(please see my NN/ntn album for the latest crossovers)
The ND105-4s are on sale for a couple months (probably) at $14.90 a pop, not $12 like last year, but still a great value. It's fine to read this earlier historical thread, and to look at the pictures, but for the latest crossover versions, you should look at the ones posted in my album. I've smoothed out about a +3dB bump around 2-3kHz, that existed last October. I've also got VERY similar response curves now for all 3 crossovers:
1) the "original" (budget) Nano Neos XO has been altered a bit, but I've held the price, so with the woofers on sale, a pair can be yours for about $61.
2) a "non-budget" XO, that includes a 2nd order HP (added a small shunt coil to help integrate the tweeter better), with a more normal looking rolloff, AND I'm suggesting using a poly cap on the tweeter instead of the npe.
3) the "ntn" XO, for my MTM version of the Nano Neos. It uses a series pair of the ND105-4s.
All resistors can be the cheap 0.24c 5w jobs, except I'd be happier if you splurge for a 10w on the "ntn" Zobel. THOSE are 0.39c each. Double drivers means more power, and more power means more heat.
These are 4" 2-ways in a 0.3 cf vented box using the ND105-4 woofer and the ND20FA-6 tweeter. They can musically output a 32 Hz test tone (REALLY, at about -10dB) and play strongly from 40Hz up. I know they can cleanly reach lower than BR-1s (as unbelieveable as it sounds).
This project really started around the Holidays when I bought a WT3 on sale (for $67 IIRC). Right around that time, the 2010 catalog came out, and I first saw the 6 "NEW" ND woofers. I thought all their Q's were a bit high for vented boxes, and the Fs figures didn't really impress me. Also, Dayton had a new (cheap) pair of 6.5" 2-ways for $30-something a pair. I started thinking about building an uber-budget project, and for a price point, I picked $55 (which just happens to be my age). All I could come up with (for $27.50 per side) was a DC130 and the ND20-6 tweeter. I couldn't afford ANY coil after the driver cost (almost $26.50 just for the woofer and tweeter), so the woofer had to run "full-range" (just like the big boys do it), and I had about $1 left for a cap and padding resistor for the tweeter. It wouldn't be pretty.
Fast forward to the March/April flyer. Hey, that ND105-4 is ON SALE for $12. That's less than half price! THAT gives me an extra $6.50 per cab I could spend on the XO. I could actually put a coil on the woofer!
Not only THAT, but hey, THESE specs are not the same as the ones were in my new catalog that I got a few months back. The 105-4's Fs has dropped from 77 Hz down to 54 ! So, off my order went.
I ran my WT3 on my 4 new drivers and got an average Fs of 1840 Hz on the tweeters. For the woofers my WT3 gave me these values (after break-in): Qts = 0.48 (quite a bit lower than advertised - which I liked), Fs = 56 (a LOT closer to the new spec of 54 Hz than to the old 77, also good), and a Vas of 0.13.
After a few runs with WinISD Pro, I decided on a 0.32 cf cab, but as I laid out a cut sheet, I discovered that I could fit all but one of the smallest panels (a 6" x 11" scrap would be needed for ONE bottom) onto a 3/4" x 24" x 48" "handy panel". I bought mine at the local "Menard's" for $3.49. I downsized the box just a bit to 0.30 cf with outside dims of 14-7/8"h x 5-7/8"w x 10-3/8"d. For the rear vent I used an old cardboard shipping tube with an id of 1-1/2" and a length of 8" for an Fb of 41Hz. WinISD predicted an F3 of 39Hz. Rediculous! How much output could a 4" woofer really have at 40 cycles, even with gobs of Xmax? I was soon to find out.
After fiddling a bit with a prototype crossover, I settled on a 6 element design that's basically 2nd order on the woofer (a coil and "Zobel") and 1st order on the tweeter, just a cap, but with a healthy L-pad for about 9dB of attenuation. The system ends up about 82dB +/-3dB, with 2-3dB of BSC. The Fc is near 4kHz. I used a 3/8" roundover bit on all external edges, and around the inside of the port exit and the backside of the baffle for some woofer relief. I used a scroll saw for the tiny 3-5/8" woofer hole, and circle hole saws for the even smaller tweeter (1-1/4" circle hole saw), the port tube (1-5/8"), and the "dreaded" spring terminals (2").
Here's a shopping cart list (the woofers are only on sale to the end of June - unless PE extends it by ANOTHER 2 mos !). As you can see, I came in 28 cents under budget! At their rated 30w, these little guys only need 7mm of throw to output 38Hz. At 32Hz they exceed that with 8 watts. I DID make them "pop" once, on the right channel, playing some Nirvana, but unless you really go nuts, they seem VERY durable for such deep bass from such tiny boxes. I've had to check to make sure my 12" sub wasn't on (low) a few times already. They can't rattle my basement door like the big sub, but for cheap little speakers, they CAN let you hear the entire recorded range.
