on Sale - $55/pr (drivers & XO)

[mikejennens]

Re: on Sale - $55/pr (drivers & XO)

Maybe I missed something earlier, but you have no drivers in your cart.
Mike

[JustinL42]

Re: on Sale - $55/pr (drivers & XO)

I never get as much done as I want to.:-( I did manage to get the cabinets bondoed where it was needed then got it sanded down and got a coat of 50/50 titebond and water mix on. I'll have to try and get it sanded and ready to prime during the week. I also opened it up more behind the woofers with the dremmel. Wasn't satisfied with how closed in the woofer still looked with the roundover I got with the router. I miss listening to them already...

Btw saw on the product page for the woofer *** sale ends 2/28 Monday ***so grab em if your going to. Had my dad grab six as he wants a pair of the ntn for fronts and a pair of nano neos for surrounds.

JustinL42

[fastbike1]

Re: on Sale - $55/pr (drivers & XO)

Ok. Another one to try, although their stock level is unpredictable, is www.Erseaudio.com. I like their stuff, especially the coils, but they are often out of stock on the ones I want. :(

Trust me, I wouldn't be here if I hadn't already found the same parts on radioshack, ebay, a variety of random electronics stores online, fry's electronics, you name it. I searched for a good 45 minutes before giving up and posting here, and with as little electric knowledge as I have, I wouldn't know what could be used to improvise.

[fastbike1]

Re: on Sale - $55/pr (drivers & XO)

I use Jeff's WB&CD and get Fb 38.8 Hz for 0.55cu ft, 2x7 port. I'd recheck the numbers. The again, I'm not a fan of WinISD.

You need to pay attention to the port velocity. I get a 34m/s velocity w/ 2x7. That may be audible. I think the box looks pretty good w/ a 2.5 x8 port. Fb 45.4, 103dB w/ 30w. F3/F10 40/34. Port velocity 22 m/s.

I have a concern here. I plugged these numbers into WinISD and a .55 cubic foot box tuned to 39 hz requires a 2"D x 8.46" port length. Any idea why that is so? A 7.09" port length tunes to 42hz...

[XtremeRevolution]

Re: on Sale - $55/pr (drivers & XO)

Maybe I missed something earlier, but you have no drivers in your cart.
Mike

Already ordered those on Friday night, before I knew I needed crossovers that were more complex than a couple of caps.

I use Jeff's WB&CD and get Fb 38.8 Hz for 0.55cu ft, 2x7 port. I'd recheck the numbers. The again, I'm not a fan of WinISD.

You need to pay attention to the port velocity. I get a 34m/s velocity w/ 2x7. That may be audible. I think the box looks pretty good w/ a 2.5 x8 port. Fb 45.4, 103dB w/ 30w. F3/F10 40/34. Port veleocity 22 m/s.

WinISD was the first program I found. Are there any other free programs out there that are better?

[XtremeRevolution]

Re: on Sale - $55/pr (drivers & XO)

I'm getting a little bit of conflicting information here from another site I've posted this project on.

An XO causes an electrical, acoustical & physical discontinuity in the speaker. The telephone band is ~300-3k, this is well esablished by the telcos as the critical range for voice reproduction. 2-4k is where the ear is most sensitive.

So you want to keep the XO outside 300ish to 5k-ish.

The acoustic & physical issues are directly related to the length of a wavelength (ideally the centre-to-centre distance at XO is <1/2 wavelength). Electrical is, in general, related to the order of the XO, how extended the drivers are beyond the XO point, and how the reactive load of the XO affects the performance of the amplifier.

A typical 2-way puts the XO right in the 2-4k range, the worst possible place. 2-ways that can push the XOs higher than that -- say 5k+ -- could really be considered almost FR + a tweeter. The best of them use the 2md order roll-off of the (well-behaved) midbass as the LP, and a 1st or 2nd order on the tweeter. Midbasses that go this high are lucky to get down to 50-70 Hz and will never produce a truly authortitive bass. This is exactly the idea behind the scheme i suggested. Since the tweeter covers 2 octaves at most, we call it a helper tweeter.

If we flip the idea over, we use a mid-tweeter + helper woofer(s). This puts the XO low, where wavelengths are long (hence it is easy to keep drivers well within that 1/2 wavelength), near the top of the range of this type of system (200-400 Hz say), the drivers are well-behaved so one can get away with a low order XO (ideal place to use a 1st order series). Below that it gets less expensive to just use a plate amp (a pair of the NHT/Foster surplus ones Jack Hidley is selling off are $70).

With the rapidly growing number of really capable FRs available today, this latter approach becomes much easier.

Going back to your original idea, 1 or 2 3" per side, + 1 or 2 helper woofers will get you a better system. And many of these FRs usable as midtweeters, in the right box, will get into the 40s, essentially a true 9 octave FR, so one can just leave off the woofer and add it later (or not)

Can anyone comment on whether or not this will actually be an issue with my setup and why I couldn't just use the capacitors I listed earlier as high pass filters for the tweeter and allow the driver to run full range?

