9.  How far away from the wall do my speakers need to be?
When we set up our speakers we need to place them such that they help create the illusion that we have performers in our room with us.  This is a basic goal for most audiophiles and music lovers alike.
We want to have what we are hearing sound as close to the real event as possible.

Where we place our speakers within the room can, and often does, have considerable impact on what we hear.  All rooms are unique, but in general, we can make some predictions and at least have a good starting point. The spacing off the front wall helps with the illusion of soundstage depth. If we place our speaker very close to the front wall (the wall we view while listening), we risk having a very shallow soundstage illusion. If we place our speakers too close together, we risk having a very narrow or congested soundstage illusion. I like to maintain several feet from my speaker to any wall.  In general, greater distances from the wall or between speakers equate to greater depth and width illusion potentials.

Clearance to side wall is less critical with OB speakers because of their intrinsic cancelation null, but we must be mindful of first reflection off of these same side walls and either place the speakers farther away from them, treat them or both.  Room treatment, as well as speaker placement, can be every bit as important a consideration as any single piece of audio gear. For more information on room treatments visit the Hawthorne Audio forum.  In all cases, remember that speakers can be easily integrated into almost any room if we allow ourselves the opportunity to position them properly for listening sessions and return them to a more aesthetically acceptable location (possibly closer to the walls) in between sessions.

10. How low will the coaxial play?
Our coaxials will extend down to a level corresponding to their natural intrinsic roll off design goals as well as being in partially determined by our baffle size and driver location relative boundaries. In general, both of our coaxial units will play close to their Fs on a modest sized baffle. This easily covers most acoustic music sources commonly found in most recordings. Exceptions include some notes on the piano, organ, contra bassoon, some drum sounds and some electronically generated bass sounds.

We do not generally recommend using large baffles, EQ or DSP in an attempt to force these drivers to play lower then what they can do effortlessly. This is in keeping with my personal design tenets but you could probably force them to play lower.  For greater bass authority and extension we recommend augmentation with a purpose built OB augmentation driver (Augie).

11. How loud can they play?
All of our drivers are very well constructed, robust with a high Pmax number.  As such, they are fully capable of playing very loud.  Actual max SPL numbers have not been established, but it is safe to assume that they will be capable of reaching realistically high levels for most any sort of music one would listen to in a domestic setting.


12. Aren't 15" drivers slow?
Yes and no.  Speed or quickness is a relative term. Can a 15" driver be made to reciprocate back and forth at high speed? Yes.  Our 15" Silver Iris driver can create a 3000 Hz note relatively effortlessly, so it could be said to be fully capable of starting, moving forward, stopping, reversing, moving backward, stopping and repeat this sufficiently fast so as to create a clean 3000Hz tone. That is very fast and well within the need for a mid woofer to hand off to a tweeter.

Other 15" drivers have been purpose built to move massive amounts of air at very low frequencies. Their design priorities are much different than a typical mid woofer and, in comparison, could be deemed slower.  Their design goals determine how they are constructed and they become much heavier and slower to react to changes in direction and incapable of reproducing the very high frequencies. A 15" sub woofer specific driver would not serve us as well as a mid woofer as one that has been specifically designed to function as such.

One must be careful never to look only at driver’s size when making performance speculations.  We would never use a 15 driver as a tweeter as its design would normally disqualify it as an ideal candidate for such a task.  However, they can be designed to play mid range frequencies very accurately with a very high level of musicality and believability.

13. Do you have spec sheets?
Yes and are located on our "Drivers" Page on the main web site


14. Why don't you publish standard frequency response plots?
Open baffle speakers are unique in that we do not try to contain the rear pressure wave coming off the back of the drivers. To fully appreciate their intrinsic sound we must listen to them with this rear wave included in their overall sound presentation.  Plotting out such a speaker’s frequency response becomes a challenge when we consider the lack of any industry standards for measuring the composite front and rear speaker response.

While this rearward firing energy is responsible for much of the natural, realistic sound typical of a dipole style speaker, it would also demand that each dipole speaker manufacturer agree on exactly what sort of room these speakers should be plotted in.  We simply cannot agree on what would be a fair and logical way of accurately representing this style of speaker in any meaningful way that the end user could really put to use in their decision making or product selection.

Depending on how we set these up for measurement, we could make them to appear on paper most any way we wished. This, in my opinion, is unfair to the customer and simply unworthy of consideration in the big picture. Independent, third party, product testing is very expensive and it is you the consumer that would be asked to shoulder these expenses. I prefer to omit this in favor of considerable listening during the design phase. This helps keep our price points low while insuring a speaker with a design priority of musicality rather than specs.

