Dayton RS125-4/-8, perfect for small 2-way?

[Landroval]

PE seems to have the 4ohm version of the RS125 out. Specs say 4mm Xmax, 91dB SPL. Very welcome changes from the 8ohm version if they are accurate. The efficiency sounds hard to believe, maybe someone already has these and could confirm?

I did run a few models in WinISD and a 5 liter enclosure with 50Hz tuning gives a quite nice responce, 50Hz -3dB.

Any comments about using these as midwoofers in a 2-way?

[fjhuerta]

I was thinking about the same thing, but decided against it, just because of the very uneven frequency response starting at around 2 KHz or so.

Maybe someone with more experience can chime in, but I suppose the crossover could get a bit complex when using this driver.

[joecarrow]

Watch out for the difference between efficiency and sensitivity. These are 4 ohm drivers, so you see a higher sensitivity than efficiency. Sensitivity is output from a given voltage, efficiency is output from a given wattage.

As far as a 2-way goes, pay attention to excursion at higher power. If these had an active highpass with a supporting sub, they might do quite well. Otherwise, you won't be able to play very loudly.

[Landroval]

I was thinking about the same thing, but decided against it, just because of the very uneven frequency response starting at around 2 KHz or so.

Hmm, do you have some measurements of this available?

Watch out for the difference between efficiency and sensitivity. These are 4 ohm drivers, so you see a higher sensitivity than efficiency. Sensitivity is output from a given voltage, efficiency is output from a given wattage.

Oh yes, you're right... Although with a capable amp it should be no problem, and with a right tweeter padding down might not be necessary. I'll have to think about this.

[cjd]

You'll get better results with the RS150 across the board.

C

[Landroval]

That's true, but the only problem is the size of the enclosure. RS150 needs around 10 liters, while both of the RS125's can work with 3-4 liters. I'm building a flat (as flat as possible) on-wall speaker, so the volume of the enclosure shoud be as small as possible.

[cjd]

I'd take a gander at the TangBand bamboo drivers or similar then. The RS125's are on the lean side already, and I've read numerous reports of them leaving a bit to be desired.

Last time I ran numbers I seem to recall box volume coming out pretty darned close RS125 vs RS150. Been a good while though.

C

[Landroval]

Hmm, interesting. Are basing your opinion on mesurements, or also listening? RJB-Roman has used the RS125 in some of his projects and doesn't complain. Also John Krutke measured it and said it was good exept for the low efficiency. But yes, I'll have to reconsider this. The Bamboo driver doesn't fit my plans this time, maybe I'd like to try something else than Tangband and preferably metal cone.

I'm getting good looking output from RS125 in 3.5 liters with 60Hz tuning and from RS150 in 10 liter with 45Hz tuning. The bigger one reaches around 10 Hz lower, but that's understandable.

Edit: And now I'm talking about the 8 Ohm versions.

[Jed]

Hmm, interesting. Are basing your opinion on mesurements, or also listening? RJB-Roman has used the RS125 in some of his projects and doesn't complain. Also John Krutke measured it and said it was good exept for the low efficiency. But yes, I'll have to reconsider this. The Bamboo driver doesn't fit my plans this time, maybe I'd like to try something else than Tangband and preferably metal cone.

I'm getting good looking output from RS125 in 3.5 liters with 60Hz tuning and from RS150 in 10 liter with 45Hz tuning. The bigger one reaches around 10 Hz lower, but that's understandable.

Edit: And now I'm talking about the 8 Ohm versions.

I've heard 2 speakers that use the RS125 and they were great for the money. One of them was Roman's microbe. Not lean sounding at all.

Jed

[dlr]

I've got measurements of the 4-ohm versions of each

That's true, but the only problem is the size of the enclosure. RS150 needs around 10 liters, while both of the RS125's can work with 3-4 liters. I'm building a flat (as flat as possible) on-wall speaker, so the volume of the enclosure shoud be as small as possible.

You won't have much baffle step with a shallow on-wall setup, so you'll not have the nearly 6db loss in the low end. That should make quite a difference over most systems that are being discussed here. Still, the RS125 is going to be fairly limited in the low end.

Dave's Speaker Pages

Go the raw measurements page. Note that these are quasi-IEC that should be reasonably close to what you'll need for the shallow wll mount.

[fjhuerta]

Hmm, do you have some measurements of this available?

Yep.

http://www.partsexpress.com/pdf/295-360g.pdf

[capslock]

Yep.

http://www.partsexpress.com/pdf/295-360g.pdf

Not sure that I'd call this uneven. Also, if Darren did not use an infinite baffle, it might well be baffle reflections.

The HobbyHifi measurement of the RS125-8 FR looked cleaner, distortion was on par with the Excel W12, and CSD looked even better than the Excel.

[Landroval]

Those are both for the 8 Ohm version, I wonder if the 4 Ohmer is more or less the same? I asked PE, but they didn't yet have the measurements available.

[Irwin AR]

The HobbyHifi measurement of the RS125-8 FR looked cleaner, distortion was on par with the Excel W12, and CSD looked even better than the Excel.

Would you mind putting the hobbyhifi measurement here if you still have them
Wanted to see if it is as good as those TI100 or maybe AL130 in distortion