Axiom Home Page Forums General Discussion Home Theater Sub crossover adjustment poll

Many people ask about the proper level of a subwoofers crossover level and it really comes down to personal preference. Out of curiousity, i wanted to know what other Axiom owners use for their crossover adjustment.
In order to compare apples to apples (as much as possible) this poll should be limited to Axiom owners all using the same speaker models but of course that is not very feasible so everyone is welcome to vote.

For those using subwoofers coupled with Axioms as mains, what is your preferred crossover level for your subwoofer? single choice
	35-44 Hz
	45-54 Hz
	55-64 Hz
	65-74 Hz
	75-84 Hz
	85-94 Hz
	95 Hz and above
Votes accepted starting: 05/24/06 10:11 PM
View Results

i think it REALLY depends on which speakers you are using.

In reply to:

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i think it REALLY depends on which speakers you are using.

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Actually, I think it depends somewhat more on your electronics. If you're limited to a single x-over frequency for all small speakers, then you're probably better off using a higher x-over even if you do have big mains, so that the performance of your smaller center/surround speakers doesn't suffer.

For instance, my mains are m60ti's, but I use an 80hz x-over since that's better suited to the center/surround speakers (VP150, M3ti's, and single QS8).

IMHO it's almost always a mistake to use an x-over below 80hz unless you have the capability to set different x-over frequencies for different speakers or you have identical towers all the way around.

Chesseroo, if you're using a receiver with bass management crossing over at 80-90hz and speakers set "small" then the idea is to get the subwoofer crossover entirely out of the way if the sub provides for a bypass or otherwise as far out of the way as possible by turning the sub crossover all the way up(150hz or whatever)and leaving it there. The receiver provides all the bass management necessary. The sub crossover can get in the way and cause phase and frequency irregularities at the crossover frequency.

Actually when the crossover was turned higher, I found that many common musical notes tended to get played by the sub as opposed to the mains (incidentally i have m60s in front set to 'large'). What should have been a regular bass drum had sounded more like a soft tire dropped from 15 feet.

My purpose for the sub is to add some ooommph and shake only in the very lower ranges of sound (and primarily for HT uses). I prefer to let the m60s handle the rest.
Hence, my tentative preference for my sub crossover is way down to around 60-65hz or so. I find it sounds alot cleaner and less mushy for music. I'm still tinkering with alot of things though.
Placement on the first day almost blew out my eardrums!

But that is part of why i wanted to see what others were using. As in some of the other replies, i would still need to be comparing apples to apples (room sizes, model types, etc.) which is just too hard to do unless someone out there has duplicated my basement based on the pics.

if you want to compare apples with apples well heres my two cents worth....
it was my experience that with different conditions comes different settings, in one set having the sub in a corner with a certain setting made it sound boomy, in an other sound almost absent, there are really too many variables to put any kind of setting on a sub as reference( thats why they are there to begin with) the variables can be the following... the electronics, room size, in the room.. the type of furnishings, speaker placement. for any settings to be of reference all of the variables would have to be exactly all the time...

....just my 2 cents

You may have already experimented with all these settings, Chess, but I'll mention them anyway. If I follow, you had the M60s at "large" and also had the sub handling those frequencies into the upper bass area. If so, the results you describe were to be somewhat expected. If however,"small" was selected for the M60s, the 80-90hz crossover in the receiver would roll off the M60s below that and the sub above that and make the sub crossover just a hindrance to the best sound. Most who have tried both arrangements have found that even with mains having good bass(such as the M60s)it was still a bit better to set them "small" and move the sub crossover out of the way. Of course,the judgment is yours to make.

