Help me me build my budget system =)

[Spades]

actually, time to recalculate. the 6x9 does have more surface area than a 6.5 oval. however, while
the driver surface is bigger allowing more air to be moved, it does not change the problem that all oval speakers suffer from...the fact that the driver is mis shaped effects sound quality especially when the speaker is being pushed hard.

round speakers are ussually the way to go, but, you ussually get more bass "hit" out of a 6x9 than a 6 round on cheaper speakers because of the larger radiating surface...same with subs. a more expensive 8" sub may sound better than a cheaper 15", but odds are in pure bass, the 15 will hit harder.

we do agree on one thing, that rear fill should be minimised, and its why I have always run them off of deck power and fader moved far forward.

but, we disagree on another. I belive that while rear sound should be minimised, it does improve sound quality to have it there, but ambient. and I disagree on bass or midbass from the rear deck. if you have subs the impact is already slamming you from the rear, and you want midbass hitting you from the front...most midbass will be obliterated or drowned out in the back if you are runned anything decent or bigger than a couple 10 inch drivers.

low bass is almost non directional, which is why subs cut off at 40 hertz or less work fine in the trunk, but the higher up the frequency, the more directional the sound. mid bass should be shifted as far forward as possible, to give the appearance of the "concert" you spoke of.

cutting a midbass driver off at 1k will most likely fry it fast, and your sound quality will be very foul. at 300hz deeper vocals can be heard, and a mid bass driver playing above that will sound very muddy normally. also, at that point, your ear can easily pick up direction of the sound, so the whole point you made about making rear fill disappear is moot.

I think you and I agree on some of the fundamentals of sound, but, we have entirely differant methods of getting it so it would seem! either way, I am not a expert by any means, and I base my opinions on my experiences and what others have said or i have read or seen.

[talnlnky]

Originally Posted by Spades

actually, time to recalculate. the 6x9 does have more surface area than a 6.5 oval. however, while
the driver surface is bigger allowing more air to be moved, it does not change the problem that all oval speakers suffer from...the fact that the driver is mis shaped effects sound quality especially when the speaker is being pushed hard.

http://www.autoneeds.co.uk/index.php...on=Prod_detail

SD = the effective radiating surface area (AKA Cone area) of a speaker. There aren't many 6x9's on the market that don't have a co-axial design which means a circle in the middle about the size of a 50cent piece is missing... which is a good portion of its cone area.

On that site. the SD is listed as 22.8 (for some reason its in sq inches, normally SD is listed in sq cm or sq m)

22.8 square inch = 147.096 48 square centimeter

compare that to a 6.5" speaker size (this is not a midbass, but a midbass would have a very similar sd)
http://www.parts-express.com/pdf/264-852s.pdf
which has 140sq cm

Difference of 7sq cm. Nothing noticeable.


Now, if you do find a 6x9 without a coaxial design... Tangband makes one. http://www.parts-express.com/pdf/264-837s.pdf
then the SD will jump drastically to around 220sq cm. WHICH IS VERY SIGNIFICANT!

Originally Posted by Spades

round speakers are ussually the way to go, but, you ussually get more bass "hit" out of a 6x9 than a 6 round on cheaper speakers because of the larger radiating surface...same with subs. a more expensive 8" sub may sound better than a cheaper 15", but odds are in pure bass, the 15 will hit harder.

all things being equal, and 8" sub won't sound better, play "faster" or any of that nonsense than a 15" sub.. thats another giant myth in audio (Le determines how "fast" a speaker is", and to a lesser extent, the enclosure it's installed in). Also, there is more to SPL levels than cone area. Volume displacement, and enclosure design make a HUGE difference. Throw a beefy 8" sub in a well tuned bandpass box, and you could be as loud (though with limited frequency range) as a 15" sub in a small sealed box setup.

Originally Posted by Spades

we do agree on one thing, that rear fill should be minimised, and its why I have always run them off of deck power and fader moved far forward.

No, i'm adamantly opposed to rear fill, unless you got a DVD 4.1/5.1 setup in your car... and even then... i'm not a huge fan.

Originally Posted by Spades

but, we disagree on another. I belive that while rear sound should be minimised, it does improve sound quality to have it there, but ambient. and I disagree on bass or midbass from the rear deck. if you have subs the impact is already slamming you from the rear, and you want midbass hitting you from the front...most midbass will be obliterated or drowned out in the back if you are runned anything decent or bigger than a couple 10 inch drivers.

you are talking about different fequencies, you will hear a 200hz tone from a midbass even if a sub is blasting away 45hz @ 130dB. IF somebody is drowing out midbass speakers with the subs, and can hear the subs from behind them pounding away at the back of their heads, then they haven't set up the subs to properly blend in with the rest of the system.

A well tuned system should not sound like subs are in the back seat.... even if they are.

Originally Posted by Spades

low bass is almost non directional, which is why subs cut off at 40 hertz or less work fine in the trunk, but the higher up the frequency, the more directional the sound. mid bass should be shifted as far forward as possible, to give the appearance of the "concert" you spoke of.

anything 200hz or below is omnidirections... HOWEVER, unless you are using a sub that uses an awesomely linear motor like the XBL^2 technology that Adire Audio patented, or the JL W7 motor tech, or the Split Coil design that TC sounds has been making for many of the DIY companies over the past 2 years... then you will get distortion... Some of which will be above 200hz... which will make your sub no longer "omnidirectional"

Originally Posted by Spades

cutting a midbass driver off at 1k will most likely fry it fast, and your sound quality will be very foul. at 300hz deeper vocals can be heard, and a mid bass driver playing above that will sound very muddy normally. also, at that point, your ear can easily pick up direction of the sound, so the whole point you made about making rear fill disappear is moot.

I was talking a low pass, running high frequencies will not kill a midbass or sub if it gets high frequencies... higher frequencies have a much higher impedence, thus amplifiers can't push any amount of power at those frequencies. I've ran tone generators to subs running upwards of 12khz before.... sounded perfectly fine... course that sub had an extremely low "Le" so it was capable of producing it.. but even if it couldn't... it wouldn't fry the sub... the sub just wouldn't play it.. but would suck up the power.

Some people run midbass drivers higher than others.. .it all depends on the speaker chosen. I personally prefer a 250hz & lower limit.

Originally Posted by Spades

I think you and I agree on some of the fundamentals of sound, but, we have entirely differant methods of getting it so it would seem! either way, I am not a expert by any means, and I base my opinions on my experiences and what others have said or i have read or seen.

I too base my opinions on what I've experienced, and what i've learned from other people. I'm happy to have met the people that I have been able to.


I don't know everything... but I do know rear fill is a waste of money.