Fancy đź“Š graphs

stevie0

Established Member
Joined
Jan 7, 2012
Messages
559
Reaction score
179
Points
159
Location
Sunderland
I managed after a lot of head scratching to run the xtz analyser pro software and below are my results.
Im Pretty sure the subs never kicked in, probably how I have it set up.
Can anyone tell me in layman’s terms what these mean ?






Thanks
 
Hi. I can give it a try. I hope I don't dumb it down too much, but you said laymans terms.

The first image shows how loud (dB on the Y axis) it is at each frequency in Hz along the X axis. It looks to my novice eye that you have a high pass filter set around 60Hz

Image 2 shows the decay time at each frequency. This is essentially how long it takes a sound played at each frequency to dissipate. Imagine clapping your hands in a hall. The "echo" is the decay time. In a Home Theater, Dolby recommend this should be between 0.2-0.4ms ideally. So you need to take a look at around 800Hz to 5kHz where these figures are exceeded. This can be helped by adding room treatments to the room such as Acoustic Panels. The gauge on the left shows the max, min and average volume (dB) across the entire frequency sweep (if i'm not mistaken). The blue line also shows you have a room null at 40Hz and 950Hz. I dont want to patronise, but since you said in layman's terms, a room null is when there is a dead spot where the sound bouncing off the walls causes the sound at specific frequencies, in specific locations within your room to cancel out, and so you have reduced volume. If you move a few feet in any direction in your room, these "Nulls" will change

I'm assuming in image 3 that the green and yellow lines are your L+R speakers measured independently. Both of these played together create the blue line I spoke about above.

Image 4 shows the frequency content (on the Y axis represented in Hz) of the sound being played vs time (X axis) Blue = low content (quiet) and Red = High Content (Loud). As you can see you have a lot of content down to about 50Hz and then the volume drops off below that frequency. This confirms image 1 having a Highpass filter at around 60Hz

Also, it looks like you may have a time alignment issue between your left and right speakers which can also cause room nulls.

I hope this info is helpful to you.
 
Hi. I can give it a try. I hope I don't dumb it down too much, but you said laymans terms.

The first image shows how loud (dB on the Y axis) it is at each frequency in Hz along the X axis. It looks to my novice eye that you have a high pass filter set around 60Hz

Image 2 shows the decay time at each frequency. This is essentially how long it takes a sound played at each frequency to dissipate. Imagine clapping your hands in a hall. The "echo" is the decay time. In a Home Theater, Dolby recommend this should be between 0.2-0.4ms ideally. So you need to take a look at around 800Hz to 5kHz where these figures are exceeded. This can be helped by adding room treatments to the room such as Acoustic Panels. The gauge on the left shows the max, min and average volume (dB) across the entire frequency sweep (if i'm not mistaken). The blue line also shows you have a room null at 40Hz and 950Hz. I dont want to patronise, but since you said in layman's terms, a room null is when there is a dead spot where the sound bouncing off the walls causes the sound at specific frequencies, in specific locations within your room to cancel out, and so you have reduced volume. If you move a few feet in any direction in your room, these "Nulls" will change

I'm assuming in image 3 that the green and yellow lines are your L+R speakers measured independently. Both of these played together create the blue line I spoke about above.

Image 4 shows the frequency content (on the Y axis represented in Hz) of the sound being played vs time (X axis) Blue = low content (quiet) and Red = High Content (Loud). As you can see you have a lot of content down to about 50Hz and then the volume drops off below that frequency. This confirms image 1 having a Highpass filter at around 60Hz

Also, it looks like you may have a time alignment issue between your left and right speakers which can also cause room nulls.

I hope this info is helpful to you.
Very helpful thanks, I feel I need to get in a pro to calibrate the speakers for me, I have no idea what I am doing.

I may have another try later and add the subs to the mix if I can.
 
What mic does the xtz software use, does it work with REW?
 
I've not used this software before. I normally use REW for subwoofers with my minidsp and then allow the marantz to do the rest of the setting up. I'll help where I can if you have any questions though.
 
I was going to ask if the kit/mic works with REW. While I'm sure the XTZ software is suitable you'll likely get more help with REW which is better supported.

The response looks ok, albeit without subs, but some of those decays look long, if that's what we're looking at. Any treatment in your room?
 
under 300ms is good. It's odd to see them get longer as you go higher though, usually things flatten out higher up.
 
I was going to ask if the kit/mic works with REW. While I'm sure the XTZ software is suitable you'll likely get more help with REW which is better supported.

The response looks ok, albeit without subs, but some of those decays look long, if that's what we're looking at. Any treatment in your room?
The room isn’t actually my final room so has no treatment, it’s just all the gear in a room testing if what I have works for now, basically I’m just messing around trying to understand how to use what I have.
Seems the mic can be used with REW though from the FAQ on the xtz site.







 
There's a lot of hard surfaces in that room. I'm guessing that if clap in a corner you'll hear flutter echo. Treatment will help, but that'll be hard to do and keep the character of the room. Maybe heavy tapestries and thick velvet curtains. That can always come later.

When I said that REW is better supported, I just meant that more people are familiar with it. As I say, I'm sure the XTZ software is great, but I have no idea how to use it - that could just be me!

How are you planning on driving all those subs?
 
There's a lot of hard surfaces in that room. I'm guessing that if clap in a corner you'll hear flutter echo. Treatment will help, but that'll be hard to do and keep the character of the room. Maybe heavy tapestries and thick velvet curtains. That can always come later.

When I said that REW is better supported, I just meant that more people are familiar with it. As I say, I'm sure the XTZ software is great, but I have no idea how to use it - that could just be me!

How are you planning on driving all those subs?
Like I say this isn’t the final room, I’m just trying to get to grips with how to calibrate (I currently only have LCR and sub channels wired up for now)
8 of the subs are hooked up to a NX3000D, 4 ohms each side in stereo mode.

I just ran audessy again and I’m about to see what has happened to the results in the xtz software now.




how do you make an image a link
 
Last edited:
Why is this thread in the diy forum? Can a mod move it to the sub forum (which seems more appropriate to me)?
That’s fair. Moved.
 
After trying to read up a little more I have decided to disregard trying to understand this software, REW or any other analysis thing.
audessy will do for now!
 
With 8 to 12 subs I'm not sure that's an option you have available to you!

It'll likely be fine to start but it'll probably need some sort of management and EQ over and above that. Just a guess, you might be fine.
 
With 8 to 12 subs I'm not sure that's an option you have available to you!

It'll likely be fine to start but it'll probably need some sort of management and EQ over and above that. Just a guess, you might be fine.
I guess so at some point, it just seems extremely complicated for a noob like me.
When I am ready I will search to see if there is anyone offering speaker and projector calibration services.
 
Just shout when you're ready. There's a bit of a learning curve, but once you have the basics you can do a lot to extract performance from kit. There's always more to learn and subtle details, but you can get a long way with some of the basics.
 
I can confirm the xtz mic does work with rew. The results are almost identical to a umik
Thanks, any tips or links how to get it up and running ?
 
It should auto detect it, you load the cal file and measurements should just work.
Are you on a PC or a Mac?
 
I’m on an old pc/ laptop
 
Ok, not a problem. Just be aware that to connect to an AVR and the discrete channels you'll need to install FlexASIO. I would start with just L and R though, get the hang of it.
 
Oooh pc, im a mac man..sorry lot easier..it just worked with the cal file and instru from xtz
I’ve got an iPad Pro if that helps 👍🏻
 

The latest video from AVForums

TV Buying Guide - Which TV Is Best For You?
Subscribe to our YouTube channel
Back
Top Bottom