running full range or not full range...huh?

I'm trying to ask this question a few ways to see if I can ask it sensibly and get some help....sorry if it seems redundant.

Here's the question: is it better to remove the low bass from the signal and not send it to floor-standers that don't go down below -- say -- 35 hz because it avoids having the speaker try to do something it can't, which in turn causes distortion.

Or, is it better to just let the speakers naturally roll off the sound, and not worry about distortion (and avoid using an external crossover of pre/pro of some type).


It's better to remove the bottom octave (20Hz-40Hz) music completely (& send it to a sub, if you have one OR live without the bottom octave if you don't have subs) because your speakers will "open up" sound-wise. From what I've heard on others' systems, it makes a big difference. It's almost like having brand new speakers!
hi Dan,

there are a few different answers to your question depending on the context of the question.

--after reading other posts and questions of yours it appears that you are asking about subwoofer integration for a 2-channel analog system and not Home Theatre from a processor. is that correct?

assuming that my interpretation of your situation is correct; then the answer to your question would depend on the output choices of your preamp and the adjustments available on your subwoofer.

there are a very few analog preamps which allow for multiple outputs that split the frequencies (and the only one i know about is $25k). so if you want to filter the bass output of your main speakers it will need to be done in another way.

one way is to use an external crossover as you mention. personally i don't like that as it comes with a sonic cost.

another way is to use a subwoofer which has a high pass filter and then simply lower the filter on the sub until you have optimal bass integration. this is the most common way to integrate a sub into a 2-channel analog system. your preamp either has two analog outputs or you use a 'Y' connector. personally; i've not heard a system done this way which intergates 'good enough' for my tastes but many people are very happy with this approach.

another version of that approach is to actually connect your subwoofer directly to the speaker terminal on your main amplifier with a high current Neurick connector. there are a few subs which have a high level input and can be connected this way. this does have the advantage of taking the signal from the main amplifier and so the bass character seems to better integrate.

personally; in a way i have a similar setup as my last description. my speakers, the Evolution Acoustics MM3's, have powered integrated subwoofers which take their signal from the main speaker terminal. they use a ICE based digital amp to power the subs and it sounds perfectly integrated and goes to 10hz flat in my room.

if your subwoofer does not have a way to adjust the crossover frequency then don't attempt to try to intergrate it with a full range speaker.

finally; if you are not using a subwoofer and just want to reduce the strain on your speakers by limiting the low frequencies, don't worry about it. the roll off of your speakers will do that anyway. they will output some signal at frequencies way below what you hear that will have benefits.

if you describe the exact gear you have it will be easier to give specific advice.
It can be done passively as well. Had Kappa8's that had a switch on the back to high pass the lowest octave to be an easier load to the amp. Dependant on the amp's capabilities. It made no difference to my amp at the time.

It can also protect the speakers from DC with direct coupled electronics, which could cause damage or reduced headroom.
I'm assuming you mean with just the floorstanders, no additional sub in the picture.

Personally, I would rely on the speakers to determine what to do with whatever clean music signal is provided to it.

I would also do everything possible to make sure the speaker is integrating into the room as best possible for listening at the primary listening location.

If non of that works to satisfaction, then it is time to find a different pair of speakers that will integrateinto the listening environment better.

I do not believe in trying to fit a square peg in a round hole. You might pull it off but usually only with greater pain and cost. If you find yourself spending a lot of time doing that, then you either need a different peg, hole, or both.
I hi-pass my mains (large monitors with integrated stands, making them appear as floorstanders) with 85Hz in-line passive filters which cleaned them up tremendously. And have stereo subs doing the LF work. Clean, full sound.
pretty simple

if you want to play difficult program loudly and your
mains are not up to it then filter

if not just add sub to bottom
It depends. Don't listen to anyone who says that it's always better one way or the other. You have to try it both ways on your system in your room and give each way PLENTY of time for hundreds of minor adjustments. - Jim
Rockadanny -- Do you put the passive filter between the amp and speakers, or between the preamp and amp ??
Filters were from ACI. I plug them right into the power amp inputs, then plug my cables from the pre amp into them. Simple, easy, and cheap. Like Aldavis says, try it for yourself and determine if you like them or not. If you get them from ACI you can return them within 30 days. ACI has 85Hz and 65Hz filters. I think they are $35 for a pair. When I had only one sub I used the 65Hz filters. I changed to 85Hz filters when I added my second sub.
thanks to all of you for the answers. I must say it's the classic audio situation of "it depends."

Mikelavigne, I'm generally familiar with all of the methods you describe, and have tried several of them. But the detail and discussion you provide is most helpful and most appreciated. You are surmising correctly -- I'm focused on using my speakers and sub optimally, with a focus on music. I will worry about multi-channel and movies with much lower priority.

But the intent of my question here is really to see if there is any clear consensus on whether it is better to send speakers a full range signal, even when you know they can't produce the lower octaves, but avoiding any fiddling with a crossover....

or if it is better to remove the lower octaves with a digital or analog crossover and let the speakers only try to produce frequencies they are comfortable handling.

Bottom line: which is better introducing a crossover (and the sonic cost that implies) or let the speakers just naturally roll off (and dealing with the possible distortion that creates either from the speakers or the amps).

And the answer seems to be: too many variables to have a clear answer.

For what it is worth, my speakers are Wilson Benesch Curves (very clean bass down to 33 Hz or so, but not much after that), and my amps are Kharma MP150s. Sub (which might get changed) is a Totem Forest.

Right now what I am doing is using a Bel Canto Pre/Pro to send 60 Hz and above to the speakers, and below 60Hz to the subwoofer. I have managed to integrate the subwoofer quite nicely with the mains. To my ears, this sounds better than using the speakers full range.

But I am eager to be done with the pre/pro -- it is a wonderful piece, but it has WAF issues for me, and does not fit well (space wise) in my system. Plus I'm mostly a 2 channel guy.

I'm intrigued by Rokadanny's suggestion. Looks like I've got a lot of listening to do.

thanks again all!
Mikelavigne said, " and goes to 10hz flat in my room."

I say, I would like to see that! How do you know this?