Filter for RS drivers

[aricaudio]

I tried doing a search and found general information about notch filters for these drivers( basically that they need one:), but nothign specific. I'm planning on purchasing a apri fo the 295-372's for my wife's car possibly paired to some Seas 25mm neo domes for a front stage. Was wondering what frequency I can reasonably cross these drivers at. Can I push it to 2.5kz on the Dayton RS150 4 ohmer? Also, is there a published notch already out there for this driver? Thanks for any help, I'm almost ready to hit the "submit" button for the woofers and am wondering what to order up for a "starter" lo-pass filter.

Thanks for any and all info,

Best Regards, Aric

[cjd]

I don't use a notch with mine 'cause I cross them steep enough - 2100hz 4th order seems to work well enough... 2500 with a C-E filter may do quite well (no dedicated notch would be required again) but is probably pushing your luck.

C

[tomdaugherty]

> I don't use a notch with mine 'cause I cross
> them steep enough - 2100hz 4th order seems
> to work well enough... 2500 with a C-E
> filter may do quite well (no dedicated notch
> would be required again) but is probably
> pushing your luck.

> C
Aric I used a 4 channel amp with a built in xo on my RS150's, works great.
Not trying to high jack your thread Aric
but cjd do you know how to design a C=E filter?

[Pete Schumacher ®]

> Aric I used a 4 channel amp with a built in
> xo on my RS150's, works great.
> Not trying to high jack your thread Aric
> but cjd do you know how to design a C=E
> filter?

A CE filter is just a filter with a notch in the stop band to aid in getting a steep slope.

They're not that tough to do if you have modeling software.

[aricaudio]

> A CE filter is just a filter with a notch in
> the stop band to aid in getting a steep
> slope.

> They're not that tough to do if you have
> modeling software.

This is what I was wondering about. As I don't have modeling software, I was kind of wondering if there was a generic notch for this driver that could be used with a standard L-R 2nd order electrical. It seems that the notch actually helps in steepening the rolloff as opposed to just reducing the peak's amplitude though. Is this on the right path? Also, Do you have any recs for specific component values of chance?
Aric

[curt_c]

Aric,

I modeled the RS150 in PCD for you, using PE's published anechoic response. -I assumed no BSC since it's an automotive application.

I managed a 4th order acoustic response at 2600 Hz using a 2nd order electrical topology, series notch, and zobel. 6 elements total. You could call it a Cauer elliptical topology if you wanted. The break up modes at 10K are down about 40 dB.

Circuit:

LP filter: A series .4 mh inductor and a shunt 20 ufd cap.

Notch: A series .15 mh inductor paralleled with a 2.2 ufd cap. No resistor.

Zobel: A shunt 15 ufd cap in series with a 4 ohm resistor.

Change the .4 mh inductor to a .5 if you want to add some BSC.

I can email you the response plot if you'd like...

C

[Pete Schumacher ®]

> This is what I was wondering about. As I
> don't have modeling software, I was kind of
> wondering if there was a generic notch for
> this driver that could be used with a
> standard L-R 2nd order electrical. It seems
> that the notch actually helps in steepening
> the rolloff as opposed to just reducing the
> peak's amplitude though. Is this on the
> right path? Also, Do you have any recs for
> specific component values of chance?
> Aric

Check out FRD Consortium. They have modeling software for free use to DIY.

As for a "generic" notch to be used with a "standard" 2nd order filter . . . not likely. The notch you use depends on the filter involved.

[aricaudio]

> Aric,

> I modeled the RS150 in PCD for you, using
> PE's published anechoic response. -I assumed
> no BSC since it's an automotive application.

> I managed a 4th order acoustic response at
> 2600 Hz using a 2nd order electrical
> topology, series notch, and zobel. 6
> elements total. You could call it a Cauer
> elliptical topology if you wanted. The break
> up modes at 10K are down about 40 dB.

> Circuit:

> LP filter: A series .4 mh inductor and a
> shunt 20 ufd cap.

> Notch: A series .15 mh inductor paralleled
> with a 2.2 ufd cap. No resistor.

> Zobel: A shunt 15 ufd cap in series with a 4
> ohm resistor.

> Change the .4 mh inductor to a .5 if you
> want to add some BSC.

> I can email you the response plot if you'd
> like...

> C

Wow Curt you are a sweetheart. I was hoping to gain enough general knowledge to experiment. This is way better than I hoped for. Thanks very much for your patronage. I've been waiting to bit the bullet & get rid of the paper-cone Audax buyouts she has now;).

Anything I can do for you, just let me know.

Best Regards, Aric Kimball

Best Regards, Aric