In my budget, I didn't include terminals, ports, foam lining (everywhere but the front baffle), or boxes. Mine cost me about $2 apiece, but this project would work very well in the 0.25 cf boxes that PE sells with very little reduction in bass extension (of course, this will triple or quadruple the project price). I'd use the 1-3/8" dia. vent (260-388) and cut it to 8" for the curved box, and 7" for the "traditional" box. The 8" won't comfortably fit in there since the box is a bit shallower.
Drawings will follow in a day or two (maybe some additional pictures too).
Chris
Last edited by Chris Roemer; 06-12-2011 at 11:35 AM.
Looks great! Perhaps people will believe you! No one seemed to believe when I finished the New Horizons they cold play to 40 cleanly... Like the white. Great lil driver! Did you run across any lead-slapping issues?
Looks great! Perhaps people will believe you! No one seemed to believe when I finished the New Horizons they cold play to 40 cleanly... Like the white. Great lil driver! Did you run across any lead-slapping issues?
Nope. I WAS testing with the driver in the vented box with all sides glued up except the top, and down at 50 and 40 cycles I could hear a loud "buzzing" sound and thought about your problem, but the little guy was lifting the inset top panel, making it resonate. A couple heavy books solved the problem.
Did you have cabinet issues as well? I made mine from 3/4" PB, and they're fully glued. I made sure I could fit the XO through the woofer hole in case it ever needed to come out. I ran a 1" sq brace from side to side, just above the port tube, but it was more for a place to mount the XO (that I could reach) than for cabinet bracing.
I've got a pair of 8" mains (DC28/DC200) in 2 cf cabs, and I got to love listening to tunes with VERY deep bass (B52's, Mark Knopfler's "Rudiger", Sheryl Crow, and other Dire Straits stuff). My BR-1 clones just can't reach that low, and so, those songs aren't as interesting to me on them, but with these little guys I can appreciate all those bottom end notes. All the box modeling I've done, even with my own T/S parms, show the output to be 9 or 10dB down at my 32Hz test tone, but it "sounds" like maybe only -6dB to me. You can really HEAR that tone as a "musical" note!
Currently I've got these up on a table that our 42" LCD sits on, with the tweeters at ear level and about 8" of clearance to the back wall. They image better pointed straight out, rather than toed in. For music (if you don't need really high SPL - I think these can almost reach 99dB), you can hear everything that's in the recording (except maybe pipe organ stuff), but I'd say that they will NOT be happy if used for HT explosions without a heftier sub. At 10mm of throw (mechanical limit) they can move more air than a "Classic" 5-1/4" MtM or a 6-1/2" TM, reach lower, AND can do all this in only .3 cubic feet. They aren't very efficient though.
Well, not exactly, but next month a pair of ND105-4's will cost $52. Get them NOW for $24 a pair, and it's like getting the ND20's and all the crossover parts for only 3 additional dollars!
As I've read over my posts on this project, I figured there might be some people out there who are on the fence since they just don't have a small scrap of 3/4" stock for the 12th box panel. Since I've stated that these would work well in PE's 0.25 cf boxes, I decided to see just what it would take to get all 12 panels out of a single 2' x 4' panel. Here's my cut sheet to do just that. It assumes that you can cut very accurately with a table saw, and that its blade is no more than 1/8" thick. If you look at my layout, you can see that my panels are also sized for my preferred method of joinery, namely cutting a 3/8" rabbet along all internal edges, as shown on the cabinet view. This sheet is labeled "Nano Neos NS", for "No Scrap" (required).
Thess will be exactly like the Nano Neos, except that I made the box 3/4" shallower, allowing all 12 panels to be cut from one handi-panel. The box volume shrinks only slightly from 0.30 cf to 0.28. I'd NOW use a 1-3/8" dia. port with a 7" length. The same one I'd recommend for use with the little Dayton cabinets.
You CAN hear air blowing out the vent around 40 cycles with test tones at high levels, even with the roundover, so if it were me, I'd still go for the slightly larger box with the slightly larger vent, but that's just me.
For an MTM, could the 105's could be wired in series for an 8 ohm load, with the coil changed to .88 mh and the zobel w/ a 4 ohm resistor and a 5uf cap?
In theory, the sensitivity of the two in series (8 ohms) should equal the single 4 ohm driver, and the tweeter x-over could remain the same?
For an MTM, could the 105's could be wired in series for an 8 ohm load, with the coil changed to .88 mh and the zobel w/ a 4 ohm resistor and a 5uf cap?
In theory, the sensitivity of the two in series (8 ohms) should equal the single 4 ohm driver, and the tweeter x-over could remain the same?
Would this work?
