Brian, I actully spent $1.50 at JoAnn for the felt, so I'm good there... and, busted on the inductors, since it was from my local surplus guy. Recommendations on GOOD inductors, since I didn't see any on eBay... this is just an area out of my league.
So, felt and poly-fil, felt without poly-fil, poly-fil without felt?
So, felt and poly-fil, felt without poly-fil, poly-fil without felt?
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I believe the felt is a good idea. I've built speakers before with mostly poly-fil and this time I used only felt and I thought the only felt was much better at controlling reflections off the back wall of the cabinet.
OK, pics... the cocobolo isn't nearly as dark in person. And, my filter parts...
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An externally hosted image should be here but it was not working when we last tested it.
Finished - would still like input on poly-fil:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
With about 20 hours on them, the imaginig is pretty good (placement is critical), but they are still just a bit 'honky' on hard rock, really sweet on Alison Krause, and all over the mid range (guitar, piano, banjo, vocals). Mayhaps a bit tinny on top. Some of this may be the tube amp, or the cheap DVD source (may have to try this with the Ayon CD-1), but I'm pretty sure the speakers need some adjustment.
Afraid the felt is insufficient - can some Poly-fil help? Will the filter help? Really close, but tweaking is what DIY is all about.
Afraid the felt is insufficient - can some Poly-fil help? Will the filter help? Really close, but tweaking is what DIY is all about.
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Hard rock and 2" drivers are a challenge, I have not found them large enough for this kind of music. The top end has been good in my case, based on use of SET with Magnum Dynalab FM tuner and a good channel. Have had good results with Dual turntable although cartridge was a bit too rolled-off on the top end compared with the tuner for my taste. Have had mixed results with CD player, seems the usual problem that most recordings are poor unless I am very selective.
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Some things are great - Beck 'Sea Change' and RadioHead 'OK Computer', and 'Sticky Fingers' is quite enjoyable. Tool (my challenge material) is, of course, less so.
Mayhaps thicker foam / felt? That they warrant the effort speaks volumes. Plenty of 'air', detail, and proper instrument / vocal placement. Guitars (my true focal point) are really quite nice.
Mayhaps thicker foam / felt? That they warrant the effort speaks volumes. Plenty of 'air', detail, and proper instrument / vocal placement. Guitars (my true focal point) are really quite nice.
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I will be watching with interest - I've not put mine through as varied selection of music as you have. In addition to lining with felt - I lined everything with felt, including the internal brace, everything. I also 'threw in' the few left over pieces of felt into the box before I screwed in the driver so I do have a little volume stuffing in there but not much.
Ok, bought some real inductors (mil parts), so my specs are 8.2r, 10w / 4.7uF / .375uH. Is the correct layout for the parts?
If so, then just between the positive terminal and speaker lead?
Finally, what is the intended impact (what spectrum is impacted)?
If so, then just between the positive terminal and speaker lead?
Finally, what is the intended impact (what spectrum is impacted)?
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with my onken speakers using fostex drivers I ended up putting the inductor in series between the speaker lead and positive terminal just as you suggest. It works fine.
But with my tube amp, the Martello doesn't need anything to help it. I'm beginning to think that Full Range are better with amplifiers that don't have aggressive damping factors.
But with my tube amp, the Martello doesn't need anything to help it. I'm beginning to think that Full Range are better with amplifiers that don't have aggressive damping factors.
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Looks good!
I suggest you dry fit all the parts to ensure they're all sized properly. The holey brace is one to be careful with - the chances that it's just the right size to butt up against the back of the drivers when they are screwed in (and using a gasket) is low - you will likely want to ajust it. I preferred to undersize the brace a little so there was a gap between it and the driver magnet and then use some padding to fill the gap and provide a tight fit up to the back of the driver.
Also be careful with cut outs for the driver, you need to shape it to allow the driver to fit through with the connecting lugs - which stick out a fair bit. But don't oversize the opening or you won't get an air-tight seal once the driver is installed. Dry fit the drivers and shape things by hand is how I would do it as I'm likely to mess it up easily !
I suggest you dry fit all the parts to ensure they're all sized properly. The holey brace is one to be careful with - the chances that it's just the right size to butt up against the back of the drivers when they are screwed in (and using a gasket) is low - you will likely want to ajust it. I preferred to undersize the brace a little so there was a gap between it and the driver magnet and then use some padding to fill the gap and provide a tight fit up to the back of the driver.
Also be careful with cut outs for the driver, you need to shape it to allow the driver to fit through with the connecting lugs - which stick out a fair bit. But don't oversize the opening or you won't get an air-tight seal once the driver is installed. Dry fit the drivers and shape things by hand is how I would do it as I'm likely to mess it up easily !
I been talking to Bigun in PM's about my own build of 5 pieces of this speaker set. These drivers/enclosure designs sound incredible on my 807 Pentode amp. I dont even feel that it needs the notch filter that people have been designing on this thread at all. Another extremely interesting thing is for such little guys they put out a ton of bass. They are putting my sub to shame. I have difficulty seeing any difference between my current sub turned on and off when it comes to sounds. I don't care for 'boomy' bass i only care about the sound... and these provide!
Probably more so means i need to upgrade my sub now... 95 hz free air resonance of these guys means i should probably go after the 30-120 hz zone and play around with LFE crossover between 95 and 120
Probably more so means i need to upgrade my sub now... 95 hz free air resonance of these guys means i should probably go after the 30-120 hz zone and play around with LFE crossover between 95 and 120