Axiom Home Page Forums General Discussion Technical Questions Bass below speaker freq = distortion or nothing

I just got the m80's and I have a setting on my AVR to send LFE to Mains, Sub or both. Now, if I'm watching a movie and the LFE dips below the m80 freq, is the speaker going to start distorting or just stop playing the freq?

It rolls off the frequency just like the graph.

So, just say for instance that the m80 freq response is 22hz. If I watch a movie like Eragon that dips to 10hz, then the m80 will play to 22hz and then slowly stop playing the freq?

The reason for asking is because I have a PC13-Ultra and if I send Bass to Both the Mains and Sub, I don't think that I'd hear if it distorted.

Alex, you didn't clearly state which of the settings that you're actually using. If you set the M80s "small" and LFE to the sub alone(generally suggested), then the M80s don't have to be burdened with any of the low frequency effects which are occasionally present during movies(this isn't regular "bass") and the sub which is designed to handle them better will do the job. In addition, the regular bass to the M80s would be rolled off below the selected crossover frequency(e.g., 80Hz), usually at 12dB per octave, and sent to the sub instead. If the M80s are set "large" and LFE to both the sub and mains, the M80s will attempt to play the LFE(and regular bass)within their ability, down to the lower limits of their frequency response in the particular room location being used.

My receiver is pretty weird that way. I have the mains set to small, but I also have the option of sending LFE to the Mains, Sub or both.

I guess it sort of contradicts itself like that, but I have noticed that if I set the Mains to Large and LFE to Sub, there's not much LFE being passed to the sub.

I have the mains set to small and LFE to both right now and it sounds pretty good and adds to the LFE effect. That's why I wanted to know if the m80's would distort (Bass wise) at lower freqs then they were built for.

Alex, if you set the LFE to sub alone then ALL of it goes to the sub. Of course, keep in mind that LFE is only occasionally present in some movies and that there isn't any in regular music sources.

Sure, the M80s(and all other speakers)show increasing distortion when required to play the lowest bass frequencies.

The loss of fidelity would come mainly from the amp chewing up headroom delivering a LFE signal to the mains which rolloff and can't reproduce the signal. Also keep in mind that Dolby soundtracks replicate LFE effects in the main right and left channels as well so running the mains large with the both setting causes cancellation and reinforcement so it is not a recommended setting for systems with capable subs and speakers. You may want to try the small setting and crossing the speakers at 40 or 50hz to ease the burden on the amp, improve dynamic range and minimize nodes.

I actually don't have a manual crossover on my receiver.....well at least none that I've found anyways.

What receiver?

Yamaha RX-V2200

Ok I believe you are skunked on bass management since you have only one 90hz cutoff frequency for the low-pass filters. But your bigger problem is whether it can drive the 4ohm M80s at any reasonable volume. I suggest you consider a more powerful modern receiver with bass management that allows variable crossovers.

I played WOTW at -15 for about 5 minutes starting at the lightning scene to where the robot comes out of the ground and kills everyone. It can handle the 4 ohm load no problems.......so far.

I think that I might just upgrade my receiver instead of looking for other "Christmas" ideas right now.

Alex, as I and others suggested to you in a earlier thread, your 2200 should have plenty of power for the M80s in nearly all uses, and this apparently is the case for your use. So, there's no compelling reason to get a new receiver for reasons of power, but the features of the 2200 are a bit dated and if you want changes made in those a new model could be justified.

I think that I'm just going through the upgrade bug right now. I need something new, but just don't know what it would be.

My receiver does everything that "I" need right now and I don't think that I should upgrade until I really need to do it.

Agreed. If you want something that will really make a difference, spend that money on a bunch of new CDs and/or DVDs so that you can enjoy the sound of your Axioms more.

I had a Yamaha until recently and, although you could technically set it to BOTH and SMALL, the manual states that the crossover will be used (sub will get the bass). However, it did not say if you would end up with more bass (3db) because of channel doubling or not. But, to go back to the topic at hand, the bass under 90hz (my old receiver's hard-coded crossover) will go to the sub.

Been a while since I posted an actual "real information" response.

For Yamaha receivers... there are two types of "bass" - lets call the stuff rolled off under the 90Hz crossover "bass" and the stuff in the .1 channel "LFE."

Your speaker size determines where the "bass" goes... if you set the mains speaker size to large - the full dynamic range of the program audio goes to the mains. If it's set to small, then it gets sent where the BASS mode (menu 1E on mine) tells it to:

SWFR - both LFE and "bass" go to the sub
MAIN - both LFE and "bass" go to the mains (even if you set the MAINS to SMALL)
BOTH - LFE goes to the sub, "bass" goes to both the mains and the sub.

Hope that clears that up?

Bren R.

Thanks for the informative post BrenR. My question now, is what's the difference between LFE and Bass?

LFE is a channel. Bass is a set of frequencies.

I always thought that Bass was LFE.

Well, LFE is composed of bass frequencies. But really, it's semantics. LFE is a channel composed exclusively of bass frequencies.

Bass frequencies up to the crossover frequency, anything above this point is strictly main speaker territory.

Alex, as Ken indicated, LFE is a specific channel(the .1, containing very low bass frequencies, almost entirely under 80Hz)that is present on occasion in 5.1(or 6.1)movie sources for handling extra-loud bass effects. Even there the LFE channel often has nothing in it when the movie doesn't have low frequency effects going on. Bass is a range of frequencies(typically defined as 20-200Hz)which can be present to varying degrees in all sound sources.