Dayton RSS210HF

[Johnloudb]

I don't think so. AFAIK, none of the modelling programs can simulate aperiodic boxes very well. You need to just build it and measure it to see what's going on.

Vance Dickason LDC 7 (Pg. 58-59) ... 50% fiberglass/50% acoustuff impedance, closely matched the aperiodic vent enclosure (50% fill). He also computer modeled & designed a MTM - Dynaudio woofers, in aperiodic vent enclosure.

I'll give it a go. 8O

[Dennis H]

Vance Dickason LDC 7 (Pg. 58-59) ... 50% fiberglass/50% acoustuff impedance, closely matched the aperiodic vent enclosure (50% fill). He also computer modeled & designed a MTM - Dynaudio woofers, in aperiodic vent enclosure.

I'll give it a go. 8O

Well, no disrespect to Vance, but which aperiodic vents? What's the diameter of the vents, what's the resistivity of each, and how many is he using? Rules of thumb are fine as far as they go but..... It's kinda like talking about a ported box without specifying the box volume, port diameter or port length. :roll:

[Johnloudb]

Yes, I agree.

Well, no disrespect to Vance, but which aperiodic vents? What's the diameter of the vents, what's the resistivity of each, and how many is he using? Rules of thumb are fine as far as they go but..... It's kinda like talking about a ported box without specifying the box volume, port diameter or port length. :roll:

Yes, I agree. vents are 4" in diameter, Scan-Speak.
Rule of thumb: 1 port for up to 50L, 2 ports for up to 80L, 3 ports for > 80L

With experimentation I hope to get great results.

[JonMarsh]

A few comments about construction

This is certainly a full fledged member of the RS subwoofer family. That's both good, and in an area or two, not so good.



First, it has a very large spider, with the tinsel leads woven into the spider. Between that and the oversized surround (in relation to the rated Xmax), the mechanical excursion capability is considerable, and it will probably handle being driven into the non-linear area without mechanical distress until you bottom out the VC. But this is a source of problems- the spider support area, which is solid, not open in the metal, is so large that the spokes supporting the frame are nearly perpendicular. And being just an 8" woofer, they're not very tall. Forget any thick baffle designs- the rear exit area from the cone will be heavily masked. I was hoping these might be an option for the three way version of the M8ta, but without changing the front panel design and somehow removing more of the wall (which is currently relieved behind the second baffle section, it's a no go. Even with a single thickness 1" baffle, I'd do some chamfering.

Another point that makes it a little harder to work with is the relatively narrow mounting baffle ring- narrower than a RS180, for example.

Still, I am thinking about a couple of other applications for this- depends on how it measures.

More later.

[Nathan P]

I'm wondering, how does the xmax rating actually compare to how far the thing can actually move? I've noticed that my RS315HO in my car seems to be moving way more than it's rated 12mm xmax with ease when I throw a 20hz test tone at it.

[JonMarsh]

Drivers can move outside the rated linear Xmax, to varying degrees, depending on the VC length and gap design. But linearity falls off and distortion rises.

[Nathan P]

So how much farther than linear Xmax can the dayton RS subs go?

[sprint_9]

Ive seen the term Xmech thrown around on this and other forums and I believe this is the figure which stats the mechanical limit of the woofer, which is probably the number you are looking for. If you hit this number then bad things happen. Also from some recent disscussions Ive gathered that this xmech varies on the sub design and may not be all that much greater then the xmax of the sub. Correct me if Im wrong.

[joecarrow]

You've got it right, and I don't see Xmech listed on the Parts Express page. You could possibly email them and get a reply, but there are good reasons you don't want to approach Xmech.

When you go much past Xmax, the voice coil starts to leave the magnetic gap, which reduces the force available to pull the cone back to the resting position. Since the cone is moving at high velocity and losing its magnetic stopping power, it can slam into whatever is physically stopping it with considerable force. This can stretch the spider, causing a change in T/S parameters, the restoring force can lose axial symmetry, causing the voice coil to lose alignment and rub, it can also slam the end of the voice coil former into the magnet, "bottoming out" the driver. This can actually deform the end of the former, causing permanent rub/buzz, or even locking the driver. As far as I know, this is a lot more common than the opposite, blowing the cone completely out across the room.

General rule of thumb- once it starts to sound bad, do something to reduce excursion. This can include changing the tuning frequency of a ported box, adding a high pass filter, turning the volume down, or adding more woofers. If it's a DB drag racing sort of situation, the mentality is kind of different... but why use such nice drivers for such brutish displays?

[Nathan P]

Oh I was just wondering for educational purposes :wink:

[kejolly]

has anyone messed with these

Just wondering if anyone messed with these yet?

Kevin