[walkern]

As crazy as this may sound, sometimes reorienting subs to 'aim' in a different direction changes the way they load a room.  I have a GR servo sub (similar design, slightly different driver) and had all sorts of headaches getting it to sound and measure well in my oddball room (sloping 14 foot ceilings, open on one side, etc).  Just for grins I tried aiming it at the wall instead of into the room in the spot that sounded and measured best, and that simple move made it sound WAY more evenly balanced (less midbass peaks), and even seemed to give it a bit more VERY low bass extension.  It measured better that way as well.  Just a thought.

[WC]

What reference do you have for that. I'm only using one sub, SVS SB3000, but am considering a second. I set mine up using the sub crawl and was under the impression if I wanted to add a second I would use the crawl's second best location.

That could get close and may work. Just have to try it. I didn’t use it when I set up my 2 subs. Subs weigh too much. 

What is not clear to me is what the original poster’s system is. Are we dealing with stereo bass or summed mono bass? If it is summed mono bass what equipment are they using? With stereo subs they should be near the mains for best blending in with the mains. This is often the worst place in the to put them to get even bass in the room. Opposite corners or opposite side walls are better for more even bass throughout the room with mono bass. I have 2 Rythmik F15HPs running off my AVR sub output. One is in the front of the room between the TV and the right speaker. The other is in the back of the room a couple of feet from the corner. The bass appears evenly distributed to me. Someday I will get around to measuring the response for use with my 2 channel system which will have DSP controlled subs.

[Early B.]

As crazy as this may sound, sometimes reorienting subs to 'aim' in a different direction changes the way they load a room.  I have a GR servo sub (similar design, slightly different driver) and had all sorts of headaches getting it to sound and measure well in my oddball room (sloping 14 foot ceilings, open on one side, etc).  Just for grins I tried aiming it at the wall instead of into the room in the spot that sounded and measured best, and that simple move made it sound WAY more evenly balanced (less midbass peaks), and even seemed to give it a bit more VERY low bass extension.  It measured better that way as well.  Just a thought.

This is a great example of experimenting to find what works best for you.

[MONKEYWICKEDMONKEY]

That could get close and may work. Just have to try it. I didn’t use it when I set up my 2 subs. Subs weigh too much. 

What is not clear to me is what the original poster’s system is. Are we dealing with stereo bass or summed mono bass? If it is summed mono bass what equipment are they using? With stereo subs they should be near the mains for best blending in with the mains. This is often the worst place in the to put them to get even bass in the room. Opposite corners or opposite side walls are better for more even bass throughout the room with mono bass. I have 2 Rythmik F15HPs running off my AVR sub output. One is in the front of the room between the TV and the right speaker. The other is in the back of the room a couple of feet from the corner. The bass appears evenly distributed to me. Someday I will get around to measuring the response for use with my 2 channel system which will have DSP controlled subs.

You’re right, I never did put system details. I must have spaced it.

The system is 2 channel stereo
Mains: Klipsch Heresy IV
Subs: Rythmik L12 running stereo via RCA from the preamp. But I can run summed, whatever works best.
Power amp: Odyssey Khartago Stereo
Preamp: Quicksilver Audio Linestage Preamp (4 outputs)

In regards to the suggestion about aiming the subs I did find a forum post about perpendicular aiming of subs relative to the listening position and am playing with that while both subs are on the front wall. When I had 1 sub behind d the listening position I tried aiming it straight at the wall and it didn’t measure any different but it was also very near field so I’ll try that too from the front wall.

Also i went and dropped the crossover to 40hz and did a little listening, mostly Mingus, but today I’ll run the gamut (Napalm Death, Trepaneringsritualen, King Tubby, PJ Harvey, etc).

[sunnydaze]

Huh?  4 outputs?   Do you mean 4 pair of inputs?   

Also, IIRC the QS linestage has only one pair of RCA outputs, which I assume you run into your power amp.  So how are you also able to connect your subs low-level via RCA?   

[MONKEYWICKEDMONKEY]

Huh?  4 outputs?   Do you mean 4 pair of inputs?   

