Dual vs Single

Love4sound

Well-Known Member
Joined
Nov 23, 2018
Messages
4,570
Points
113
Location
Chennai
I expect it’ll be a worth a try with the options I’d posted above. On the basis of my listening (haven’t measured yet), this was a noticeably positive difference.
Sure will try it once. The thing is m not suggesting duals subs aren’t worth it. Definitely there is a huge difference when implemented correctly. Just for my low listening levels and my room response a single good sub will be good enough.
 

Love4sound

Well-Known Member
Joined
Nov 23, 2018
Messages
4,570
Points
113
Location
Chennai
Are you still using MSO to integrate your subs? If so, can you change things so that your PEQ filters are all RBJ type and set the limit for Q to <=7? (effectively eliminating narrow bandwidth filters). Let us know if that improves things audibly from a time domain perspective.
I just checked my old MSO file and i actually used RBJ type only. Q filters I remember leaving it at defaults which was 5 or 6 if I remember. To be honest dual LV12F vs single LV12F in my room after various tests and watching a movie last night it’s clear the single dual LV12F is no match for the duals. I just watched two or 3 scenes repeatedly and analysed wrongly. The balance in bass and slam I get with duals is not even comparable. What I was thinking is based on my room response may be a single 15 inch sub like E15 rated at 600 watts can give better performance then dual 12 LV12F rated at 300 watts.
 

Donivlapog

Well-Known Member
Joined
Oct 14, 2020
Messages
1,823
Points
113
Location
Chennai
Mr.Harwin of volumate insisted that i use dual subs in both my installations where he even used a splitter in one soundstage with a pioneer 7.1 and the Taga dual subs placed within 2 feet apart made no sense to me or anyone who visited my home. However my room amp which is 7.2 happily passes the oomph on to the subs and there is a difference atleast to my ears. I could have saved 50-60k or more if Mr.Harwin wasn't as rigid though. In the USA and other advanced countries they advocate 7.2 as a routine thing. It has caught up a few in India as well.
 

Love4sound

Well-Known Member
Joined
Nov 23, 2018
Messages
4,570
Points
113
Location
Chennai
Mr.Harwin of volumate insisted that i use dual subs in both my installations where he even used a splitter in one soundstage with a pioneer 7.1 and the Taga dual subs placed within 2 feet apart made no sense to me or anyone who visited my home. However my room amp which is 7.2 happily passes the oomph on to the subs and there is a difference atleast to my ears. I could have saved 50-60k or more if Mr.Harwin wasn't as rigid though. In the USA and other advanced countries they advocate 7.2 as a routine thing. It has caught up a few in India as well.
There is no doubt dual subs are superior but the implementation has to be right,If not it will be much worse then a single sub. Dual subs gives a balanced,tight and smooth bass. In my room based on frequency response there are chances a bigger and better single sub may be awesome. We’ll time to experiment and find out :)
 

liverpool_for_life

Well-Known Member
Joined
Feb 2, 2015
Messages
1,038
Points
113
Location
Madras Nalla Madras
Q filters I remember leaving it at defaults which was 5 or 6 if I remember.

The default maximum is 25, which can result in some very narrow bandwidth filters. Moving this down to 7 made a pretty audible difference in my setup in the time domain and the associated bass impact.

To be honest dual LV12F vs single LV12F in my room after various tests and watching a movie last night it’s clear the single dual LV12F is no match for the duals.

As it should be, if the subs combine constructively and provide a more consistent bass response across the seating area. FWIW, I agree with those calling for subs with bigger drivers, with one caveat: As long as you don't have major dips in FR with just the one sub. Not just for HT as is commonly assumed, but also for music. You can get wonderfully articulate 15/18 in subs that when integrated well with your mains (not always a given) can get you a step closer to audio nirvana.
 