15. Can the coaxials be upgraded?
Yes. If we break this coaxial design down into its component parts, we see two drivers and a purpose built crossover. Either driver or any component in the matrix of parts could be changed to a higher performing substitute.

16. What is a mid grade xo?
As the name would suggest, a mid grade crossover is simply a crossover that has been built up using components that are ranked somewhere in the middle of two ends of the performance spectrum from performance (entry level) grade to top of the line (money no object) offerings.  We offer performance grade, mid grade and Sterling grade component options. We strive to offer true value across each grade level.

17. What's the difference between SSI and PSI?
These are the abbreviated designations for the two performance levels of drivers we offer. Performance grade Silver Iris and Sterling grade Silver Iris.  In casual conversation it takes too long to write out Sterling Silver Iris 15” open baffle specific coaxial drivers, so we simply refer to them as the Sterling’s or SSI's.  Here is a link to a more detailed explanation of their differences:

http://www.hawthorneaudio.com/forums/viewtopic.php?f=18&t=3166


18. What is an "Augie" driver?
 Augie is the name I gave to our purpose built open baffle bass augmentation drivers.  The Silver Iris Augies take over where the coaxials naturally roll off and supply support to these low mid/ upper bass frequencies. Think of Augies as helper woofers specifically designed to augment any mains speaker needing a little help on their bottom end. Augies can play down to their Fs (27 Hz) on a modest sized open baffle and can be used to provide very realistic dipole bass energy. They have been successfully integrated with not only our speakers but also with many other speaker manufacturers’ offerings.


19. How much power do I need to use your Augies?
Augies are intended to cover the very demanding low mids and upper bass frequencies. Because of this they need considerable more power than our full range coaxials . They can safely handle several hundred watts of clean power. I would recommend a power amp range from 100 to 350 watts. Because OB speakers are run in free air and do not require enclosures they do not depend on the air spring safeguard of typical box speakers but instead rely on xmax and heavy duty construction practices. Augies, like all Silver Iris drivers, share a pro-sound heritage and are very well built.

20. Can I use the Augies with my current full range drivers?
 Yes. Augies can be easily integrated with any full range speaker needing a bit of help on their bottom end.

21.  Do the coaxial crossovers also supply the Augie?
No. The crossover supplied with the coaxials is a two way only design. We recommend bi-amping your Augies using separate amplifiers and a separate low pass crossover.  Plate amps work well in this application.

22. Can I use one amp for the coaxials and Augies?
Yes, but this is not the preferred method of integrating an Augie. Because of the two very different amplifier needs of the coaxial and the Augie, finding a suitable amplifier to drive both would be problematic as well as expensive.  This application would be lacking in system flexibility and a compromised approach compared to bi-amping with a separate amplifier and separate low pass crossover.

The Silver Iris coaxials are considered to be very high sensitivity and are often driven with very high quality yet low power amps.  Many run tube amps or very small wattage solid state amps. As an example, I am currently running a small "Spud" valve amp rated at around 3 watts per channel on my Sterling coaxials.  I then bi-Amp in my Augies using a 350 watt solid state plate amp that has a built in variable low pass crossover and additional bass management features.  I am supplying each driver with the best possible amplifier for its needs without any consideration for the other driver’s special needs. I also enjoy considerable system flexibility going this way over a single amp set up.  I can independently determine gain settings for each driver and this allows me to better control their relationship and output relative each other. Sometimes, you just need more bass, and this helps insure this potential.

23. Can I add an Augie to my Solo at a later date?
Yes.  One could start with a Solo speaker with just the coaxial, and enjoy this until such time that you could invest in the augmentation system and integrate as need and budget permits. All of our production finished speakers have this upgrade potential designed right into them from the start. All of our speakers can be field converted at a later date to include the Augies. This can be done by the owner with minimal time and tools required.

24. Can I schedule an audition to hear the SI's?
Yes. Please write for more details.

25. Why do you prefer e-mail over phone?
I do not publish a phone number for my shop and understand that this is somewhat out of the ordinary.
 I do this for several reasons, but please understand that this is simply part of my efficiency strategy and nothing personal.  I love talking with our customers.

With e-mails, I can better keep custom speaker build specifics from ever getting misremembered. I keep each e-mail exchange and hard copy this to a project file for each build that I can refer back to should I ever forget a detail.  I generally have several finished speakers going at the same time and the potential to misremember something becomes greater with these higher volumes. This is especially true whenever we are doing custom works.