It SHOULD work. AND, two of them should be able to move as much air as a single Classic 8" at about 9mm of throw. Their Xmax is only 4mm, past that, the coil is moving out of the gap (added distortion), but they don't hit the back plate until 10mm; unlike the Classics which can sound like a machine gun when transients come along.
If I wanted to break my budget though (as you're suggesting), one of the 1st things I'd want to do would be to add a shunt coil to protect that little tweeter better.
this thread encouraged me to order 4 ND105's that i'll make MTM's out of....someday Any thoughts on a design for this? Musings? OP, that is a really sweet setup...i've been dying to take advantage of this deal You don't have a picture of the finished xover do you?
this thread encouraged me to order 4 ND105's that i'll make MTM's out of....someday Any thoughts on a design for this? Musings? OP, that is a really sweet setup...i've been dying to take advantage of this deal You don't have a picture of the finished xover do you?
that's all I could think of as I listened to thses after work tonight. Again, I HAD to physically get up off myass to make sure the sub wasn't on, even a little (we used it for a movie last night, but it was OFF !). I built these, and I can't believe how they perform. As the poster who built a small "sub" with one of them said, this little 4" Neo woofer is the "star of the show".
Pic 1 shows the relief on the backside of the baffle behind the woofer which IMO is crucial, otherwise there's almost no room between the frame and the straight cut hole for any air to move.
Pic 2 shows the box before glueup. I had a side off to check the fit and wiring of everything. I put "kangaback" carpet (it has a closed cell foam back, kinda hard to find nowadays) on the right side ONLY (the side that's off has the convoluted foam on it) to make mounting the XO a little easier, but next pair will be foam on all 5 sides.
Pic 3 shows a prototype 5 element board. This is the board I used in the final, but the caps and one resistor have been altered, and a 3rd resistor was added.
To the previous poster, we all have different parameters that "drive" us into any particular design. For this design, my $55 budget was (for me) the only thing that was not negotiable. When I had to increase the cap values a tad, and add an extra resistor, I had to rob Peter (somewhere) to pay Paul. In this case, I had enough in the budget to drop 2 of the resistors from 10w down to 5w. (I also looked at using a #20 coil.) YOU can use botique caps and resistors when you build it if you want to. That's kinda what DIY is all about. I don't believe that this XO is the best that can be designed for this driver set, but it very well MIGHT be the best XO for them that costs less than $7.
These DO have good imaging, and I've bottomed out the woofer on one channel and the tweeter survived. Over time, if I "toast" a tweeter, I'll pop another one in there for $8. Both of these drivers should be around a while. The woofer series is new, and I think the tweeters have only been out a few years. This is the first time I've used a Dayton Neo tweeter.
Anyway, adding a shunt coil to the HP might require a cap and L-pad change. It will definately shift the phase. All things are related. I might look at the MtM idea, but I wouldn't be offended if someone else designed it either.
Right now I'm just wondering who will be the second one to hear these little monsters, and if they'll be as impressed with them as I am.
that's all I could think of as I listened to thses after work tonight. Again, I HAD to physically get up off myass to make sure the sub wasn't on, even a little (we used it for a movie last night, but it was OFF !). I built these, and I can't believe how they perform. As the poster who built a small "sub" with one of them said, this little 4" Neo woofer is the "star of the show".
Pic 1 shows the relief on the backside of the baffle behind the woofer which IMO is crucial, otherwise there's almost no room between the frame and the straight cut hole for any air to move.
Pic 2 shows the box before glueup. I had a side off to check the fit and wiring of everything. I put "kangaback" carpet (it has a closed cell foam back, kinda hard to find nowadays) on the right side ONLY (the side that's off has the convoluted foam on it) to make mounting the XO a little easier, but next pair will be foam on all 5 sides.
Pic 3 shows a prototype 5 element board. This is the board I used in the final, but the caps and one resistor have been altered, and a 3rd resistor was added.
To the previous poster, we all have different parameters that "drive" us into any particular design. For this design, my $55 budget was (for me) the only thing that was not negotiable. When I had to increase the cap values a tad, and add an extra resistor, I had to rob Peter (somewhere) to pay Paul. In this case, I had enough in the budget to drop 2 of the resistors from 10w down to 5w. (I also looked at using a #20 coil.) YOU can use botique caps and resistors when you build it if you want to. That's kinda what DIY is all about. I don't believe that this XO is the best that can be designed for this driver set, but it very well MIGHT be the best XO for them that costs less than $7.
These DO have good imaging, and I've bottomed out the woofer on one channel and the tweeter survived. Over time, if I "toast" a tweeter, I'll pop another one in there for $8. Both of these drivers should be around a while. The woofer series is new, and I think the tweeters have only been out a few years. This is the first time I've used a Dayton Neo tweeter.
Anyway, adding a shunt coil to the HP might require a cap and L-pad change. It will definately shift the phase. All things are related. I might look at the MtM idea, but I wouldn't be offended if someone else designed it either.
