Jim,
Do you just cut it on the table saw? Can you share what glue you use to assemble the cabinet? Also - can you really "screw-in" the drivers? Feel free to take it to PM.
Thanks,
D
The mic's are fine, sometimes the calibration files are a bit suspect. As it is an analogue mic you can use a loopback cable to fix the timing and that should resolve the random start times. If you know the exact distance you can then set it in the REW measurement window timing offset to remove the time of flight distance from the measurements.
https://kimmosaunisto.net/Software/VituixCAD/VituixCAD_Measurement_REW.pdf
Yes, I use all the normal woodworking power tools... table saw and band saw. I cut the recess for the driver with a router+ circle jig. I make holes with a drill. The difference between foamboard and plywood is: (1) foamboard cuts very fast, so the feed rate can be much faster, (2) it is so light that what is normally a two-man operation can now just be a one man operation (3) there is very little dust (4) the risk of kick back is null (5) it is cheap.
For glue I use either tite-bond wood glue, or loctite power-grab. The tite-bond takes a long time to cure, longer than when used with wood, but it is nice to work with. The loctite power-grab is a caulk type adhesive sealant, it is the consistency of peanut butter, and it hardens up fast. I usually apply a small bead and then use a putty knife to smooth it into a thin flat layer.
Foam board will NOT hold a screw. To attach a driver, I use #6 a Phillips-head machine screws (a "bolt"), with a washer and nut on the back side. For a big woofer I would probably use a #8 fastener.
I had actually used loop back timing as reference using a physical cable (and not internal loop back in sound card) and still was getting these wierd results.I even did the sound card calibration for this loopback path. I also measured the distance between baffle and mic and adjusted it to be exactly 1 m and gave timing offset as 2.907 as mentioned in the instructions.
Till 50 degrees off axis measurement, i had no issues regarding the software automatically adjusting the starttime once i told to take loopback timing as reference.
I think, after 50 degrees, the software crashed multiple times and this might have caused issues with the loopback setting not being taken or something.. Next time i will be more careful and will monitor this..
I just heard this crossover (hopefully, at least something close to it) live in action on an hour long listening session on the single prototype speaker..
I have no words to explain... Beyond my wildest dreams about what this thing can achieve..
One thing is for sure.. I am not going back to small speakers again..
I have no words to explain... Beyond my wildest dreams about what this thing can achieve..
One thing is for sure.. I am not going back to small speakers again..
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Did you compare it to the version where the on axis was flat but there was the 500Hz off axis peak?
Hi hifijim,
could you be more specific, I have just searched for "tite-bond wood glue" and there are several with the term "wood glue" in the name?
Kindest regards,
M
could you be more specific, I have just searched for "tite-bond wood glue" and there are several with the term "wood glue" in the name?
Kindest regards,
M
The actual glue I use is Titebond III ultimate wood glue. I am sure that Titebond II would work just as well, as I have never been able to tell much difference between titebond II and III.
http://www.titebond.com/product/glues/e8d40b45-0ab3-49f7-8a9c-b53970f736af
http://www.titebond.com/product/glues/e8d40b45-0ab3-49f7-8a9c-b53970f736af
I didn't get time for that yesterday..
Most of the time yesterday I was just surprised and couldn't believe the sound I was hearing.
So I just ended up playing more songs than I ever played at a time, eager to hear how they sound like on this system..
(Maybe this is because I have never heard bigger speakers properly. My experience has been limited to 6inch woofer+1inch tweeter kind of speakers at home and random big speakers with bad sounding music at hifi shows)
There were some issues regarding gain settings and EQapo-to-sound card channel mapping with the first FIR filter. So I never really heard it properly.
Now I have solved above issues. So, by today or tomorrow, I will try to compare between the filter settings and report back..
I don't know how this sort of thing will work but here is a video of the above system playing at relatively low volume levels (Captured on my not so good mobile phone. Hence it sounds nowhere near it sounds in person but maybe able to get some sort of idea).
Please note the the woofer and tweeter may not be level matched. In short the highs could be hotter than they should be.
I have to measure and adjust this and refine the setup further. Filters are the FIR ones above..
Here is one more:
Oh.. And I think I am playing 128kbps or so MP3 file..
Please note the the woofer and tweeter may not be level matched. In short the highs could be hotter than they should be.
I have to measure and adjust this and refine the setup further. Filters are the FIR ones above..
Here is one more:
Oh.. And I think I am playing 128kbps or so MP3 file..