Also, IIRC the QS linestage has only one pair of RCA outputs, which I assume you run into your power amp.  So how are you also able to connect your subs low-level via RCA?   

4 outputs meaning 2 stereo pair. I had Mike Sanders turn the tape outs into main outs when I bought it.

[sunnydaze]

Gotcha.  Thanks.   

I also have a pair of subs and get confused when connecting them to line stage w/ RCA I/C.....
(my line stage also has 2 pair of RCA outputs)

do you simply run one IC into each of the subs?

[MONKEYWICKEDMONKEY]

Gotcha.  Thanks.   

I also have a pair of subs and get confused when connecting them to line stage w/ RCA I/C.....
(my line stage also has 2 pair of RCA outputs)

do you simply run one IC into each of the subs?

It’s all good. I appreciate the time and all suggestions. Yes, I run red to the right and then a splitter into the low level inputs then white to the left also with a splitter.

[WC]

So as I understand it you are connecting the right channel into one sub and the left channel into the other sub. So you have stereo bass. I would try them both up by your mains and see how that is. Also need to play around with your crossover setpoint to get them to blend well. Since you aren't high passing your mains, you should be on the lower end of the crossover range.

[WGH]

...today I’ll run the gamut (Napalm Death, Trepaneringsritualen, King Tubby, PJ Harvey, etc).

New subs bring out the 16 year old in all of us. It will take a couple of months before the newness wears off, then you will slowly realize that every song has big thumping bass like it is being played through Cerwin Veva speakers. Once a sub is adjusted properly you will never hear it, music flows from 20 Hz and up without calling attention to itself. It seems like once a month I get down and listen to the sub wondering "is this thing on?" It always is, I have just been playing music without any deep bass.

You will also discover music with 25 Hz bass like Cowboy Junkies "Trinity Sessions" and David Crosby latest "Hear If You Listen". You will also discover anemic rock and roll with no deep bass at all. If you want to tax your system and maybe break something try the "Blade Runner 2049" soundtrack by Hans Zimmer with really deep bass down to 15 Hz. I just know you are running the subs volume too high so before playing Blade Runner reduce the subs volume by 1/2, trust me on this. Your Klipsch 12" drivers will not be making sound but flapping like they are trying to fly.



The Ultimate List of BASS in Movies w/ Frequency Charts
https://www.avsforum.com/threads/the-ultimate-list-of-bass-in-movies-w-frequency-charts.2763785/

[MONKEYWICKEDMONKEY]

New subs bring out the 16 year old in all of us. It will take a couple of months before the newness wears off, then you will slowly realize that every song has big thumping bass like it is being played through Cerwin Veva speakers. Once a sub is adjusted properly you will never hear it, music flows from 20 Hz and up without calling attention to itself. It seems like once a month I get down and listen to the sub wondering "is this thing on?" It always is, I have just been playing music without any deep bass.

You will also discover music with 25 Hz bass like Cowboy Junkies "Trinity Sessions" and David Crosby latest "Hear If You Listen". You will also discover anemic rock and roll with no deep bass at all. If you want to tax your system and maybe break something try the "Blade Runner 2049" soundtrack by Hans Zimmer with really deep bass down to 15 Hz.



The Ultimate List of BASS in Movies w/ Frequency Charts
https://www.avsforum.com/threads/the-ultimate-list-of-bass-in-movies-w-frequency-charts.2763785/

I don’t mind a touch of “bump” or “thump” but no boom. Yes, most of my music is bumpy/thumpy so I’m trying to find a good middle ground. The relatively small amount of boomer jazz means less priority but I do want to get the detail from stand up bass as best I can as well. I’m not looking for ruler flat, but within 5-8 hz would indicate I am getting the best of what I have in this terrible room.

As for bass music, I have a Scorn record with bass so low my mains’ woofers didn’t move but the sub could make milkshakes. Bass lines at 14-22hz, window rattling stuff.  I’ve spent so much money (relatively speaking) on this system so far that I want everything to be put in a position to do its best job.

 

[MONKEYWICKEDMONKEY]

So as I understand it you are connecting the right channel into one sub and the left channel into the other sub. So you have stereo bass. I would try them both up by your mains and see how that is. Also need to play around with your crossover setpoint to get them to blend well. Since you aren't high passing your mains, you should be on the lower end of the crossover range.

