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
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
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
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
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
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 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.
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.
I don't really see sensitivity as an issue.
Most users are bi-amping anyway, so matching sensitivity to the mains isn't a problem.
Watts are cheap, and at the frequencies we are talking about, the quality of the amp isn't hugely important. An inexpensive plate amp will suffice.
The less significant T/S parameters aren't a big deal when you are talking open baffle, especially when you know the driver in question was designed for open baffle. It's pretty simple and effective to experiment with baffles (even cardboard works), to tune the sound. If you really want the other T/S parameters, I'm sure Darrell Hawthorne has them all. Post a request on the Hawthorne Audio forum and you should get what you need.
I don't understand your point about higher efficiency equalling lower distortion. Keep in mind, however, that the Augie has almost double the Xmax of the Alpha 15A. You will need twice as many of the latter driver to match the output of the Augie.
Price is certainly a consideration, but 2 x Alpha 15A is $120 and 1 Augie is $150. That's not a big difference.
Most users are bi-amping anyway, so matching sensitivity to the mains isn't a problem.
Watts are cheap, and at the frequencies we are talking about, the quality of the amp isn't hugely important. An inexpensive plate amp will suffice.
The less significant T/S parameters aren't a big deal when you are talking open baffle, especially when you know the driver in question was designed for open baffle. It's pretty simple and effective to experiment with baffles (even cardboard works), to tune the sound. If you really want the other T/S parameters, I'm sure Darrell Hawthorne has them all. Post a request on the Hawthorne Audio forum and you should get what you need.
I don't understand your point about higher efficiency equalling lower distortion. Keep in mind, however, that the Augie has almost double the Xmax of the Alpha 15A. You will need twice as many of the latter driver to match the output of the Augie.
Price is certainly a consideration, but 2 x Alpha 15A is $120 and 1 Augie is $150. That's not a big difference.
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I used to think this way. But I noticed that even on OB, my woofer sounded too much like an ordinary boom boom sub. So I sent my sub amp to a 'modder' and HOLY crap what a difference. Night N' day. Much tighter and quicker. It resembles music now. But it did cost $700 for the upgrade.
I can't recommend stock rack or plate amps for any high end application. Their sound is just too 'slow and tubby' for lack of a better term.
I used to think this way. But I noticed that even on OB, my woofer sounded too much like an ordinary boom boom sub. So I sent my sub amp to a 'modder' and HOLY crap what a difference. Night N' day. Much tighter and quicker. It resembles music now. But it did cost $700 for the upgrade.
I can't recommend stock rack or plate amps for any high end application. Their sound is just too 'slow and tubby' for lack of a better term.
Anyway, my point was that nobody is going to be driving these with their flea powered tube amp, so high efficiency is not a consideration.
BTW, an 8 dB efficiency difference requires an amp 6.3x as powerful, not 100x.
I don't know about that. If is could get bottom efficient enuff to use our 4 W PP EL84 i would, because it has REALLY good bottom end.
dave
preiter:
the Augie has almost double the Xmax of the Alpha 15A. You will need twice as many of the latter driver to match the output of the Augie
Yes it does have a greater Xmax (assuming they're measured the same way) but in this usage that's not an issue. At the equivalent volume level the Augie should have a deflection around 4 mm (again according to the guessed T/S values) when the Alpha's are only around 1 mm. (Remember there are two Alphas which are about 8 dB more sensitive).
BTW, an 8 dB efficiency difference requires an amp 6.3x as powerful, not 100x
Yes - you're right. I went back and checked my calculations and I can't figure out how I came up with 100 watts.
If you really want the other T/S parameters, I'm sure Darrell Hawthorne has them all. Post a request
I hate to disagree with you (again!) but I have tried obtaining the all of T/S parameters w/o success through Hawthorne Audio. Again I have high regard for Darrell Hawthorne and his products but seemed to hit an impass here.
the Augie has almost double the Xmax of the Alpha 15A. You will need twice as many of the latter driver to match the output of the Augie
Yes it does have a greater Xmax (assuming they're measured the same way) but in this usage that's not an issue. At the equivalent volume level the Augie should have a deflection around 4 mm (again according to the guessed T/S values) when the Alpha's are only around 1 mm. (Remember there are two Alphas which are about 8 dB more sensitive).
BTW, an 8 dB efficiency difference requires an amp 6.3x as powerful, not 100x
Yes - you're right. I went back and checked my calculations and I can't figure out how I came up with 100 watts.
If you really want the other T/S parameters, I'm sure Darrell Hawthorne has them all. Post a request
I hate to disagree with you (again!) but I have tried obtaining the all of T/S parameters w/o success through Hawthorne Audio. Again I have high regard for Darrell Hawthorne and his products but seemed to hit an impass here.
Here is what i measured for a pair of (EnABLed) Augies. Probably very little change from stock (which i might also have but buried). Strange attitude to not freely supply T/S if you are selling a driver.
Having had both thru here, i'd choose 4 Alphas over 2 Augies. Except for the cast basket, build quality is approximately equal, 4 would allow for push-push use and could be used to help better match sensitivity.
dave
Having had both thru here, i'd choose 4 Alphas over 2 Augies. Except for the cast basket, build quality is approximately equal, 4 would allow for push-push use and could be used to help better match sensitivity.
dave
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20% deviation on mass and 12 on dc resistance? No wonder they don't disclose specs. It shouldn't be hard to get all units in a production run or across runs to within 5% all specs, should it? I'm glad I didn't buy any.
I notice it says '20% is normal factory deviation' but wtf that's awful.
I notice it says '20% is normal factory deviation' but wtf that's awful.
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Yes, cost/benefit is always a must to consider. You'll get over 4x the output from that arrangement for less money. Another thing to perhaps look into is Acoustic Elegance AE Speakers --- Superb Quality, Unforgettable Performance, Definitely.. They have some nice woofers built for OB and IB.
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