Hi every one.
I visited a good friend this afternoon and had a rather interesting listen to a pair of 15" speakers in an Onken style box. The highs are taken care of by an Altec Lansing 908-88.
Sound was very open and dynamic, but I noticed that he was running the 15" fullrange and it was far from ideal.
Can someone please help with a possible crossover for him, or at least a place to start so that he can enjoy the speakers without the nasty peaks coming from the woofer.
Driver specs are as follows:
Thiele-Small parameters:
Fs = 46.10 Hz
Re = 13.80 ohms [dc]
Le = 6171.43 uH
L2 = 2634.74 uH
R2 = 35.26 ohms
Qt = 0.27
Qes = 0.30
Qms = 3.04
Mms = 45.42 grams
Rms = 4.320739 kg / s
Cms = 0.000262 m / N
Vas = 253.67 liters
Sd = 829.58 cm ^ 2
Bl = 24.635715 Tm
ETA = 7.99%
Lp (2.83V / 1m) = 98.76 dB
Added Mass Method:
Added mass = 77.00 grams
Diameter = 32.50 cm
Resonance: 45 Hz
Type: ARO 9415
Diameter [mm]: 390
Impedance [ohm]: 15
Max. Power capacity [W]: 100
Own resonance [Hz]: 25
Frequency response [Hz]: 25-6 000
Efficiency [dB]: 98 (some have this as 100).
Weight [kg]: 10,5 (per unit)
AlNiCo magnet
Compression Driver is:
Altec Lansing 908-88
Power rating – 150 watts continuous program (1000 Hz to 20 000 Hz)
Frequency response: 500 Hz to 20 kHz
Pressure sensitivity: 105 dB SPL measured 1 meter from mouth of Altec 511B horn with 1 watt (2.83 V)
Minimum impedance 8 Ohms
Flux density: 1.8T
Thanks in advance
I visited a good friend this afternoon and had a rather interesting listen to a pair of 15" speakers in an Onken style box. The highs are taken care of by an Altec Lansing 908-88.
Sound was very open and dynamic, but I noticed that he was running the 15" fullrange and it was far from ideal.
Can someone please help with a possible crossover for him, or at least a place to start so that he can enjoy the speakers without the nasty peaks coming from the woofer.
Driver specs are as follows:
Thiele-Small parameters:
Fs = 46.10 Hz
Re = 13.80 ohms [dc]
Le = 6171.43 uH
L2 = 2634.74 uH
R2 = 35.26 ohms
Qt = 0.27
Qes = 0.30
Qms = 3.04
Mms = 45.42 grams
Rms = 4.320739 kg / s
Cms = 0.000262 m / N
Vas = 253.67 liters
Sd = 829.58 cm ^ 2
Bl = 24.635715 Tm
ETA = 7.99%
Lp (2.83V / 1m) = 98.76 dB
Added Mass Method:
Added mass = 77.00 grams
Diameter = 32.50 cm
Resonance: 45 Hz
Type: ARO 9415
Diameter [mm]: 390
Impedance [ohm]: 15
Max. Power capacity [W]: 100
Own resonance [Hz]: 25
Frequency response [Hz]: 25-6 000
Efficiency [dB]: 98 (some have this as 100).
Weight [kg]: 10,5 (per unit)
AlNiCo magnet
Compression Driver is:
Altec Lansing 908-88
Power rating – 150 watts continuous program (1000 Hz to 20 000 Hz)
Frequency response: 500 Hz to 20 kHz
Pressure sensitivity: 105 dB SPL measured 1 meter from mouth of Altec 511B horn with 1 watt (2.83 V)
Minimum impedance 8 Ohms
Flux density: 1.8T
Thanks in advance
Hard to say with vintage woofers like that. What is the crossover high pass filter for the horn? And what is the horn? That would at least give us a start.
Hmm, a 15" driver is ~100 deg/1 kHz, same as the 511, so this low, a simple 2nd order BW plus CD horn EQ and TD aligning the horn or could just do a 3/2 to back the woofer down some more.
Need to know the system's output impedance though.
GM
Need to know the system's output impedance though.
GM
The Yuichi 480 is about the same size as a 511, right? That would make GM's suggestion a good place to start. I've often had better luck with 3rd order crossovers, but you may find 2nd order works well for your friend. A 1kHz crossover can be tricky as it's a region where you'll notice little a mismatch. Getting the horn level just right could take some patience.