Taiming the shreil!

[kegger]

what is the best way to taim just the very high
end of the tweeter.

i've got the l-pad in the curcuit and the system
plays very nice and flat except the extreme top
end cimbals are just slighty to crashy. "not bad"

just wondering what people use for this and what
values they generally are.

i'm using the audax two25a26 tweeter and you can
even see on the graph that the extreme top end
increases quite a bit.

just wondering if this is a fairly common type of
thing and what to try.

thanks in advance for all you help!

[sreten]

Believe it or not the most common way is grille cloth, which can
lose around 2dB at the top end, most modern grille cloths used
don't do this as they are very skimpy.

But also to consider is the sound may be related to the 1st
resonant mode of the tweeter and be impossible to correct,
If the speakers are toed out or fire straight ahead usually
response at the listening position is pretty flat / rolled off.

sreten.

[Timn8ter]

How about using a small Zobel along with a series padding resistor? Would that compensate for a rising response?

[Bill Fitzpatrick]

Some say the zobel alone does the job!

[kegger]

hey guys thanks for the info. (Timn8ter i see your hear also) nice!

anyways i know how to create the zobel for the woofer impeedance.


but what would the curcuit look like for the tweeter for
this application.

as i stated above i allready have an l-pad on the tweeter
attinuating it very flat with the system.

it's just the extreeme highs.



again thanks for all your help! still learning new things all the time.

[Timn8ter]

Here's an example.

[kegger]

thanks guys i posted the same question on the partexpress
website and got the same info as you guys.

i'm pretty sure i got it right.

it looks like people basically do it 2 ways.

either a .1 mh coil in series or somewhere around a 1uf cap and
12 ohm resistor in paralell after the xover curcuit.

i used what i had on hand a .69 cap and 10 ohm resistor.
"it seems to work"

thanks for the curcuit layout tim.

so i will try both.

if it's not that big a deal don't need to respond,but
would their be a preferred method one versus the other.

again thanks guys for all the input. really appreciate it.
and tim your website is very nice congrats!

[sreten]

The effect of the zobel will tame extreme treble a touch,
but its effect is influenced by the series and parallel
resistance of the L-pad connecting the tweeter.

With no L-pad treble response will be barely effected.
The series resistance of the L-pad will increase its effect
and the parallel resistance decrease its effect but with
less influence than the series resistance.

Note the "Zobel" values in this case don't need to
be related to the parameters of the tweeter.

10R sounds fine but you should tweak the capacitor by ear,
as the L-pad position will effect its frequency of operation.

sreten.

[Timn8ter]

Would a series resistor work better than the L-pad in this case?

[kegger]

yah i ended up playing with values a little more last night and
i think i'm real close if i'm not there.

need to do some critical listening tonight after work.

anyways my l-pad is 4ohm series and 8ohm paralell . (6db)
that tweeter is really hot.

the zobel is now at 1uf and 6ohm resistor.

i picked up the new version of the excel spreadsheet xover (2.0)
program a couple days ago and plugged some more values in it
last night to see what these changes look like to the signal.

i ended up changing my first cap in the woofer curcuit down
by 1.4 uf and my first cap in the tweeter curcuit down by 1.35 uf
to smooth out the response a bit (4th order)

right now i'm just doing minor tweeking to finish the xover and
it sounds very good.