Mr_Bob wants to blow his head off with bass
http://www.caraudioaustralia.com/forums/in...showtopic=14568

Shiny_car asking for help!!!
http://www.caraudioaustralia.com/forums/in...showtopic=12464

Bobby_Digital questions the absolute nature of the speed of sound
http://www.caraudioaustralia.com/forums/in...ndpost&p=223593

can't be bothered finding more

P.S. I've already checked my own first posts and nothing incriminating exists

Well, i got one from you stazed.
http://www.caraudioaustralia.com/forums/in...63&#entry462263


"by the way, the aim was to blow my head off."

I'm keeping that quote. absolute classic

"i may be wrong so someone pls correct me, but i think im right, i am always right!!"

Lol, another keeper.

Then theres me asking if a component set came with left and right speakers :/

I can see a lot of old threads getting bumped soon.

*cough* I bought a cap once to actually use, instead of test and debunk much to the horror of n00bs everywhere who pissed $100's into the stupid things.

i brought a cap for the sole reason of rice. never was going to be hooked up and never has.


and stazed, speek for yourself! i was never a noob!
i still stand by that comment,
mount the tweeter forward and the higher freq will get yo your ears quicker!

thats why Dual Concentric speakers are gods!

so co-axials are ambrosia?

i still am a n00b!

Actually as stupid as this sounds I still agree with Bobby_D's opinion in that thread. What scares me is I remember reading most of these threads when they were new.

speed of sound at sea level = 340 m / s (approx)

Distance between tweeter cone and woofer cone - 25mm (one inch approx)

1000mm in a metre

speed of sound = 340000mm / s

340000/25 = 13600

Time delay:
340000mm/13600 = 1s/13600
25mm = 0.000073529s

When you hear a 1/13600th of a second time delay, come tell me

You'd get more time delay with your tweeters mounted in the kicks instead of the woofers!
Tell me the last time you applied separate time delay to the woofer and tweeter!


Audible Time Delay Figures:


1 millisecond = 0.001 seconds
Your hearing = 0.00007 seconds

All bow to Bobby, the man with the golden ears!

Anyway, I was not disputing there was some negligble time difference.

Allow me to quote you:



THE FREQUENCY FROM THE TWEETER WILL MOVE FASTER THAN THE MIDBASS - I don't think so Bobby!

Hence why you then said, AND having the tweeter at the front.

Are you seriously going to tell me that high frequencies "move" faster than low frequencies

also called Phaze aligment.

http://www.silcom.com/~aludwig/Time_alignment.html


now go look at hi end home audio and notice how the tweeters are set back a little to the midbass.

then go read through the tannoy site on why Dual Concentric speakers work.

Yeah true bobby but i thought that had more to do with the relationship of the proximity of the speakers to your ears at normal listening height.

I still think that higher frequencies travel maybe not so much faster but they cut through other frequencies or something - i dont know what my theory is but i still think that im not sure now im all bloody confused

okay bobby.

lets call 0 degrees rest point
180 degrees out of phase

That article doesnt take into account that in any given distance, theres going to be more complete wavelengths produced by the tweeter than by the woofer (shorter wavelengths produced by the tweeter=more points that are at 0 degrees in any given distance)

thus, the tweeter can be "in phase" with the woofer many times in the distance pictured. For our purposes, we want the sound to arrive at our ear at the same time. This article seems to prove nothing but time alignment.

Also it mentions the tweeter being 180 degrees out of phase. Of course the tweeter is therefore going to need to be positioned further back than the woofer in order for the sound to be in phase again. I'd hazard a guess and say that it could be the same distance CLOSER to you, and still sound fine.

hmm.

ahhh...alot of names you don't see around these days. Learnt alot from the likes of T-Bro,the[kid], Critter/Sonic Nirvana etc.

Yeah Lots of old names on there that we dont see so much (some not at all) these days Its not untill we dig up posts this old that we see these names and think where the f*** did such and such go. what happened to T-Bro and those guys i wonder.

i thought sound travels at the same speed, wether 30hz/200hz/990909635710370123470213740982374hz, it's the distance that it can travel over with the same amount of energy applied.

eg something that is 900hz with 1w can travel x amount, something that is 10 hz can travel further with 1w.

*shrugs* don't quote me on that though...

Theres some technical issues with volume, as at a certain point you compress the air drastically, and therefore the sound will travel faster in that compressed air...but its nothing we need to worry about in the average sound system.

i don't even want to know what some of my first posts were

- Stooge007 out

Super compression horn 6be9z!!!!




Yep you were a noob

still am

- Stooge007 out

Not going to bother starting a new thread, but since we're talking about "noobs", there seems to be a lot more noob(damn I hate the word noob) bashing going on. Especially by members who havn't been here for all that long(Under a year) thinking they are all that.

^^^ i know what you mean

- Stooge007 out

so very true!

Ummmm Bobby you linked me to some guy's site, who builds his speakers and admits design faults, and measured using the old software, and has a website hosted under his ISP, and I'm meant to believe this guy is a credible source? Why not link me to a Tannoy article or someone credible!

Can you find me the technical article you were referring to back about 3 years ago when you made that post please? I do not know much about dual concentric and I doubt you own a pair of them to have heard them and compare either.

Although you were never a noob so perhaps you just innately know these things. I find it arrogant to say that you were never learning, never uninformed.

I hate that word too. Dammit. Say it right now guys. It just sounds dumb. Why dont we call each other pooheads, at least it sounds funnier.

Quote:
speed = distance/time
The faster which a sound wave travels, the more distance it will cover in the same period of time. If a sound wave is observed to travel a distance of 700 meters in 2 seconds, then the speed of the wave would be 350 m/s. A slower wave would cover less distance - perhaps 600 meters - in the same time period of 2 seconds and thus have a speed of 300 m/s. Faster waves cover more distance in the same period of time.

It's true the lower frequencies take longer to travel a given distance than high frequencies. This is why time correction is widely used in Live sound renforcement (PA) Delay the high end to align it with the lower end. heres good references with just a google:
http://www.doctronics.co.uk/signals.htm
http://www.glenbrook.k12.il.us/gbssci/phys...und/u11l2c.html

i said i was never a noob, but i am always learning

I'm contesting that.
Sound travels at the same speed, regardless of frequency. The only determining factor of the speed of sound is the density of the medium. There are SOME exceptions, but only between the solids and liquids.

From memory, delaying the high end is done to address inherent "group delay" in certain types of speaker set-up.

The only situation in which lower frequencies travel faster than high ones, is when the sound waves are passing through a flexible barrier. A barrier that allows partial transmission of the original source. This is due to the higher energy of the lower frequencies.

A barrier that totally reflects sound (non-elastic) will not effect the speed of the waves.

Interesting OT side note : You can hear a train coming a long time before anyone else if you put your ear on the steel track

ive been here a while, still probably quite a bit of a noob

High Frequencies travel faster than low as they have a narrower sine wave.
This is why we delay the top end not the bottom.
It's a known fact quidy, so you may contest it all you like

p.s. I'm forgetting that usually the sub is in a J or W bin which increases the distance of the signal path compared to the flared horn which has a direct line to the listener.

you really need to do some research as you dont really grasp the theory of frequency wave lengths.

Click to view attachment

here is a website i'm sure you will find very interesting liquidity

edit: this one is much better http://www.sengpielaudio.com/calculator-wavelength.htm

I feel left out

Where's my stupid noobie posts?

I had the classic noob question when I was being curious about Dacron... Bobby_Digital, Marc and Blanketman made me remember that post up for months and months afterwards.... actually, they still do remind me of it :blinks:
I still consider myself a noob. I still ask questions about car audio constantly. There are times when I feel confident that I know about a certain car audio topic, but I will say I ain't TOO clear on the advanced stuff.
But hey, we all learn at ALL times... not ONE time. That's what life's about. That's why I stick on this forum like glue. I may may not post up anything MAJORLY constructive, but I know I'm reading the questions and answers of everybody else and I'm soaking all that up like a biscuit in milk.

that doesnt prove me wrong at all

The speed of sound there is a constant that you change, its not affected by you changing the wavelength or the frequency.

You guys are completely off. A narrow sine lenght just means more wavelengths over a given distance. It doesnt mean it travels faster.

Wavelength and frequency relate to speed, but doubling wavelength does nothing but half the frequency.

I can link you to the equation relating wavelength, frequency, and speed if you like. Its in the year 11 physics syllabus in SA.

Speed is the constant. Contest it all you like.
Go find a graph comparing distance over time to frequency.

Electromagnetic waves are slightly different.

**yawn**

and i thought this topic was ment to be about noobies

once again
good one guys

it's the same in year 11+12 physics in wa!

i'm still a n00b but meh... who listens to n00bs aye?

id love to laugh at those old posts....but for fear of someone going back a whopping 2 months to find one of my earlier posts im not going to to lol (could probably find one within the last 2 weeks from me let alone 2 months)

only been in here what...2 months...friggen rippa.....jus tryin to soak it up........all good....like knowing wtf im talkin about...(atleast neraly know wat im talking aobut anyway)

hmm...if i hadnt had a couple of tins tonite i might try to think about the speed of sound conversation which has emerged from this thread.....but no i cant be bothered...and i am sooo over grade 12 phyiscs at the moment you wouldnt believe it lol (one more exam left....!!)

anyway..back on topic.....good to see im not the only one who feels dopey after reading my own messages a while later on lol

I just noticed that all our join dates are... odd, or I'm just old and losing it... more likely the 2nd option i think!

Oh alright then





Well you were pro-eBay.....
http://www.caraudioaustralia.com/forums/in...04&#entry103404

And you tried to find a dodgy way to get warranty for your overpowered subwoofer...
http://www.caraudioaustralia.com/forums/in...topic=13567&hl=

DODGY BASTARD!!

This thread?
http://www.caraudioaustralia.com/forums/in...opic=46116&st=0

Did you seriously not know about Dacron only 10 months ago??!!!

Seriously! hahaha
And Icacha with all his maco in it I haven't changed muuch since then! Bloody hell, I still ask stupid questions as such! hahahaha

I'm glad my noobness pre-dates these forums

LOL Im glad my old username info got lost and yes I have been around since the Yahoo group days And no im not telling you what name i used to go by (mostly cause i cant actually remember)

Just bringing this old thread up again about myself... SHISH! WHAT WAS I THINKING!!!!
I know what I'm doing with my Corolla now, but back then when I was interested in an install... I never knew how much the mind can restrict the outcome of an installation. It pays to have either imagination or stupidity... or both!!! hahahaha
Check my stupity level here!

go the 7x 10 speakers on the rear shelf


bloody dago wog

he's not a wog he's maco, there's a diff you know

Oi.... 7x10s rocked when i was 21
Alots changed since then!

Your older now?

Try 24

still a wog
still a dago
still a bloody