Allen's Listening Room

socfan12 said:
:roflmao: Hopefully this episode will pass quickly and in the end you'll have a brand new pair of Alexia's, too! :woot:

The plans for your room sound great! I hope to get some kind of wine credenza for my room, to house a few bottles, glasses, decanter and what not. Feel free to ask me any q's, but definitely talk to Jeff. He gave me great tips and ideas that really have worked out wonderfully!

Good luck on your journey! I'll be posting mine on this thread as things progress and look forward to seeing/hearing about yours Bob.
Click to expand...

Nice system.
 
Allen, I see power, and speaker cables, but don't see what is feeding that amp? Where are your other gears?
 
Bobvin said:
Allen, I see power, and speaker cables, but don't see what is feeding that amp? Where are your other gears?
Click to expand...

It's on the long wall. You can see one or two pics here:

I look forward to your room buildout, Bob!:woot:
 
So I finally took the wraps off the XTZ Analyzer Pro kit and did some test measurements. First, here's the kit if anyone is interested:

D7K_6298.JPGD7K_6301.JPGD7K_6302.JPGD7K_6304.JPGD7K_6305.JPG
2014_03_01 - wo TT Run 03.jpg


attachment.php



It comes in a nice carrying case, with everything foam padded for traveling:
attachment.php



Inside, you get requisite cables, microphone, USB sound card, and a little tripod to put the mic on!
attachment.php



You get this pretty cool looking keychain USB drive with the manual, but you have to download the software using the S/N from the kit.
attachment.php


attachment.php



I took a number of measurements. They have 3 tabs corresponding to 3 analyses they do. I focused only on one of them, called the Full Range analyses, where they graph frequency response and RT60 over that range. I did several measurements, and throwing out the extremes, this one looked to be like the average of my measurements:

attachment.php



What's interesting how close my room comes to how Stereophile measured the Alexias in Atkinson's room as well:
Walexfig07.jpg



I'm not sure if I'm comparing the right graph in Stereophile's measurements, so someone please correct me if I'm offbase here. But you can see in both graphs the bass being reinforced at around 25hz, only to dip around 45-50hz, the mid bass hump around 60-80hz, then another dip around 125-130hz, another one at 260-300hz, then fairly flat until a suckout at 4khz, and then about 6-8khz, the treble just drops off precipitously. I thought the two graphs really resembled each other remarkabley close given two totally different rooms.

I think the rise in response at the frequency extremes is due to non-linearities in the mic, so I am going to ignore them. I certainly don't hear that energy at either end.

In the time domain, my RT60 times (if these are accurate) doesn't seem too bad (if I'm reading the graph correctly). Definitely some work to do, but 300ms is a good place to start and I'm not too far off in some frequencies.

Anyway, lots to learn about this tool and using this analysis to tune the room. More to come.
 
Hi Allen,

I also have the XTZ Pro II room measuring system and included some measurements from it in my system profile (see signature).

Just a couple of comments on your measurements:

1. You appear to have selected anechoic measurement but your microphone is over 4m from the loudspeaker. The measurement will be heavily influenced by the room and therefore not really anechoic at all. Better to select ambient or raw at that measuring distance - which I assume to be your listening chair distance.
2. Your test signal is too low in amplitude. It looks like around 60dB SPL? To be more accurate you want to measure at a higher volume; typically at least 40dB above the noise floor of the room.

Cheers
Ralph
 
That's a great piece of equipment Allen. So how do you determine where you need work done, and is it through trial and error and re-analyzing that you come to find the best positioning of treatments?
 
Thanks Mike & Steve! This is fun stuff. But if you want to really see someone who knows what he's doing, check out Ralph's (kiwi_1282001) thread. Amazing journey.

Doug, one of the objectives is to get the red bars all lined up to be the same time. This way there's no overhang from any one frequency smearing the rest of the music. You would add acoustic treatments to help with that, be it absorption or diffusion. And of course, you generally want as flat a frequency response. Here again, acoustic treatments help, but you can also try (and should try first) moving speaker/listening positions to smooth things out, adding subs, using dsp, etc.

Ralph, thanks again for pointing out the errors. I hope to do another set of measurements later today/tonight.
 
Thanks Allen. That makes perfect sense. So can you leave the mike "open" and change things up on the fly allowing you to see the graph change as you do so?
 
dlb2 said:
Thanks Allen. That makes perfect sense. So can you leave the mike "open" and change things up on the fly allowing you to see the graph change as you do so?
Click to expand...

Hey Doug,

You can as there is a real-time room analyzer. But I'd think you want to use the point in time measurements and plan ahead instead as they seem more accurate to me.
 
rockitman said:
Fantastic job on the room Allen. Basement Man caves rule !
Click to expand...

Thanks, Christian. Still very much a work-in-progress: measurements, treatments, some other furnishings (a wine credenza), etc. A lot of work, but a lot of fun, too!:happy:
 
socfan12 said:
Thanks, Christian. Still very much a work-in-progress: measurements, treatments, some other furnishings (a wine credenza), etc. A lot of work, but a lot of fun, too!:happy:
Click to expand...


Well done, you can never have enough wine in the listening room....;)
 
TheSaint, first, welcome to AS!:hey: And thanks for looking at my thread.;)

Sorry I missed your post, Doug! But my system is sort of going through a metamorphosis right now, mostly due to accommodate an analog rig within current budget. Once the dust settles, I'll post the changes in my thread. And like you, Kev, I'm discovering the allure of tubes, a la Allnic.;)
 
You must log in or register to reply here.
Back
Top