Thanks and yes you are correct. Right now they are inside the mains and crossed at 40hz / 12db slope. I did flip one (right) to some into the dining room to see if I hear a diff. But yeah originally I was aiming for opposite walls at opposite ends of the room to distribute the bass and hopefully fill in the holes.

[sunnydaze]

It’s all good. I appreciate the time and all suggestions. Yes, I run red to the right and then a splitter into the low level inputs then white to the left also with a splitter.

Sorry, I'm slightly confused....

What does the splitter do?  Does it turn the single male RCA connector (at the sub end) into two male connectors, for input into the sub's L / R inputs?

If so, I've been doing it wrong!   

For each of my subs, I've been running a single RCA IC from preamp to sub with only one male connector on each end.  On the sub end I just plug it into either the L or R input.  I get output from the sub but it's much diminished compared to running a pair of L / R IC into it.

Is this the type of splitter you use?



             

[MONKEYWICKEDMONKEY]

Sorry, I'm slightly confused....

What does the splitter do?  Does it turn the single male RCA connector (at the sub end) into two male connectors, for input into the sub's L / R inputs?

If so, I've been doing it wrong!   

For each of my subs, I've been running a single RCA IC from preamp to sub with only one male connector on each end.  On the sub end I just plug it into either the L or R input.  I get output from the sub but it's much diminished compared to running a pair of L / R IC into it.

Is this the type of splitter you use?



             

Correct. As I understand it this adds 6db of gain so it’s probably not critical. I had them on hand so I use them.

[sunnydaze]

Oh, OK.  Thanks.

You think it's OK running them as I do?  Is it just a matter of turning up the sub's gain control to compensate for the lost output (which is what I do), or is there something lost in the signal with my setup?

PS:  sorry for the sidetrack

[MONKEYWICKEDMONKEY]

Oh, OK.  Thanks.

You think it's OK running them as I do?  Is it just a matter of turning up the sub's gain control to compensate for the lost output (which is what I do), or is there something lost in the signal with my setup?

PS:  sorry for the sidetrack

Hahahaha, I’m the last person you should ask 

[MONKEYWICKEDMONKEY]

Update: no frequency sweeps but it sounds much more controlled although less bass than I’d like. I should be able to run a few sweeps tomorrow.

When sitting at the listening position my head is about 18” from the back wall and I feel like I’m getting some cancellation. If I sat all the way back on the couch I get very low bass though it lacks some punch. If I lean forward the low frequencies seem to drop out but there’s a decent amount of mid bass. I pulled a chair and moved the coffee table so that I’m now sitting the depth of the couch in front of the couch and it’s mostly all midbass save for of the really boomy albums.

Thoughts?

[Tyson]

Part of the reason I run Roon is they have a pretty good digital EQ that lets me manage the most obnoxious parts of the bass in my upstairs system.

[rodge827]

I had good results with the Dspeaker Antimode 8033s wich is made for stereo/dual subs. It’s very simple to use and goes between the preamp and sub amp. You can place your subs where you want, put the supplied microphone at your listening position, and run the sweeps. Simple and effective.

http://www.dspeaker.com/en/products/anti-mode-8033.shtml

Can be purchased here: https://www.underwoodhifi.com/products/dspeaker

[MONKEYWICKEDMONKEY]

Hope everyone had a good weekend.

I did some sweeps with the subs crossed at 36hz. I did both 12 and 24db slopes. Not too much difference. I feel like 44hz is a room thing. Seems to always be there.

Both subs on the front wall. The right sub is facing right, left sub facing straight ahead.

12db slope


24db slope.


The volume was not changed so I cannot understand the difference in volume. That’s a mystery to my ignorance.

So I feel like I should go back to the 12db slope and acknowledge the 44hz peak but look past it and bring up that trough above it. What’s going on at 125 I have no idea. 63hz is always the low point in that part of the frequency range. No idea what to do about that either. Maybe this is the point where I run the full
Frequency sweep and then play with reflections and then dive into a mini DSP?