[ericJ]

Re: on Sale - $55/pr (drivers &amp; XO)

It's funny how many guys seemed to go with the rabbet joinery that I've used. You CAN build these with buut joints (or any other method you prefer), but you'd have to change the cut sheet (which is VERY tight - especially for the 0.28 cf boxes). Changing the box dims slightly wouldn't be a problem, just aim for the same volume (even THAT isn't horribly critical - PE's Dayton 0.25 cf cabs could make some nice looking Nano Neos, OR ntns in 0.50 cf). I don't even have a router, I use my dad's (it's his rabbet bit too, and I use his roundovers as well). I use particle board too (it's 1/2 to 1/3 the price of MDF), and you CAN cut the rabbets with a table saw as well (yup, my dad's), but THAT really ripped up the PB, whereas the routered ones are VERY clean.

Chris

I've never done any "rabbeting" before and I really like how the joints look with them. Thought I would give it a shot. I have left over MDF from my LWS build last month. I'll still need to pick up another handi panel to finish. Should leave me with enough for a Pico Neo build :D

[Herman Trivilino]

Re: on Sale - $55/pr (drivers &amp; XO)

Can anyone comment on whether or not this will actually be an issue with my setup and why I couldn't just use the capacitors I listed earlier as high pass filters for the tweeter and allow the driver to run full range?

I think that if you wanted to follow that advice, you'd have to use different drivers.

Your best bet is to instead follow the designer's instructions. He's already matched the crossover to these drivers. And tested them.

Also, since you need to get this build done quickly, have you considered buying pre-assembled cabinets?

[XtremeRevolution]

Re: on Sale - $55/pr (drivers &amp; XO)

I think that if you wanted to follow that advice, you'd have to use different drivers.

Your best bet is to instead follow the designer's instructions. He's already matched the crossover to these drivers. And tested them.

Also, since you need to get this build done quickly, have you considered buying pre-assembled cabinets?

That kinda defeats the purpose of DIY in my opinion. Part of the process is making my own cabinet. I'm actually going to some length to make this customized. You guys will see the surprises I have in plan when I get these done.

[Chris Roemer]

Re: on Sale - $55/pr (drivers &amp; XO)

I have a concern here. I plugged these numbers into WinISD and a .55 cubic foot box tuned to 39 hz requires a 2"D x 8.46" port length. Any idea why that is so? A 7.09" port length tunes to 42hz...

There's nothing wrong with WisISD. I use both the "beta" (easier) version, and the "Pro" (alpha) version.

Don't use PE's T/S numbers. They have two conflicting sets between their catalog and their website. Use MY T/S numbers. I've measured 10 of the ND105-4 woofers already with my Woofer Tester.

Qes: 0.523
Qms: 7.10
Qts: 0.487
Vas: 0.12 (cu.ft.)
Fs: 62
Re: 4.0
Le: 0.79
SPL: 84
Pe: 30
Dd: 3.20 (in)
Sd: 8.04 (sq.in.)
Xmax: 6mm

The Dayton 3.5", 4", and 5.25" ND woofers, all have a published Xmax of 4mm, and an Xlim of 10mm (mechanical limit before they "bottom out").

If you use an Xmax in WinISD of 6mm, and let the excursion approach 8mm in worst case scenarios, you'll get a good practical model.

Chris

[Chris Roemer]

Re: on Sale - $55/pr (drivers &amp; XO)

Already ordered those on Friday night, before I knew I needed crossovers that were more complex than a couple of caps.

I looked at your cap links, and I THINK (IIRC) that they were approx. 0.6uF and 0.1uF caps. These are really not in the typical range of caps used in XO work. 6uF and 10uF caps would be useful.

[Chris Roemer]

Re: on Sale - $55/pr (drivers &amp; XO)

I'm getting a little bit of conflicting information here from another site I've posted this project on.



Can anyone comment on whether or not this will actually be an issue with my setup and why I couldn't just use the capacitors I listed earlier as high pass filters for the tweeter and allow the driver to run full range?

Yeah, I'll make a comment.

THAT little blob is absolute garbage. Don't go to that site anymore.

It takes easily over 100 hours of study (and I'm talkin' GOOD source material, not any old internet garbage that's out there) to get a grasp on proper speaker design. 1000 hrs to get competant at it. The best book out there right now is "Speakerbuilding 201". Reading that will give you a good start.

Speaker systems that ran woofers "full range" (like the "Smaller ADVENT Loudspeaker" from the 1970's) used a woofer specifically designed to "roll off" on its own near the point where the tweeter took over. ADVENT used a "fried egg" tweeter that crossed down near 1000 Hz on a LOT of their original designs. The ND105-4's DO have output above 3-4k, but you don't want to hear that. Also, almost NO tweeters can just use a single cap for a crossover. Today, most systems that use a cap on a tweeter and run a woofer full range, are carp.

Chris

[XtremeRevolution]

Re: on Sale - $55/pr (drivers &amp; XO)

Yeah, I'll make a comment.

THAT little blob is absolute garbage. Don't go to that site anymore.

It takes easily over 100 hours of study (and I'm talkin' GOOD source material, not any old internet garbage that's out there) to get a grasp on proper speaker design. 1000 hrs to get competant at it. The best book out there right now is "Speakerbuilding 201". Reading that will give you a good start.

Speaker systems that ran woofers "full range" (like the "Smaller ADVENT Loudspeaker" from the 1970's) used a woofer specifically designed to "roll off" on its own near the point where the tweeter took over. ADVENT used a "fried egg" tweeter that crossed down near 1000 Hz on a LOT of their original designs. The ND105-4's DO have output above 3-4k, but you don't want to hear that. Also, almost NO tweeters can just use a single cap for a crossover. Today, most systems that use a cap on a tweeter and run a woofer full range, are carp.

Chris

Excellent. I will need some help with figuring out what that diagram means for the crossover, but past that I think we'll be alright here! I do think my father in law will enjoy these speakers a lot. I figured after a lot of stress fighting his lung cancer (even having one lung removed), a gift like this would be appropriate.

In other news, I'm going to run an interesting little project.

2 of these:

http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=290-206

1 of these:

http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=310-300

Going to try to make "cute" full range satellites in sealed boxes. My wife will be designing the enclosures and selling them on etsy. I'll make sure to post some pictures of these when I'm done. Should make for some excellent little drivers for MP3 players and the like.

[Chris Roemer]

Re: on Sale - $55/pr (drivers &amp; XO)

[QUOTE=XtremeRevolution;1716275]

I thought I already had the I-core coil in my cart?

Anyways, here's an updated cart:


Your Shopping Cart
Item Qty. Price Total Remove
Dayton DNR-2.0 2 Ohm 10W Precision Audio Grade Resistor
Part Number: 004-2
In Stock
$1.25 $2.50
Dayton DNR-20 20 Ohm 10W Precision Audio Grade Resistor
Part Number: 004-20
In Stock
$1.25 $2.50
4 Ohm 10W Resistor
Part Number: 016-4
In Stock
$0.44 $0.88
2.2uF 100V Non-Polarized Capacitor
Part Number: 027-324
In Stock
$0.35 $0.70
6.8uF 100V Non-Polarized Capacitor
Part Number: 027-336
In Stock
$0.56 $1.12
2.0mH 18 AWG I Core Inductor
Part Number: 266-554
In Stock
$7.87 $15.74
Dayton Audio DMPC-5.6 5.6uF 250V Polypropylene Capacitor
Part Number: 027-425
In Stock
$2.63 $5.26
Jantzen 0.25mH 20 AWG Air Core Inductor
Part Number: 255-026
In Stock
$3.70 $7.40
45 Day No Hassle Return Policy Order Subtotal: $36.10


Anyone have any suggestions before I pull the trigger?

Sorry, you DID have the proper I-core 2mH coil. I didn't have part numbers in front of me, and didn't look up the one you listed. When you said "18 gauge", I thought you were talking about one of two #18 air cores that PE carries.

[XtremeRevolution]

Re: on Sale - $55/pr (drivers &amp; XO)

There's nothing wrong with WisISD. I use both the "beta" (easier) version, and the "Pro" (alpha) version.

Don't use PE's T/S numbers. They have two conflicting sets between their catalog and their website. Use MY T/S numbers. I've measured 10 of the ND105-4 woofers already with my Woofer Tester.

Qes: 0.523
Qms: 7.10
Qts: 0.487
Vas: 0.12 (cu.ft.)
Fs: 62
Re: 4.0
Le: 0.79
SPL: 84
Pe: 30
Dd: 3.20 (in)
Sd: 8.04 (sq.in.)
Xmax: 6mm

The Dayton 3.5", 4", and 5.25" ND woofers, all have a published Xmax of 4mm, and an Xlim of 10mm (mechanical limit before they "bottom out").

If you use an Xmax in WinISD of 6mm, and let the excursion approach 8mm in worst case scenarios, you'll get a good practical model.

Chris

My cabinet choice: 28"h x 6"w x 9.5"d. 0.55 cf
A 2"d x 7" long rear vent centered 10" up from the bottom tunes this box to 39 Hz yielding an F3 of 38. I'd mount the upper woofer's center 4" down from the box top. This puts the tweeter at about 21", so theese should sound best on about 12" high stands.

Are the above dimensions internal or external with 3/4" board? I have lots of 3/4" MDF lying around from previous subwoofer box builds; would this be suitable?

Thanks.