modifiyng to enhance sound

[zullo]

hello all. i posted about this same subject on two other forums and was directed this one. i am seriously getting into speaker building/improvement now and i have some ideas to improve my system.

i currently have a set of 3way speakers, vented 54l, 10Kg. The subwoofer is a 10" from QSL(QS10P30), a midranger and a tweeter from the same unfamiliar brand(Atlanta). The sub has now lowpass filter and plays up to 8000Hz. The midranger has a first order high pass filter at ~ 800Hz and the high pass on the tweeter is at ~ 1400Hz.

My original idea was to play with the settings of the crossover, placing a lowpass at 700Hz on the subwoofer(preferably 2nd order) a bandpass for the midranger(going from 500Hz to 4000Hz) and a highpass on the tweeter(at 3000Hz). Of course these values are subject to change and i would very much like to read your ideas on them.

As the box is rectangular on the inside, i had some doubts on the standing waves issue. At first i had a simple idea, making the inside trapezoidal but, reading the replies on other topics i was suggested to stuff the box with acoustic foam and i am evaluating this idea.

The box has the midranger and tweeter side to side and below them, on the center, is the subwoofer. there is no separation between them, they share the same space on the inside. If I put a piece of wood to isolate them would it do any good? Then, the sub would be in the vented part and the mid and tweeter on a sealed part. Would i have to open a hole in their enclosure or not?Something else that i can work with is the resonance of the box, opening or closing the vent as needed.

in the future i intend to buy better tweeter and mid drivers, but for now i have to work with them.

this might be one of the most stupid questions, but since i am starting with this i have to ask. Do speakers made for cars work with home audio amplifiers or not? Although i looked at several websites, i couldn't find an explanation on this subject. I judge that they don't, since the voltage and current levels on the car are different than on the wall outlet. I ask this because its much easier to find car audio speakers then home ones, if they have any difference that is.

i am sorry to make such a long post, but i have know this and i have very little room for failure, since the budget is short.

thanks for your time.

[navin]

Originally posted by zullo
i currently have a set of 3way speakers, vented 54l, 10Kg. The subwoofer is a 10" from QSL(QS10P30), a midranger and a tweeter from the same unfamiliar brand(Atlanta). The sub has now lowpass filter and plays up to 8000Hz. The midranger has a first order high pass filter at ~ 800Hz and the high pass on the tweeter is at ~ 1400Hz.....

The box has the midranger and tweeter side to side and below them, on the center, is the subwoofer.... then, the sub would be in the vented part and the mid and tweeter on a sealed part.

this might be one of the most stupid questions, but since i am starting with this i have to ask. Do speakers made for cars work with home audio amplifiers or not?

ok one thing at a time.

1. u dont state state the size of the midrange. i can assume the tweeter is a 1" dome. i assume the mid is 4" dia. cone. does it have a foam, rubber or pleated surround? this can dictate how low it will play.

2. we have no idea on the type of music and levels you like. this will dictate the XO points as well. if you like trance for example a higher XO point on the woofe will save your midrange, if oyu like classical you could use a lower xo point between the woofer and mid and maybe get a more accurate midrange.

putting a divider may ot maynot improve the sound. if the midrange is a sealed back it wont make much of a difference to the mid and usually the tweeter is sealed anyway.

what might help are a couple of braces.

as far as car speakers go they are usually 4 ohms. most home amps prefer higher impedances. however at lower levels when within safe current levels of the amp a car speaker can be used in a home speaker. this is as simple an axplantion i can give. others might be of more help.

[zullo]

i listen mostly to drum&bass and trip hop. Sometimes i get into james brown and the likes. You guessed correctly about the sizes.

by bracing you mean to reinforce the internal wall of the speakers?

i hope i have clarified a bit more and people can help me better now.

thanks for clarifying the car speaker issue.

[navin]

with that music and assuming the drivers are average poly/paper/dome (woofer/mid/hf) and the mid has a ribbed/pleated surround i would suggest 1st trying with 1st order XO at say 700Hz and 4000Hz. I cant image the tweeter operating at 1400Hz as mentioned by you. most 1" domes would fry unless the filter is of very high order (18, 24 /db oct or more).

1st order at 700/4k will give you starting point. remember w are working without the T/S specs, internal box size, etc....

yes bracing and damping can help. bracing reinforces the internal walls and drives teh resonance freq. of teh walls up. then damping is usually more effective at upper freq. and can absorb the resonaces. bracing usually requires 2 or so wooden braces running from one wall to the opposite wall and damping usually means padding the walls with 2" or so of glass wool, open ell foam, etc...

[zullo]

i'm sorry, but i didn't read the measurement on the tweeter correctly. it's a 3" dome and the midranger is a 4 1/2" with a ribbed/pleated surround.

from what i could tell they're 1st order passive filters. the midrange has two 22uF capacitors wired in parallel and the tweeter has one 22uF capacitor. and by these values, the crossover points i told you were incorrect. Although, it might be 2.2uF capacitors. This way, the high pass on the tweeter would be 9000Hz.(in my opinion, as strange as before).

Unfortunately, as the midranger and tweeter drivers are from an unfamiliar brand i couldn't find their TS specs. I might need to go back to the store and see if they have any datasheet.

As for the woofer, i found the TS parameters.