Rythmik Subwoofer Owner’s Official thread

[vamsikrishna919]

Ok using Java i set the fronts crossover at 250 and disconnect them to measure sub response. Only to integrate the sub with mains i connect them and measure. Since you are not going to experiment different positions you can just run audysey and check the response of the sub alone first and then integrate it with the mains. Eq will not help with any big nulls but trim the peaks for a smoother response.

Let me try that tonight and report. Thanks for the help!

 

[alphacentury100]

There was an option to select output as L and R, so I ran the tests separately.

But I have run the test in L+R mode now. Below are the new results with some changes in sub position. Its a pure direct graph, I have not smoothened it. As it was nigh, I ran this with a slightly lower reference volume of ~70db.

I cannot make any additional changes to sub positions, wondering how can make the response flat now.

The graph shows very bad response with Audyssey L&R bypassed. The only reason why the graph looks decent is because you have set the Decibel scale to 20Db. Change the vertical Decibel scale to 5db without smoothening, and you will see how bad the response is.

Like the graph below with 5db scale, which is obviously mine!

 

[Love4sound]

Dam totally missed the DB scale. Please refer my graph and go to limits to set both frequency and DB limits accordingly. Set volume axis to 40-110db and frequency axis to 10hz-120hz. As stated above it seems like a poor response.

 

[RajithKumar]

There was an option to select output as L and R, so I ran the tests separately.

But I have run the test in L+R mode now. Below are the new results with some changes in sub position. Its a pure direct graph, I have not smoothened it. As it was nigh, I ran this with a slightly lower reference volume of ~70db.

I cannot make any additional changes to sub positions, wondering how can make the response flat now.

U are doing it wrong. If u are using ASIO , U can select the subwoofer channel to measure seperately.
If JAVA is used then increase the crossover to 250Hz in AVR and then u can select either L or R and then u can measure .This way all signal goes to sub.
Alternatively if ur room is Rectangular , instead to shifting and placing the sub manually and measuring.You can use REW room simulator where u can enter your Room dimensions , listening position distance etc. And then u can give input of Sub placement,no of subs used ,driver facing direction with respect to room dimensions etc.
By this u can get the simulated response without measuring it. There is also an option of Time alignment delays to get better simulated response. This will give a fair idea of where to place the sub .
Hope you got it.
Good luck .

 

[alphacentury100]

Let me try that tonight and report. Thanks for the help!

My understanding is that, you have DUAL FV15HP and a MiniDsp2X4Hd & Umik-1. If so, they you have all the necessary equipments to caliborate your sub to a very flat response within +3 to -3 db from 10hz to 80hz.
Caliborating the sub is mostly trial and error method but you just have to remember what to adjust.
If you don't have placement freedom of the subwoofers then place each(2) subs in the available but different location. Nver stack the subs as stacking the subs will defeate the purpose of multiple subs, which is producing smooth and even response.
Connect the minidsp using single sub out from the AVR because it will be easy if you are planning to use BEQ in the future, which can be included in the Input section of the sub.
Connect each sub to separate output section of the Minidsp and enable those sections only and disable the remaining 2 lines etc. and run a sweep. Infact, you will have to run a REW sweep each time to see if there is any improvement.
Now try changing the timing of one sub by 1ms in the output section of the Minidsp app(For Reference: 1milli second delay = One feet distance) and see if the graph improves. You can also inverse one sub and check for improvement.

 

[vamsikrishna919]

My understanding is that, you have DUAL FV15HP and a MiniDsp2X4Hd & Umik-1. If so, they you have all the necessary equipments to caliborate your sub to a very flat response within +3 to -3 db from 10hz to 80hz.
Caliborating the sub is mostly trial and error method but you just have to remember what to adjust.
If you don't have placement freedom of the subwoofers then place each(2) subs in the available but different location. Nver stack the subs as stacking the subs will defeate the purpose of multiple subs, which is producing smooth and even response.
Connect the minidsp using single sub out from the AVR because it will be easy if you are planning to use BEQ in the future, which can be included in the Input section of the sub.
Connect each sub to separate output section of the Minidsp and enable those sections only and disable the remaining 2 lines etc. and run a sweep. Infact, you will have to run a REW sweep each time to see if there is any improvement.
Now try changing the timing of one sub by 1ms in the output section of the Minidsp app(For Reference: 1milli second delay = One feet distance) and see if the graph improves. You can also inverse one sub and check for improvement.

I have only one FV15HP. I will try to fix this with MiniDSP once it arrives and will report the progress here.

U are doing it wrong. If u are using ASIO , U can select the subwoofer channel to measure seperately.
If JAVA is used then increase the crossover to 250Hz in AVR and then u can select either L or R and then u can measure .This way all signal goes to sub.
Alternatively if ur room is Rectangular , instead to shifting and placing the sub manually and measuring.You can use REW room simulator where u can enter your Room dimensions , listening position distance etc. And then u can give input of Sub placement,no of subs used ,driver facing direction with respect to room dimensions etc.
By this u can get the simulated response without measuring it. There is also an option of Time alignment delays to get better simulated response. This will give a fair idea of where to place the sub .
Hope you got it.
Good luck .

It's not an even space, but there are pockets and colmuns, which i’m finding it difficult to simulate in REW.

 

[RajithKumar]

I have only one FV15HP. I will try to fix this with MiniDSP once it arrives and will report the progress here.

Its wiser to invest in minidsp only if u have/planning to have atleast 2 subs.
For only one sub, there are plenty of manual options available in for Rhythmik,make use of that and then do Audyssey ,things will be good.

 

[trumee]

I have installed a new FVX12 as the only sub in my home theatre. I ran Audyssey on my Denon X3700 for the initial calibration. After reading this forum i have bought a Umik-1 which will arrive soon. Will Umik-1/REW allow me to upload the calibrated curves to Denon similar to Audyssey?

 

[Love4sound]

I have installed a new FVX12 as the only sub in my home theatre. I ran Audyssey on my Denon X3700 for the initial calibration. After reading this forum i have bought a Umik-1 which will arrive soon. Will Umik-1/REW allow me to upload the calibrated curves to Denon similar to Audyssey?

No. You can use umik/rew only for measurements.

 

[liverpool_for_life]

Will Umik-1/REW allow me to upload the calibrated curves to Denon similar to Audyssey?

No. You’ll need a minidsp (or equivalent) to allow for the processing of filters generated on the basis of your REW measurements. HST, it is rare, but not impossible, to make a justifiable use case for a minidsp with only one sub.

 

[RajithKumar]

I have installed a new FVX12 as the only sub in my home theatre. I ran Audyssey on my Denon X3700 for the initial calibration. After reading this forum i have bought a Umik-1 which will arrive soon. Will Umik-1/REW allow me to upload the calibrated curves to Denon similar to Audyssey?

It's not possible. With Umik & REW you can know the response of sub. For uploading correction filters you should have some dsp devices.

 

[alphacentury100]

I got my FV15HP couple two days ago

As you mentioned COUPLE, I assumed you have a pair (2 subs).

 

[alphacentury100]

I have installed a new FVX12 as the only sub in my home theatre. I ran Audyssey on my Denon X3700 for the initial calibration. After reading this forum i have bought a Umik-1 which will arrive soon. Will Umik-1/REW allow me to upload the calibrated curves to Denon similar to Audyssey?

Its also not necessary to spend around 30k on a miniDsp while you have only one sub.
now that you know the measurement, you can move the sub around or change the phase (delay) and see if there is improvement.

 

[trumee]

Made my first measurements of the sub using Umik-1. I have a computer network switch in the room whose fans make a continuous sound. How bad are these graphs?

Without Audyssey (Pure direct)



With Audyssey


Both together

 

[Love4sound]

Made my first measurements of the sub using Umik-1. I have a computer network switch in the room whose fans make a continuous sound. How bad are these graphs?

Without Audyssey (Pure direct)

View attachment 58800

With Audyssey
View attachment 58801

Both together
View attachment 58802

Which sub is this? And also filter the graph 10hz-120hz

 

[trumee]

This is FVX12. Here is the filtered graph (no smoothening)

 

[Love4sound]

This is FVX12. Here is the filtered graph (no smoothening)

View attachment 58803

Ok it’s bad after 50hz. More details on room and placement please. Mine is a dedicated 11*10 room. Very basic acoustic treatment and the LV12F gave much better smooth response compared. Orange is PD graph and green is after audysey

 

[trumee]

The room size is 9*12 foot. The sub is placed midway off one of the walls. The ambient noise in the room is about 58db (from REW), which is coming from the computer equipment in the room. There is no acoustic treatment in the room. One wall of the room has wooden almirahs.

You audyssey plot looks great.

 

[Love4sound]

The room size is 9*12 foot. The sub is placed midway off one of the walls. The ambient noise in the room is about 58db (from REW), which is coming from the computer equipment in the room. There is no acoustic treatment in the room. One wall of the room has wooden almirahs.

You audyssey plot looks great.

Ok do you have the flexibility to place the subs at different locations? Normally front corners or flanking it between the LCR works.

 

[trumee]

Unfortunately, i dont have much flexibility in placing the sub. However, agree it is worthwhile to move it around atleast temporarily and check the response.

On another note the tripod which came with the umik-1 is pretty small. Are you using any stand/tripod with yours?