Right now I'm just wondering who will be the second one to hear these little monsters, and if they'll be as impressed with them as I am.
Chris
Chris,
Thank you VERY much for the thoughts and pictures. I've been modeling an MTM configuration all evening, which honestly is nothing more than an evolution of the Nano's with the previously suggested xover mods. It looks good. real good. This driver models like Adriana Lima. I have great respect for your firm budget...the only reason i'm looking at MTM is because i would like to transition these to entry level HT duty in the not-to-distant future. Assuming no extra cost from swapping the value of the xover parts, the only price increase is in materials and the two extra drivers. Enter the classic sob-story about no time for hobbies...it's going to be a few weeks before i can get rolling on this. I absolutely can't wait to hear these guys make noise. Thanks again for the design, impeccable clarity of instructions, and insight!
Thank you VERY much for the thoughts and pictures. I've been modeling an MTM configuration all evening, which honestly is nothing more than an evolution of the Nano's with the previously suggested xover mods. It looks good. real good. This driver models like Adriana Lima. I have great respect for your firm budget...the only reason i'm looking at MTM is because i would like to transition these to entry level HT duty in the not-to-distant future. Assuming no extra cost from swapping the value of the xover parts, the only price increase is in materials and the two extra drivers. Enter the classic sob-story about no time for hobbies...it's going to be a few weeks before i can get rolling on this. I absolutely can't wait to hear these guys make noise. Thanks again for the design, impeccable clarity of instructions, and insight!
HP - 2nd order for safety: 4uF cap stays, then a #20 0.30mH shunt coil (to ground). Change L-pad to 5 ohm SR (series) and 3 ohm PR. Tweeter keeps positive polarity.
LP (for two ND105-4's in series): bigger coil - a #18 1.4mH (0.6 ohm DCR). Zobel changes to 6 ohm resistor and 4uF cap.
About 82+/-2dB, with 3dB BSC and an Fc near 3.3 kHz.
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.
Off you go.
Chris
Last edited by Chris Roemer; 03-16-2011 at 09:27 AM.
Well, I'm sold. I'm making a pair of these as my left and right front channels for use in my home theater. They will be used in conjunction with a powered sub and an AviaTrix sealed center channel.
These are going to be on a shelf (unfortunately) with about 3 -4" maximum clearance behind them, and hoping that will be ok... this leads me to a couple questions before I order my parts.
1) Because of spacing issues, I'll be building these in the smaller cabinet size and using the 7" port option... willl the lack of space behind my speakers affect the port negatively? Should I move the port to the front or side of the cabinet?
2) I read this thread a few times before posting, so I hope I didn't miss an answer to this question ... there was mention of an upgrade to the original crossover using a shunt coil on the tweeter... I see the model for the MtM crossover upgrade... is the original Nano Neo (Mt) crossover upgrade modeled or available before I submit my PE order?
Thanks in advance for the help, and thank you Chris for this design... I've been on the fence for a while as to picking my next build. Just couldn't pass these up.
Johnny Ravo
"I could get a better look at a t-bone steak by sticking my head up a bull's a**, but I'd just as soon take my butcher's word for it."
Well, I'm sold. I'm making a pair of these as my left and right front channels for use in my home theater. They will be used in conjunction with a powered sub and an AviaTrix sealed center channel.
These are going to be on a shelf (unfortunately) with about 3 -4" maximum clearance behind them, and hoping that will be ok... this leads me to a couple questions before I order my parts.
1) Because of spacing issues, I'll be building these in the smaller cabinet size and using the 7" port option... willl the lack of space behind my speakers affect the port negatively? Should I move the port to the front or side of the cabinet?
2) I read this thread a few times before posting, so I hope I didn't miss an answer to this question ... there was mention of an upgrade to the original crossover using a shunt coil on the tweeter... I see the model for the MtM crossover upgrade... is the original Nano Neo (Mt) crossover upgrade modeled or available before I submit my PE order?
Thanks in advance for the help, and thank you Chris for this design... I've been on the fence for a while as to picking my next build. Just couldn't pass these up.
Johnny Ravo
As long as the air coming out the vent can get out w/out restrictions, you should be OK (like the way a fridge's heat can escape from the radiantor on the back as long as there's enough room above the top of the box. You shouldn't really put them on a shelf that's only 15" high, for example. I've used vented cabs angled up against an obstruction, and although I've never measured the effect, I think you probably lower the cab tuning if it's restrictive, but that's not necessarily a bad thing.
The original Nano Neos XO is fine w/out an "upgrade". I did add a coil (for safety) on the MtM request, because they'll probably get cranked louder.
on Sale - $55/pr (drivers & XO)
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Originally Posted by mzisserson
OP, that is a really sweet setup...i've been dying to take advantage of this deal 
