Hey,

Just wondering at what frequencies do we start hearing the direction the sound is coming from?

I've installed my mids in the door (slightly angled up towards the centre console), but I'm wondering how high I should cross them so that they arent playing too highly into the directional freq. range.. I'm worried that if crossed too high, I wont be able to hear the highs due to off-axis'ism (real word? )

Basically, the mids are heavilly off-axis.. whereas the tweets will be mostly on-axis.

I plan to do a listening test to determine the best sound.. but I'm also interested in the theory.

Thanks
Ice

200hz is directional.

I was under the impression that mid-bass was highly directional (well as direntional as anything much else). This is of course why you put your midbasses in the front rather than in the back parcel shelf (aside from rattling issues).

I believe *most* mid-basses will be being run above 200hz

I know mine are.

what about the tweeter and subwoofer frequency? if i have 30 bands eq and want to increase mid-bass and sub bass, what frequency range should i need to start to increase db?

PHD

well i can hear where my sub bass comes from (over ~30hz and depending on volume)

...

Cheers.

My 6.5" mids are installed like this: http://www.caraudioaustralia.com/forums/in...pe=post&id=3811

which gives them that slight angle towards the centre of the car.
The tweets will not be in the doors (unless for some reason they sound fantastic there), and I'll find a position for them by trial and error and bluetac

I usually say 80 hz.

But as with Rob, my subs play 40 hz down and I know they are coming from behind me...

It's a sliding scale.

Just to add what abmolech was saying: to understand the phenomena relating to binaural cues (which include inter-aural time difference and inter-aural intensity difference) have a look at this: Wikipedia Entry: Sound Localization.

Also, I think for a given driver you'd want to use a crossover point/frequency that has a wavelength equal or larger than the diameter of the driver. For instance, assuming that the speed of sound is 343 m/s then for a 6 inch midbass driver you'd want to use 2000 Hz as your low pass crossover frequency. This is because the length of a 2000 Hz soundwave is about 6.7 inches or 17 cm, and at frequencies higher than, say 2200 Hz the wavelength would've fit between the diameter of the driver. This could result in "beaming" and gives away the location of the driver.

Off course, the above concept is mathematical in nature and we all know that real world implementation does not always agree with theoretical analysis. So use it as a starting point, then experiment.

Cheers,

Bon

Dont forget about crossover slopes. Though you may have a sub's cut at 40hz, it may play up into "directional frequencies" quite happily with a shallow slope. I know on my system, a 50hz low pass with a 6db slope sounded quite clear and interesting.

I always used below about 100hz and you couldn't localize it. Had heaps of people tell me this. Looks like I will have to research it some more.

James

its been a while since GAIT training but roughly its
20-70ish Hertz no timing cues and non directional.(any sympathetic resosnance will be higher freq and so give directional cues)
70ish to 900 ish its volume dependent
900 to about 5-6K its time and volume dependent
above 5-6 K its just time dependent
peace
Cyberpunky

and a quirk, at 1kHz, you can't tell front from back.

I reserve the right to say 'you' referring to 'most people' as there are always differences among us.

Cool

Ice, i reckon it'll depend a great deal on where you locate tweeters and cross those tweeters over, my guess would be around2k 2.5k, remember you do have some direction on them which is more than most people have, next point is are you keen on rebuilding your door to obtain the right axis for your mids....

PS car is coming along well i see

Thanks mate.

Nope, I'm not keen on rebuilding. not keen at all!

The mids are on a slight (factory) angle, but I'm hoping to get tweets that can be crossed fairly low. This is to alleviate being able to pinpoint the midbasses when playin in the higher freqs.

for a 6" approx woofer, you'll need to cross over at 600Hz or lower to alleviate the problems of off-axis response.

I reacon its realitive to frequency and the the actual sound in its self.
ie a note roughly 60 htz thats short and sharp i can tell is coming from my boot. but a 80htz rumble type sound I just hear envelope the whole listening area

It must have been a while because you have it backwards.

less than ~100hz is non directional.
100~1000ish is time dependent.
1000~4000ish is a bit of both.
above 4k its primarily intensity based.
(all approximations)

The wavelengths at 5k+ are far too short for us to be able to tell the time difference using our two ears.

Basic explaination from Bodapa and I in this thread a while back:
http://www.caraudioaustralia.com/forums/in...showtopic=42966

So in that sense, given a listening position to the left or right of the middle, you can alter the time and intensity of the signal on one side to compensate - however, it will then be even worse on the opposite side of the car.

This is all very nice until you take into account the other factors - the axis of the speaker, the reflected sound (and other interior resonances).
The higher in frequency you go, the greater the difference in the on and off axis frequency response. When the angle to the left speaker is significantly different to the angle to the right speaker, then your ears may notice a difference in frequency response, leading to directional cues. This is also why people tend to mount speakers in the kick panels - mounting them as far forward (as practical) lowers the difference in angles to each speaker and also lowers the difference in distance from your head to each speaker.

dead right. in some songs, like(i cant think of anything ) the short bass kicks i can definatley tell they are coming from behind me. but a song such as go to sleep, by eminem dmx obie trice, where the song has a bass rumble thru the whole song, the sound is everywhere