A
AuralFission
Enthusiast
Fin.
Now here's where the fun begins. I had a gallon of high gloss, oil based polyurethane laying around and thought I'd experiment. I originally wanted to spray it on using the HVLP gun but after I shot a test piece, there's no way I'd want to do that again. It got on EVERYTHING and surface wasn't that smooth. The paint was a little messy and somethings got overspray on them. With poly, everything gets nasty. My arm hair was forever frozen in the overspray of polyurethane.
So out with the HVLP gun and in with the cheap, foam brushes. I did the test on the top surface of my speaker stands that have the same paint. I applied probably 6 coats at 2 coats a day. Of course applying poly with brushes leaves pretty extreme brush marks but because I built it up so much, I could wet sand it smooth pretty easily without sanding through the poly. By the way, it's advised to let the final coat of poly cure for at least a week.
Here are some pictures of my progress.
Here, I've done some wet sanding to smooth out the brush strokes with 600 grit.
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1000 grit.
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2000 grit.
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After sanding, I used some Maguiars Cutting Compound followed by a random non abrasive polish I had laying around. I have to stress that these products applied the way I applied them is not ideal, it's simply what I had laying around.
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Here's what 10 minutes of work looks like.
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And here's what about 20 minutes of work looks like. Again, if I had better products, I probably would not have needed to spend so much time on them.
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Here's a picture of a somewhat finished surface showing a reflection of my
TV. The result is an almost mirror like finish that feels like glass. I really like the end result. It's a lot of work but it's very rewarding. When I return from Utah, I will start on the enclosures!
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Thanks for the frequency response traces. I am waiting for Dennis Murphy's response. I hope he can make sense out of them.
Did you ever hear back from Dennis, @Swerd ?I take it Dennis never came back?
No I never did. Lately he's been very sick, was in the hospital for 2 months. I'll try getting back to him after he convalesces.Did you ever hear back from Dennis?
First question is, where were the speakers placed in the room? I would like to see you repeat those measurements with the speaker far from any room boundaries.Ok, so after a year or so of Storage i decided to pull them back out to see what i think now, so i connected them to my stereo amp in the living room With no dsp, filters or other stuff, just pure analogue sound.
I still think they sound somewhat dark and "enclosured" (does that make sense in English?) but definitive not bad, so i took a New set of measurements of one speaker only With the Umik1 placed at tweeter height one meter (3') in front of the speaker, measured Three times With the exact same graph, so here it is:
4m/s gating, 1/24 smoothing:
View attachment 29853
6m/s gating, 1/24 smoothing:
View attachment 29854
8m/s gating, 1/24 smoothing:
View attachment 29855
No gating, 1/24 smoothing:
View attachment 29857
And last, no gating and 1/6 smoothing:
View attachment 29856
To my brief experience a 1/6 smoothing tells me more about what i am hearing as it shows the bigger Picture.
As you can see, all but 4m/s gating have a dip in the 400hz region, which i believe is what make them sound dark combined With the high levels in bass, although it is not much more then recommended in housecurves from Dirac and others.
Since it is present in the 6m/s gating and up, but NOT in the 4m/s i suspect this dipis not room related, but actually gating related on the 4m/s. And therefore a real issue With the speakers.
Any ideas of what i can do to fix this? I dont believe they are designed like this...
Btw: the crossovers are working fine, With tweeters in opposite phase they have a significant dip centered at 2000hz.
BSC is baffle step compensation. It is the frequency at which a speaker transitions from being a half space monopole to an omnipole radiator. The narrower the front baffle the higher the transition frequency. Basically it requires a 6 db increase in output below the transition frequency.Stupid question; what is BSC?
The speaker was about 1' from the front wall, no side bounderies.