, DSP, parametric EQ, phase, gain, delay, etc. Very nice.
I had quite a nightmare trying to find drivers that would work for the IB. I looked at FiCar in LasVegas as well as Acoutic Elegance (AE). Both companies were willing to ship drivers to me but the cost would have been insane. These things are seriously heavy...
I started doing some homework on local drivers, measuring just about everything I could get my hands on. I eventually found a driver that would work, and it was in the most unlikely candidate (in my mind) of them all:
Starsound 15" SVC from autostyle (SSW 381 SVC). Free air specs (run in) measured by my as follows:
* Qts - 0.445
* Qms - 5.299
* Qes - 0.485
* Re - 3.401 Ohm
* Fs - 21.53 Hz
* BL - 13.3 N/A
* Le - 3.59 mH
* Mms - 186.7 grams
* Vas - 282.9 lit
* SPL - 89.54 dB
* SD - 825.4 cm^2
Compare to AE's IB15 specs (from their website):
* Fs: 16Hz
* Qms: 6.8
* Vas: 439L
* Cms: .45mm/N
* Mms: 220g
* Rms: 3.239
* Xmax: 18.5mm
* Xmech: 25mm
* Sd: 830sqcm
* Vd: 3.07L (p-p)
* Qes: .78
* Re: 5.5ohm
* Le: .33mH
* Bl:12.49
* Pe: 500W
* Qts: .7
* PL: 86dB
There is quite a difference between the two in terms of Fs. I am sure this has to do with the Mms however. 186.7g vs 220g should drop the Fs from 21.53 to about 16Hz if need be. Not sure this will be necessary, but the microphone will show the truth when the time comes.
The SSW 381 has higher sensitivity, lower Qts (I can increase this electronically if need be), similar BL strength, lower Vas. I am sure the IB15 will have higher XMax, and surely has a better motor and basket as well as lower distortion. That being said, the Starsound only costs R650 inc. VAT and is easily available here.
Some pictures of the build progress so far:
