Also, you might want to consider flipping the cabinet sideways and doing vertical spin measurements as well. But since your model will be somewhat inaccurate anyhow, I don’t know if you want to get involved with this type of measurement. Verticals are very diffcult on a tall cabinet like this. I just got done setting up a tripod platform so that I could measure verticals on my current build, and it was a real challenge. Just be aware that your model will also suffer from a lack of accurate vertical information.
I can do it. I don’t think I will worry about vertical FRDs because these are just for watching TV shows. I am going to encourage my wife to Bluetooth music with her phone instead of playing candy crunch or whatever its called.
I thought you guys said that moving the mic. was a no no?
Can I do all measurements on tweeter axis?
You are correct. My bad. I was mixing up single verses dual channel procedures. Measure it all on the tweeter axis with your mic. Try to get the woofers high enough off the floor, at least 3 or 4 feet, so that you can obtain a reflection free measurement out to about 4 or 5ms or so.
I edited my post above to correct my boo-boo. Sorry about that.
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Are these the same height as your large flat screen and will flank it? They look somewhat deep. Will the TV be out from the wall a bit instead of hanging on it?
Guessing old school entertainment center, depth to hold old school tube TV?
Nope its even weirder than that
When I converted my garage into a sunken living room I put in a header and a six foot french style patio door, but rarely used it. So my wife came up with the idea of making a bump out for the TV to go into with small windows on each side. Sliding wood panels would cover the windows when watching TV or cover the TV during the day, when nobody watches TV. We have 42 inch soffits so that made it easy. I had to put two small headers above each window but it was worth the effort and it doesn’t look bad on the back of the house. So the alcove goes back about 9 inches then 45 angle about 9 inches for a total depth of 14. If you live in a house long enough you will have to fix it up at least twice.
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kitty stuffed animal FTW!
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TV Speakers.zip (246.1 KB) I think I did it right
Thanks, Clay. I loaded the data into VCAD and calculated the driver delay offsets (-12.2mm delay for the tweeter; +221.7mm delay for the woofers; 0mm delay for the midranges). I could not get a perfect SPL match of the “Mid 0 + Tweet 0” model to the actual T+M measurement, but I was able to solve the problem by using minimum phase data to calculate the -12.2mm offset. This should be close enough.
Still need the following:
- Dimensional cabinet drawing showing exact positions of all drivers and ports.
- Near Field (NF) midrange measurement.
- NF woofer measurement
- NF port measurement
These items are needed to set up the diffraction and merger models in VCAD.
221mm offset?
Yes. Woofers are mounted on the side panel. So this would be the total distance offset from the tweeter 1 meter on axis measurement position in front of the speaker. Seems reasonable.
TV HorV speakers.pdf (186.8 KB)
tvmidsnear.frd (24.5 KB)
tvwoofsnear.frd (24.2 KB)
tvwoofnear.frd (24.5 KB)
tvterminus.frd (24.7 KB)
If the woofs near and terminus near do not merge as expected that is ok because I am of the belief that they are 90 degrees out of phase at the tuning freq.
Thanks, Clay. That should give me enough information to build the model and start crunching the data. I’ll let you know how things go when I attempt to merge the NF woofer cone + NF woofer port data.
I thought that was the estimate for the Z axis - I get it now.