AVS Forum banner

1 - 10 of 10 Posts

·
Premium Member
Joined
·
776 Posts
Discussion Starter #1
Ok so I meant tweaking, lol


I have two subs hooked up to two individual sub outputs on an AVR with multi sub EQ and Audyssey XT32.


Measuring subs separately they both have some dips here and there, but they don't have the same troughs showing up on each. When I measure them together, there are dips in different places.


Using a mini dsp, what can I do to give Audyssey the most 'help' at giving me the flattest output response?


1. Should I measure both subs together pre-Audyssey? And then use minidsp to reduce the peaks by applying the same PEQ to each sub?


2. Or should I measure each sub by itself and apply PEQ to each sub separately to reduce peaks?


Would that help Audyssey? Which one would you do?
 

·
Registered
Joined
·
2,850 Posts
Ok so I meant tweaking, lol


I have two subs hooked up to two individual sub outputs on an AVR with multi sub EQ and Audyssey XT32.


Measuring subs separately they both have some dips here and there, but they don't have the same troughs showing up on each. When I measure them together, there are dips in different places.


Using a mini dsp, what can I do to give Audyssey the most 'help' at giving me the flattest output response?


1. Should I measure both subs together pre-Audyssey? And then use minidsp to reduce the peaks by applying the same PEQ to each sub?


2. Or should I measure each sub by itself and apply PEQ to each sub separately to reduce peaks?


Would that help Audyssey? Which one would you do?
Have some graphs you can post showing the subs individually and together?

I have had success defeating "troughs" (nulls) with A) phase (set one sub to 0, the other to 180 (or if variable phase control, slowly raise it while taking measurements)) and/or B) delay (don't know if miniDSP gives you delay options?)

For B), I adjust delay in 1/2 foot increments on my nu1000DSP, take measurement, repeat if necessary. I believe there is a calculation you can use to determine a decent starting point, but am unable to locate it ATM.
 

·
Premium Member
Joined
·
776 Posts
Discussion Starter #3
Have some graphs you can post showing the subs individually and together?

I have had success defeating "troughs" (nulls) with A) phase (set one sub to 0, the other to 180 (or if variable phase control, slowly raise it while taking measurements)) and/or B) delay (don't know if miniDSP gives you delay options?)

For B), I adjust delay in 1/2 foot increments on my nu1000DSP, take measurement, repeat if necessary. I believe there is a calculation you can use to determine a decent starting point, but am unable to locate it ATM.
The subs have 'in' and 'out' switch. I thought if you set it to out, then messing with phase switches on AVR would not do anything?

Either way, I thought Audyssey set phase correctly.

I'll try changing sub phase switch between 0 and 180 on each sub though and see what happens.

Can anyone else who uses minidsp on dual subs tell me which of these below you do PRIOR to running Audyssey?

1. Do you reduce peaks with some peqs on each sub individually (after measuring each individually) or
2. Do you measure both subs together and then reduce peaks by adding same peqs to each sub?
 

·
Registered
Joined
·
3,943 Posts
Whether Time Aligning your subs or not all equalize your sub/subs as one complete unit. Additionally Ominmic and REW are capable of Autoeq to a set curve you want and make a custom Biquad filter set that you can save and upload to the Minidsp. Some say the IIR used in the Minidsp are preferred for sub eqing and other say the FIR in Audyssey are better so try different both options out yourself.
 

·
Registered
Joined
·
3,943 Posts
The subs have 'in' and 'out' switch. I thought if you set it to out, then messing with phase switches on AVR would not do anything?

Either way, I thought Audyssey set phase correctly.

I'll try changing sub phase switch between 0 and 180 on each sub though and see what happens.

Can anyone else who uses minidsp on dual subs tell me which of these below you do PRIOR to running Audyssey?

1. Do you reduce peaks with some peqs on each sub individually (after measuring each individually) or
2. Do you measure both subs together and then reduce peaks by adding same peqs to each sub?
There 2 different things. Phase adjustment on a powered sub adjust for smooth transition/integration(no excessive null) at the sub and main crossover point. TAing delays each speaker and sub/subs to achieve the max efficiency/sensitivity at the MLP.

1. No
2. Yes
 

·
Premium Member
Joined
·
776 Posts
Discussion Starter #6
Whether Time Aligning your subs or not all equalize your sub/subs as one complete unit. Additionally Ominmic and REW are capable of Autoeq to a set curve you want and make a custom Biquad filter set that you can save and upload to the Minidsp. Some say the IIR used in the Minidsp are preferred for sub eqing and other say the FIR in Audyssey are better so try different both options out yourself.
I have XTZ room analyzer and although it won't let me save and upload a file of peqs... I can adjust peaks on screen and it shows the Q, DBs, and frequency values, so I can manually add them to the mini.

What is IIR and FIR?

At what frequency should you stop adding filters to subs at? For example I was showing a trough at 125hz, and I added 10db to both subs in minidsp at 125hz and FR chart showed it was gone. But then someone told me that trough at 125hz was probably more from the speakers.

So should I stick to adding peqs to subs at like 100hz or less?
 

·
Registered
Joined
·
3,943 Posts
I have XTZ room analyzer and although it won't let me save and upload a file of peqs... I can adjust peaks on screen and it shows the Q, DBs, and frequency values, so I can manually add them to the mini.

What is IIR and FIR?

At what frequency should you stop adding filters to subs at? For example I was showing a trough at 125hz, and I added 10db to both subs in minidsp at 125hz and FR chart showed it was gone. But then someone told me that trough at 125hz was probably more from the speakers.

So should I stick to adding peqs to subs at like 100hz or less?
Eq only below xover point. You can google IIR and FIR for an explanation. They are types of filters.
 

·
Premium Member
Joined
·
776 Posts
Discussion Starter #8
Eq only below xover point. You can google IIR and FIR for an explanation. They are types of filters.
Ok thanks when i added 'filter' to IIR and fir Google search that worked. I had no clue that my subs weren't to blame for a 100hz null I always seem to have. I don't have dsP for regular speakers.

I'm assuming moving speakers, adjusting toe-in is best way to deal with a 100hz null?
 

·
Registered
Joined
·
3,943 Posts
Ok thanks when i added 'filter' to IIR and fir Google search that worked. I had no clue that my subs weren't to blame for a 100hz null I always seem to have. I don't have dsP for regular speakers.

I'm assuming moving speakers, adjusting toe-in is best way to deal with a 100hz null?
Most of the time its room modes due to distance of your LCR's driver baffles to the front and side walls and floor. You can play around with the placement of your fronts. Don't get to hung up with nulls you see here. Any peak filtering to try to smooth response here will almost always sound worse. You could put any number of different speakers in the that spot with midbass drivers ranging from 4-15" and the response will be the same. Its the room not the speaker.
 

·
Registered
Joined
·
12,983 Posts
Phase adjustments will do nothing when using SubEQ HT....once you run Audyssey, it will just set a different delay for that sub and cancel out any phase adjustment you made. Let Audyssey get the subs time aligned with each other (both phases set to 0), there is really nothing more you need to do concerning that since you have XT32.

Always EQ both subs as one "system". Personally, I prefer to EQ after Audyssey though - get the best response you can via placement and time alignment ---> run Audyssey ---> add EQ (if needed).
 
1 - 10 of 10 Posts
Top