The Behringer is a good starting point. If you need it cheaper - buy a Panasonic WM61 capsule ( there is a guy from the UK that sells some for 5 pounds per pair on ebay.co.uk ), follow the steps described on Linkwitz`s website on how to construct your own mic and do it 
Will cost you about 20 euro to build. Then you must calibrate it. When done it should have better results than the Behringer and will be cheaper.
Will cost you about 20 euro to build. Then you must calibrate it. When done it should have better results than the Behringer and will be cheaper.You don't need to calibrate either of these microphones for what you're worried about, so don't let that slow you down. I calibrated my Panasonic mic against my B&K measurement mic and it just rolled off slightly at low and high frequencies. You're not trying to do exacting research - just to get an idea what your speakers do and what's going on in your room and an uncalibrated mic will be fine.
May be a good point
It was 12db/18db, right
Thats "usually" used when drivers are NOT physically phase alligned
I seem to remember your tweeter is sort of waveguide mounted
Thus its physically phase alligned, therefore...
Just a single component can do pretty strange things
Soundstage, I dont know if talk about the same
What I hate most is when parts of a person or instrument is moving with frequency or in the wrong place, or in several places at one time
Or when some space/air creating sound effects seem to come from one side only
It ruins any illusion, and very annoying
Always seem to be xover and phase related
It can literally move sounds from on side/channel to the other, pretty strange stuff really
Focus on what happens in the stopband, beyond the xo points
It also appears that whn this is sorted, the rest comes by itself, almost
To me its the most difficult aspect of xovers, and speaker design
It was 12db/18db, right
Thats "usually" used when drivers are NOT physically phase alligned
I seem to remember your tweeter is sort of waveguide mounted
Thus its physically phase alligned, therefore...
Just a single component can do pretty strange things
Soundstage, I dont know if talk about the same
What I hate most is when parts of a person or instrument is moving with frequency or in the wrong place, or in several places at one time
Or when some space/air creating sound effects seem to come from one side only
It ruins any illusion, and very annoying
Always seem to be xover and phase related
It can literally move sounds from on side/channel to the other, pretty strange stuff really
Focus on what happens in the stopband, beyond the xo points
It also appears that whn this is sorted, the rest comes by itself, almost
To me its the most difficult aspect of xovers, and speaker design
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I've been reading Toole's book and trying to apply that to situations like these to help myself learn the material in a practical way. I couldn't remember this one, so I went back and looked for some information. From Toole's book, p174, talking about perception of distance:
"It is a complicated process, relying a little (very little) on sound level, a lot on a running comparison between the direct sound and early reflections, and a lot on information about the environment and past experiences with familiar sounds. For example, a shouted voice is automatically assumed to be farther away than a conversational or whispered voice, irrespective of sound level... Distance perception is another perceptual dimension with a cognitive component; it is not simply a mechanistic process... Inevitably, there will be a superposition of all these sounds, meaning that each of the recorded direct and reflected sounds will have a set of accompanying reflections associated with the listening room."
And then, to summarize, he says we really don't understand the psychoacoustics behind distance perception fully yet and more research is needed, but that the way the recording is made will determine the perception of distance to a large degree.
However, if the reflections play a role, I'd think you'd want symmetric reflections, and it sounds like your setup is asymmetric? If so, I'd try a setup that's symmetric to the side walls first, and then maybe try rotating your setup and positioning the speakers equidistant from the sidewalls and your listening position away from the rear wall. I've done extreme near field listening before (a stereo triangle around 2 feet on a side) and gotten good distance perception, so it could be a small setup if necessary.
"It is a complicated process, relying a little (very little) on sound level, a lot on a running comparison between the direct sound and early reflections, and a lot on information about the environment and past experiences with familiar sounds. For example, a shouted voice is automatically assumed to be farther away than a conversational or whispered voice, irrespective of sound level... Distance perception is another perceptual dimension with a cognitive component; it is not simply a mechanistic process... Inevitably, there will be a superposition of all these sounds, meaning that each of the recorded direct and reflected sounds will have a set of accompanying reflections associated with the listening room."
And then, to summarize, he says we really don't understand the psychoacoustics behind distance perception fully yet and more research is needed, but that the way the recording is made will determine the perception of distance to a large degree.