You have understood my situation exactly JohnK.
I have tried the M60s at the 'small' setting as you mentioned but i found the bass from the EP350 to be too large (for lack of a better word) and, well, obviously not the bass from a 6.5" driver.
The smaller tight bass of the M60 6.5" woofer appealed to me more than the boom from the sub playing the same range.
Of course when i switched over to the 'large' setting for the m60s then ya, i had the mushy bass problem, corrected by lowering the crossover frequency.
But now, the m60 bass starts to trail off at the bottom end (somewhere under 40 Hz maybe?) where the sub maintains its expected presence and with most music playing notes typically above the 65 Hz range (my crossover level), the sub does not come into play as much for music.
I've read posts from people (not necessarily on these forums) who have complained about their subwoofers not being very musical and i would agree to SOME extent (my fiance loves the big bass for dance and pipe organs). I think perhaps these people should review their crossover settings and think some more on how much they really want their sub to take part in music playing.
Other people really love the big heavy bass presence and find no issues with intergrating the subwoofer right into their system as is. (I would say the poll results are not particularly surprising).

So my solution for minizing the presence of the sub for music while still being available for the heavy base notes and HT applications (explosions, thunder, etc.) is to do what i've done with the 'large' settings for mains and a lower crossover for the sub. It really has a nicely integrated sound that i'm quite enjoying.

I actually had my 2 dogs sitting in front of the speakers the other day and one of them is scared of thunder. It has taken her awhile to adjust to the constant booms she now hears from my EP350. I really should write my thoughts on the EP350. It is something i haven't done yet. I wonder if anyone is interested.

I would say that a good sub can indeed be musical. I'm very happy with the performance of my SVS 20-39PCi sub.

One thing that can make a big difference though is room response. Initially, my new SVS actually sounded way too boomy; I'd say it was worse than my old 8" sub. The reason for this is room response, I had some major spikes in the in-room frequency response, such that a few certain frequencies were totally overpowering everything else.

Using a computer and some software called ETF I was able to measure the frequency response of the sub and equalize it using a BFD. Now I get a pretty flat response through the sub's range. This made a huge difference, probably one of the biggest "tweaks" I've ever implemented short of replacing speakers. Now I get clean, tight bass that isn't over-powering, and when watching movies I get that last octave of LFE impact (which wasn't really there before because I had to turn the sub level down to compensate for the spikes). I have all speakers crossed over at 80hz and am very happy.

Even if you're not willing to buy an equalizer (the BFD was $129), I would definitely recommend experimenting with sub placement within your room to try to get the flattest response possible.

Now try this on for size, move your HT setup from a basement with cement walls to a room with wood flooring!
I had to change a wackload of settings around when i did that.

I completely agree that testing testing testing is the only way to eventually squeak out the sound you like.

That's a neat idea with the software. Can you post a link to the software company?

Chess, since Jeff hasn't checked back in let me point out that the BFD( Behringer Feedback Destroyer) site is at behringer.com and that there's a very detailed discussion of it at snapbug.ws/bfd.htm. Software at etfacoustic.com/

Just to add to what JohnK said, the ETF sofware is pretty expensive to buy but the demo version works fine for measuring your sub's freq response (you just can't save data files). You can find more info about using ETF and the BFD together by searching for the two terms in the Speakers section of www.hometheaterforum.com. Also, here's a page that has a pretty good guide of the process: http://www27.brinkster.com/jmag999/

I recently found an interesting article right on this topic at hometheaterhifi.com...

Miscellaneous Ramblings on Subwoofer Crossover Frequencies

It recommends, among other things, an identical subwoofer crossover frequency for all main channels.

They bring up some good points in that article on a variety of ups and downs using multiple methods of subs and crossovers.
As per usual, it comes down to room dynamics and personal preference.
In using my EP350 as the sole LFE channel while setting the M60s to small, the bass produced was way overbearing and too heavy for music. The port chuff was also more prominent into higher frequencies.
The M60s handle the bass in a far superior way than my EP350 so i've turned the crossover down to a bit less than 50Hz where the M60 and EP350 bass notes no longer sound muddy as they cross on the frequency scale. I have accepted the trade off that there is a short hole in the frequency spread between the bass of my surrounds and sub, but hey, how often should heavy bass (below the QS8 cutoff approx. 95Hz) be played by surrounds anyway?
The QS8s were not exactly designed to rumble the walls beside my head.

They are right. Fast bass is an oxymoron. But if i had wanted a dance club in my basement, i would have added a disco ball along with the booming bass. I think i'll keep my EP350 tucked away small to continuing managing the 50Hz and less range.