Help me correct bass

[Love4sound]

Dear Fm's

I need your big big help with bass correction. Please find screen shots of my sub measurements. 1st image shows only the sub measured in pure direct and with audyssey enabled which is placed in the front in-between LC. second and third images are of LCR crossed over at 120.4th image is pure direct response for sub placed in the rear right corner as seen in the 5th image with the sub front facing the MLP. The response seems good over 40HZ compared to the current position but a nasty dip in the 30HZ region so may loose the lower bass which is very good at the current sub position. I measured the LCR by selecting L+sub,R+sub and C+sub individually.18hz to 42 is smooth. 5th image is my room with speaker and sub placement. There are certain scenes bass is amazing and guess its in the lower region. But after 42 hz its so crappy. Most of the scenes feels like hearing in a poor ear phones. For example bomb blast i do not hear any thump sound or feel it but once the blast is over, the rumble and pressurized feeling due to the bass extension is good. Gun shots are flat. I hear or feel nothing except a flat sound. Also in action sequences it feels like bass is going mute and coming back. So i have few ideas in mind. First is if a mini dsp can help my situation to correct the house curve. Has any one used it for a single sub and found major improvements. Second is if room or xtz is the culprit? Will a better sub have better response or any sub will have similar response due to poor room acoustics. Final option is dual subs. Since the current position has good lower bass response 18-42 and the other spot has better middle and upper can adding a dual sub even out the curve. @rainbowsong2000 Biggest thanks to my rew guru ji, not only did i borrow the mic from him he also helped me with the set up and measurement process

 

[delhite2]

Well, in my opinion minidsp is a great addition to any HT but how much will it help for single sub depends on what you intend to use it for.
If you wanna use the EQ feature then it will be useful, other than that i dont see a use for you in a single sub setup.
Buying a second sub will help flatten the dips in the room, but before doing anything i suggest you look into trapping the bass.
Look into placing some corner bass traps made of rockwool / glass wool in a couple of corners atleast to start with. (if using glass wool, make sure to wrap it in plastic or something.)
Make sure they are atleast 2 inches thick and try to leave certain breathing room between walls and them.
Bass traps are definitely going to help there are no 2 ways about it, so even if you eventually decide on a second sub, bass absorption will help.

 

[ShaQ.Blogs]

Mini DSP wont help much as you have a massive dip of about 30dB around 30Hz. The miniDSP would create an inverse response to compensate. This compensation is done by your amp. With 30 dB to make up on top of the house curve + other corrections, the entire load is on the amp. IMHO not advised. (I would assume that the amp would be pushing out more power at those frequencies to fix it. Which would mean more Xmax required. 30dB correction???)

Fix this the right way.

1. One sub, Try different positions. Try the sub crawl, it usually helps. Alternatively, try placing in 4 different corners to begin with, and measure each time. Then try different other positions. You will likely not get a flat one. Look for the best compromise. Lot of measuring and work.
2. Dual subs go a long way. I had similar responses in my room when i measured my dual subs separately. Dual subs placed correctly made up for much of the dips. And then mini DSP does the work. 2 subs is better than 1. . 4 subs is better than 2 .
3. Room treatment.

 

[syednizamudeen]

As far as I know, no free tweaks is going to save your 30 Hz drop in your room. Even a bigger sub won't guarantee that it will fill in the nulls.

I believe multiple subs are laziest and easiest way to make the bass hit smoother throughout a larger listening space and a practically known method to tame peaks and nulls,IMO

 

[Love4sound]

Mini DSP wont help much as you have a massive dip of about 30dB around 30Hz. The miniDSP would create an inverse response to compensate. This compensation is done by your amp. With 30 dB to make up on top of the house curve + other corrections, the entire load is on the amp. IMHO not advised. (I would assume that the amp would be pushing out more power at those frequencies to fix it. Which would mean more Xmax required. 30dB correction???)

Fix this the right way.

1. One sub, Try different positions. Try the sub crawl, it usually helps. Alternatively, try placing in 4 different corners to begin with, and measure each time. Then try different other positions. You will likely not get a flat one. Look for the best compromise. Lot of measuring and work.
2. Dual subs go a long way. I had similar responses in my room when i measured my dual subs separately. Dual subs placed correctly made up for much of the dips. And then mini DSP does the work. 2 subs is better than 1. . 4 subs is better than 2 .
3. Room treatment.

There is no dip in 30hz when the sub is placed in front which is where I have placed .The one with the big dip at 30hz is in the rear right and same in rear left as well which I just took for checking room response at different location.For now I am skipping rear placement. So sharing graph of pure direct response of my sub in front left and right. The blue graph is front right and red is front left.Even without any room correction and eq the response is smooth from 18-40hz.

 

[liverpool_for_life]

What are your room dimensions and what is the distance of the sub from the MLP?

 

[Love4sound]

What are your room dimensions and what is the distance of the sub from the MLP?

Dimensions are 10*11. From MLP sub distance is 8ft.

 

[liverpool_for_life]

Dimensions are 10*11. From MLP sub distance is 8ft.

When you place the sub in the front, is it approx. 5 ft from left side wall?

 

[Love4sound]

When you place the sub in the front, is it approx. 5 ft from left side wall?

