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Newbie sub crawl

I typed a whole tome in here and it popped so...poop.

anyway, short version is I bought a Rythmik L12 sub. I wanted to replace the cheap HT sub with something good for music. Deep, tight and fast.

i crawled the room and found my default spot to the right of the couch/sitting position to be good but not great. The front wall by the mains was deep and mushy and surprisingly the far end of the front wall, at the end of the record bins, just inside the dining room was less deep but more articulate.

i have questions though. The more I think of things the more I feel I did this wrong.

1. I turned off the mains so all I was hearing was the sub. It occurred to me later this might be a bad idea as obviously all will be playing during listening.

2. The bass is good here next to the listening position but it seems I can locate it due to the punchiness. I guess that’s the drawback to being close. Anyone else run one or more subs close to the sitting position?

3. As with speakers, my ear coming out 12”-24” from the wall tights everything up. Anyone running subs away from the walls? It’s a living room and there’s no WAF but it’s the living room so it has to make some sense.
Anything else I missed/brainfarted?
Also, my plan was to replace junky sub with good sub. Integrate good sub and add 2nd sub down the road. Just so that’s out there.

I’m incredibly happy with how things have progressed. I’m close to finishing this system and be relieved of expensive and stressful gear buying.

record bins dividing living room (left) from dining room (right)
https://i.imgur.com/qLt99x8.jpg

gratuitous system shot. It’s funny how empty it all looks. Doesn’t look that sparse in real life al though I do live like a peasant.

https://i.imgur.com/j5tvNO4.jpg

subs: new vs old. 42lbs vs 23lbs

gochurchgo
10 responses Add your response
gochurchgo OP
920 posts
 
So my sub has been rolling and I’ve been happy. It’s on the back wall slightly behind the couch on the listener’s right.

As was the goal all along, I added a matching 2nd sub. Now in playing with placement. Currently, the new sub is on the  front wall to the listener’s left. According to the crawl (done correctly) these 2 spots were the right spot. But is it?

i notice a lot of people run their 2 subs straddling the rack inside or outside the mains. Is this better even though the area to the right of the rack had less bass than it’s current back wall location in my room?

all the things I read says to run one on the front and one on the rear wall on opposite
sides of the width of the room to fill
the room better with bass. But maybe that’s home theater only?

I’m confused...
gochurchgo OP
920 posts
 
@millercarbon I redid the crawl with the interconnects crossed and it’s all felling really well now. I tried your suggestion about turning the sub around and it sounded odd. I did also play with phase but it seems off somehow.

Thanks again. Now I need to work on that 2nd sub.
gochurchgo OP
920 posts
 
@millercarbon yes I run the interconnected from pre to power normally but reverse the speaker cables polarity.

I played around for about 30 minutes again and with swapping the interconnects to the sub (polarity) it seems tighter.

I will redo the crawl as you instructed. Something tells me this time I will get it closer to correct.
millercarbon's avatar
millercarbon
12,531 posts
 
Reversing phase of main speakers will ruin imaging but with subs a phase change is roughly equivalent to physically moving the sub. So yes it can cause a change like you heard.
gochurchgo OP
920 posts
 
@millercarbon my preamp inverts phase and it just occurred  to me that since the sub is running from a 2nd set of outputs I should swap the rca connections at the sub? I tried this and maybe it’s placebo but it seems tighter to me.
gochurchgo OP
920 posts
 
Thanks @millercarbon I’ll redo the crawl with the mains on. The mains go down to 48hz and are very punchy but I’ll mess with it more.

As for the junky sub, I donated to my daughter’s music sensory therapy classroom. They run a cheap AVR and little satellites but no sub. They were thrilled and I feel like the class is less helpful without the bass but like all schools here they operate on a penny budget so I was happy to donate.

I’m really hoping to avoid REW and all that as I will get OCD over it. I feel like I did a good job with the junk sub but this one being not-boomy-but-way-punchy makes it localizable. I’ll flip the sub so the driver aims at the wall. Hadn’t thought of that.

thanks
millercarbon's avatar
millercarbon
12,531 posts
 
1. I turned off the mains so all I was hearing was the sub. It occurred to me later this might be a bad idea as obviously all will be playing during listening.

Right. You want as many bass source locations as possible. They interact and add together. Locating subs based on how they sound alone, it will be different when the mains are on.
2. The bass is good here next to the listening position but it seems I can locate it due to the punchiness.
Right. And also the frequency. And because there's only one. Subs work much better- go deeper, more articulate, smoother, harder to locate- the more you have. One thing you can try, point the sub at the wall. At bass frequency it makes no difference but the wall will reduce the amount of higher frequencies you hear, and that is what is localizing it.

3. As with speakers, my ear coming out 12”-24” from the wall tights everything up. Anyone running subs away from the walls? It’s a living room and there’s no WAF but it’s the living room so it has to make some sense.

Its always like this. Bass is always strongest by the wall, that's where the pressure wave stops and reflects back. If you want more bass sit by the wall, or put the speaker by the wall. Want less move em out. Want definition do like I do, speakers and seat way out, subs right by the wall. Mine are out about 2" firing into the wall. 
Also, my plan was to replace junky sub with good sub. Integrate good sub and add 2nd sub down the road.

Good idea except don't replace, add. The more subs the better. 
https://systems.audiogon.com/systems/8367
Think 5 is a lot of subs? Ha! Not even! https://systems.audiogon.com/systems/8690#&gid=1&pid=2
m-db's avatar
m-db
971 posts
 
Not sure what your using but your can go here and downlod the Test Tone CD zip file which might be of help.

https://realtraps.com/test-cd.htm



gochurchgo OP
920 posts
 
@dbtom2 which is what I did thanks 
dbtom2
382 posts
 
I read someplace (in several places, actually) to place the sub in your listening position and then "crawl the room."

Good luck and enjoy!

Tom
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