# Does Audyssey XT32 normally do this



## gperkins_1973 (Aug 25, 2008)

Hi all,

I ran some graphs of my new drivers in old boxes today and was not very happy with how Audyssey XT32 has done my low tune.

I have 3 tunes. 12.5hz, 17.5hz and 21.5hz. This was a sub I built a while ago but sold my old FI Q drivers and have now replaced with two Havoc drivers.

The alignment is better than before but for some weird reason the low tune has come out with a very large dip between 10 and 20hz.

I ran Audyssey in my middle tune as I did this last time. My low tune came out ok last time too when I ran some REW sweeps.

The only difference this time is that I am using windows on my mac via bootcamp. I am using the same external turtle beach sound card too. 

I have also attached my winisd graphs to show what it should look like without room gain etc...

Should I run Audyssey in my low tune instead or do something else.

I have the inuke 6000 DSP and have EQ'd them but to be honest I am not that keen on the EQ function on it as I prefer the BFD route but thought I would give this a go.

I guess I need to take some nearfield measurements of each sub and see what the room is doing to the response too.

Any other suggestions would be grateful too.

cheers

Graham


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## gperkins_1973 (Aug 25, 2008)

no takers? :huh:


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## jtalden (Mar 12, 2009)

I don't know your priorities so these comments may not meet you liking.
I would not worry about the SW anechoic response. If the correct parameters are entered into winisd the calculated responses are accurate enough and are basically info only from a practical perspective. The fine detail of the anechoic SPL response is washed out in the room anyway.

Thoughts:
> Use winisd to calc the max LP output of the SW for each alignment and decide how loud you want to go with a little safety. It really takes a bunch of SW capacity to design flat below 20Hz in a reasonable size room. If we calc 100 dB at the LP at 20 Hz as an example, it is probably not a good situation if we intend to actually listen at levels that may cause SW overload on LF content.

> If we want to see accuracy what Audyssey actually did we should average similar mic points that were used for the Audyssey calibration. The average response will sometimes differ from a single mic location, particularly near a room mode.

> From your data It appears your noise floor is being reached at maybe about 13 Hz. Values below that values are questionable. You can test the noise floor and if that is the case and your need to go lower you can increase the testing level.

> Audyssey may have seen the slow rolloff of the low tune as the low limit of the SW and stopped EQ at a higher level than you wanted. There is good reason for this as Audyssey doesn't know the capacity of the SW and doesn't want to boost below the natural cutoff. I wouldn't do it manually either, but many do.

Why not run Audyssey on the tune you comfortable with from a capacity standpoint and then manually use the inuke to adjust the issues remaining?


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## JohnM (Apr 11, 2006)

Never used Audyssey myself so can't really comment on what it gets up to. Might get more people in the know on the Audio Processing forum?


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## gperkins_1973 (Aug 25, 2008)

After playing I managed to get these two EQ'd responses with the inuke. They are not perfect as you only have 8 filters on the inuke and 12 on the BFD which I could get much flatter.

I applied a wide 10db boost on the low tune with lots of other cuts and 5db boost on the mid tune with lots of cuts.

Low tune 

*Freq Gain DB Bandwidth 
20 +10 0.79 

23.3 -1 5.00 

30.3 -7 4.00 

35.3 +2 8.00 

38.5 -6 10 

56.8 -8 5.5 

75.4 -5 8.00 

 Mid tune

Freq Gain DB Bandwidth
23.3 5.00 2

28.4 -3 8.00

38.5 -3 8.00

43.8 2.7 10

54.4 -2 8.00

59.4 -6 10

77.1 -2.5 9.00*


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## gperkins_1973 (Aug 25, 2008)

These are my original FI Q18 audio measurements before any Audyssey which were in the same boxes.

The alignment was not a million miles away from the Havocs.

I didn't need much EQ'ing and the subs were located in the exact same place.


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## jtalden (Mar 12, 2009)

Very nice!


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## AudiocRaver (Jun 6, 2012)

A few thoughts:



> Low tune
> Freq Gain DB Bandwidth
> 20 +10 0.79


That is a lot of gain. The amplifier will be pushing 10x the power at that frequency. Even assuming the iNuke 6000, I would hesitate to apply that much boost without knowing how much headroom would be available at peak signal levels in that frequency range. When applying EQ, it is wise to not boost very much (3 dB max is my own rule of thumb) and to only apply broad-band boost (which you have done). You are starting with a big scoop in your pre-eq curve at that frequency, so your options are: 1. try it and see how it sounds, or 2. consider that tune unusable. Consider factors like: can the speaker handle that much power? can the amplifier provide it cleanly under normal operating conditions? does it sound good?



> 35.3 +2 8.00
> 38.5 -6 10


Narrow-band gain when EQing is not a good idea. It is usually simply feeding energy into room cancellation modes, which means that a bad-sounding response peak could be forming as a result only a short distance away in the room - at least that is how I understand it. Try eliminating the 35.3 boost and minimizing the 38.5 cut (which appears to be there largely to compensate for effects from the 35.3 boost).



> Mid tune
> Freq Gain DB Bandwidth
> 23.3 +5.00 2


Again, quite a bit of gain, but perhaps tolerable under the circumstances. Carefully consider the same factors mentioned above.



> 43.8 +2.7 10


Not a good idea, see reasons above.

The other filter choices appear reasonable.

When EQing, the general rule is: less is better, a "pretty good" curve with minimal filtering will almost always sound better than a "really good" curve with lots of filtering.


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## gperkins_1973 (Aug 25, 2008)

Ah I see. I presumed a large boost was ok as along there was sufficent cuts which lead to a smaller overall boost.

I did play a really low bass track in my low tune which has the 10db boost at -12db on the MV and the inuke lit up 2-3 lights and stayed cold with modified quieter fans so I presumed it was ok.

The drivers are not run in properly at the moment so I will re run Audyssey and graphs again in a few weeks to see if anything has changed to the original response.

With the low tune based on the dip between 10-20hz I would have to boost more than 3db as the inuke only EQ's to 20hz.


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## AudiocRaver (Jun 6, 2012)

gperkins_1973 said:


> Ah I see. I presumed a large boost was ok as along there was sufficent cuts which lead to a smaller overall boost.
> 
> I did play a really low bass track in my low tune which has the 10db boost at -12db on the MV and the inuke lit up 2-3 lights and stayed cold with modified quieter fans so I presumed it was ok.
> 
> ...


Understood. Bottom line: if it works, go with it. Just wanted to be sure you understood the potential issues.

Cheers.


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## gperkins_1973 (Aug 25, 2008)

Thanks. I don't listen to reference so it should be fine. Max normal levels are around -25db on the master volume and I mainly use my middle tune for movies and only use the low tune for silly low bass music.


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