I picked up a 1.5mm HVLP spray gun today Neiko 1.5mm HVLP Air Spray Gun - Gun Metal Finish - Amazon.com
Only $40, seemed a bit nicer than the $17 harbor freight model (which plenty of people have had good results with, but hopefully the Neiko will be a bit better in some respect, it comes with the regulator, and a metal cup, for example).
I also dropped $14 on a 50 pack of paint filters to strain the medium (may not be entirely necessary in this case, but we shall see.)
I'll practice spraying a bit on cardboard, and the small test scrap that I dyed, pictured on a prior page, but don't expect a huge learning curve as I've sprayed plenty with an airbrush in the past.
I also picked up a quart of Zinsser Bulls Eye Sealcoat. While sold as a sanding sealer, this is just blonde dewaxed shellac in a ready-to-spray 2 pound cut. Because it's dewaxed, it should dry fairly hard. The key with shellac seems to be to avoid excessive orange peel. This product will dry fast and non-toxic. (Use respirator during application of course, but no hazmat suit required unlike lacquer.)
I plan on very thin coats as with any finish for best results. Probably wait for a dry day and do it in the shade rather than a sunny spot so that the alcohol solvent won't evaporate excessively fast.
At a much later time I'll decide if I want to add something over the shellac, such as one of General Finishes' products, but don't anticipate it being necessary.
Only $40, seemed a bit nicer than the $17 harbor freight model (which plenty of people have had good results with, but hopefully the Neiko will be a bit better in some respect, it comes with the regulator, and a metal cup, for example).
I also dropped $14 on a 50 pack of paint filters to strain the medium (may not be entirely necessary in this case, but we shall see.)
I'll practice spraying a bit on cardboard, and the small test scrap that I dyed, pictured on a prior page, but don't expect a huge learning curve as I've sprayed plenty with an airbrush in the past.
I also picked up a quart of Zinsser Bulls Eye Sealcoat. While sold as a sanding sealer, this is just blonde dewaxed shellac in a ready-to-spray 2 pound cut. Because it's dewaxed, it should dry fairly hard. The key with shellac seems to be to avoid excessive orange peel. This product will dry fast and non-toxic. (Use respirator during application of course, but no hazmat suit required unlike lacquer.)
I plan on very thin coats as with any finish for best results. Probably wait for a dry day and do it in the shade rather than a sunny spot so that the alcohol solvent won't evaporate excessively fast.
At a much later time I'll decide if I want to add something over the shellac, such as one of General Finishes' products, but don't anticipate it being necessary.
I saw those and thought I could get away without one as my compressor has no tank and the humidity is pretty low here. But, based on your good prompting, I went ahead and bought Neiko Tools Water and Oil Separator for Air HVLP Spray Gun - Amazon.com
I am looking forward to posting photos of the finished center channel. Waiting for the weather to improve again (having a rainy spell).
After that, I'll say a few words (or more than a few, possibly) about how it sounds (to me) after appropriate break in.
Progress update on the finishing. We had a little nice weather so I've been practicing with the spray gun on boxes and plywood, etc.
I found that the shellac will have wavy, stringy lap marks if too much material is applied. The way to avoid that is to tighten the flow knob of the spray gun down all the way (clockwise) and then loosen it just a little bit (maybe 3-4 turns) so the gun lays down material very lightly. Also helps to hold the gun maybe a foot away from the surface, rather than too close, which seems to cause the material to pool slightly.
Before I identified both of those key issues, I sprayed the small dyed test scrap I had made up and the dye ran all over toward the edges and made strange designs, making a mess of the piece.
I have a good feeling about it now though, and will make sure to spray very little shellac on the first and second coats in particular. I'll start with the removable back panel, of course.
One other thing, this stuff must be sprayed on a horizontal surface only, runs down like crazy on anything vertical, not even an option.
I found that the shellac will have wavy, stringy lap marks if too much material is applied. The way to avoid that is to tighten the flow knob of the spray gun down all the way (clockwise) and then loosen it just a little bit (maybe 3-4 turns) so the gun lays down material very lightly. Also helps to hold the gun maybe a foot away from the surface, rather than too close, which seems to cause the material to pool slightly.
Before I identified both of those key issues, I sprayed the small dyed test scrap I had made up and the dye ran all over toward the edges and made strange designs, making a mess of the piece.
I have a good feeling about it now though, and will make sure to spray very little shellac on the first and second coats in particular. I'll start with the removable back panel, of course.
One other thing, this stuff must be sprayed on a horizontal surface only, runs down like crazy on anything vertical, not even an option.