Love4sound

Well-Known Member
Joined
Nov 23, 2018
Messages
4,570
Points
113
Location
Chennai
The default maximum is 25, which can result in some very narrow bandwidth filters. Moving this down to 7 made a pretty audible difference in my setup in the time domain and the associated bass impact.
For me I get good results with mini dsp eq itself so left MSO after few attempts.
As long as you don't have major dips in FR with just the one sub.
Yes and getting a smooth,flat response isn’t an issue in my room. But I have bad decay time,a nasty room node at 50hz along with SBIR issues.
 

liverpool_for_life

Well-Known Member
Joined
Feb 2, 2015
Messages
1,038
Points
113
Location
Madras Nalla Madras
For me I get good results with mini dsp eq itself so left MSO after few attempts.

You're generating the EQ filters through REW, then? If so, check the auto-generated filters for the Q values.

Yes and getting a smooth,flat response isn’t an issue in my room.

My point was with respect to single sub vs duals. If you get a response without major dips with a single sub, do carry on.

But I have bad decay time,a nasty room node at 50hz along with SBIR issues.

Filters have an effect on decay times. If a flat response at 50 Hz is a result of a filter, might be worth examining it to see if it makes the time domain worse.
 

Love4sound

Well-Known Member
Joined
Nov 23, 2018
Messages
4,570
Points
113
Location
Chennai
You're generating the EQ filters through REW, then? If so, check the auto-generated filters for the Q values.
Yes with REW. I have attached the image of the auto eq filters. I normally don't check these values and just load the eq
 

Attachments

  • Filters.PNG
    Filters.PNG
    29.8 KB · Views: 28

Sugar

Member
Joined
Sep 1, 2022
Messages
43
Points
18
Location
Bangalore
Dear Fm's

I just wanted to know how many here have used dual subs and gone back to a single sub? Been 8 months i have been using dual subs. Few times i accidentally watched some contents with a single sub cause i would have forgotten to turn on the other sub or my daughter would have unplugged it. Didn't notice much change and noticed some area of the bass being smooth and tight. My room is very small and its just 10*11 so technically doesnt need a dual subwoofer. I also verified by measurements that there isn't much difference with dual subs apart from a 5-7db boost which can also be achieved by increasing the gain of the single sub or a better and powerful single sub-woofer. There is a dip in 105-110 with a single sub which shouldn't have any impact with bass. I have shared the pure direct and EQ graphs. In both graphs blue is the dual sub response and red,orange is the single sub response. I am in a huge dilemma to go back to a single lv12f or sell both and get a better single sub-woofer.
Hi - In my view a single sub is better. What is more important though is the placement of the sub. What I do is use a long cable, place the sub on my listening spot and then crawl on the floor all over the room to find the spot where I like the sound of the sub and place it there.
Then tweak it a bit - vol, cut off and phase.
I think using 2 subs will complicate placement. In any case the sound of the sub is not meant to be directional and so I am not sure what problem having 2 subs solves.
Best of luck.
 

liverpool_for_life

Well-Known Member
Joined
Feb 2, 2015
Messages
1,038
Points
113
Location
Madras Nalla Madras
Yes with REW. I have attached the image of the auto eq filters. I normally don't check these values and just load the eq

At least 3 of the filters have Q values greater than 7. Run MSO by limiting Q to <=7 (ignore the FR which is likely to be worse than what you got with REW) and listen to see if things get audibly better in the time domain. You can then decide if the trade off vs a better FR is worth it.
 

