New Dayton RS 2" mids in the house!

[Brian Bunge]

OK, so I "won" a pair of Dayton RS mids yesterday at the Palm Bay DIY Event and am trying to get a handle on how I should use them. At first, I was wondering what the big advantage it would be using it over say the RS125 for a mid. The 125 would go lower obviously. But it looks like the mid would extend higher, possibly allowing for the use of a smaller 3/4" tweet, which should give me greater dispersion if I understand correctly.

Also, the mid is about 4.5dB more sensitive than the 125 so I'm thinking that would keep me from having to pad down the tweeter used, which keeps sensitivity higher. Am I correct in assuming that I could use something like dual RS150's in parallel to take care of baffle step and keep overall system sensitivity up in the 90dB range?

My thought process is that I could build a fairly slim tower that could be used in the formal living room, which will be Ashley's reading/sitting room and she can put on her music in there when she wants to get away from me and the kid!

So what do you guys think of this? These aren't necessarily something that'll get pushed overly hard so I'm not worried about max SPL's. We'll use my large 3-way towers for that purpose!

[Brian Bunge]

Just wondering if Jon or Chris (or anyone else) happened to miss this thread and might possibly have some input for me.

[ThomasW]

You're talking about a TMWW? If so sounds fine.

[Brian Bunge]

Yes, it will be a TMWW.

[JonMarsh]

Aw, 'cmon, Brian, push them!!!

Seriously, my day job has turned into a whole new bigger can o'worms than I ever dreamed it would be even a month ago, so I don't drop by hear nearly as often as I'd like.

My own experience working with dome mids suggests going for a baffle size where baffle step will be in the range of 800 Hz and down, or wherever you're happy crossing into the dome mids. Then, the upper crossover is chosen based on the linearity of the dome mid (seemingly excellent in this case) and the center to center limits for crossover frequency (say, 3.2 kHz is a number I've used in the past, which gives me two octaves from 800 Hz). Then, BSC is completly within the midwoofers.

C'mon, don't you want to go a little bigger and put some RS180's in there? More Xmax, more Sd, more of what makes it a woofer, not just a midrange?

OK, I know, I'm a little over the top on RS180s vs RS150's. I think of the RS150 as a possible midrange, though I'd be more inclined to use the RS125 if it was a true midrange I was after. Just personal preferences.

Which ever way you go, it will be a nice speaker. Whatcha gonna use on the top end? I'm still looking for a good 3/4" tweeter cheaper than the Accuton C13-6; I haven't liked the test results for anything else I've tried yet.

~Jon

[dlr]

Midrange tweak page coming

Just wondering if Jon or Chris (or anyone else) happened to miss this thread and might possibly have some input for me.

Brian, I haven't used them yet, though I will just to experiment, but I've got a pair of RS52s that I've played with and measured. I'm in the middle of a writeup. I'm also trying to decide how to pair them. My first thought was the XT19, but in a budget system, the new silkie would work as well. On the woofer side I'll probably go with a 7" or 8" driver (whatever I have on-hand). Something that can cross somewhere around 800-1000 would probably be best, unless the absolute SPL requirement is limited.

There are two related issues in my results that some may find interesting. I was really surprised at one aspect, something I never would have expected. And I may not be done yet. The easy stuff is done, however.

I'll also be adding the large baffle raw measurements to my site for download.

[JonMarsh]

Brian, I haven't used them yet, though I will just to experiment, but I've got a pair of RS52s that I've played with and measured. I'm in the middle of a writeup. I'm also trying to decide how to pair them. My first thought was the XT19, but in a budget system, the new silkie would work as well. On the woofer side I'll probably go with a 7" or 8" driver (whatever I have on-hand). Something that can cross somewhere around 800-1000 would probably be best, unless the absolute SPL requirement is limited.

There are two related issues in my results that some may find interesting. I was really surprised at one aspect, something I never would have expected. And I may not be done yet. The easy stuff is done, however.

I'll also be adding the large baffle raw measurements to my site for download.

Me thinks Dave's holding out on us a little bit....

Anyway, he's whetting my curiousity.

[Jonasz]

Dave, me think RS225, RS52 and H1283 could be a very high performance budget system! :P And pleeze when you're at it, make a version for us OW1 lovers too will you... :twisted: :B

[dwk]

Me thinks Dave's holding out on us a little bit....

