What are the differences (if any) between woofers that have a central bump, like the NS10s, vs completely smooth like the KEF R3?

[Diplo]

^

 

[dfuller]

One has a dust cap that is convex, one has one that's concave. That's about all you can draw from that.

 

[Diplo]

One has a dust cap that is convex, one has one that's concave. That's about all you can draw from that.

Ah, dust cap. I wasn’t sure of the name…

Does the dust cap have any sonic implications?
I ask as there are some speakers like the Amphion One15 that have a more convex shape, and wondered if it’s anything more than aesthetics.

 

[thulle]

The goal is to have a cone that behaves as a rigid object, without getting too heavy. How to reach that goal can be done in different ways though, with different materials and shapes.

If they fail to make a cone that stays rigid you get cone breakup distortion:

 

[Diplo]

The goal is to have a cone that behaves as a rigid object, without getting too heavy. How to reach that goal can be done in different ways though, with different materials and shapes.

If they fail to make a cone that stays rigid you get cone breakup distortion:

I’m doing a build with a 3 1/2” sealed mixcube style monitor, and probably won’t play anything below around 70hz.

Even though it’s only a small full range driver, do you think it’s worth integrated a high pass into the circuitry.

Also, what’s your take on aluminium for woofer material?

The woofer is the Dayton ND91, I’m not sure whether to build a 4 or 8ohm.
The EBP is 164, so I may need to go for a passive radiator.

 

[thulle]

I’m doing a build with a 3 1/2” sealed mixcube style monitor, and probably won’t play anything below around 70hz.

Even though it’s only a small full range driver, do you think it’s worth integrated a high pass into the circuitry.

I'd definitively implement a highpass if I had the slightest plan to play somewhat loud. Having subwoofers play the lower frequencies could trick you into thinking the monitors are ok. You'd probably see issues excursionwise though.

Also, what’s your take on aluminium for woofer material?

The woofer is the Dayton ND91, I’m not sure whether to build a 4 or 8ohm.

I'm pretty fond of anodized aluminium for the looks, and there are a few aluminium-coned drivers that measures very well.. but there are aluminium drivers that measure like crap too. It just isn't a way to distinguish between good and bad drivers, you have to look at the measurements. Implementation is everything

And 4- vs 8 Ohm is kind of one of those questions too. It depends. Generalizing a bit I guess I'd say 8 Ohm measures slightly better, and for small single driver fullrange you probably won't have issues finding an amplifier that could manage it with ease. But there are plenty of more knowledgeable people to discuss design with. I've only dared taking on subwoofer construction so far, which are pretty easy in comparison.

 

[dfuller]

Does the dust cap have any sonic implications?

it... can? Depends on the driver.

Also, what’s your take on aluminium for woofer material?

Can be very good, but be careful of breakup modes. Not a good choice for full-range.

 

[Diplo]

it... can? Depends on the driver.


Can be very good, but be careful of breakup modes. Not a good choice for full-range.

Are full range drivers ever filter down and used as the mid bass in a 3-way (as opposed to an dedicated mid woofer)?

I ask as the Dayton ND91 seems to be very linear in the mids and has almost perfect off-axis response if filtered between like 200-3000hz.