Where abouts in the freq. spectrum does bass start to loose its non-directional-ness ?
I have an idea for better bass staging, dynamics and sub-to-mid progression.

Damned KRS-1 getting me hooked on positional bass

up to 100Hz is pretty non-directional. and less than 70Hz is pretty safe.

mind you, it's often the higher frequencies that 'sneak' through the LP filter that cause probs (eg: above 150Hz), so a steep LP filter helps (eg: at least 18dB/oct ).

what'cha got in mind???

If your cross over or amplifier is continuosly variable then just experiment until it sounds just right. Shiny is on the money though a steep slope is essential.....of course if you cross your subs over at 50hz and your fronts are 6.5" which are crossed over at 90hz....your system might lack a bit of midbass weight....have a play around with it and let us know how you go....

Hmm, I think we had a thread on this before if someone wants to dig it up...

Anyway, spose if we wanted to get serious, we could look at *why* we can't pick the direction bass comes from, then work out how to 'beat' it

it's because the wavelength is so long there is practically no pressure differnce across out two ears. there will be like 95% similarity betweenwhat each ear is hearing so it cant computer where its coming from.

Give the man a cookie
See here for some fancy math mostly pulled from dark places: http://www.caraudioaustralia.com/ubbcgi/ul...c;f=13;t=003792

Basically, once we get below a few hundred Hz, we begin to lose the ability to pick the direction of noises. The lower it goes, the harder it gets. Plus we are better with side to side, than back to front. If you think your bass sounds nice and up front, try facing sideways in your car, it can sometimes be rather surprising

Right now its just an idea.. Thanks to not quite so wise purchases when I first got into serious car audio I am stuck with what I like to call "My Secret Stash of Goodies", and some big assed holes in my car that need filling.

So what I was thinking is...

Mr.15" sub LP at 80hz
6"x9" driver (not co-ax) in the rear shelf BP @ say, 80hz-200hz
1" tweeters in the rear HP @ 33khz, attenuated for ambience
5" driver in the front doors BP @ say 200hz-800hz
3" driver in the kicks BP @ say 800-33khz
1" tweet mounted between the kicks and woofer

The idea being to fill the *huge* gap between a 15" subbie and 5" woofer, plus fill the 6"x9" hole in my rear shelf

[ December 12, 2002, 09:29: Message edited by: BlackIce ]

High passed at 33kHz AND attenuated?!?! you're going to have a hard time hearing anything from those tweeters I think

hee,hee, 33kHz!

if you use an active xover for all your settings then it will make tuning and experimenting much easier.

to minimise adverse soundstaging, consider BPing the rear 6x9s between 70~120Hz; not much, but probably all you need.

then BP the front 5" woofers from 120~800Hz, no probs. good luck

With most of the 200 down range coming from behind, I'd guess the stage would be pulled back at any low notes. I'd say get rid of the rear tweets (unless you want full range rear fill) to keep the sound stage up front. Of course, 8's up front would be nice, but hey, some times you got to work with what you got.

On the note of bass direction in general, playing with some settings today, and I could tel the bass was coming from the rear with the LP at less than 80Hz, but I think thats mainly because the FS couldnt play strongly that low. I guess it's not where it is, its how we can trick our ears into thinking its where we want.

I want rear fill highs for rear seat passengers.. and yeah I know most of the bass will be from the rear, but thats the way I like it .

As for the 33khz typo I have the hearing of a wolf

my front speakers are HP@70hz and my sub is LP@50hz. this removes virtually all boominess and 'directionality' from the subs, and does not weaken midbass at the sub's don't roll off that quickly thanks to 12dB/Octave.

worth trying

I use underlap(gap between X over points) in my system and I have steep 24 Db xovers. I always suggest ppl play around as usually underlapping provides best results espesh with shallower slopes
Crossovers are not brickwalls that can be matched as the slope means we need some underlap. Mines about 10 Hz gap.
peace
Cyberpunky

Im the same as cyber. Ive noiced that under lapping the subs and the fronts helps to remove directionalaty of the subbass. Ive got my Sub lowpassed at 63hz, and the fronts highpassed at 80hz. The sub with a 24db/octave and the fronts with a 12db/oct. Provides a good transition, without a hole appearing in the midbass region.