However, if the reflections play a role, I'd think you'd want symmetric reflections, and it sounds like your setup is asymmetric? If so, I'd try a setup that's symmetric to the side walls first, and then maybe try rotating your setup and positioning the speakers equidistant from the sidewalls and your listening position away from the rear wall. I've done extreme near field listening before (a stereo triangle around 2 feet on a side) and gotten good distance perception, so it could be a small setup if necessary.
Morning all.
So:
1. After bringing the speakers as far into the room as possible (800mm from front of cabs to rear wall-apparently we still need to walk through the lounge to get to the kitchen-pfft ).
2. Bringing the back of the chair 300/500mm from the rear wall
3. Reversing the polarity of all drivers at the back of the amp
With these changes I suspect i may have moved into a nearfield position and have gained considerable improvements in focus and depth, although bass has lost some oomph.
Rather than being an overwhelming success in any particular regard I have managed to at least make a solid start on defining the relationship and limitations of these units in this room.
I am unable at this point to create a symmetrical boundary environment without moving rooms of which there are non spare
I have also decided to invest in a mic (probably the Panasonic WM61 capsule) and start a process of elimination. It seems that I will be able to create much more repeatable changes once I am dealing with a flatish freq response and correctly phase aligned driver outputs.
Can I get a few suggestions for measurement software. I have downloaded the latest version of ARTA out of interest, will that work with my old SB16 and the Pana mic or will I need other gear?
Cheers all
Dean
So:
1. After bringing the speakers as far into the room as possible (800mm from front of cabs to rear wall-apparently we still need to walk through the lounge to get to the kitchen-pfft ).
2. Bringing the back of the chair 300/500mm from the rear wall
3. Reversing the polarity of all drivers at the back of the amp
With these changes I suspect i may have moved into a nearfield position and have gained considerable improvements in focus and depth, although bass has lost some oomph.
Rather than being an overwhelming success in any particular regard I have managed to at least make a solid start on defining the relationship and limitations of these units in this room.
I am unable at this point to create a symmetrical boundary environment without moving rooms of which there are non spare
I have also decided to invest in a mic (probably the Panasonic WM61 capsule) and start a process of elimination. It seems that I will be able to create much more repeatable changes once I am dealing with a flatish freq response and correctly phase aligned driver outputs.
Can I get a few suggestions for measurement software. I have downloaded the latest version of ARTA out of interest, will that work with my old SB16 and the Pana mic or will I need other gear?
Cheers all
Dean
Software: HOLM Acoustics
See the threads on diyaudio that are linked on that page for some back ground / explanation how to use it.
See the threads on diyaudio that are linked on that page for some back ground / explanation how to use it.
The XT25 apparently struggles below 2k without a 24dB acoustic filter, since I am running it at 1700hz (the best freq I have yet tried for smooth hi/mid integration) changing that could be a problem.. Actually, would it be considered a symmetrical network since both slopes = roughly 24 acoustical?
I use speaker workshop - that's also free, but some people have trouble getting it going. I've been using it for ~10 years though, so I don't have many problems. It can also measure impedance and simulate passive crossovers using your measured response and impedance (impedance measurement tends to give some people fits setting up as well). I've played with Holmimpulse and thought it looked pretty easy, and Earl Geddes really likes it. I've never used ARTA. I took a look at it and it seems you can't save files without buying it for 79E. Of course you could take a screen shot, but my preferred method is to measure response, change something, remeasure and overlay the two responses to see the differences easily. I can do that just fine with my free programs.
As I said I haven't been able to measure anything at this point, so will leave things electrically as they are until I get a mic and do some measurement.
I have had more success today with adjusting the distance between speakers and toe in and am talking my better half into some discreet absorption panels "hidden" around the room. Wish me luck!!
Dean
I have had more success today with adjusting the distance between speakers and toe in and am talking my better half into some discreet absorption panels "hidden" around the room. Wish me luck!!
Dean
WM61B is described as a replacement for the original WM61. Here is a link to the guy I bought my capsules - eBay My World - wittonwilly
I bought them a few days ago and I have not received them yet, but this is a cheap item so he should be fine. If by a chance you have a mixer - it may have inbuilt mic preamps, so it will be easier. I can supply a schematics for a balanced input, it is simple and cheaper
I bought them a few days ago and I have not received them yet, but this is a cheap item so he should be fine. If by a chance you have a mixer - it may have inbuilt mic preamps, so it will be easier. I can supply a schematics for a balanced input, it is simple and cheaper
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