Hawthorne Silver Iris - New OB driver

[johninCR]

I got a pair of Silver Iris's from www.HawthorneAudio.com on Monday. If you go to the website, understand that it's a work in progress and their great customer service makes up for anything lacking on the web page. The Iris is a 15" coaxial unit with a Qts of .91, Fs 41.8hz, Vas 244L, Xmax 3.45mm and a sensitivity of 95.8db/w/m.

I've been searching for an ideal single driver solution for use on OB and had pretty much resided to the fact that no full ranger was going to provide enough bass on OB.

Boy was I wrong. I've had a modified Ubaffle in the back of my mind for some time and decided to try it with the Iris's. They worked so well that I named them "The Joint Chiefs" in honor of their pentagon shape. At a max depth of only 16" and a front profile barely big enough to fit the driver, my baffle has an expected Fequal of 73hz which I thought would get me some solid bass since it's equivalent to a 5ft by 6ft flat baffle. I still thought I'd need another bass driver for really full bass at the 95+db levels I often listen. Wrong again.

I'm getting nice solid bass into the 30's and that's with the Joint Chiefs on another cab 27" off the floor! eg I love Pink Floyd, but that part of my collection has gone unused since I've been using OB's because I hadn't found the proper OB bass solution. While they may not go deep enough for trance music, if they can handle Pink Floyd with authority, they can play most anything else.

At first I thought the tweeter was going to be a slight problem with a little harshness, but after a few days of playing they have really smoothed out and I really can't find anything that I would consider a compromise. I don't get pure dipole radiation with my baffle, so I get only about an 80% null at the sides, but that is offset by a wider prime area of bass response out front and I haven't noticed any modal problems crop up, so who cares about a perfect figure 8.

The Iris's just as happy with my HT sand amp as they are with my SET amp. I did, however, hear of one problem using a very underdamped PP amp and the cone started flopping around.

They've got nice full clear OB bass right up to 100db. As typical with OB's the mids are as sweet as can be with those crystal clear vocals and dialogue (for you HT fans), plus the high end is detailed and well extended with all the harshness gone after a few days. Did I mention this all comes with that wide open OB sound? In addition the 15" driver launches a big wavefront, so the sound is big and they have a nice rich tonality that the popular narrow speakers just can't duplicate.

This only thing I can think of that might improve them is going active and biamping and time alignment which is already close to spot on with the coaxial alignment of the tweeter.

All I need is 5 more for my HT setup and I'm done, at least until Hawthorne introduces it's bass augmenter for OB use, since I'll need 2 of those for my HT sub.

Anyone who's on the fence about giving OB a shot, this is the driver you've been waiting for. Their supplies are somewhat limited on this initial run, so you might have to wait 6 weeks or so for the next run to arrive if you procrastinate. Plus he's running an introductory special at $139/driver. Those of us who know the owner, Darrel Hawthorne, from over at the Decware forum are snapping them up pretty quick after the first reports came in about how good they are.

Someone asked me in another thread to report on these drivers once I got them and this is a much more reliable "2 thumbs up" than Siskell and Ebert ever dreamed of giving, so all you fence sitters, it's time to find out what the OB fuss is all about without sacrificing your bass.

[Scottmoose]

Aha! The return of the reasonbly priced 15" Tannoy Dual Concentric! Or, at least, that's what they appear to be going. What a lovely, lovely driver. Perhaps I should sell someone else's soul to get a pair...

Seriously though, those things look very impressive indeed. That's a heck of a good price too, especially the introductory one. Providing they ship to the UK, I'm starting to run out of reasons not to buy a couple to play with. My old Tannoys are still in the garage -they need a re-build really, and they're not so good on open baffles, but these could be a good substitute. Thanks for letting us know!

Best
Scott

[Magnetar]

It sure looks like a re-badged smaller magnet version (weaker chinned) of the cheap Eminence coax to me. Beta 15 Coax

[tubesguy]

The drivers sound enticing, but could you post a pic of the baffle? I'm having a little problem visualizing it. TIA - Pat

[johninCR]

Originally posted by Magnetar
It sure looks like a re-badged smaller magnet version (weaker chinned) of the cheap Eminence coax to me. Beta 15 Coax

I'm sure Eminence didn't totally retool for Darrel's run, so I'm sure a lot of the parts are the same. The conical horn seems to be different and the modded tweet is world's better than Eminence's old one (I know because I have some). Was there a problem with the Beta15CX, which is now discontinued? I realize these aren't going to keep up with your big horn loaded system, but for under $300/pr plus some wood and an easy build I don't think they can be beaten. I was just expecting decent bass in a single driver OB, but I was quite pleasantly surprised by the SQ. These are the best speakers I've built and the easiest to construct (except for some cardboard OB test baffles). To give you an idea, I've already gotten them to pull the disappearing act, which is no easy task with OB, and that's with only a few days of break in.

Originally posted by tubesguy
The drivers sound enticing, but could you post a pic of the baffle? I'm having a little problem visualizing it. TIA - Pat

The front baffle is a pentagon that barely fits the driver. The pentagon shaped U baffle in back has a maximum depth of 16". I'm not quite ready to publicize the exact shape of the back of the baffle, but they killed the resonances except when fairly close to the rear wall and some 1/2" open cell foam clears that right up. Pics will be a few weeks once I figure out a heavy stable base and build a pair with some beautiful exotic hardwood I've had curing for over a year.

