Is passive delay circuit possible?

[MXM]

Hello.
A friend of mine uses 4th order bandpass subwoofer, and bass is REALLY late. Is there any way to make a delay on other speakers without digital processing? I couldn't think of any way but making cables really long, but that's obviosly not an option (300km for 1ms ).

[Bill Fitzpatrick]

What do you mean exactly by "the bass is really late?" Just how late is it? 1ms? 5ms? 10 minutes? And, how can you tell?

[MXM]

Well, I can hear it and it's disturbingly late.
I tried to simulate it in JBL speakershop, roughly estimating dimensions of chambers (i know parameters of driver) and it is somewhere near 30ms at worst.

But do anyone have answer to original question? Is such thing possible?

[Bill Fitzpatrick]

No, such a passive analog delay line is not possible.

[sdoom]

modern/better head units have a time-control function . There you can adjust the delay there or you need a seperate sound processor.

[Bill Fitzpatrick]

30ms. Group delay. Varies with frequency.

Solutions I know of:

Lower the cut off frequency of the box.

Go to a sealed system.

Use a Linkwitz transform circuit to lower the cut off frequency of the system.

[urosst]

you have problem in bas selection .You have hole betven
60 to 150 Hz.First you must modify front sistem.
Time corection doesn't work in your problem.

[Stephen Soosai]

Such delay is really possible, but I dont think we, humans, can detect it.... I have seen such delay circuits employed in old full-analog color tv to delay the chrominence signal (C signal) few hundreds of nano seconds to properly catch up with luminence signal. It works there because the C signal is at 4.33 (PAL) or 3.58MHz (NTSC).

The bass spectrum of audio lies just between 20 to 500Hz and these low frequencies cannot be delayed at much as 30mS by passive networks. It should be much less than few hundreds of nano seconds.

Obviously such delay, if present in audio circuit, we wont be able to sense it.