A disastrous subwoofer journey

[Love4sound]

The more I spend and upgrade on subs it just keeps getting worse. I got a single rythmik and it was so good and I was able to enjoy my movie experience. Now that I got a dual rythmik it just killed all the quality bass a single rythmik sub was producing. Lost all the punch and accuracy going duals. Xtz duals was so good and I assumed rythmik would be even better after using one rythmik. 1st image has single and dual response of rythmik. 2nd image is dual xtz. Xtz duals where 10.17, 12.17 and non identical but had no issues integrating. But dual identical LV12F just isn’t integrating. Red graph in 1st image is dual post eq and audysey. Blue graph is single post eq and audysey. Single was much accurate and punchy. With duals all I get is rumble and grunt with no punch at all. For example alita battle bar fight. Lot of punch and kicks and with a single sub it was tight and punchy. With dual there is no tightness and punch. It’s just rumbling when alita attacks or punches others. Thinking of selling both now and just get one fvx12.

 

[Nitin K]

It could be an integration issue. If other experts in Rew/Umik can help you out, then would be great in solving your issue.
In my case a single sub was more than enough and very satisfying in a small room. Never felt the need for a 2nd one .
In worst case scenario if you were happy with just one sub then better to sell the other one rather than selling both as you would lose more money in resale.

 

[Love4sound]

It could be an integration issue. If other experts in Rew/Umik can help you out, then would be great in solving your issue.
In my case a single sub was more than enough and very satisfying in a small room. Never felt the need for a 2nd one .

I have even mixed 12.17 with a 50 watts 6 inch Yamaha sub and it integrated much better without a minidsp.Dual LV12F is the worst I have ever experienced. Not sure why both are not integrating. Even mini dsp is not able to trim the peaks and smoothen the curve. I will be much happier with the single LV12F performance over the duals

 

[Nitin K]

I have even mixed 12.17 with a 50 watts 6 inch Yamaha sub and it integrated much better without a minidsp.Dual LV12F is the worst I have ever experienced. Not sure why both are not integrating. Even mini dsp is not able to trim the peaks and smoothen the curve. I will be much happier with the single LV12F performance over the duals

If the services of a professional integrator could be availed then maybe that could solve your issue as long as the service charge is reasonable.

 

[Love4sound]

If the services of a professional integrator could be availed then maybe that could solve your issue as long as the service charge is reasonable.

Not sure if I can find one or they will be of much help as I have only one spot for subs

 

[sunshine_vsk]

do you hear any difference with both your LV12F's when you play them individually from the same position?. may be your 2nd LV12F needs more break in time for better integration?..

 

[liverpool_for_life]

Not sure if I can find one or they will be of much help as I have only one spot for subs

One final shot: https://www.andyc.diy-audio-engineering.org/mso/html/index.html

Gain match your subs, run the measurements, give it to MSO and use the delay and filters that it generates as is.

 

[Love4sound]

One final shot: https://www.andyc.diy-audio-engineering.org/mso/html/index.html

Gain match your subs, run the measurements, give it to MSO and use the delay and filters that it generates as is.

Will check this out

do you hear any difference with both your LV12F's when you play them individually from the same position?. may be your 2nd LV12F needs more break in time for better integration?..

They measured the same and don’t think it’s break in issue. Single front is very good and I can settle. Dual just messed it up completely

 

[Decadent_Spectre]

Time domain

 

[amrutmhatre90]

The more I spend and upgrade on subs it just keeps getting worse. I got a single rythmik and it was so good and I was able to enjoy my movie experience. Now that I got a dual rythmik it just killed all the quality bass a single rythmik sub was producing. Lost all the punch and accuracy going duals. Xtz duals was so good and I assumed rythmik would be even better after using one rythmik. 1st image has single and dual response of rythmik. 2nd image is dual xtz. Xtz duals where 10.17, 12.17 and non identical but had no issues integrating. But dual identical LV12F just isn’t integrating. Red graph in 1st image is dual post eq and audysey. Blue graph is single post eq and audysey. Single was much accurate and punchy. With duals all I get is rumble and grunt with no punch at all. For example alita battle bar fight. Lot of punch and kicks and with a single sub it was tight and punchy. With dual there is no tightness and punch. It’s just rumbling when alita attacks or punches others. Thinking of selling both now and just get one fvx12.