Quick update: Delayed on this project due to family health crisis. Now that that's more stable, I'm back at it.
The shellac went on nicely with the HVLP, much to my relief. The key as mentioned above was to use very little material and super fast, light strokes with minimal overlap on a horizontal level surface only. I did four light coats this way. Satisfied.
The dye job could be more even, but with a spliced veneer with different absorbency characteristics going on across the surface, not bad.
Now that the finish is done, I'll be using a black marker around the driver cutout to eliminate the eyesore of a tan ply sliver visible around the driver, and then mounting the driver, the binding posts, and, finally, showing you all some final photos of this long awaited center channel! I think you all will enjoy how unique this looks.
The shellac went on nicely with the HVLP, much to my relief. The key as mentioned above was to use very little material and super fast, light strokes with minimal overlap on a horizontal level surface only. I did four light coats this way. Satisfied.
The dye job could be more even, but with a spliced veneer with different absorbency characteristics going on across the surface, not bad.
Now that the finish is done, I'll be using a black marker around the driver cutout to eliminate the eyesore of a tan ply sliver visible around the driver, and then mounting the driver, the binding posts, and, finally, showing you all some final photos of this long awaited center channel! I think you all will enjoy how unique this looks.
Thanks for your encouragement, fellows.
Here's a small update:
Crimped gold-plated .25 and .187 fastons to the hookup wire, the driver and binding post ends, respectively:
Connected wire to driver, some effort required to slip .25 faston on, good sign. Also shows mounting hardware chosen, blackened 8-32 socket cap screws and 8-32 tee nuts:
Back of mounted driver. It was tedious to get the gap even around the driver. Folded paper wedges helped. You can see how snugly the driver magnet fits against the holey brace. Overtightening was a concern as we don't want to distort the driver basket with too much torque. Also found that the notch in the tee nuts had to fit around one of the basket's ribs to fit, as the mounting holes are quite close to the basket frame on the driver:
Next, I'll drill holes in the back panel for the binding posts, secure the .187 fastons to those (plenty of wire length to later remove back if needed), screw the back panel on, and take some finished photos. Then, onward to break in.
Here's a small update:
Crimped gold-plated .25 and .187 fastons to the hookup wire, the driver and binding post ends, respectively:
Connected wire to driver, some effort required to slip .25 faston on, good sign. Also shows mounting hardware chosen, blackened 8-32 socket cap screws and 8-32 tee nuts:
Back of mounted driver. It was tedious to get the gap even around the driver. Folded paper wedges helped. You can see how snugly the driver magnet fits against the holey brace. Overtightening was a concern as we don't want to distort the driver basket with too much torque. Also found that the notch in the tee nuts had to fit around one of the basket's ribs to fit, as the mounting holes are quite close to the basket frame on the driver:
Next, I'll drill holes in the back panel for the binding posts, secure the .187 fastons to those (plenty of wire length to later remove back if needed), screw the back panel on, and take some finished photos. Then, onward to break in.
After listening to the completed center channel for a while, I can say that it is very good.
I previously used a commercially produced Dynaudio brand center channel (retail almost $1000 USD), and the Alpair based unit I built is noticeably clearer with better vocal articulation and intelligibility. The new CC definitely provides 'you are there' realism.
That said, I find dialog in some films to be sometimes unintelligible, but firmly believe that this is improved vs. the prior CC in place. For example, despite the accents used in the film, The Book Thief, the dialog was all understandable. Jason Statham probably could not be understood half the time on any system, anyway, as most lines are delivered under the breath and mumbled with a heavy brit accent -- the man needs to learn to enunciate, which is unfortunate as I do want to hear what he has to say -- oh well, I digress.
I listen to the Blu-Ray DTS-HD Master Audio track on almost all of the films I see, and I believe the new CC helps to discern between these and the occasional DVD track (Dolby Digital) that I watch -- it takes a pretty nice system to tell the difference and the Alpair can resolve that.
Associated system:
Amplifier: YAMAHA RX-V573
Cables : DIY 14AWG OFC with soldered gold plated bananas
Mains (for now): DIY Scan-Speak driver (D2905/930000 + 18W/8543-00) based two-way with Isobaric configuration a la Totem Mani-2, double hardwood/MDF sandwich cabinets, separate crossover enclosures
Subwoofer: B&W ASW2500
Surrounds: Atlantic Technology 254 SR
Projector: Acer H9500BD DLP, 1080p native
Screen: DIY 85" (might be 90", it's been a long time) 16:9 aspect, wooden frame wrapped in black cloth, stretched white "black out cloth" screen surface
I do notice that center channel routed dialog is clearer, that is, more intelligible with a finer, breathy type of resolution than voice (soundtrack songs, directional effects) routed to the mains, which shows hope that the overall system will improve yet again once the matching Alpair mains per the original post have been completed.
