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I have a square living room which creates a subwoofer null (1 Viewer)

Mike Up

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I can adjust the sub up to get correct levels but other listening positions probably have 6 db more output than they should have.

I have 2 ways of combating this which not sure is the best. I have my Velodyne Subwoofer in the corner facing straight out toward toward the room and TV wall. I've tried the sub facing all directions and tried the phase switch. Its the same no matter what, but having the sub positioned like I do offers the best quality.

My media room is a square room as well but the sub is not in the corner, but maybe 1/3 of the wall length away from the corner. The subwoofer output is consistent through out the room except at the door opening (as would be expected).

So I'm thinking of doing the same with a ~$300, 8" sub. The Kanto Sub8 or Audio Engine S8, both have the small foot print I need to fit on the wall away from a corner. The benefit is it will be right next to my main speakers.

Or using a Jamo S-810 subwoofer at the same position, maybe even closer to center of the wall due to it's flat cabinet and use it along with the Velodyne CT-100 subwoofer. The Velodyne obviously blows all these subwoofers away in low end frequency extension and output but having more accurate and consistent frequency response trumps it's solo performance. It's huge and only fits in one corner of the room that causes these issues. Previously when I was a single man with less stuff in the living room, I had more flexibility in placement but NO MORE.

The reason I chose the cheaper Jamo is because I would add it. The others would be themselves alone as I would sell my Velodyne and some other speakers not used, to pay for the more expensive, smaller, higher performing subs.

So what is your guys recommendations and experiences?
 

Wayne A. Pflughaupt

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Bass frequencies “chase” room boundaries, and the closer you move towards a wall, the stronger (SPL) the signal is, with the dead-center of the room being a kind of “bass hole” where the bass level is the weakest. Perceived bass levels would be strongest near a corner where two boundaries meet. The problem is most noticeable – and irritating – in in small rooms with shoebox or square dimensions. Thus I’m surprised that you report the problem is lessened in your media room, unless it’s significantly larger than the living room.

It's impossible to predict if the second smaller woofer will take care of the problem in the living room. It has the potential to make things worse, as the smaller sub will not have the capabilities of the larger one, and will be the weak link in the signal chain, peaking out and making rude noises long before the Velodyne starts to break a sweat.

Not to mention, having two subs operating in say, the 80-40 Hz range will make that frequency range stronger, at the expense of perceived less performance below 40 Hz, which will all be generated by only one of the subs (the Velodyne).

One solution could be staggered seating, something like the main seat near the back wall, with two others to the sides of it moved forward a few feet.

Regards,
Wayne A. Pflughaupt
 

Mike Up

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Thanks for the help, the family is gone so I got to changing things and experimenting. Turns out if I put my Polk TL1600 8" subwoofer on the front wall and 1/4 of the wall length away from the side wall, even next to the hallway opening, I get flatter response like I do in the media room. It sounds really good and that is with the smaller sub that has a -3 db of 45Hz compared to the Velodyne's 28 Hz. I must say I think the Polk goes lower.

But since it's right next to the hallway, is sucks the SPL out of it, so I have to crank the sub up louder. However the payoff is worth it for a better sound quality.

I do have 2 TL1600 subs I could use, one on the front wall and one in the corner where the velodyne is or go to the Jamo. I've been measuring and not many subs will fit where the Polk sub was on the front wall. While many of those same size subs go 5 - 7 Hz lower than my Polk Sub, their amps are still small like the Polk's 50 watt RMS amp.

Funny is before my family's things were on the living room side wall, I had the velodyne there and never any issues but having it on the same wall as the listening position causes this awful null and I noticed that some lower frequencies are OK while others aren't. So it's just not a volume drop but an inaccurate frequency response as well.

Putting the Polk sub on that front wall even with it right next to an opening for the hallway, smoothed everything out plus got rid of the null.

I really would like to try the Jamo 10" flat sub there but just realized it's low end is 36 Hz and it's NOT at -3db. So I have to assume it's at the useful response measurement of -10db. That making the sub have a frequency response not much better than the Polk and it's amp isn't much better either.

I do have to say is that I have a new found respect for the TL1600 sub. I paid $230 for the 5.1 set and the sub is really good. Finding a comparable sub in an 8" cone size is between $250 - $350. So the Jamo subs looked like a great deal but I have the Polk subs already and even have a lesser quality Yamaha 8" sub I could put in the media room (but it sounds awful next to the Polk).

I was hoping to get a high quality 8" sub but they're ridiculous in how expensive they are. Most companies that offer a good 8" offer high performing larger 10" and 12" subs for less money and they have much more powerful amps and low end frequency outputs. Hard to pay more, for less.

I'm still debating what I'll do.

Thanks for the help.
 
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Mike Up

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Well, I did some moving. I moved my TV entertainment center and speakers around so that the Velodyne would fit behind the right speaker and to the side of the entertainment without sticking out into the hallway. Wife wasn't happy but I may have won this battle. Yet to be determined.

BUT OMG, the bass I remember from when we first were married is back again. My daughter couldn't believe how she could feel the low bass of Beastie Boys Intergalactic besides just hearing it. Listening to Snoop Dogg's "Pump Pump" played all the low extended bass with authority. I'm more a Metal Head but these are great tests for Bass. I also got my kick drum back with really deep dynamic and punchy bass! Putting my Velodyne on the front wall really flattened out the response, got rid of the null, and extended the bass at the listening position. Corner placement seems to be the worst place to put the subwoofer! Now I don't have to find a different, inferior, subwoofer! The down side is that I did have to jack the volume up 5 db but that's a small price to pay and I have more then enough headroom with that Velodyne. This is the exact Velodyne I have, same year and version.
 
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Wayne A. Pflughaupt

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Glad you were able to figure it out! Corners have always worked best for me. But I’ve always had largish, irregular rooms, not square or shoebox rooms.

Regards,
Wayne A. Pflughaupt
 

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