Love4sound

Well-Known Member
Joined
Nov 23, 2018
Messages
4,570
Points
113
Location
Chennai
At least 3 of the filters have Q values greater than 7. Run MSO by limiting Q to <=7 (ignore the FR which is likely to be worse than what you got with REW) and listen to see if things get audibly better in the time domain. You can then decide if the trade off vs a better FR is worth it.
OK i will try MSO with what you have suggested later. Totally forgot how to set it up so will have to check the tutorial again. In the meantime ill try the same approach in REW with the existing measurements. What you are suggesting is the Q values should be less then 7. So i tried to achieve the same in rew eq modifying the the filter tasks. I disabled "allow narrow filters below 200hz" and now the q values are below 5 for all the filters.
Hi - In my view a single sub is better. What is more important though is the placement of the sub. What I do is use a long cable, place the sub on my listening spot and then crawl on the floor all over the room to find the spot where I like the sound of the sub and place it there.
Then tweak it a bit - vol, cut off and phase.
I think using 2 subs will complicate placement. In any case the sound of the sub is not meant to be directional and so I am not sure what problem having 2 subs solves.
Best of luck.
Yes as you said 2 subs will have complications but when you implement them correctly its well worth it
 

Attachments

  • Filters 1.PNG
    Filters 1.PNG
    30.2 KB · Views: 23

ankitbhargava

Well-Known Member
Joined
Oct 29, 2012
Messages
1,190
Points
113
Location
Udaipur
My personal observation is, HT users suffer from "low SPL" disease most of the time and they feel lack of excitement.
Tighter and cleaner bass could be achieved with a good subwoofer, its placement and integration/alignment with mains but you can't treat "low SPL" easily with such measures and specially when you are generally listening at lower levels.

I keep pumping up my average listening levels close to reference level to feel that "lower bass and LFE excitement" :)
Your second sub is definitely helping you to gain a couple of DBs and still have a good headroom and if you aren't chasing "low SPL" problem, you are good with one Sub also.
 

Love4sound

Well-Known Member
Joined
Nov 23, 2018
Messages
4,570
Points
113
Location
Chennai
but you can't treat "low SPL" easily with such measures and specially when you are generally listening at lower levels.
The issues with bass I am facing are definitely not due to spl. Denon and marantz has a feature called dynamic EQ which boosts bass as per the master volume. The chest slam, low end grunt and room shaking slam is all there. If spl is the issue I won’t get all these. I am having phase issues, SBIR and bad decay time. Anyways If I am going single it will be a 15inch. I will decide based on my sale.
 

Love4sound

Well-Known Member
Joined
Nov 23, 2018
Messages
4,570
Points
113
Location
Chennai
Cool. Is there an audible difference to the sound and is it for the better?
I listened to few music tracks and watched few action sequences. Measurements are almost the same with very minor variations. But there was some decent improvements in how bass sounded. Some boomy and localised bass notes are gone.Very minimal improvements with decay time as well.Thanks for the suggestion
 

Love4sound

Well-Known Member
Joined
Nov 23, 2018
Messages
4,570
Points
113
Location
Chennai
Can you post the before and after waterfall/spectograms?
Sure but not much difference. In decay graphs there is improvements . Audible difference is i do not hear some of the bass notes strong and loud.
 

Attachments

  • Spectrogram with narrow filters.jpg
    Spectrogram with narrow filters.jpg
    214.2 KB · Views: 8
  • Spectrogram without narrow filters.jpg
    Spectrogram without narrow filters.jpg
    213.6 KB · Views: 8
  • Waterfall with Narrow filters.jpg
    Waterfall with Narrow filters.jpg
    285.9 KB · Views: 7
  • Waterfall without Narrow filters.jpg
    Waterfall without Narrow filters.jpg
    308.4 KB · Views: 7
  • Decay with narrow filters.jpg
    Decay with narrow filters.jpg
    159.6 KB · Views: 8
  • Decay without narrow filters.JPG
    Decay without narrow filters.JPG
    152.3 KB · Views: 9

Donivlapog

Well-Known Member
Joined
Oct 14, 2020
Messages
1,823
Points
113
Location
Chennai
Reminds me of a creative cartoon of mad angles. I hope there is a one size fits all solution here but this is just sheer cumbersome minute audiophille level or personal preference level tweak. What you hear is what you get!!
 
For excellent sound that won't break the bank, the 5 Star Award Winning Wharfedale Diamond 12.1 Bookshelf Speakers is the one to consider!
Top