[Paul Ebert]

Is there a frequency response graph for this driver? Also, I'd like to know some information on the crossover (order and cut-off frequency).

Looks quite cool, in concept... And the price is good. I'll certainly consider it, though my initial impression is preference for the B200 (augmented with a tweeter as needed). I guess I'm concerned about beaming.

I am very interested in the 15" bass augmentation driver.

Time to add the Hawthorne site to my favorites and check out the Decware forum. Thanks for letting us know.

Paul

[Magnetar]

[QUOTE]Originally posted by johninCR


I'm sure Eminence didn't totally retool for Darrel's run, so I'm sure a lot of the parts are the same. The conical horn seems to be different and the modded tweet is world's better than Eminence's old one (I know because I have some).

Who makes them? Bet it's Eminence - they DO make good drivers regardless. I've been through some speakers and I've been sold on good high efficency coaxials (prefer a 15) for a record 7 months now. The 15CX I heard had a very simular horn but had a TAD 2001 for the tweeter. It was good with the TAD but I think the little alnico Emilar 175 driver is better in the treble. I think that would be a pretty sweet coax for a direct radiator and not a lot of money.

[johninCR]

Originally posted by Paul Ebert
Is there a frequency response graph for this driver? Also, I'd like to know some information on the crossover (order and cut-off frequency).

No graphs that I know of. If I ever get around to measuring, it would be with my baffles, but I'm not sure my SPL meter will even measure correctly since it's OB. I read somewhere recently about mics not registering dipoles.

The XO is 2nd order, but I don't know at what point.

Looks quite cool, in concept... And the price is good. I'll certainly consider it, though my initial impression is preference for the B200 (augmented with a tweeter as needed). I guess I'm concerned about beaming.

I was leaning the B200 route too, but any way you slice it, the B200 requires bass augmentation, and I question the top end too.

Shouldn't beaming be less of a problem with the horn loaded tweeter?

I am very interested in the 15" bass augmentation driver.

I believe it's at least a few months away. I thought I'd need the augmenters too, all the way up until I put the Iris's in my Joint Chiefs. Without a 5-6ft flat baffle or some form of U baffle, EQ will be required in some form with ANY OB configuration, bass augmenter or not, to achieve a meaningful bottom end with a reasonable efficiency. You can utilize the high Q of some drivers to offset some baffle size, but drivers that can do that below 40 or 50hz are highly suspect in terms of SQ.

One valid approach is what Linkwitz uses. Take drivers with high quality sound and appropriate capacity, then use electronics to shape the response you want. For a cheap minimalist, like myself, that's not acceptable. All we have is our drivers and our baffle. Personally, I want it as simple as possible and the fewer sound sources the better. I've been looking hard believe I've found the ultimate solution, for me. If it takes a tweeter, a woofer, 2 resistors, 2 inductors, and 2 capacitors between my amp and my ears so be it. At least it helps that the tweeter output comes from the middle of the woofer. I tried to take a full ranger (FE206) plus a woofer and only one inductor as far as a could, but this new driver surpasses it by a significant margin in several respects and I haven't begun to tweak my baffle yet.

[Paul Ebert]

Originally posted by johninCR

Shouldn't beaming be less of a problem with the horn loaded tweeter?

Well, the horn loading should allow for a lower crossover point, so in that regard, yes (assuming this was taken advantage of in the crossover design).

But, a 15" driver has a horizontal polar response that is 3 dB down at 661 Hz and 6 dB down at 1043 Hz (according to my worn copy of The Loudspeaker Design Cookbook).

If you are getting your Joint Chiefs to disappear (did I read you correctly on that?), then, perhaps, the horn loading really does let the tweeter integrate with the 15" to reduce beaming to an acceptable level. That would be exceedingly cool.

Do you notice the treble changing much as you change listening position?

[Variac]

The Hammer speaker also uses a custom Eminence Beta, but based on the one with a whizzer cone.

I looked into this a bit a couple of years ago, wanting a driver very similar to the Silver Iris , and being desperate enough to consider trying to get a group buy together.

First, Eminence claims to be the largest driver maker around, but I suspect that there is some qualifier limiting it to musical equipment drivers or PA drivers. Regardless, they are huge. They have lots of interchangable cones, magnets, etc. which they can mix and match to create custom drivers. It seems they can also make custom cones, etc. For what you get, they seem to be an incredible bargain.


The Bastani OB speakers use custom Eminence, the Basszilla now uses an eminence Magnum 15 HO. Adire Audio uses the stock version of the co-ax, but they are more tightlipped about the high end horn that they use. Probably the new Eminence, but no sure info.

If you read the Silver Iris web site they say it is an Eminence I believe. It probably really is custom, because from what I read on the Eminence site, they will make you a custom speaker for a minimum order run of 100 drivers. This seems to include some consulting. Another place where some modification is available is avaialable to all is the tweeter horn. This has a standard thread mount and there are a lot of choices out there.

I would sure be interested in possible tweeter candidates such as the TAD 2001 and Emilar 175.

HEre is the Emilar site. I never heard of them! Anyone know how much this driver costs?

http://www.plusoneengineering.com/drivers.htm

Sems like there might not be much of a supply- they say that they are using all their production to make siren drivers at the moment!!