Transient response on underdamped sub with EQ

[mikee12345]

Hi all
One thing isnt clear

If i use a 15" adire tempest for example,
on 115Litres tuned to 33hz,
Then use Parametric -5db gain,Fc=50hz,Q=0.4 EQ..

this results in a flat response.

BUT transient response must equal what the final FR is yes?

with a flat response i expect good quality bass,not quite overdamped control,but 'okay'

i certainly dont like the underdamped peaky box,which is why i thought about applying EQ.

btw with this alignment it can handle 750watts easily,xmax peak in midbass only 8mm..ofcourse subsonic filtering would be best to keep it safe below 25hz.
---just in theory---

Cheers!

[roddyama]

Mike,

I would expect the transient response would be that of the box alignment even though the total response is flat. I run an over damped alignment with electronic bass boost.

[richie00boy]

I think that because the box is a 4th-order system and you are skewing the frequency response with a different order response, i.e. are not exactly cancelling/moving the poles and zeroes, then the transient response is not properly improved.

However, the bass sounds better because of the reduced amplitude exaggeration.

[sreten]

The transient response will theorectically ~ be the same.


The end result is a FR and TR not normally available from the driver,
but it will be nearly equivalent to another driver with that alignment.

(some minor ripple difference is to be expected)

sreten.

[roddyama]

Originally posted by sreten
The transient response will theorectically ~ be the same.


The end result is a FR and TR not normally available from the driver,
but it will be nearly equivalent to another driver with that alignment.

(some minor ripple difference is to be expected)

sreten.

So the ringing, characteristic of poor transient response and higher order box alignments, will be cured by an overdamped electrical filter? This doesn't seem right.

[sreten]

Well if it wasn't right the Linkwitz Transform would be a non-starter.

But I'm not saying it is the same in all respects, port utilisation
would be different and low bass power handling affected by this.

sreten.

[roddyama]

Originally posted by sreten
Well if it wasn't right the Linkwitz Transform would be a non-starter.

sreten.

Ah, sorry, I meant the driver ringing (overshoot and recovery) as in impulse response, not the ripple in the FR.

[sreten]

The Linkwitz Transform also converts the transient response of
an underdamped sealed box to that of the target TR and FR.

The same applies to a second order notch filter applied to an
underdamped 4th order reflex response, both FR and TR.
I don't think it works well in practise due to effects at high levels.

sreten.

[mikee12345]

thanks guys for clearing that up!

[mikee12345]

Originally posted by sreten
The Linkwitz Transform also converts the transient response of
an underdamped sealed box to that of the target TR and FR.

The same applies to a second order notch filter applied to an
underdamped 4th order reflex response, both FR and TR.
I don't think it works well in practise due to effects at high levels.

sreten.

the LT or the notch filter doesnt work well at high level?