Axiom Home Page Forums General Discussion Home Theater Another Freakin' Sub Post....

Interesting. That big hole at 38 hz has to come from somewhere. We're looking for about 7.5 feet... I'm guessing (a) ceiling height is 7-8 feet, and (b) the sectional is about 7 feet on a side so the EP350 is 7-8 feet from the left hand wall in your drawing ?

If you put the sub in the corner that will certainly reduce the 38 hz hole... I'm on dial-up now so I can't go back and check the MOAP for details, any chance you could post back the height of your room ?

Hey Mark--You got me worried here buddy--I have a room 18 X 18.5 and I was going to buy Epic60--2-M60ts, 4-QS8s,VP150 and a 350 subwoofer (my wife hates bass) but what if I have the same problem --not enough bass? How common is this? Due to the room I have to put the 60"LCD in the corner with the M60ts on either side. Axiom people said I could put the 350 subwoofer anywhere. Are other people having the same problem with the 350's?? Your thoughts? Should I get the 500?

Hey John!
The sub is 10' from the corner behind the sectional to the center of the dustcap.... three feet to the wall where the eqpt. closet is. The ceiling height is 8' 4".

Hi Chivas!
I'm no expert here...John (Bridgeman), JohnK...oh hell, everyone here knows more than I do.

What I have learned is that square rooms are problematic.... and small square rooms compound the issues. I don't think your room will fall under the small category. Hopefully others will chime in.

It's not that the 350 is a bad sub, I'm particularly looking for that "hit you in the chest" feeling and combining that desire with a problematic room. That being said, my gut feeling is to go with a 500 instead of a 350 for three reasons:

-- More and more, movies are making real use of that LFE (sub) track. I think a good sub is more important now than it was 5-10 years ago.

-- You can always turn down the 500 when your wife is watching... you can't turn a 350 up beyond it's capabilities.

-- She might end up appreciating the bass.

I don't mean to be too forward with that last one. I know some people that have hearing issues that have a problem with bass and that or any other reason could be legitimate. But... not knowing the situation and playing Devil's Advocate... Is it possible that she's saying she doesn't like bass because of the ear-splitting thumping she hears from the cars next to her at stop lights? I'm not trying to be facetious... but some people that say they don't like something have only been exposed to poor samples of it. If the bass is tight and well-controlled and just adds some "weight" to the presentation, and doesn't just go BOOM BOOM BOOM, THUMP, THUMP, THUMP she might actually enjoy it???

I would say if you can swing the extra $$ for the 500, go for it. You're assemblinfg a top-notch system there and more and more, proper LFE playback is a big part of that satisfaction.

shivas, also what you can do is order the EP350 sub and listen to it for yourself. if your not happy with it you can upgrade it. thats what i did. just wasnt enough bass for me. the EP500 is almost to much bass for me!! haha. i love it.

>>The sub is 10' from the corner behind the sectional to the center of the dustcap.... three feet to the wall where the eqpt. closet is. The ceiling height is 8' 4".

Hmmm. That doesn't work out at all

The graph didn't mention crossover frequency... there's no chance you were crossing the mains over at 40 Hz, were you ? Doesn't seem likely -- that's the kind of thing HK owners do, and I don't think you have an HK...

The bigger thing nagging at me is that there are some big up/down spikey things going on in the response curve but it's not really all THAT bad. The problem may be nothing more than the combination of a decent midrange sub and a small room which doesn't give much reinforcement below 40 Hz, that being a combination which doesn't give you much output in the "wow did you feel that ?" frequency range. Perversely enough the 350 in a larger room would probably be quite a bit more satisfying because of the room reinforcement at lower frequencies.

I'm having a tough time believing that the BFD is really going to make a big difference except by using it to boost the 20-35 Hz region, where a larger room would give you some reinforcement. It may be time for someone who lives near Mark and has one of those "flat below 20 hz" subs to pay a visit and see if an EP500, SVS or VTF-3 fixes the problem.

I would like to understand that suckout at 38 Hz though, just in case that is also affecting your lower frequencies. I do think the sub in the corner gave you a better starting point for BFD-ing than the sub by the radiator and from your earlier graphs it definitely eliminated the 38 Hz hole.

It probably is worth trying the "sub in the center of the room" placement, maybe even on the coffee table. JohnK (I think) said that you won't get much effective room gain that way but your room is only giving you gain in the "boom" frequencies, not the "holy $#%" frequencies anyways.

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The graph didn't mention crossover frequency...

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Unfortunately, I didn't have the crossover frequency listed on the original chart from April. I did note that on the top of the chart…but that's not much help! It's very likely 80Hz since that's the setting that I've used for the vast majority of listening since buying the Denon.

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a combination which doesn't give you much output in the "wow did you feel that ?" frequency range. Perversely enough the 350 in a larger room would probably be quite a bit more satisfying because of the room reinforcement at lower frequencies.

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Well, maybe that just makes this whole situation moot.

I've had two goals here: To try to smooth out the frequency response and to get bass that I can feel. I have been assuming that any sub I use in the same position (and without the BFD) is likely to give me the same spikes/null as if have now with my 350 as they seem to be primarily room-related. Yet, if I replaced my 350 with a 500 I could reach the depths to produce bass that I can feel. If what you're saying is true, my room might "fight" the 500s abilities to play lower anyway?

I have to check my PMs… you might have told me something along these lines several days ago!?? I guess I thought that getting the best sub position possible, using a BFD to knock down some of the spikes and using a sub that goes stronger and deeper will offer reasonable gains in my room. Maybe not? Geeez, now I'm depressed…..

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It may be time for someone who lives near Mark and has one of those "flat below 20 hz" subs to pay a visit and see if an EP500, SVS or VTF-3 fixes the problem.

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Geez, again. No one lives near me. Well, among Axiomites anyway. Where in the World? Yup. Lonely out here.

So let me cut to the chase here: looking at the room layout and the freq. plot above (I won't re-post in deference to our dial-up friends), is there anyone here that thinks a 500 will or won't help with my goals above? (with the BFD I already on, of course…)

Taking bets……

So, a remodel is out of the question, then?

I sure do learn a lot from your tribulations, Mark.

I'll drive my PB12 out there if you pay my mileage and expenses. IRS rate. Shouldn't be more than about four grand. I'll throw the "whack in the chest" for free.

Have you actually called Axiom on this?

How about an infinite baffle sub? Would putting a IB manifold in the basement be feasible or would doing so change the wavelength problems?

Tactile transducers?

You just keep that hairy eyeball to yourself.

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Have you actually called Axiom on this?

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Not meaning to sound too obtrusive but I often find myself asking this very question upon reading some of the inquiring post and replies on this site.

I dont know what kind of receiver you have but if it is like my HK AV 300 at -30 the .1 of the 5.1 signal is pretty weak. I would go ahead and turn it up to plus 6 or 7 or 10. and see if it sounded louder. I like to listen at -25 with the sub level at plus 4 or 5. I am not familiar with Axion subs but crank the gain up to about 50% and see what happens.