I'm not sure I understand the how/why/where/when etc. of these items, so if you'll humor me, I've got a few questions.
#1- Is a crossover a combination of HPF's & LPF's?
#2- Is the only difference between an active crossover and a passive crossover it's location in the signal path (active=before the amp, passive=after the amp)?
#3- Is there any benefit of using a SSF with a sealed enclosure, ie: if the amp doesn't recieve any signal below the SSF freq it can't/won't waste any power amplifying it ?
#4- If running 2 amplifiers (a 4ch amp & a separate 2ch amp for the subs, both class A/B), would it be beneficial to filter out freqs (before they get to the amps) below 250 hz for the 4ch amp, and freqs above 250hz & below 35hz for the 2ch amp being used for the subs? (again, if the amp doesn't recieve a signal in a particular range, it can't/won't waste any power amplifying it, correct?)
Am I way off base here?
Replies (1)
swez on 02/28/2005 09:46:56
OK, let's walk ya through each question...
1. Crossovers come in several configurations
a. HPF to block bass to mids and tweets
b. LPF to block mids and highs to subs
c. SSF is used to block lows in a ported/vented system. Protects the sub(s) from getting signals below tuning frequency.
2. Active filters have a power supply voltage and often have some form of gain control preamp in them. (best choice here)
Passive filtering is a series of coils, caps and resistors used to filter or pass a given frequency range, to their respective speakers. (Ie: Subs, Midrange and tweeter). These passives are generally inserted between the power amp output and speaker inputs.
F-Mods are a passive filter network that is inserted into the amp input signal lines. They are passive to be sure, but they act like a psudo-active filter because their output, goes into the amp inputs.
3. Not a real benefit to use SSF in a properly designed sealed system. The sealed box will naturally roll off bass below ~35 Hz.
4. The 4 channel amp needs to employ the HPF at 80 -100 Hz to block lows that go to the amp & associated speakers. If you have small format speakers like 3.5", 4" and 4x6" format, may need to filter them higher.
As for subs, below 100Hz LPF is needed.
Hope that helps,
Swez
#1- Is a crossover a combination of HPF's & LPF's?
#2- Is the only difference between an active crossover and a passive crossover it's location in the signal path (active=before the amp, passive=after the amp)?
#3- Is there any benefit of using a SSF with a sealed enclosure, ie: if the amp doesn't recieve any signal below the SSF freq it can't/won't waste any power amplifying it ?
#4- If running 2 amplifiers (a 4ch amp & a separate 2ch amp for the subs, both class A/B), would it be beneficial to filter out freqs (before they get to the amps) below 250 hz for the 4ch amp, and freqs above 250hz & below 35hz for the 2ch amp being used for the subs? (again, if the amp doesn't recieve a signal in a particular range, it can't/won't waste any power amplifying it, correct?)
Am I way off base here?
Replies (1)
swez on 02/28/2005 09:46:56
OK, let's walk ya through each question...
1. Crossovers come in several configurations
a. HPF to block bass to mids and tweets
b. LPF to block mids and highs to subs
c. SSF is used to block lows in a ported/vented system. Protects the sub(s) from getting signals below tuning frequency.
2. Active filters have a power supply voltage and often have some form of gain control preamp in them. (best choice here)
Passive filtering is a series of coils, caps and resistors used to filter or pass a given frequency range, to their respective speakers. (Ie: Subs, Midrange and tweeter). These passives are generally inserted between the power amp output and speaker inputs.
F-Mods are a passive filter network that is inserted into the amp input signal lines. They are passive to be sure, but they act like a psudo-active filter because their output, goes into the amp inputs.
3. Not a real benefit to use SSF in a properly designed sealed system. The sealed box will naturally roll off bass below ~35 Hz.
4. The 4 channel amp needs to employ the HPF at 80 -100 Hz to block lows that go to the amp & associated speakers. If you have small format speakers like 3.5", 4" and 4x6" format, may need to filter them higher.
As for subs, below 100Hz LPF is needed.
Hope that helps,
Swez
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