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Big speakers are so much fun! No comparison to small ones even if they were higher fidelity, and when you get some fidelity on the big ones.....
I have no words to explain... Beyond my wildest dreams about what this thing can achieve..
One thing is for sure.. I am not going back to small speakers again..
SPL capability and wide bandwidth goes long way, anything sounds better by just turning it louder and when one can turn system up until not comfortable anymore but it still sounds good without problems peak goodness is achieved and system SPL capability is enough. At comfortable loud listening level jaw drops
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Exactly..Big speakers are so much fun! No comparison to small ones even if they were higher fidelity, and when you get some fidelity on the big ones..
You've summarized the feeling better than I ever could do..
Exactly..
You've summarized the feeling better than I ever could do..
Hi Vineeth- Ooh you know you gotten the bug bad when you’re building speakers with dual 12” woofers in the kitchen…
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Wow..
Now you've also given me ideas about how I could easily do some measurements once my twin Satori boxes arrive..
With whatever little time I got yesterday, I tried the following IIR-based crossover on the speaker. I also level matched the system my measuring and adjusting the amplifier gains. There was around 4dB difference between levels of the two drivers around the crossover point region.
Technically it is still FIR crossover in implementation but the target transfer functions are generated using IIR filter targets...
I have also included a 150uF capacitor in the tweeter branch to protect it from DC but it does not affect the below transfer functions much and is not shown in diagram.
Shown as overlays in the Power & DI plot are the results from previous FIR-filter based implementation posted above.
It looks similar I think. But to my ears, it felt like a lot of difference.
Hearing impressions-wise, suddenly it seem much more enjoyable..
Earlier I felt it was a bit hot in the highs and vocals-region and details were being thrown to face but but now the balance seems like it has fallen into place, sort of and system seems more effortless to the ears.. Again all this might be due to 'N' number of factors and I am certainly not going to say pointless statements like 'IIR filter slopes-based crossovers are better than FIR slopes with perfectly flat ON-axis' etc.
In fact I have no motivation to change from this crossover at least immediately so that I can find its weaknesses and learn from it before trying a next one..
From the system point of view, the compression driver is awesome, I think.. I should say that I am hearing little nuances in songs that I never heard before.. I can hardly turn up the volume control on it before I go uncomfortably loud. There is a little bit of audible 'hiss' if I put my ears into the horn mouth even when nothing is playing. Maybe the amplifier noise is on the higher side compared to the best? (I am using this cheap amp for driving the CD: https://www.allo.com/sparky/volt-plus-amp.html )
Will try more things and post impressions..
Technically it is still FIR crossover in implementation but the target transfer functions are generated using IIR filter targets...
I have also included a 150uF capacitor in the tweeter branch to protect it from DC but it does not affect the below transfer functions much and is not shown in diagram.
Shown as overlays in the Power & DI plot are the results from previous FIR-filter based implementation posted above.
It looks similar I think. But to my ears, it felt like a lot of difference.
Hearing impressions-wise, suddenly it seem much more enjoyable..
Earlier I felt it was a bit hot in the highs and vocals-region and details were being thrown to face but but now the balance seems like it has fallen into place, sort of and system seems more effortless to the ears.. Again all this might be due to 'N' number of factors and I am certainly not going to say pointless statements like 'IIR filter slopes-based crossovers are better than FIR slopes with perfectly flat ON-axis' etc.
In fact I have no motivation to change from this crossover at least immediately so that I can find its weaknesses and learn from it before trying a next one..
From the system point of view, the compression driver is awesome, I think.. I should say that I am hearing little nuances in songs that I never heard before..
I can hardly turn up the volume control on it before I go uncomfortably loud. There is a little bit of audible 'hiss' if I put my ears into the horn mouth even when nothing is playing. Maybe the amplifier noise is on the higher side compared to the best? (I am using this cheap amp for driving the CD: https://www.allo.com/sparky/volt-plus-amp.html )Will try more things and post impressions..
For sure the comparison is not a fair one between an FIR crossover and an IIR one. Using the Vituix Gf function to create a completely flat on axis is somewhat fraught with danger.Again all this might be due to 'N' number of factors and I am certainly not going to say pointless statements like 'IIR filter slopes-based crossovers are better than FIR slopes with perfectly flat ON-axis' etc.
A better option would be to replace the IIR crossover with an FIR one and leave the rest alone. Even that may not be fair as there may be phase changes that affect the magnitude and need to be compensated.
Thanks fluid.. I will definitely try along these lines once I am back home..
For the next one week, I will be traveling.