I believe the effectiveness of using a high-pass filter depends on the main speakers, the amplification, and the quality of the high-pass filter. If you are using good subwoofers (at least two) then a high-pass filter should theoretically improve linearity and reduce distortion by relieving your amplifier from the need to amplify the more demanding low frequency signals, and by relieving your main speakers from the need to try and reproduce the lowest frequencies. However, in the case of my acoustic suspension speakers that roll off bass at around 40Hz and that have the ability to handle high power and deep bass, having the additional high-pass circuitry in line and affecting all of the upper frequencies was not sonically worth the trade-off. As the manufacturer of my speakers and subs recommended, my system sounded better running the main speakers full-out (i.e., without the HP filter) and rolling in the two subs at a relatively low frequency of around 45Hz. I believe it is also helpful that my amplifiers have more than ample power (650 wpc into 8 ohms) to drive the low bass loads.
My high pass filter experiment and a couple of questions
Prior to this "experiment" I was running my Maranztz SA10 with balanced Kimber Silver Streak to my Cary SLP05 and from there I was using balanced Kimber Silver Streak to my Cary V12; from my SLP05 I was going out of the RCA outs with some old Monster Cable to my ancient M&K MX-100.
Back in ’95 I bought a M&K LP-15 passive high pass filter and I liked it with the gear I was then using, but as the gear got bigger and better and I also started using balanced interconnects I quit using it.
A few days ago I dug it out and I left the balanced connections from CDP to the pre the same, but from the pre I went with some Kimber PBJ RCA (because I don’t have any Silver Streak RCA that is long enough) from my pre into the high pass filter, and from the high pass I went with Kimber PBJ RCA to my amp; I hooked up the Monster Cable (that I had been going from the pre to the sub with) to the high pass filter and went to the sub with that.
Initially I kind of liked it, but tonight I wasn’t so sure. (It almost seems as if I am prone to INITIALLY like any change I make.)
I have a lot less gain and a lot more real extate available on the volume knob of my pre. That part I do like. I assume that is because I am going into my amp with RCA connection versus balanced and less voltage?
The high pass filter does have a treble control and a bass control. Initially I was reticent to use it any way except with both controls turned all the way to full. However, I did find that by playing with the treble control a smidge I could take the hard (bright) edge off of certain (not all) CDs. I left the bass control turned all the way to full because I am thinking it is supposed to do the same thing that the level control on the sub is doing, so why defeat that on the sub?
Another question is: since the LP-15 is theoretically supposed to roll the bass off at 85 Hz and the Revel M126Be’s I am now using are supposed to be trying to go down to 54 Hz, if those speakers are only being sent 85 Hz and above from the amp, this should make them an easier load to drive? I would think that their sensitivity doesn’t change, but now the impedance should not have to dip as low?
And still another question(?) does balanced from CPP to pre and RCA from pre to high pass and then to amp seem problematic? And I suppose I should consider upgrading the PBJ RCAs to Silver Streak RCAs?
Showing 2 responses by mitch2
Hi Erik, I am curious about your single capacitor solution. If I bi-wire my speaker connections, can I wire a single capacitor in line with the LF speaker wires to limit the low frequency signal going to the woofers? How exactly would you wire that capacitor, to the positive terminal of the LF binding posts, only? Would that have any effect on the high frequencies? Since that capacitor would come after the amplifier, would that solution benefit both the speaker (which would not need to reproduce the very lowest bass) as well as the amplifier (since the speaker wouldn't be drawing current to power the lowest frequencies)? How would I figure out the capacitor parameters to use for a certain high pass value, like 40Hz? If it were this easy, why aren't the speaker manufacturers recommending this solution and why do people purchase more expensive solutions as provided by Vandersteen or Marchand? FWIW, I owned the XM446 fully balanced high pass filter, which was in-line prior to the amplifier thus affected the entire signal. BTW, I am not challenging your comment, but sincerely want to understand. Also, my acoustic suspension speakers do not have ports. Thanks for any further clarification/explanation. |