Film-Tech Forum ARCHIVE: Crown XTi 4002 sub sonic filter

This is topic Crown XTi 4002 sub sonic filter in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Jarod Reddig (Member # 6363) on 07-14-2017, 03:14 PM:

Hello,

I am looking at getting a JBL 4645c sub and I want/need an amp with a sub sonic filter that goes as low as 22-25hz. Says to use a 25hz/3rd order/Butterworth High pass filter.

Does anyone know how low in frequency the sub-sonic filter goes on a Crown XTi 4002. I combed thru the online manual and it only confirmed that it indeed has high pass and a low pass filter and also the db and slope of each kind of filter just not how low of frequency the sub-sonic filter can go.

Anyone know for sure on this model of Crown?

Thanks

Posted by Marco Giustini (Member # 4544) on 07-14-2017, 03:47 PM:

I do not know that amp but from what I can see you can select any frequency as HP, LP or crossover with the following slopes:

quote:
The crossover section provides users with the ability to enable a HighPass and LowPass filter per channel along with BandPass gain and the ability to change the polarity. This allows the Crossover section to be customized to most system configurations. For the HighPass and LowPass Filters, you have the choice of the following filters: Butterworth 6dB/oct, Butterworth 12dB/oct, Butterworth 18dB/oct, Butterworth 24dB/oct, Butterworth 48dB/oct, Linkwitz-Riley 24dB/oct, and Linkwitz-Riley 48dB/oct.

I see there is a "CUSTOM" setting for setting the frequency, I do not know how low it goes.

Posted by Jarod Reddig (Member # 6363) on 07-14-2017, 08:42 PM:

Thanks Marco. I had read that too. I believe I remember hearing that on the custom setting like you referenced, you can go as low as 20hz. I imagine if thats the case you can select any frequency above that i.e. 21, 22, 23hz etc.

Before I commit I will make for certain though.

Posted by Marco Giustini (Member # 4544) on 07-15-2017, 04:34 AM:

I would probably ask Crown sales dept.

That said, why not finding a more basic amplifier and an external DSP?

Posted by Jarod Reddig (Member # 6363) on 07-17-2017, 03:22 AM:

Ya when the time comes I will reach out to them.

Im in the early stage of this project so I will be on the look out for other amplifier solutions other then this. The XTi 4002 was recommended on the Harmon page for the JBL 4645c I plan to get so I started from there. Plus $1k will be about my budget for an amp and that seems to be its going rate.