Amplifier function - cut low frequencies from the stereo speaker outputs only

[sarumbear]

Any integrated amplifier with a built-in crossover, but without delay adjustment, no matter how much it costs, is pretty much useless, because it forces you to place the subwoofers in the same plane with the main speakers, which may not be the optimum placement for subwoofers in a certain room configuration.

Technically correct but what about in practice. 1m is 3mS. Is that an issue at 4 times the wavelength at, say 80Hz?

 

[djtetei]

Simple and short answer: it's there and it should be corrected.

 

[DonH56]

A cross-over as the the name suggest is a combination of cross between a LP and a HP filter. Both filters must have the same frequency in order for a cross-over to work. Here is a layman explanation.

To add to the above every speaker driver is a LP filter. Sealed enclosures have 2nd order (12dB/oct) and vented ones have 4th order (24dB/oct) responses at f3, the cut-off frequency of the filter. A stand mounted speaker mostly have a f3 around 60-80Hz. That is very near to the subwoofer frequencies used with subwoofers. This makes subwoofer matching not a trivial job.

Naturally, you can just ad a sub to your speakers and get more bass. That doesn't mean it is correct. Then again I assume anyone on this forum is searching for the correct solution?

I understand what a crossover does. But in your previous post you are describing the response of the enclosure plus driver, which describes the frequency roll-off below the box tuning frequency, not the crossover that sits between subwoofer and main speakers. It was not clear to me (or apparently to @restorer-john) that you were talking about the main speakers and not the sub's roll off. I chose my mains to roll off well below the crossover frequency to avoid the mess that happens combining physical plus electrical crossover responses. A decent DSP can solve it handily but as you say it is in general non-trivial. Before DSP I used analog filters including all-pass designs to compensate the phase.

 

[Spkrdctr]

Powered subwoofer manufacturers have recognized this forever. They roll off the mains, offer frequency, level and variable phase (polarity in some cases) control of the sub. What more do you want? A naked woman delivering champagne? (that's be nice for sure)

Yes!! Please send her over right away........

 

[sarumbear]

I understand what a crossover does. But in your previous post you are describing the response of the enclosure plus driver, which describes the frequency roll-off below the box tuning frequency, not the crossover that sits between subwoofer and main speakers. It was not clear to me (or apparently to @restorer-john) that you were talking about the main speakers and not the sub's roll off.

Cascading filters is adding two same type but different spec filters one after another. It happens on the main speakers when you drive a speaker via a HP filter as the speaker’s woofer driver is also a HP filter.

I chose my mains to roll off well below the crossover frequency to avoid the mess that happens combining physical plus electrical crossover responses. A decent DSP can solve it handily but as you say it is in general non-trivial. Before DSP I used analog filters including all-pass designs to compensate the phase.

That mess is caused by the cascading of physical plus electrical crossover responses. As you eloquently said, it is a mess. The market’s solution for using a sub is a mess. It doesn’t follow engineering.

Because of that mess you end up using EQ.