Passive radiator 2290 (PR 15)

[Tomas M]

Hello!

I’ve just bought four of these.

They contain 2205, PR 15, 2410, HL 87 and N 1200. I’m planning to use 4 of the woofers in a sub, but I also have four PR 15. Shall I use them too or is it better to build a bass reflex system?

Tomas

[Guenter]

Aye, Tomas, there's the rub. I've been pondering the same with my 4 LE15's and 4 PR's. The best conclusion I could come up with is that the PR's are worth it with our speakers but not with, say,
the 2235's that are inherently better woofers. You do in fact eke out a smidgen more lows at the slight expense of loss in extension that corner placement might bring (steeper roll-off). the differences are very small though. So, if you didn't have the PR's it likely wouldn't be worth buying them. However, since you DO have them (and myslelf) and in view that the 2205 (I think they are identical to the LE15) will benefit from any extension at all - install them.
Further You will now have the added benefit of (1) port noise will be truly minimal and (2) you can tune them much easier compared to a port and finally (3) you can use more compact cabinet dimensions where a port would not work. I, for example, have used a very small, just over 4 ft^3 box and I equalize the low end for increased extension with an 1/3 oct equalizer. Probably not optimal in terms of Q etc, but hey, the bass seems nice and they play loud enough (too loud actually) without appearing to be stressed.

- hope this rambling helps to focus your thoughts a bit

[Alex Lancaster]

Hi.

The 2205´s are the antecessor of the 2225´s, the LE15's equivalent is the 2215; none of the above will go very low, but the 2205´s will really kick around 70Hz.

Alex.

[GordonW]

:eek: My first thought, was: "Oh my god, it's the WORLD's BIGGEST LANCER 77!" :D

Seriously, I think Alex is right... the 2205 will not do much in the way of low bass. However, these baskets should be reconable as 2235s, and the PRs could be rebuilt with foam surrounds and more limber surrounds. In that case, I'd say YES, use them... as was mentioned, there would be a TOTAL ABSENCE of port noise, which will make the sub VERY CLEAN sounding.

However, the expense of rebuilding the PR15s may not be worth it... in that case, you would probably be better off just using ports. With the size enclosure a 2235 needs, PRs aren't really manditory... even with 2 or 3, 4" diameter ports, the ports still usually fit in the box OK...

Regards,
Gordon.

[Mr. Widget]

Hi Thomas,

A number of years ago I tried a pair of 2205s in a sub application. I was very disappointed. In a home stereo
environment they will run out of Xmax before appreciable deep bass will be produced. (In a concert system with
a couple of dozen working together it is a different story.) I would seriously consider reconing them as 2235s. It
will cost about $135 each, but you will have true earth moving deep bass. You could recoup part of the cost in
selling the PR15s. A clean pair will usually go for about $100.

Good luck,

Widget

[GordonW]

Widget has the right idea, I think. If you DID want to use a PR, there's more modern designs, that would be MUCH more suitable for use with a 2235, they're out there. For example the Madisound Sledgehammer 15" passive radiator, is only about $40 each... one of those, with added mass (I installed a bolt with fender washers clamped into the hole where the voice coil would go, so I could add weight by adding steel or lead washers) would easily out-perform the PR15 in this application... and it's cheaper new than the PR15s sell for used...

I still think, with the box size required for a 2235 (at least 4 cubic feet) a port should be quite do-able, though. Probably no need for a PR, unless you're planning to run it up into the midrange (as a WOOFER, not a subwoofer)...

Regards,
Gordon.

[slxrti]

The 2235 complements well with a passive radiator. Several years
ago I build a 6-7 cft box for use with a 739 gram 15" passive radiator.
The passive needs a 2x throw over the 2235. The bass produced
had a tonal quality that was very natural.

The 2205 is a very fast woofer, more so than the 2235. can it produce
deep bass be low 20 hz, most likely not. If music is your game then
30hz is very do able. A passive will work with this driver.

slxrti

[Tomas M]

No really deep bass in those!

Will it be better if I replace the PR 15 with one more 2205? If I take out the horn, will the port be big enough?

[Guenter]

Tomas, you might want to look at the thread immediately below yours

- regards

[bldozier]

was this topic ever updated. I'm interested in a similar configuration.
brian.