No kidding - what a tease!.

I cut down one of the PE 12" waveguides and duct-taped an RS52 to the back after removing the grill screen. Seems to work OK, but I'm uncertain enough of my current measurement setup that I can't draw any conclusions just yet. Compared to the response in a flat baffle, it gets a boost between 1k and 3k - peaks at about 8-10dB. Both the flat baffle and the waveguide roll off below 1k which is not consistent with other measurements, so I don't trust that. A 2uf cap made things look great from about 1.5 to 10k, but it killed the sensitivity, and who the heck wants a 2" midrange that you cross at 1.5k? I need 7-800Hz for my purposes, so I'm hoping I can get it to work..

That's one nasty 13.5k breakup, though. gadzooks. It'll take a bit of work to tame it, and may greatly limit the practical HF extension due to HD.

[poneal]

Dave, me think RS225, RS52 and H1283 could be a very high performance budget system! :P And pleeze when you're at it, make a version for us OW1 lovers too will you... :twisted: :B

Me thinks the dual RS225s, MDM-55 and H1283 are excellent choices also. I'm not sure if you can get the c-t-c spacing needed using the 1283 and the 52. Pretty large footprint, but it might work.

[Brian Bunge]

Jon,

What type of baffle width would be be talking about for baffle step in the 800Hz range? I'd like to keep baffle width fairly narrow.

As far as tweeters go, that's one reason why I was posting. IIRC, you tested that new Seas 3/4" metal dome, right? I'm assuming you didn't like it very much. I could probably just go with the 27TDFC or metal version, but I believe that it's been said that you get better dispersion with a smaller dome. Is this correct? That's the only reason why I'm looking for a 3/4" dome, but I can't see spending $100+ on it. The Seas' tweets have always sounded nice to me and I'll just go with a 1" if I have to do so.

[JonMarsh]

Well, you can simulate that easy enough with The Edge, and practially speaking, you have some wiggle room, as it "peaks" before it drops off, but I'd plan on 8-10" at least.

I would also simulate some variations on the front panel layout to get the smoothest response from the drivers in their pass band; I've doing this routinely for a while, and it really prevents some headaches later on. Personally I find The Edge easier to use in some ways than FRD Consortium FRD; it's a standalone program in Windows. Doesn't do some things BDS does, but for evaluating baffle shapes and one driver and location at a time, it works pretty well.

~Jon

[dlr]

There's good and bad to modifications

Me thinks Dave's holding out on us a little bit....

Anyway, he's whetting my curiousity.

The issue relates to on-axis vs off-axis for one aspect. Up front I'll point out that the off-axis when treated shows improvement and detriment. Testing mods on-axis only can be misleading for overall performance. This driver is really good out of the box IMO.

But it can be improved somewhat depending on ones needs.

Darren put me onto a possible way to open up the chamber in a way that isn't destructive, though that's yet to be determined. I'd like to see what can be done inside of it.

On an aside, have your purchased any of the Hales domes? I put in an order, but it's back-orderd 1-2 months. I jumped in to do so when the Mad page was updated to indicate that they may not be available in the future.

[JonMarsh]

Interesting. I used to spend some time tweaking the MB Quart dome mids, too. Probably for similar reasons.


Regarding the Hales domes, no, I hadn't yet, but I was planning on placing a Mad order today. Thanks for the heads up.

[dlr]

The peak is significant

That's one nasty 13.5k breakup, though. gadzooks. It'll take a bit of work to tame it, and may greatly limit the practical HF extension due to HD.

I worked on that peak with moderate success. The magnitude was reduced on-axis, but it became higher Q, harder top to fix with a passive XO. With some mod arrangements, the off-axis non-linearity increased dramatically, so it's not a straight-forward situation.

Without having done a XO, I would still suggest as a first attempt to use an inductor for initial lowpass, then a series trap in parallel as the parallel XO leg, letting it do dual duty. Sort of like Jon's Cauer filters, only you can just match a standard 2nd or 4th order target if desired.

That's what I like to do even with more typical mids and even woofers, as long as the overall impedance cuts it in the end. But as in other endeavors, where there's a will, there's a way.

