Micro Sub using ND105 4" driver

[Chris Roemer]

Re: Micro Sub using ND105 4" driver

Xmax is the factor of the maximum linear excursion in one direction, which is to the point the Bl product drops by a certain percentage, or mathematically;

Overhung; (coil length - gap height)/2
Underhung; (gap-height - coil length)/2

Usually, it is defined as a one-direction movement, or the added "p-p" for total excursion of both directions.

Later,
Wolf

IOW, exceeding Xmax pushes the driver into non-linear excursion, with distortion being a byproduct.

On the Dayton Classics, Xlim and Xmax are the same.

chris

[jcpahman77]

Re: Micro Sub using ND105 4" driver

I get it. Thanks for the education Wolf. In my circle of friends I'm often the "goto" guy for mobile subwoofer questions, but up until now I've done everything by ear and experimentation. This site has given me the opportunity to learn things "by the numbers". I'll always keep the experience/knowledge that I have, but if I can add some "book smarts" to it I may avoid making some mistakes.

[DDF]

Re: Micro Sub using ND105 4" driver

This driver looks perfect for a DIY HPAS sub

[greywarden]

Re: Micro Sub using ND105 4" driver

XMAX = good noises

XLIM = bad noises

:D

[Wolf]

Re: Micro Sub using ND105 4" driver

IOW, exceeding Xmax pushes the driver into non-linear excursion, with distortion being a byproduct.

On the Dayton Classics, Xlim and Xmax are the same.

chris

I don't believe that is correct, Chris. The DC160 will move more than 5mm mechanically. Are you sure it doesn't say 'Xlin' for linear? If it's on the data sheet, I have not looked at it. Xlim does not equal Xmax.

Later,
Wolf

[Wolf]

Re: Micro Sub using ND105 4" driver

I get it. Thanks for the education Wolf. In my circle of friends I'm often the "goto" guy for mobile subwoofer questions, but up until now I've done everything by ear and experimentation. This site has given me the opportunity to learn things "by the numbers". I'll always keep the experience/knowledge that I have, but if I can add some "book smarts" to it I may avoid making some mistakes.

Glad it's clear for you now!
You're welcome,
Wolf

[djkest]

Re: Micro Sub using ND105 4" driver

that is 1 liter - what do you think ;)

Your making a huge assumption here. I said 5" width, I said nothing about height or depth. I was talking 1 dimension, not all three.

You know, briefcase sub, for example.

Also had another idea. What about a mini version of lilmike's tapped horn design? I mean, the whole thing would have to be smaller, but this driver might work for that. I guess more analysis of the driver's parameters would have to be done. There's also 4th order bandpass, and push/pull type enclosures to think about.

[Chris Roemer]

Re: Micro Sub using ND105 4" driver

I don't believe that is correct, Chris. The DC160 will move more than 5mm mechanically. Are you sure it doesn't say 'Xlin' for linear? If it's on the data sheet, I have not looked at it. Xlim does not equal Xmax.

Later,
Wolf

Can't say that I've ever seen an "Xlim" spec before the 6 ND woofers (FR) came out a couple years ago. It certainly isn't a parm that's given up very often.

I have used at LEAST 3 pr of the 295-310's (4.5mm Xmax), 4 pr of the 160's (3.15mm?), and probably 5 pr or more of the 10" (4.5mm IIRC). I've never heard the 10's bang, but all the 6.5" and 8" make quite a racket when pushed too far. The 160's would throw +/-3.15mm, for a total throw of about 1/4", right? They just can't go much further w/out slamming (the back plate, I assume).

It's always seemed to me that an overhung coil would have less leeway than an underhung one, simply 'cause the coil is longer than the gap and (probably) would run out of room to move mechanically. IOW, when an overhung coil, with 5mm Xmax approaches 5mm, the opposite end of the coil would be sticking out past the gap by 10mm, wouldn't it?

Chris

[bmaupin]

Re: Micro Sub using ND105 4" driver

Your making a huge assumption here. I said 5" width, I said nothing about height or depth. I was talking 1 dimension, not all three.

Yes, I read that as a 5" cube - sorry. 5" width is not a problem.

[DjDisturbed]

Re: Micro Sub using ND105 4" driver

I use the ND105 for my 2.1 computer media speakers and it sounds great. It plays loud enough that it will shake the walls.
For the size and money (even at the current price) it's a great little woofer.

Little Sub

[johnnyrichards]

Re: Micro Sub using ND105 4" driver

I think it is important to consider that recent Klippel testing of drivers is probably redefining what we consider "linear" Xmax. Many of the drivers tested exhibited a lot of distortion well before mechanical Xmax was reached, much less before dipping into the Xlim region. Some people are sensitive to bass distortion, not sure if I am one of them though.

[djkest]

Re: Micro Sub using ND105 4" driver

Contemplating actually making this to go in my truck. I have an Alpine amp that I believe will deliver 200 Watts bridged mono @ 4 ohms, so I could run 2 of the 8 ohm in parallel... not sure what this would sound like though, or how deep I'd be able to go. Also considering the Tang Band underhung 8, that might be a better choice. I have a space about 12x20x6" under the rear seat I can use.. that's it.

[jcpahman77]

Re: Micro Sub using ND105 4" driver

If you're cramped for space grab the TC sounds Epic 8", it'll fit, but you'll need more power.

[Wolf]

Re: Micro Sub using ND105 4" driver

In both directions it would, yes. But I meant that Xlim is not equal to Xmax. Xlim is equal to Xmech.

I've run the Bitty Booms pretty hard, and at low frequencies, and they moved 10mm p-p without backplate-a-whacking, IME. That's why I questioned you saying Xlim equals Xmax for DC woofers.

Later,
Wolf

[isaeagle4031]

Re: Micro Sub using ND105 4" driver

Has anyone modeled these with a PR? Maybe the dayton 8" and a pair of the 105s?