Hello,
I have a Quest QM215FR dual 15” with 1.5” HF.
The speaker is a 3-way quasi design (specs attached) with the upper 15” speaker operating as a midrange extension. The cabinet has both LF and MID driver rear cone open to each other, No baffle. From the specs the LF to mid crosses at 400Hz and from mid to HF crosses at 1.6Khz.
The crossover is somewhat huge. Large inductors. The LF has a second order Lowpass with the mid a having a bandpass second order. HF has a high pass with attenuation network of resisters. No bulb protection. Simple as it gets however, there is an additional rather large LCR series network across the LF speaker acting like a band stop filter or to remove a resonant peak from the sub LF?
I like to remove the x-over altogether and operate the speaker with a 3-channel plate module. LF/MF/HF an Amp driving each speaker.
Has anyone configured a crossover curve to work with quasi 3-way using the Mid LF quasi principal of extending the mid range to 1.6K without effecting the Sun LF response? I’m not sure about what I need to do with this LCR across the LF for best performance? Guessing it’s purpose is to dampen the peak in impedance at free air resonance? I could be wrong. Or is it to improve the mid LF influenced by the low LF?
Both Low LF and Mid are the same speaker eminence 15” driver bass/mid speaker.
Anyone delt with this type of design have any tips for configuring?
Any advice appreciated.
Rob
I have a Quest QM215FR dual 15” with 1.5” HF.
The speaker is a 3-way quasi design (specs attached) with the upper 15” speaker operating as a midrange extension. The cabinet has both LF and MID driver rear cone open to each other, No baffle. From the specs the LF to mid crosses at 400Hz and from mid to HF crosses at 1.6Khz.
The crossover is somewhat huge. Large inductors. The LF has a second order Lowpass with the mid a having a bandpass second order. HF has a high pass with attenuation network of resisters. No bulb protection. Simple as it gets however, there is an additional rather large LCR series network across the LF speaker acting like a band stop filter or to remove a resonant peak from the sub LF?
I like to remove the x-over altogether and operate the speaker with a 3-channel plate module. LF/MF/HF an Amp driving each speaker.
Has anyone configured a crossover curve to work with quasi 3-way using the Mid LF quasi principal of extending the mid range to 1.6K without effecting the Sun LF response? I’m not sure about what I need to do with this LCR across the LF for best performance? Guessing it’s purpose is to dampen the peak in impedance at free air resonance? I could be wrong. Or is it to improve the mid LF influenced by the low LF?
Both Low LF and Mid are the same speaker eminence 15” driver bass/mid speaker.
Anyone delt with this type of design have any tips for configuring?
Any advice appreciated.
Rob
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If the plate amp has DSP for crossover duties and EQ then you don't need to keep any passive components. To dial in the EQ and crossovers you will need a measurement system but that doesn't have to cost much, for example I have a Dayton EMM6, a copy of REW and a USB interface with phantom power(live sound mixer with USB), then you just need an outdoor space that is away from structures to do some test sweeps.
The LCR across the LF woofer is likely there to counter the impedance peak above the port tuning frequency. That way, the low pass filter can do its job.
Some protection for the HF driver is a good idea, unless you exactly know what you are doing. I would keep its high pass filter.
Some protection for the HF driver is a good idea, unless you exactly know what you are doing. I would keep its high pass filter.
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