Is it the phase issue? had noticed in one of your pictures that subs are located and front and back. I think the responses are getting canceled out.
Try changing the sub phase to 180 degree and check.

Also for temporary basis, can you move both subs in front and check if it is still bad.

 

[Love4sound]

Time domain

Please explain

Is it the phase issue? had noticed in one of your pictures that subs are located and front and back. I think the responses are getting canceled out.
Try changing the sub phase to 180 degree and check.

Also for temporary basis, can you move both subs in front and check if it is still bad.

The phase settings in sub will only work in line in and not with LFE in the LV12F. I will swap the sub and update later. For now I switched back to a single sub and the quality of bass is very enjoyable. Bass is tight punchy and accurate. With dual it’s muddy, inaccurate and muffled.

 

[Decadent_Spectre]

Tight/punch is almost always the result of sufficient top-mid-low end, properly time aligned in a well treated room.

I don't know your room but since it is the same room we can relatively infer that the room hasn't changed, I also assume your speakers are the same. Hence the most likely culprit is the time domain. Please note that time domain encompasses both time(distance) and phase.

If you delay a loudpseaker (in ms/feet etc) all frequencies are delayed by the same time length. If you adjust the phase however, the delay (in ms/feet etc) is different at different frequencies. You can have a system that measures in phase (6db summation at XO) but may be one or more cycles ahead/behind in time.

IMO it is best to set time/phase by ear rather than a measurement.

 

[Love4sound]

IMO it is best to set time/phase by ear rather than a measurement.

I do use my ears for finalising the delay value. For example if the best delay value in measurement is 9 I experiment from 7-12 and choose the value that sounds best. Today I moved back to a single sub and performance is much better. I shouldn’t have gotten greedy and listened to other fm’s who suggested I just go for a single sub for my room. Just wondering how come other subs blended well in a dual setup in my room but dual identical rythmik failed. I have even integrated a xtz12.17 with non identical subs like Bic and even a Yamaha 6 inch 50 watts sub without a minidsp. For some reasons the rear sub just doesn’t integrate with the front sub. It cancels the accuracy, tight bass of my front sub.

 

[Decadent_Spectre]

If you have a minidsp then experiment with both phase and delay (ms/feet). Do not be shy about the value , explore to the limits and then reduce as needed. Say go to max delay and then cut down on the delay slowly, for both subs, one at a time. It's time consuming but may give you some good results. Make sure to listen to it for at least a few minutes before going to the next delay setting.

 

[Love4sound]

If you have a minidsp then experiment with both phase and delay (ms/feet). Do not be shy about the value , explore to the limits and then reduce as needed. Say go to max delay and then cut down on the delay slowly, for both subs, one at a time. It's time consuming but may give you some good results. Make sure to listen to it for at least a few minutes before going to the next delay setting.

Yeah and currently 4 for second sub seems to be the right value based on listening and measurements. I will complete various testing like others have suggested as well and update later on my findings

 

[insane79]

How are the subs placed? I got dual Rels & very happy with the result, could be they aren't placed well? The setup of dual must have worked for the XTZ but not working for the Rythmik?

 

[Decadent_Spectre]

I wouldn't recommend measurements but as you please.

 

[Love4sound]

How are the subs placed? I got dual Rels & very happy with the result, could be they aren't place well?

Front right near corner and rear left near corner. So diagonal and ideal for a dual sub placement. Not sure why it isn’t integrating. Both subs seems to be fighting with each other. For example look at both the pure direct graphs. First image is dual LV12F pure direct graph and second is dual xtz. Do note xtz is not identical but still see how well they align. Graph is so smooth and was very easy to eq.

 

[MaSh]

Both are cutting each other and hence you are getting a null. There is nothing Disastrous about it and very very common. As suggested by others, you need to either find an alternative location to place the sub or experiment with the phase.

When you are integrating, are you integrating them separately or together?

MaSh

 

[Love4sound]

When you are integrating, are you integrating them separately or together?

MaSh

Taken sub 1 out from avr and connected with mini dsp input 1. Output 1 from mini dsp is connected with sub 1 and output 2 to rear sub. Adding delays to rear sub which is near to MLP. No matter what values I experiment the results are the same