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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

Showing 7 responses by erik_squires

erik_squires
16,682 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.
erik_squires
16,682 posts
 
Leaving ports open will extend the low frequencies of the mains and allow the sub to come in at a somewhat lower frequency that is less directional and less likely to call attention to a single subs location in the room.


True but if your mains are 2-way, they will have more IM distortion in the midrange, and will have much more excursion below resonance, leading to limited dynamic range. Well integrated, an 80 Hz cut off is just fine. Maybe even 100 Hz.


Honestly though, in my mind integration is such a difficult task for most that whichever way you find easiest to integrate well s probably the right one and then leave it alone. :)

Best,

E

erik_squires
16,682 posts
 
I see that you read the article Erik wrote and posted on his website. In it he devotes a fair amount of virtual ink to discrediting the distributed multi-sub concept by labelling its advocates "cultish". If you are open to hearing an opposing viewpoint on the merits of a distributed multisub system, let me know.


The only negative thing I have to say about the concept and technology is the added complexity of the idea. Hawk it all you want to, I won’t interject.  It is the behavior I have been subjected to.  Be nice and I'll be nice.  Simple enough concept for most.

erik_squires
16,682 posts
 
I should say the problems the OP listed can be dealt with crudely but effectively.

On Android, get a calibrated mic:


https://amzn.to/3eYDGBa


 and AudioTools. Play the crappy songs. You’ll see the frequencies that are bad. Add a PEQ to kill them. Done.
erik_squires
16,682 posts
 
Plugging ports on a speaker isn’t the same as the speaker having been designed with a sealed cabinet to begin with

@nekoaudio is correct in absolute terms but...


I think this is OK. Plugging a port leaves you with an over damped and close to second order high pass. The 2nd order makes it easy to add 2 more, to get 4th order, and with a little tweaking, make up for the excess damping. That is, since an ideal ported speaker is larger than the same ideal sealed, you end up with too much cabinet, resulting in too little bass before you add the sub, which is all about adding bass. :)

With the right integration / EQ to deal with this, you can end up with higher dynamic range in the main speakers with better sub integration.

Best,

E
erik_squires
16,682 posts
 
You can use a miniDSP in your sub chain, or Roon which I do and it works great, but then I make my own loudspeakers, so the learning curve and application is not the same as it is for others.  The alternative is to use a preamp with room correction built in, and honestly the relief from pain and suffering you get from a device like this cannot be undervalued:


https://www.anthemav.com/products-current/model=str-pre-amplifier/page=overview
erik_squires
16,682 posts
 
https://speakermakersjourney.blogspot.com/2020/04/how-to-not-buy-subwoofer.html
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