Anyone tried HSU hi-pass filter?

drphoto · « **on:** 1 May 2003, 01:12 am »

Just wondering how it sounds. The ACI passive line level h-pass filters didn't work in my system....muffled the sound too much.

I like the idea of hi-passing my Maggies, and if could be done on the cheap...all the better.

audiojerry · « **Reply #1 on:** 1 May 2003, 02:46 pm »

not familiar with either the ACI or the HSU, but was wondering if the filters are caps built into a short male/female RCA or XLR cable?

I've done this in the past and felt they work much better than a high pass after the amp stage. A high qulaity cap must be used; the most difficult part is getting the right value cap to match the amp impedence.

Bwanagreg · « **Reply #2 on:** 1 May 2003, 04:04 pm »

I just bought a pair of the ACI filters - I'm awaiting a Rava sub before I try them out.

The filters are built into a barrel-type connector, with male and female rca plugs on either end. I believe they also load the capacitor with additional resistance to make the cutoff more consistent across different amps, but I may be wrong. The reason I say this is that I have been told to expect to need a higher preamp setting to achive the same power level from the amp.

I'll post comment when my Rava shows up in (hopefully) 2-3 weeks.

audiojerry · « **Reply #3 on:** 1 May 2003, 06:18 pm »

Drphoto, if there is a resistor in ACI highpass, it may be the culprit.

There is a formula for calculating cap value by supplying desired cutoff frequency and amp impedence to achieve a 1st order rolloff (6db/octave):

C = 1/(2*3.14159*f*R)
where
C is capacitance
f is frequency in Hertz
R is the input impedance in ohms

I don't know how this was derived

Bwanagreg · « **Reply #4 on:** 1 May 2003, 06:26 pm »

From the ACI site:

ACI Filters are 1st Order, (6db/oct), and resistively loaded to allow use with virtually any power amplifier. Choose between two crossover frequencies of: 85Hz or 65Hz.

Den · « **Reply #5 on:** 3 May 2003, 09:40 am »

http://www.hsustore.com/high-pass.html

I haven't heard this 12 dB/oct filter, but the 24db/oct filter in the amp of my Hsu 12v is worse than the ACI passive filter.

Val · « **Reply #6 on:** 3 May 2003, 11:42 am »

I have listened to the High End Crossover Hsu sells for around $450 and it is as transparent as anything out there, I would recommend it without a doubt. Don't know about the rest.