Axiom Home Page Forums General Discussion Stereo got a sub!

not a fancy high end one at all....its an Infinity that I got a terrific deal on, used, to use with my M3's.
My receiver is a new Harman Kardon and since Infinity and HK are kinda "related" I thought it might be a good match. What I like very much is that the sub doesn't give annoying pops when powering on or off, like my old Dayton one did - also it just melts into the sound of my left Axiom so seamlessly, like warm butter - love it!. Wish I had another, for the right side.
(am going to play with position of it soon, but the room is absoloutely cluttered so there is no other place for it and my hands are tied)
Fact is I have no business spending the $$ right now on one of the Axiom subs, tho I'd love to - so I have the Infinity.

I also just bought a DAC and am looking forward to adding that to the scenario soon.

Question: will adjusting the knob on back of the sub that "tells" the sub at what frequency to kick in ALSO feed info back through the receiver to my Axioms, giving them a signal that does not include the real low frequency stuff? Or do I need to add some kind of crossovers?

I want to take some of the load off the Axioms. Feels like that might already be happening - not sure.

thanks!
Aunty Em
Tampa
M3's, Infinity 10 in sub, Harman Kardon 3390 receiver and iMac/itunes as source

I'm not familiar with the technical side Infinity subs although I have heard a few. A good sub makes a huge difference in your audio experience so enjoy.

Regarding the crossover dial on the back of the sub. No, the receiver has no idea what you are setting it to. Things can get out of whack if you try to use both crossover settings so I suggest that you set the crossover dial on your sub to "Off" or whatever setting means that it won't do any crossover function at all and then let the receiver do the job.

What type of Axioms do you have for your front mains? 80 HZ is probably a safe bet to set the X-over for just about any set of Axioms.

Another hint. Subs (good subs) work in frequencies that are pretty much non-directional. So from that point of view, it's not just blending in with your left speaker but it's blending in with the whole room.
(If you walked into a strange room blindfolded, you should be able to hear the lows from a subwoofer but not be able to point out what direction it's coming from.)
On that basis, you do not need to worry about getting a matching one for the right side. HOWEVER, you may be able to improve the sound a lot by experimenting with it's location and adding a second sub is often a good idea when you can afford it to help get rid of any areas where the room is canceling out some frequencies.

So yes, long for that second sub and by all means, play with the positions. But take comfort that you don't need one on both sides just because you have a main speaker on both sides.

Any deep bass that draws your eyes to the left is most likely your mind getting tricked by mid-low bass coming from your left front speaker.

"Any deep bass that draws your eyes to the left is most likely your mind getting tricked by mid-low bass coming from your left front speaker. "

hehehhh, inna-resting! OK I will try to just sit back and enjoy, for now.
thanks... it is very enjoyable...

Em, no your 3390 is a 2-channel receiver without the bass management provisions that multi-channel Home Theater receivers have. So, your M3s continue to run full-range and the sub doesn't take any of the low bass load off of them. The control on the back of the sub that you're referring to is just a low-pass filter that rolls the sub off above the frequency set; it doesn't affect the speakers. The idea is to try to set it at a frequency, maybe 60Hz or so, that blends with where the M3s roll off naturally. Making this tougher is the fact that the frequency markings on the control often aren't accurate.

Incidentally, a separate DAC isn't needed, since any equipment that involves a change from digital to analog(e.g., a player or receiver)already has a DAC to perform that function.

Does the sub have speaker inputs?

If so (and the way they used to be hooked up all the time before receivers had good bass management) is that you run from the receiver to the subs speaker inputs, then from the sub's output on to your speakers.

That way a crossover in the sub would 'take in" the bass portion of the signal, and "pass on" the rest of the frequencies to your smaller speakers.

THAT would take the burden of bass off the M3s.

John, wouldn't the cross overs in the M3's attenuate any signal below their designed response range?

Most speakers are designed with a high-pass for the tweeter, a band-pass for the mid-range, and a low-pass for the woofer. So the tweeter goes off into the ultrasonic, and the woofer into the infrasonic, with only their physical properties limiting output.

EDIT: 1500!

Hey, stop catching up with me. I'm still trying to catch up with JohnK. In post count, anyway. I'll never be as useful even at a million posts.

Mark, there is no "crossover" in the sub; as I pointed out to Em, it's just a low pass filter which rolls off the sub above the set frequency, but has no effect on the speakers, even if they're connected through the sub. A very few subs have a separate high pass filter on speaker level outputs to the mains, fixed at 100Hz or so, but that has nothing to do with the frequency control on the back of the sub.

No, Dak; as Chris points out, the filter in the M3 crossover which affects the woofer is a low-pass filter which lets the lows in and rolls off the highs, so the speakers are given the full-range of the bass.