[dlr]

Tweeter pairing with RS52

Dave, me think RS225, RS52 and H1283 could be a very high performance budget system! :P And pleeze when you're at it, make a version for us OW1 lovers too will you... :twisted: :B

I'll give a look at the Seas. I've never actually used any of them, only tested some loaners. I'm liking more of what I see in them. As to the OW1, I no longer have a working pair. A SoundEasy glitch when running actively blew them, the reason I threw in the XT19 I had on hand.

I may make use of the XT19 with the RS52 because I have my own hybrid of OW1 motor and Scan-Speak D2010 diaphragm assembly to replace them, so I won't be buying any OW1's any time soon.

The Seas is 98mm diameter, same as the SS 2010. I think that the SS is being passed over by almost everyone anymore, even though for half the price of the OW1, it's nearly the same driver, designed by Oscar Wroending now of Hiquphon, I believe.

The XT19 and OW1 are 93mm, so they're probably a better match, but I'm less concerned than some with absolutes on CTC spacing. Since I generally listen in one spot, not moving up or down, once integrated at the XO, I fell it's less of a concern, given the higher absorption rates of carpeting and such a the Mid/Tweeter crossover region. Just don't be up and moving around while listening.

My first plan had been to use a pair of MDT-44's I have on hand, but I've got to say they don't measure like the published specs. Got a big dip around 1.5K certainly due to an internat resonance and are not nearly as linear above, either.

Since I have the XT19's I'll probably go with them, but the H1283 intrigues me a bit. I just wish that the new silkie didn't have that huge faceplate. I've never understood why any tweeters were made that size.

I haven't used the RS225, but I'm skeptical of using it given the need for an 800Hz or higher XO point being needed. I also already have a number of 7" and 8" drivers on-hand to use.

[dlr]

I'll echo that

Well, you can simulate that easy enough with The Edge, and practially speaking, you have some wiggle room, as it "peaks" before it drops off, but I'd plan on 8-10" at least.

I would also simulate some variations on the front panel layout to get the smoothest response from the drivers in their pass band; I've doing this routinely for a while, and it really prevents some headaches later on. Personally I find The Edge easier to use in some ways than FRD Consortium FRD; it's a standalone program in Windows. Doesn't do some things BDS does, but for evaluating baffle shapes and one driver and location at a time, it works pretty well.

~Jon

What I plan to do is to see what baffle dimensions and driver position add only a small boost before rolloff and below the 2K shelving native to the RS52. There ought to be a way to minimize the need to complicate a XO for the baffle step that will be an issue given the wide dispersion this driver has.

[Brian Bunge]

Jon,

An 8-9" baffle should be doable for me. I'm considering using the RS180's but if the bass response of the 150's is as good as Chris says, I think they'll work fine for me. I'll see what kind of driver layout I can come up with using The Edge. I might even give BDS a try again.

[Brian Bunge]

Well hell! After talking to Ashley she might have nixed my tower plans. Based on how she wants to lay out the room there may not be room for them. I may have to go with small speakers sitting on top of a short bookshelf in order to get her some sort of speakers in there.

No matter. I'll still design and build a 3-way tower. I mean, I've got the mids. I've got to do something with them! I guess someone will get a nice set of towers for a gift sometime this year. At least it opens up the possibilities of using larger woofers. I just have to decide who I'm building for so I can make sure they can handle the larger cabinet.

I looked at the SS 2010 and realized I've heard it in a couple of designs before and thought it sounded very nice. Keep in mind that the design philosophy was completely different. They were used on some Meadowlark Audio 3-ways which used all 1st order crossovers. Still, the tweeters sounded pretty damn good to me, as did the entire speaker. IIRC, the design also used an Audax Aerogel 4" driver and dual 7" Vifa PL and eventually SS 7" woofers (upgraded model) in a TL design. It was definitely an interesting design and sounded great. But they were $$$$ and didn't go with my usual listening preferences at least 80% of the time. With the right setup they were damn smooth though.

[Marzen]

That's one nasty 13.5k breakup, though. gadzooks. It'll take a bit of work to tame it, and may greatly limit the practical HF extension due to HD.

I think I stayed clear of that by crossing at 3Khz with a LR4 BP & used a notch in both the HP & LP ckt. That gives me about 48dB roll off below the F3 points. Getting a flat response in that 1.5K - 3Khz region involved more tweaking than I'd anticapted. Impedance is currently to low for me at 2.5 ohms minimus, other than that, it mated nicely with the RS180 & RS28.
-Ward