Axiom Home Page Forums General Discussion Home Theater Any ideas? Sub seems to be lacking....

Living Room Setup

So I spent lots of money on a couple of Axiom's nicest subs, and the other night I put in the most recent Startrek movie hoping to wow my wife with some awesome sound; however, I couldn't help but feel quite underwhelmed/dissatisfied with the low end.

I'm open to input/ideas. I can see both subs working during the movies (sometimes more than I'm comfortable with), but their output isn't providing much thump effect like I think it should. I know I have a large room size, but movie theaters (which are quite large) provide lots of thump. How do I reproduce that?

The link at the top will give you some pics of my room. Let me know what I can do to make it better.

thanks

Have you run any frequency sweeps to see what areas might be deficient?

how do I do that?

Well, I've never done it, because I don't really want to know, but basically you get a sound meter (or download one for your smartphone) and a CD of test tones (many available free for download online), and sit there and write down the loudness at each tone. That way you'll be able to tell if you've got a flat response, or a big dip somewhere, and the like. Then you can take corrective action by either moving the subs, recalibrating in some way, or using a sub equalizer like the one from SVS or Velodyne.

Another question would be whether there's anywhere in the house that the bass is really loud. I've got a bass null right on top of my couch...

Do the sub crawl.

Surprising, since you have two subs. Still, it seems like the most likely scenario is a placement issue. Like Ken and Rick said. Get an SPL meter, download some sweeps, walk around the room and see what you see. Hsu used to have test tones posted. Home Theater Shack is a good resource for stuff like that, too.

Watch Inception on Blu-ray with your audience.

Not wanting to seem crude, but if you want more volume from the subs, try turning up their volumes.

Also, try using just the EP800 or changing the phase on one of them.

Just moving the couch a foot or two one way other other (front to back) could make a huge difference too.

It could be that the thump you're looking for are bass notes higher than what the subs produce. So, the problem may not be the subs, but the mains. The way I understand it, the goal of the subs is not to produce loud noises, but to fill in the missing lower end. A lot of the thump that I hear others talk about here on the Axiom site is the lower end of the M80/M60 speakers.

Yep. Subs rumble. The punch comes from mid-bass.

The 'punch' is around 50-70hz give or take a few hz. I run my M80 at 40hz just to get more punch/feel from the system.

Do you stil have the SVS subs running as well? You could also just be used to the more punchy bass the SVS subs pump out compared to the smoother sounds an Axiom sub produces.

If you're crossed over at 40Hz, wouldn't you get less punch compared to crossed at 80Hz since 50-70Hz will be played mostly by the M80s instead of the sub?

Not if you set the M80s to large. In any case, the OP has M22s.

That punch is lost when going through a linear sub as it is really designed to play lower than that, well some subs play that range very well, the PB12-nsd comes to mind, but it had a different feel to it than the M80s bring and the PB12 also had a hump in its FR right in that 50-70hz range which is why it had the punchy sound.

The M80s crossed at 40 are right in their prime bass range. I set them to small so my PB13 can work on what it does best, really low notes. I also found that during movies the sub is so busy hitting those low notes that the punch of gunfire etc. has much less impact with the higher crossover points. I am also sure alot of what I have found is room dependent, so YMMV. However, a better upper bass is the main reason I went from M22's to M80s, their ability to play that mid bass with more authority.

Good to know. Thanks Jason.

Andrew, on thing to consider is following up with your receiver tech support to make sure the HK box is acting properly. For example, many AVRs have a 10dB boost option for LFE as the reference levels are quite high for most home users. Some label it as -10dB -> 0dB while others note it as 0dB to 10dB.

Also the configuration of the AVR has a lot to do with the overall impact of the sound. For example, your BD player may be trying to decode the sound and send it as analog out in which case the speaker setup with the player is important.