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?
While true for many, for the most part I find these approaches barely scratch the surface of what good subs can do. Depends on the full range speaker. Mid to small floor standers do much better being high passed IMHO. If your sub doesn't make your system sound glorious you are just gilding lilies. |
@erik_squires , there have been sessions with certain source materials that I honestly did feel my system sounded glorious, but I would also add that it was not because of my sub. I truly believe that my sub is the weak link in my system. |
Most who’d implement a high-pass filter over the main speakers would do so over an existing, passively configured speaker setup (i.e.: with a build-in crossover "seen" by the amp on its output side), meaning an extra layer of signal processing/filter of some kind is added to cut off the main speakers below a given frequency in the bass area. If a DSP is suggested for this purpose it runs contrary to the desire of quite a few audiophiles to avoid added (or any) conversion steps in the signal chain (not least A/D conversion with an analogue input only, which would then be followed by the necessary D/A conversion step for the signal sent to the analogue input on the amp - unless it’s a digital variety), and so an analogue HP-filter may be preferred here. Purists on the other hand would rather avoid any kind of added HP-filter. Previously I used my current DSP/digital crossover (Xilica) over my passively configured main speakers to cut them off below some 80Hz to be augmented with a pair of subs below, and being it’s a high quality DSP (even with A/D to D/A conversion steps) the result was great; I could detect no lack of transparency, resolution, change in tonality or other with the inclusion of the DSP, and being able to experiment with and find the sonically most desirable cut-off frequency to the subs (with both low and high-pass filtration) proved very worthwhile, also in relieving both my previous all-horn speakers and Class-A amplifier in the bass area. Which is to say: with a high quality and transparent DSP/HP filtration device any remaining slight influence the filter may introduce by its mere existence in the chain as an added element (and thus, strictly speaking, can’t be claimed to be fully transparent in an isolated sense) is likely to be alleviated by the positive outcome it creates with relieving bass to amp and speakers, in addition to providing for the opportunity to tweak more effectively with the crossover range to the subs. If on the other hand you’d run a fully active speaker setup, which I know you aren’t, the digital crossover/DSP or electronic XO(i.e.: non-DSP) would act as the only filtration means in the chain (remember: the passive XO is a filtration/equalizing device as well, and a sonically detrimental one at that) that could also apply a high-pass filter over the main speakers. This way the crossover you’re already using as a wholly necessary component (just like the passive XO) can simply be asked to perform another task, and that way you’re more effectively approaching your speaker setup + subs as a single speaker system per channel - they’re merely divided into separate boxes. This also means that the separate amps to each driver section work independently of each other; whatever goes on in each of these amps and corresponding driver sections won’t affect the other, which is a further bonus - and hardly an insignificant one. It seems that many who attempts a high-pass solution over their passively configured main speakers for the use with subs don’t approach it all-out enough, be that both with regard to the added filter component used as well as and perhaps not least where the implementation goes; sometimes such a project is indeed doomed to begin with. Therefore, give it a good shot before coming to a conclusion. |
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. |
