Axiom Home Page Forums General Discussion Technical Questions Crossover Setting for Subwoofer?

I just recalibrated again last night and I am now swimming in excellent audio. I am curious though. With the M60s/VP100 and an SVS 20-39 PCi, what is the suggested crossover setting? (All speakers are set to "small")

I have a Denon AVR-1803 and it allows for 80/100/120. I currently have it set at 80. From a technical perspective, would going to 100 provide any improvement?

With your choices limited to 80/100/120, I'd definately keep it at 80. Your M60's can handle everything down to 80hz with ease and control. They can infact do better than 80 even. Setting the crossover higher would take a bit more of the strain of your receiver, but if your receiver is handling it set at 80 just fine (and it should) I can't see any reason to set it higher.

Ray, just for comparison, you might try setting your M60;s to large and then set the sub parameters in your receiver to LFE + main as opposed to just LFE. This will use some additional resources on your receiver but at least try it and see which you like better, after all sound is VERY personal. I've found that some mucic I like better that way and others just LFE is better.

I have my 1804 set with all speakers set to large and the lfe + mains turned on. I like the better overall sound that you get when you let the speakers decide what they can handle and the sub still works for the rest of what the speakers can't handle. It might be taxing the receiver a little but I prefer it this way. Play around with the settings while listening to music then with your favorite movie and decide what YOU like best and leave it that way. That is the joy of HT. Good Luck setting up.

Jake, it's good that you're enjoying your speakers, but that isn't exactly the way that the bass management works. When the speakers are set "large", the poor things can't decide what they can handle because the receiver is forcing them to try to handle the full frequency range down to 20Hz or whatever the sound contains, even if they're not very good at it. When the speakers are set "small", as the Denon manual suggests generally gives the best results, they're much happier, since they only have to do what they do best(e.g. the frequencies above 80Hz)and they play cleaner for you. The sub is also happy since it's playing those very low bass notes that it was designed to do and it doesn't have to share much of them with the other speakers, as it would have to do if a LFE+Mains setting was in effect. The receiver is also happier since it thinks that it's already working hard enough on the frequencies above 80Hz and that the big amp in the sub can take care of itself on the very low stuff. Happy components make for better sound.

Great input. Looks like some debate will occur, but I'll try the current suggestions and see what results emerge.

JohnK, I agree that what Jake is saying is not how the bass management is SUPPOSED to work according to convention, but who's to say really that Jake is wrong? As we can all agree, if it sounds better to him, well, that's a major thing. But it's more than that.

I put up a post on this whole topic of bass frequencies "taxing the receiver" and "taxing the speakers" several weeks ago. Even Alan couldn't point to any scientific evidence on the subject -- evidence for example that speakers play "cleaner" or more accurately at 80 Hz and above when they are not asked to reproduce 80 Hz and below. A lot of people wrote about woofers moving in and out, but that's mechanical, and not a description ultimately of acoustic evidence. As far as I can tell from having looked into this, there's folk wisdom out there on the subject, but no evidence (other than, in this case, the evidence of Jake's ears, which deserves a hearing). If someone does an anechoic chamber test (for example, channelling bass to a non-existent or very distant sub, so the mains can "concentrate" only on the above-the-crossover frequencies), we might just find out that the accuracy and imaging are the same as they are with the sub-xover frequencies going to the mains. Until there are tests, the best we can say is the sound we like (and even with tests, that's the most important part). And while powerful forces from industry tell us about bass management, it's worth recalling that these same forces sell lots of c#ap to consumers and love the advent of proliferating ranges of speaker configurations to sell us. (A variation on Sartre: "If seven speaker configurations didn't exist, the hifi industry would have had to invent them.")

As for the receiver and its workloads: The receiver is a machine made of wires and metal. I don't think it gets "taxed," though it can smoke and fire, like any machine. The notion reminds me of how shocked my wife was when she discovered that even after major transatlantic flights, airliners typically "rest" for a half hour or less, with a quick refueling and the usual maintenance checks. "Don't they get tired?" "They're not animals," our pilot friend said, "They're machines. They're built to do that."

Now, if there's some testing or scientific evidence that shows receivers and speakers aren't built to play their full range, I will bow to it. And I'd be fascinated to learn more on the subject, but in the interim, I think the answer as to what's best is what Jake or someone else likes.

First, a terminology clarification: by LFE we mean LFE plus bass frequencies, not just the Dolby LFE information.

For a bass management setting of LFE+mains with M60s or larger, isn't there a potential problem with "bass doubling?" IOW from 60 to about 200Hz you have both M60s and sub producing bass. OTOH if you calibrated at the LFE+mains setting, shouldn't it be OK? That assumes the sub calibration tones honored the LFE+mains setting, and didn't just drive the sub alone.

My Yamaha RX-V1400 can switch instantly between LFE, mains, and LFE+mains while playing music. I've done this many times. It's very subjective -- sometimes it sounds better one way, and sometimes another.

I usually leave it on LFE, since my SACD player (which bypasses receiver bass management) only does LFE, not LFE+mains, and I didn't want different setups for different material.

Jakewash,
have you calibrated your system using test tones and an SPL meter? I wonder if you're getting too much bass and that's making it sound better. A lot of people equate higher bass level to 'a better sound'.

Ah JohnK, taking a new approach to the 80Hz cutoff or bust again eh?
Happy components make for better sound?
I could almost swear that was a salesman line.

Three thoughts (one i've brought out before):

1) I don't like the boomy sub sound for music, that is why i set my crossover for the sub at the point where my M60s (set to large) begin to dropoff. The sound is not any cleaner when switched. It is boomier.

2) Good electronics means minimized taxing for any config, period. Relieving the electronics of the low end bass should only make a difference when high volumes and electronics limits are approached. Even then, just how much further could you go anyway? Probably not alot.

3) If 80Hz were always the BEST for sound, why bother with towers at all? Everyone should own nothing more than bookshelf style then add a sub since the lower bass drivers of the towers are essentially unused yet paid for items.

The THX spec of 80Hz cross is only a guideline, it is not an absolute.