Klipsch woofer oscillating slowly on some recordings?

[Brit01]

I have noticed than on some recordings the woofer cone on my Kipsch F-1 oscillates in and out quite significantly but very slowly. The music doesn't seem to be affected.

Why do the cones move so slowly back and forth? is this due to very low frequencies on the recordings that the 6.5 inch cones cannot reproduce?

Is this where a subwoofer and correctly adjusted crossover comes into play??

Amplifier: Carver TFM-55 and pre CT-3.

Thks

[badman]

This is rumble, is it a safe bet that you're using a turntable?

Harrison Labs makes some rumblefilter solutions you can use to cure this.Filters

It can be pretty benign, or totally destroy your speakers. Best to filter it if you can.

[Brit01]

Hi Badman,

No turntable in the equation.

Does this shed a different light on the matter?

Cheers

[richie00boy]

It's a similar issue to turntable shake, but this time the cause is in the studio. Things like extremely heavy trucks etc passing by the studio can cause it when the mastering does not address (filter) it.

It is exagerated by vented boxes as the cone is basically running in free air below port tuning. The solution is to fit a subsonic filter.

[Brit01]

Would a subwoofer with the appropriate crossover and filters do the same trick?

I was considering adding one of these to my system anyway.

Cheers

[richie00boy]

If the sub has high-pass filtered satellite outputs, then yes it would. However, as most of these are implemented by a simple inline capacitor at speaker level, their performance is not ideal.

[badman]

Indeedly Doodly, richie00boy is correctomundo. You can high-pass your mains for use with a sub by utilizing some of the same filters you see at the site I linked before.

And a sub is always a good idea

[Graham Maynard]

This is likely an ADC/compression artefact via the studio mastering suite.

Often the sub-sonic excursion plus subsequent resettlement arises with a suddenly loud burst which is level compressed; and not only at bass frequencies.

Can be worse if the reproducing bass driver cone is not adequately loaded by enclosure air; as on a baffle/rear shelf or below resonant frequency with a ported cabinet.

Cheers ....... Graham.

[PB2]

Originally posted by Brit01
I have noticed than on some recordings the woofer cone on my Kipsch F-1 oscillates in and out quite significantly but very slowly. The music doesn't seem to be affected.

Why do the cones move so slowly back and forth? is this due to very low frequencies on the recordings that the 6.5 inch cones cannot reproduce?

Is this where a subwoofer and correctly adjusted crossover comes into play??

Amplifier: Carver TFM-55 and pre CT-3.

Thks

I have noticed this also. Can you list some of the cuts and the time when it happens so that others can confirm that it is in the recording?

Pete B.

[Graham Maynard]

Can't remember actual disc - by Pete Tong - Ministry of Sound - was so extreme I used it to watch/listen to sub driver behaviour through X.max limits. Possibly a 1994 boxed set but pre 1999.

Another notable one is on a Newspaper compilation freebie - the drum solo lead in to Blondie's 'Rapture' - Chrysalis Music/ Monster Island Music - the compresser level changes are affecting zero level which subseqently recovers with its own time period - captured by the excellent LF spec of CD.

There are other examples but I never noted them, because as Brit01 says - it does not affect normal reproduction. Also tends to be individual tracks on a disc, not entire discs.

Cheers ...... Graham.