Dayton pro 18" woofer w/4" VC

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I wonder if anyone has any comments or experience with the Dayton pro series 18" woofer p/n 295-085 from PE? I am looking at this driver as a potential candidate to use in an H open baffle up to 200-400 Hz in a two way FR enclosure. I do not need the high power capability of this driver but do need the high efficiency which is rated at 97 dB. My goal is a speaker for use with a low power SET amplifier. Drawbacks with using a single 18" driver instead of multiple smaller ones to get enough piston area are high cone mass related 'speed' issues with the single driver vs multiple HF source drawbacks at the high end of the desired passband. The group delay on this driver seems to be lower than many other 18"ers I've seen.

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-085

Suggestions for a more suitable driver are of course welcomed.
 
RCA,

Funny you should bring this up. I've been playing with this driver in a pair of ~15 ft^3 MLTLs for some time now and just this week, I've had to rethink my impressions of it.

I've always liked the driver but I've primarily been using it as a semi-sub, meaning I've never tried to low pass below 80Hz or above 200hz (LR4 active). With the various systems I've had it in, it seemed to always work best below 150hz so I just never tried to push it.

This week though I decided to take another look at it and started dialing the XO point beyond 200hz. I've been swapping systems in and out over the past month, playing with a 16 NSB/8 PT2 driver line array and an odd but rediculously good sounding reflector speaker. I've posted these before but here they are again just so you'll know what I've been using the Daytons with.

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An externally hosted image should be here but it was not working when we last tested it.


I've since replaced the upper FE164 with a Fountek JP3 ribbon tweeter, so the dual-single driver arrangement has changed on the reflector speaker.

At 400hz, the Dayton has taken on a new life in the reflector speaker setup. For whatever reason, and I'm beginning to think it's a room artifact, the blend of the FE164/JP3 with the Dayton is absolutely superb and "speed" is not an issue at all. At a 200hz XO point, it's a mud bog, so your guess is as good as mine why it's happening. I experienced the same exact problem with a pair of sealed FX200 drivers so it seems to be consistent anyway.

There's other issues with crossing that high to the line arrays, but it's more about a mismatch with the wave front properties of the LA vs the point source. It still works better when crossed at 100hz.

I guess what I'm trying to say is that the driver has more potential than I ever thought it did, especially out to 400Hz (with a 4th order lowpass anyway). I wish I could say I've had it in an open baffle, but I haven't. I can't be much help to you there, but I can say that it's a heck of nice driver for the price.


On another note, a friend and I modeled a pair of these same Daytons for an HT sub woofer built into an unused alcove in his video room. This project turned out very well and the drivers are just plain kick-a** in this setup. :)

An externally hosted image should be here but it was not working when we last tested it.


They're mounted in 49ft^3 of cinder block and brick lined corner space so he's getting pretty much all he can get from the setup. Unfortunately, I live in Oregon and he lives in New York so I'v enever had a chance to hear it. Wired in parallel and along with mult-driver gain and an extremely rigid corner, he's probably seeing 103db of very low distortion efficiency outta this puppy.

I'd say buy it and try it, but I really hate to spend other people's money. :D
 
AJ,

Thank you for the detailed report and fine pictures. I see you make good use of the redwood from where you live! ;)

That reflector speaker certainly is odd. I won't ask why but applaud you for the effort. I respect DIY'ers who do stuff, especially unusual stuff that threatens to push the corner of the envelope.

I am encouraged by your comments on the big Dayton. I presently have a pair of 18" drivers that I have used in a cold cellar cinder block room sub much like your buddy in NY. I plan to borrow them and try my OB idea. They are pretty efficient although nowhere as high quality as the Dayton. They should tell me if I am off on the right foot or not. If it looks promissing I'll then probably spring foor the Daytons. That looks indeed like a lot of driver for the dough.
 
I purchased a pair of the dayton 18's just last week. Parts Express was selling them for $138 each. I intend to build 8-10 ft ported cabinets triangular in shape with corner placement. These will be for subwoofer only duty, operating from 50-60 hz down. I'm excited to experiment with them. Good luck! Jerrod
 
I won't ask why but applaud you for the effort.


heh heh...It came about when I was thinking about an "omni" speaker and ran across a new Loth-X design that uses a Lowther driver down-firing into an angled reflector. I had a bunch of unused plywood, a coupla FE164's, and an over-active imagination so I put them all together and came up with a double reflector. When I first fired them up I had a barf-bucket handy, thinking I'd probably be needing it. :D

It turns out though, that Loth-X had done their homework and these were a very pleasant surprise. The obvious answer to "why" is dispersion and the reflectors are aimed at that goal. They overcome some of the problems of beaming and provide a more natural response throughout the FR. They are by no means "ommni-directional" though and another big surprise was the way they imaged. I expected a thin, wandering center image like a Bose-type setup where imaging is everywhere and nowhere all at the same time. :D Instead, it's rock-solid and instruments and vocals are precisely placed in a very 3-D space. The sound stage and sweet spot are very wide but they do have limits, so there's still a good amount of directionality to the speakers.

