toning down highrange

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
D

damianl

Member
Joined 2006
Just say i have a speaker that goes from 200hz to 20k (fairly flat) and the bass from 200hz to 80hz is only -4db, can i use some sort of a crossover to "tone down" the 200hz-20k range at a level of -4db.
This would give me a response of 80hz to 20k. I dont care about sensitivity.

What about L pads can i get them to cover such a range?


thanks
 
D

damianl

Member
Joined 2006
sorry i didn't mention it is one full range driver...its a tang band w3-593sf.
im trying to boost its bass by lowering its high range. im still fairly new to this but wouldn't the resistor you just mentioned be for a 2 or 3 way system to lower the db of the mid/highrange drivers
 
Cloth Ears

Cloth Ears

Member
Joined 2001
damianl said:
Just say i have a speaker that goes from 200hz to 20k (fairly flat) and the bass from 200hz to 80hz is only -4db, can i use some sort of a crossover to "tone down" the 200hz-20k range at a level of -4db.
This would give me a response of 80hz to 20k. I dont care about sensitivity.

What about L pads can i get them to cover such a range?


thanks
Click to expand...

Sooo, what your saying is that you have a speaker that goes from 80Hz to 20kHz? But that it is down 4dB at 80Hz? Is the roll-off smooth from 200Hz down to 80Hz, or is there a definite step down at 200Hz and it's relatively flat the next octave and a bit down?

Or am I swinging the wrong end of the cat?

You might be able to make do with a R||L||C filter if it's a smooth roll-off from 200Hz down to 80Hz, otherwise I think you might be stuck with only using 200Hz up (or even higher as the big step will affect the crossover anyway).
 
Cloth Ears

Cloth Ears

Member
Joined 2001
damianl said:
the rolloff from 200 to 80hz is quite smooth. Is it worth just sticking to an equalizer to do this job? or is what im saying actually quite possible?
Click to expand...

It's a bit hard (and expensive) to try to do it with passive components. Much easier (and possibly better sounding as it won't steal as much power as a passive set-up) would be to use a parametric equaliser between your pre-amp and amplifier to boost the signal from 80-200Hz. Behringer makes some cheap non-digital mono ones (PEQ2200) and some not quite so cheap stereo digital ones (FBQ-something). And then there's Rane and other people who make better ones. Passive would probably cause the sound to end up too muddy that low in the spectrum.

Neither way will be really good unless you get lucky with a great balance of EQ/amp/driver. I'd really start looking for solutions such as having your speaker run full-range , but un-aided - and then look for a set-up (2 bass drivers) to fill in the missing pieces. As you mains already have a 6dB/octave rolloff, you only need to work on a LP filter for your bass at the same slope at about 80-100Hz. So it wouldn't be a subwoofer, just a woofer.
 
Pano

Pano

Administrator
Joined 2004
Paid Member
damianl said:
not exactly fully flat but there in only about 1db difference between 20k-200hz then a smooth rolloff
Click to expand...

Color me doubtful, but I find that hard to believe. Extraordinary measures are needed for a system like that.

But I'm with Sreten - it's just a BSC you want. AKA - a shelving low pass.

Not hard to do. Rule of thumb is to figure what inductor you would need for a 1st order filter at the frequency you want to bend. Use that inductor but bypass it with a resistor about the same value as your driver impedance. Start there and adjust. Have look at the calculators and tables online.

Changing the impedance value will move the frequency point up and down. Changing the resistor value will give you more or less effect - and can roll of the high end if too high a value.
 
S

sreten

R.I.P.
Joined 2003
damianl said:
http://www.tb-speaker.com/detail/1208_03/w3-593sf.htm

Thanks for your help anyway guys I'm thinking of just using an equalizer...
Click to expand...

Hi,

that chart - free air (no box) and a very large baffle is relevant to,
but does not reflect its response in a box, see Zaphs articles.

You need a BSC circuit. In box they will not go down to 80hz with
an Fs of 110Hz (free air) and probably around 140Hz in box.
Your 200Hz and below boost will not work.

:)/sreten.
 
S

sreten

R.I.P.
Joined 2003
damianl said:
http://www.tb-speaker.com/detail/1208_03/w3-593sf.htm

Thanks for your help anyway guys I'm thinking of just using an equalizer...
Click to expand...

Hi,

that chart - free air (no box) and a very large baffle is relevant to,
but does not reflect its response in a box, see Zaphs articles.

You need a BSC circuit. In box they will not go down to 80hz with
an Fs of 110Hz (free air) and probably around 140Hz in box.
Your 200Hz and below boost will likely not work well.

:)/sreten.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom