Dayton HS315HF crossover q

[Coby]

I've got over 50 hours of reading and modeling drivers in since last I posted. I can see why folks are so gaga over the Dayton drivers; they model very well and most people report that the manufacturer's data is pretty spot on. Impressive drivers.

With that in mind, I've looked for but can't quite find some info on this sub. Given a steep crossover slope of the DCX of 48db, how high can this sub be crossed over at without issues like distortion and beaming cropping up? Can I get it up to 400hz or higher? Could it be crossed over with the RS52, for instance? Or does it have to be something like the RS150?

[JonMarsh]

Taking a 12 up high in the midrange is a dicey proposition, due to accumulating energy storage issues, cone breakup amplification of distoriton products, and as you mention, beaming. 350-400 Hz is probably a wise point to say "enough is enough" even for the RS315, which has a very stiff and reasonably damped cone for a metal driver. That's high enough to work with more extended range cone midrange drivers, but not with a dome middrange like the RS52, which is limited by swept volume displacement (Xmax X Sd). It might be possible to take the Aurasound NS12-513A up to 600-800, but there you run into beaming. The differences in radiation pattern make the off axis balance hard to achieve at the same time as on axis response.

Well behaved metal cone 10's can be useful up to 600 Hz or so- that's still low for the RS52. Even with a project I'm considering with the RS270, which isn't a sub driver, I'll be using cone mids, like the Tangband W4-1337S.

The largest driver I'd use with a dome mid would be something like the RS225- I've done quite a few 8" three ways with dome mids over the years. Attempted a 10" three way back in the 70's, and played around with the Ascent type configuration (Eton woofer, MB Quart Mid), but wasn't fully satisfied with how it turned out.

It's not too hard to manage baffle step with 800 Hz crossover points, but going to a cone mid with a lower crossover creates other problems to solve- something to keep in mind?

[Coby]

Makes sense...kinda what I was afraid of. If I went with something like dual rs150's I might be able to use that. It'd give me the ability to get an f3 in the low 20's with all 7 speakers and still push a fairly high spl with decent distortion characteristics.

I can't seem to get the idea of 7 true full range speaker out of my head. I really like the idea of 7 subs in the room. The thoughts of a 2 way crossing to my single sub are pretty much gone.

I think I can get away with 3.5 to 4 cu ft for the woofer, as long as the enclosure for the mids is fairly small. I think I can run the 150's sealed and do a wmmt all the way around.

Behringer says that you can daisychain the DCX's. Does that mean I can pass signal between units? That might let me do some creative things with the LFE signal

[Amphiprion]

IIRC my measurements the 12" was very clean resonance-wise up until 900Hz or so. Fs and Qts were as dead-on as they can be (I think Fs was 1Hz high). Didn't measure Vas, hard to do accurately so I don't usually bother if the other two match.

I would look at what the harmonic distortion curves look like above 100Hz. See if that 900Hz breakup is going to be excited by anything that can't be fixed with a crossover. If you haven't done that already that is.

[Coby]

IIRC my measurements the 12" was very clean resonance-wise up until 900Hz or so. Fs and Qts were as dead-on as they can be (I think Fs was 1Hz high). Didn't measure Vas, hard to do accurately so I don't usually bother if the other two match.

I would look at what the harmonic distortion curves look like above 100Hz. See if that 900Hz breakup is going to be excited by anything that can't be fixed with a crossover. If you haven't done that already that is.

are there some distortion curves posted somewhere? I was having difficulty finding that

[Amphiprion]

Here are some but they only go up to 200Hz. You'll have to download the zip file.

http://www.mfk-projects.com/rs_12_hi-fi.htm

[Coby]

excellent info; much thanks!