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Subwoofer. Great one song. Not so great the next song.

I'm not a subwoofer guy. Played around with one in my primary system (Aerial Acoustics 7Bs, Proceed 250w amp, AR LS-16 tube preamp). Big B&W powered, not sure which. Didn't think it added anything. Ditched it.


Recently got a pair of Aerial Acoustic 6Ts for my secondary system. They have no place to be but right up against the wall. Maybe a foot out. Can't decide if they sound better with a sock in the rear facing bass port or not. Its a wash. Overall they sound pretty dang good though.


But, I played around with a JL Audio e110 sub. Pretty nice unit. Put the socks back in the bass ports.

On some songs the combo with the sub just sounds stellar. On others it sounds boomy and thumpy. My audiophile hang up is taught, clear, concise bass. I do not like boomy and thumpy at all. I can get up and turn the output on the sub down a little and it sounds okay again.

But I don't want to do that every time a different song comes on.

Now, on this sub you can change crossover frequencies, phase and also a polarity switch. I don't know _anything_ about that stuff. I've got it set on the more or less default settings in the manual. The only thing I've messed with is the polarity switch and for reasons I don't understand it sounds better on 180 than 0. I have not messed with the crossover frequency and phase dials.

Is there any chance that changing any of those settings would allow me to reach a sweet spot where I don't have to change settings on the sub frequently? I may or may not keep this sub. If I can't find that sweet spot I'll let it go as alone the 6Ts don't sound bad by any measure.

Thanks,
George


n80
erik_squires
16,386 posts
 
Eric that is true and always an option but an external crossover would be needed to limit the low end on the mains with most subs. Not sure about this one in particular.

Um, sealing will raise the -3 dB point of the mains and, most importantly, limit driver excursion which id what I was getting to. Even without an active filter. Below resonance the port is basically just a huge hole, and the suspension value of the air trapped in the cabinet vanishes. Take a look at the very last graphs on this article, and compare to the 2nd pair of graphs:


https://www.audioholics.com/loudspeaker-design/sealed-vs-ported-subwoofers



By sealing the port, the cabinet volume maintains it’s suspension value below resonance, and therefore limits this movement, allowing the driver to handle higher output than it would otherwise. Also, this raises the speaker’s effective -3dB point, perhaps only by 10 Hz or less. Assuming it was ported before, and you seal it, the speaker would become over-damped and roll off too soon compared to an ideal sealed. Again, with the right EQ on the sub, the combination can be pretty good.

Limiting excursion means you can apply more power before the driver taps out. 

Not as good as an active, carefully integrated solution, but some important benefits to be considered when adding a sub.
audiokinesis
2,750 posts
 
@erik_squires wrote: 

"Um, sealing will limit the mains and, most importantly, limit driver excursion which is what I was getting to. Even without a filter. Below resonance the port is basically just a huge hole, and the suspension value of the air trapped in the cabinet vanishes." 

I agree.  Sealing the port(s) is certainly worth trying, and if you can avoid having to insert a highpass filter in the signal path going to the main speakers, so much the better. 

If you have multiple ports and can plug some of them, or otherwise lower the tuning frequency to simultaneously get some low-bass contribution while protecting the woofer better than the normal tuning did, that may blend even better with the sub(s).  

Duke
mapman's avatar
mapman
22,457 posts
 
Well you can certainly try it both ways with and without port and listen to determine which is better.  
I recently removed the port plugs on my kef ls50s for the first time to see how that worked.  I felt soundstage  and imaging was a bit off with more bass out of the single sub compared to past setups in that room.  Seems better now with KEFs doing more work.   Of course every case is different and there are always trade offs. 
bigkidz
3,404 posts
 
The sub is actually not for bass but the mid-range.  It relaxes the mids so there is better sound, details and more accurate.  If you re trying to improve the bass response for your speakers it actually is not the best way to do it.

Happy Listening.
mapman's avatar
mapman
22,457 posts
 
Well I don't see how one can argue a sub is not for bass, but I will agree how it is done will likely have an impact on mid-range.
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