A previous thread asked about 6*9's and Subs, in regards to Bass cancellation.

Who knows a little more about this? As far as I knew, Different cones (eg different sized subs or 6*9's) playing at the same frequency, producde different waves. It is these different waves that cause bass cancellation.

If I'm wrong. I want to know about it. If it's right? I want to say that DMac was right.

not really cancellation, more a different frequency. and cones that are designed to respond differently at different frequencies will never sound the same. a 6x9 wont be efficent at say 80HRZT (LPF) than say a 10" or 12" sub. and so thus due to excess volume the subs will go louder without s**t themselves than a set of 6x9's will.

Cancellation more about phasing (i.e. if a speaker is wired up in reverse the waves to phase and cancell out frequencies and do really weird s**t)

Maverick,

Haven't you totally contradicted yourself there? You have said, not cancellation, more a different frequency. I am talking about "at the same frequency".

its phasing as the man said but honestly why have bass through the 6x9s, or better still why have 6x9s and a sub!!!

its phasing as the man said but honestly why have bass through the 6x9s, or better still why have 6x9s and a sub!!!

Its been said over and over again, yet nobody listens? The 6*9's arent as clear at producing the upper and mid range sounds as a decent set of 6 inch, so buy some decent six inch. Subs are better than 6*9's, so theres no need to have the bass from the 6*9's which is the main reason people buy them. So if you want bass, get 6 inch, and subs, not 6*9's. Ive currently got some pioneer 6 inch, looking at getting some subs. But for the speakers running off one of the lower model pioneer head units, theyre quite nice. Make the rear view mirror vibrate, and rattle the boot, so the bass is there if needed

Rightio ,I think I understand your point. It's just it's always said never to mix sub sizes...... even if the crossovers are done perfectly.......
so why wouldn't it be the same for 6*9's and a sub?

Imagine a rectangular pool, now imagine a person at each end jumps in. The waves generated by this jump will emanate from each person (in the same mannor sound emanates from a speaker) and meet in the middle of the pool and come to a stop. this is cancellisation.

If the timing and placement is spot on, there will be no sound coming from the speakers, but the slightest offset will mean you can hear something.

The opposite effect is achieved by having 2 or more speakers facing in the same direction - you will double/triple/quadruple etc the sound.

Phasing refers to which direction the speaker moves when its being jolted by the amp. Imagine having 2 subs facing each other (one on each side of the boot for example) having one running in phase and the other running out of phase will mean that you can achieve the sound doubling effect. What phasing does is kinda hard to describe, basically when a speaker is in phase, it'll move (example only, i dont know which way around it is) out then in then out then in etc etc. running out of phase means it'll move in then out then in then out.

Im 99% sure thats what it is.... makes sense to me anyway

They dont exactly come to a stop, but one produces a peak (up) one produces a trough (down). so you end up with a theoretical lack of sound.
As soon as the waves continue past this point, you get more sound, until the peak and trough meet again, so you end up with no sound again. Hard to exlpain but i might tr and find a sound wave example