Any other Hawthorn Silver Iris users here?

[Rick J. B.]

These were my first venture into open baffle speakers and I'm really pleased with them.

What I have is the SI coaxial drivers running with the 15" augie woofers on a common baffle. I probably could have gotten by with just the SI's, but I certainly don't regret obtaining the augie's as these speakers have a rock solid bottom end. Right now I'm crossing them over at 100hz.

I'd post some pics but I don't have any on this computer and I'm fixing on building some new, nicer baffles anyway.

So, any other Silver Iris fans around these parts?

Rick

[boywonder]

IIRC Tubelab George has a pair as his main speakers mounted in some antique radio cabinets for increased WAF. Do a search over in the tube forum, I recall he posted a few pics somewhere.....

[dantheman]

So you just want to know if there are other SI users here? Do you have any questions about them? I have plenty experience with the drivers and I might be able to answer your questions.

Dan

[Rick J. B.]

Originally Posted by dantheman

So you just want to know if there are other SI users here? Do you have any questions about them? I have plenty experience with the drivers and I might be able to answer your questions.

Dan

Howdy Dan, no, no real questions, just curious if many users here listened to them. I've had mine for about 3 years now and believe they give a lot of bang for the buck.

I'm especially impressed with the Augie bass drivers. Best bass reproduction I've personally owned.

Rick

[holdent]

I have the SIs and love them. I'm in the process of pairing them with 2 Eminence Alpha 15As per side in a baffle 18" x 48". (I was able to get the 4 Alpha 15As in Canada for cheaper than a pair of Augies). The baffle will be supported using 4" wide sides running from top to bottom at a 45 degree angle.

Unfortunately I broke my router bit this morning and haven't been able to finish the driver cut-outs for test baffles yet.

I plan on using an active xover at 350 Hz (LR 4th order) to cross from the SI to the Alphas. Modeling this design with MJK's MathCad application shows some impressively flat results. The Alphas combined are more sensitive in *modeled* baffle than the SIs which will require a cut of approximately 5 dB at the xover

[Geek]

I heard them a few years back at the Victoria Audiofest and liked them best of all the OB we used

Cheers!

[preiter]

Originally Posted by holdent

I have the SIs and love them. I'm in the process of pairing them with 2 Eminence Alpha 15As per side in a baffle 18" x 48". (I was able to get the 4 Alpha 15As in Canada for cheaper than a pair of Augies). The baffle will be supported using 4" wide sides running from top to bottom at a 45 degree angle.

I don't know that the 15As are going to buy you much. The Silver Iris is pretty good down to 50 Hz. The Alpha 15A has a FS of 40 Hz. That's not a lot of extra bottom end you are adding.

Go for the Augies, they are well worth it.

[dantheman]

Originally Posted by preiter

I don't know that the 15As are going to buy you much. The Silver Iris is pretty good down to 50 Hz. The Alpha 15A has a FS of 40 Hz. That's not a lot of extra bottom end you are adding.

Go for the Augies, they are well worth it.

I'll second that.

Dan

[just a guy]

I won't. It depends heavily on the size and shape of the baffle, but in "regular" baffles, the PSI will be at least 6 db down on the bottom end, making helper woofers necessary even if they don't go any lower than the main driver.

[holdent]

I believe that the SIs or PSIs need a helper woofer, simply because the optimal location for the SI is at ear height which is suboptimal for anything below 100 Hz.

I was attracted to the Alphas over the Augies for several reasons:
a) Cost. The Augies cost $150 US each compared to $60 each for the Alphas.
b) Sensitivity. The Augies have an advertized sensivity of 88.7 dB 1w/1m. The Alphas advertized sensitivity is 97 dB 1w/1m although they are more like 94 db 1w/1m in the range I'm interested in using them.
c) Potential for lower distortion. All things being equal you need to pump a lot more power into one Augie to reach the same SPLs at 40 Hz than the 2 Alphas. My guess is that you need almost 100 watts to reach the same SPLs with the Augies than possible with 1 watt with 2 Alphas. (The Alpha is roughly 5 dB more sensitive, 2 together will be roughly 8 dB more sensitive).
d) Availability of measured T/S parameters. Since I don't have a woofer tester, I have to rely on published T/S data to model the speakers. Data on the Alpha is widely available both from Eminence and published by third parties (ex. Martin King). Unfortunately the same measurements aren't as available for the Augie. You have to make Sd and Bl guesses to model the Augie. I guessed 10 N/A for the Bl and 896.5 cm2 for the Sd.

Don't get me wrong - I understand the Augie is a great driver. No question 2 Augies will be better than 2 Alphas. They just exceed the cost/benefit ratio for my budget.