If I place the sub front right it’s 1.5 feet away from the right wall and if I place the sub front left it’s 3 feet. Placing it 5 feet away from side wall will place the sub exactly at the Center of the room and straight to the MLP.

 

[liverpool_for_life]

Dear Fm's

For example bomb blast i do not hear any thump sound or feel it but once the blast is over, the rumble and pressurized feeling due to the bass extension is good.

Unfortunately, the two positions you measured in your room give you an either-or. You can either get the feeling of being pressurized (reasonably flat till 40) or the "chest" impact (reasonably flat between 40-80).

A minidsp (or any other EQ device) cannot help with nulls of the magnitude you're seeing. You can do one/more of the following:

1. Change sub position.
2. Change listening position.
3. Add more subs.
4. Bass traps.

Sorry, but that's just the reality of bass in small/medium rooms. Which is what the large majority of us have.

 

[Love4sound]

Unfortunately, the two positions you measured in your room give you an either-or. You can either get the feeling of being pressurized (reasonably flat till 40) or the "chest" impact (reasonably flat between 40-80).

A minidsp (or any other EQ device) cannot help with nulls of the magnitude you're seeing. You can do one/more of the following:

1. Change sub position.
2. Change listening position.
3. Add more subs.
4. Bass traps.

Sorry, but that's just the reality of bass in small/medium rooms. Which is what the large majority of us have.

Ok one major point I didn’t mention here is I did not have this issue before. The first image was my previous set up. The LR have much breathing space as the tv is 43 inches. The next image which is my current set up and I had to move the LR 2 inches away to install the 65 inch tv. Even then the LCR is placed so close to the tv and has no breathing space and the LR z3 are rear ported. The tv also has around 5-6 cms gap behind the wall and it’s not sticking to the wall. Can this be the reason? Cause all these problems I have mentioned here are after I installed the 65 inches tv only. I used to listen in pure direct and enjoy music. Bass was tight and punchy. Now in pure direct the bass is flat and muffled while listening to music.

 

[liverpool_for_life]

Placing it 5 feet away from side wall will place the sub exactly at the Center of the room and straight to the MLP.

Right. Might be helpful to put the sub at the center of either front/rear wall to see if it helps with the big null around 55 Hz.

 

[liverpool_for_life]

Now in pure direct the bass is flat and muffled while listening to music.

I assume pure direct doesn't involve the use of subwoofer. Why are you looking at the sub's response at all then?

 

[Love4sound]

I assume pure direct doesn't involve the use of subwoofer. Why are you looking at the sub's response at all then?

Yeah it doesn’t. But if the mains are producing muffled and flat bass won’t that have an impact in movies as well. My reference is just how the bass sounded before in my room. So the clear change noticed here first is with the bass from LR in pure direct while listening to music. I did try measuring the sub at centre. The response is more or less same in all the front positions. I guess what I can try is getting a wall mountable sealed or front ported LCR before I can think of dual subs and a mini dsp

 

[Love4sound]

So below is the graph of subwoofer response after audysey in red colour positioned at right front. Other 3 graphs are individual measurements of L+sub, R+sub and C+sub crossed over at 80. The 80 dip is not due to phase issues but because of the dip already present in that region guessing by the sub response alone. Some movies I do enjoy bass very much which I think is in the 20-45 region. Post that it’s a mess.

 

[liverpool_for_life]

So below is the graph of subwoofer response after audysey in red colour positioned at right front.

The best of the responses you've posted from your room, IMO. Personally, I'd listen to music with the sub engaged and limit Audyssey's correction to the minimum possible. Do you know if that is possible and what the frequency limit is, if so? This ought to be better than Pure Direct, based on what you're describing as lacking.

 

[Love4sound]

The best of the responses you've posted from your room, IMO. Personally, I'd listen to music with the sub engaged and limit Audyssey's correction to the minimum possible. Do you know if that is possible and what the frequency limit is, if so? This ought to be better than Pure Direct, based on what you're describing as lacking.

Yeah right now I don’t use pure direct. I listen in stereo mode and it’s much better. In my 4500 there is a separate 2ch settings so I have kept LFE as sub+mains and music is decent enough for normal listening. To limit audysey correction we need to use the app and filter the desired frequency in multi eq filter frequency range right? I randomly tried 500 and 1000. The brightness was very much reduced and it was nice but some times feels flat so disabled it. But music wise I am all good for now. Thanks a lot. I actually arrived here with your suggestions to measure in the other thread.

 

[Sony4ever]

when you are auto calibrating.. try placing mic in higher height above head level... these all chinese instruments have these issues.. better to go for good branded systems next time which have better calibrated amplifier ..like bose ,sony

 

[Tuhin Lavania]

when you are auto calibrating.. try placing mic in higher height above head level... these all chinese instruments have these issues.. better to go for good branded systems next time which have better calibrated amplifier ..like bose ,sony

Which Sony system do you own ? Is it better than the systems owned by people here ? Can you post some videos/photos ?

 

[Love4sound]

So after so Many testings with multiple position there was 0 improvements. Couldn’t get rid of the huge dips after 60 hz.Finally gave up and on route for dual subs. So borrowed a Yamaha 6 inch 50 watts ported sub and paired it with my xtz. Good results. Adding a sub equal to xtz or another xtz May give ultimate results. First image is dual sub curve after audysey. 2nd image red curve is single xtz after audysey