What I like most about them is the 3-D airiness. It's much better than what a direct-radiating FE164 can produce and the lack of beaming is just downright comfortable to listen to. I've been crossing the ribbon tweeter at 4khz to 5khz and again, the reflectors are doing a marvelous job of minimizing the vertical dispersion limitations of the tweeters. The sound is big, coherent, airy, and with pin-point imaging to boot. Subjectively, they're very relaxing with amazing detail that comes thru without straining. And all of this from a driver that I don't even like. :D

I'm satisfied that the concept is doable, so I'm in the process of putting together another version using a driver that I DO like. It'll use a pair of FX200s with the same ribbon and I expect some great results. I'm gonna buy a pair of Audax PR170M0 mid range drivers on Monday (I've been hearing raves about them) and mate them up with a pair of Fountek JP2 tweeters in yet another version. The JP2s come closer to the sensitivity of the Audax units, and now that I know the Daytons will do okay up to 400hz, I can get a reasonable XO point to the mids. I'll use some fresh lumber on these two sets so they don't look like Frankenspeakers when they're done. :)
 
jlharden said:
I purchased a pair of the dayton 18's just last week. Parts Express was selling them for $138 each. I intend to build 8-10 ft ported cabinets triangular in shape with corner placement. These will be for subwoofer only duty, operating from 50-60 hz down. I'm excited to experiment with them. Good luck! Jerrod


When I first started contemplating this driver last week they were on special. Unfortunately I was not ready to 'take the plunge' and now they are no longer on special. :(

I am in Canada and I have to think long and hard, and then think again about any purchases of this magnitude across the border where a shipper becomes involved. The costs can quickly get out of control at our border. Free trade my *ss! :(
 
Is there a free air response graph for them? I only see the ported rolling off at 50. I'm sure the high end will be fine. My concern would be what goes on in a dipole setup below 100.

H baffles? Didn't you read my example of how H baffles are a waste of wood? Save $ and some trees at the same time.
 
johninCR said:
Is there a free air response graph for them? I only see the ported rolling off at 50. I'm sure the high end will be fine. My concern would be what goes on in a dipole setup below 100.

H baffles? Didn't you read my example of how H baffles are a waste of wood? Save $ and some trees at the same time.

Hi John,

No graphs could I find. BTW, I don't use wood, I use pressed, glued sawdust. How about a link to your discussion about how H baffles are a waste of glued sawdust? ;)

I do not want to use EQ on this woofer, and it is running on just a few watts total, for the full range, so efficiency is critical! That is why a large baffle will be needed because there ain't no EQ to make up for 'around the baffle side cancellation'. I might even have to make a labyrinth behind the woofer to increase the path length. :eek:
 
Hi Rob,

For that flat response ported it's likely to start rolling off way before 50 in free air. If 95 db is ok, then here's a better cheaper option in a 12 or 15" (the 15 is discontinued, so if you can find some, they may be even cheaper). Good efficiency and a significantly higher Qts. In dipole air that Dayton will resist making bass due to the low Qts, since you aren't EQing.
http://editweb.iglou.com/eminence/eminence/pages/products02/speakers/beta15cx.htm

Another alternative is to just use the BetaCX12 and buy Adire's compression tweet (the eminence one isn't good enough), if you are handling your own Xover, then you've got high efficiency and OB friendly in one driver for everything but an extreme bottom end which that Dayton isn't going to do anyway. If I didn't already have a multitude of drivers already and needed a speaker, that's what I would do.

The wasted part isn't so much the wood that's important. I was joking about that. IMO it's the wasted space and wood at no gain. A laborinth will really throw you into cardiod dispersion instead of dipole. A better option might be the Nao U frame which picks up 6db at the bottom end vs dipole.

Here's the link to that to the thread where I shrank 25k sq cm of wood to 10k with the same depth from the driver to the back edge and actually pick up some bass. Go deeper and it becomes the Nao woofer cab.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=14179&perpage=10&pagenumber=35
 
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