The B&W ASW2500 blends perfectly with the speakers, you would never be able to tell there is a separate woofer. This is not an overwhelming sub, but rather a musical, quick woofer, a good match for the Alpair. The Yamaha is configured with YPAO automated setup with the included microphone, and seems to set the crossover to the sub at 110 Hz for the center channel. I'm sure this CC could go lower, but I trust the electronics to determine the best crossover point for HT volumes.
That's my review for now. Happy listening, all.
I previously used a commercially produced Dynaudio brand center channel (retail almost $1000 USD), and the Alpair based unit I built is noticeably clearer with better vocal articulation and intelligibility. The new CC definitely provides 'you are there' realism.
That said, I find dialog in some films to be sometimes unintelligible, but firmly believe that this is improved vs. the prior CC in place. For example, despite the accents used in the film, The Book Thief, the dialog was all understandable. Jason Statham probably could not be understood half the time on any system, anyway, as most lines are delivered under the breath and mumbled with a heavy brit accent -- the man needs to learn to enunciate, which is unfortunate as I do want to hear what he has to say -- oh well, I digress.
I listen to the Blu-Ray DTS-HD Master Audio track on almost all of the films I see, and I believe the new CC helps to discern between these and the occasional DVD track (Dolby Digital) that I watch -- it takes a pretty nice system to tell the difference and the Alpair can resolve that.
Associated system:
Amplifier: YAMAHA RX-V573
Cables : DIY 14AWG OFC with soldered gold plated bananas
Mains (for now): DIY Scan-Speak driver (D2905/930000 + 18W/8543-00) based two-way with Isobaric configuration a la Totem Mani-2, double hardwood/MDF sandwich cabinets, separate crossover enclosures
Subwoofer: B&W ASW2500
Surrounds: Atlantic Technology 254 SR
Projector: Acer H9500BD DLP, 1080p native
Screen: DIY 85" (might be 90", it's been a long time) 16:9 aspect, wooden frame wrapped in black cloth, stretched white "black out cloth" screen surface
I do notice that center channel routed dialog is clearer, that is, more intelligible with a finer, breathy type of resolution than voice (soundtrack songs, directional effects) routed to the mains, which shows hope that the overall system will improve yet again once the matching Alpair mains per the original post have been completed.
The B&W ASW2500 blends perfectly with the speakers, you would never be able to tell there is a separate woofer. This is not an overwhelming sub, but rather a musical, quick woofer, a good match for the Alpair. The Yamaha is configured with YPAO automated setup with the included microphone, and seems to set the crossover to the sub at 110 Hz for the center channel. I'm sure this CC could go lower, but I trust the electronics to determine the best crossover point for HT volumes.
That's my review for now. Happy listening, all.
I'm still alive! Happy New Year all.
I finally took a measurement of the finished Alpair 10.2 center channel loudspeaker I built (described above).
I used REW with a radio shack SPL meter and a calibration file for it.
Please see attached.
The green line is close mic, the red line is 1 meter (room starts to cause chaos).
15 dB rise in the highs, is that normal for this driver....? Chris / Dave ?
I finally took a measurement of the finished Alpair 10.2 center channel loudspeaker I built (described above).
I used REW with a radio shack SPL meter and a calibration file for it.
Please see attached.
The green line is close mic, the red line is 1 meter (room starts to cause chaos).
15 dB rise in the highs, is that normal for this driver....? Chris / Dave ?
Attachments
Happy new year.
The frequency response of RadioShack SPL meters vary quite a lot and a generic calibration file probably doesn't help much. You would need to get the meter calibrated against a known reference, e.g. Cross·Spectrum Labs - Sound | Vibration | Engineering
There are better measurement mics out there, e.g. UMIK-1, EMM-6, etc.
RealTraps - Measuring Microphones
The frequency response of RadioShack SPL meters vary quite a lot and a generic calibration file probably doesn't help much. You would need to get the meter calibrated against a known reference, e.g. Cross·Spectrum Labs - Sound | Vibration | Engineering
There are better measurement mics out there, e.g. UMIK-1, EMM-6, etc.
RealTraps - Measuring Microphones
Thanks Pnix. I suspected that might be the case, so last night I ordered a Dayton Audio UMM-6 which was on sale at PE. Thanks for confirming it was not a waste of money.
Will update the measurements in a couple weeks.
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