Sunfire HRS-12 Measurements and Conclusion
Initially, MLS time domain measurements were performed for the HRS-12s to determine frequency response and output characteristics. Unfortunately, subsequent review of the measured data indicated problems with the measurement itself after the subs had been returned to the manufacturer and as such, the plots will not be presented.
As part of the measurement process, I typically run an independent measurement with an SPL meter to provide a reference point when back checking the primary measurements.
Measurements performed nearfield at the approximate acoustic center of the driver, about 2 inches (5 cm), indicated a peak SPL of 120 dB. At this point, the protection/limiting circuitry kicked in and additional preamp gain would not increase the output.
Sunfire claims the maximum output that the HRS-12 subwoofers are capable of is 108 dB at 1 meter with room reinforcement. Acoustic losses into free space are widely known to be –6.02 dB for each doubling of distance from the sound source. The addition of reflective surfaces that are large compared to the wavelength of the sound near the source decreases the loss. With a single surface, also known as an acoustic half-space, the loss is –3.01 dB for each doubling of distance.
Correlating nearfield SPL output with the more common 1 meter anechoic measurement results in an acoustic half space yields the following results:
The calculated result is consistent with Sunfire’s claim of 108 dB at 1 meter in room where the addition of one or two walls to the presence of the floor would provide additional SPL reinforcement. The result is also consistent with my subjective observations about the HRS-12s ability to provide substantial bass output under real world usage conditions. This is a significant amount of output particularly when considering that it comes from a 38 lb sealed subwoofer with an internal cabinet volume that is defined by dimensions that are no larger than the diameter of the driver in any direction.
Conclusions & Recommendations
The Sunfire HRS-12 is quite a potent little package.
To get good monster bass, usually some fairly mongo subs are required. Brutes the size of tables, denizens of the corner, which make their presence obvious even without speaking. Those who have been constrained by space or WAF have had to go without. The HRS-12 can provide those poor, deprived souls with the bass they need without taking up significant room space or upsetting the Misses, at least, not too much.
It is rare to find a sub this small that can not only provide copious bass output, but also can provide deep and accurate bass output as well. Cabinet size, maximum SPL, and deep frequency response are competing demands in subwoofer design and these conflicts are more easily solved by throwing money at a design than by skillful balancing at a price point. While not cheap by some standards, the HRS-12 subwoofers do an excellent job balancing the design and providing outstanding performance without skyrocketing the price.
The HRS-12s represent what can be done in comparison with extreme designs and these Sunfire subs can certainly hang in there with products at that level even if they can not best them in an absolute sense. Considering that the HRS-12s can easily provide better than two thirds of the performance of subs like the Fathoms at a mere one third of the price, the HRS-12s are a well engineered, high value product that represents a very good bargain for anyone looking for extreme levels of bass performance at less than extreme prices.
The HRS-12 subwoofer can certainly belt out the bass, definitely making an excellent choice for anyone looking for depth, clarity, and good high SPL performance at a more reasonable size or price.
Sunfire Corporation
1920 Bickford Ave
Snohomish, WA 98290
800-554-0150
Canada 800-387-9101
www.sunfire.com
The Score Card
The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:
Performance × Price Factor/Value = Rating
Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.
Audioholics Rating Scale




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— Very Good


— Good

— Fair
— Poor
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| Fit and Finish | ![]() ![]() ![]() ![]() ![]() |
| Ergonomics & Usability | ![]() ![]() ![]() ![]() |
| Features | ![]() ![]() ![]() ![]() |
| Performance | ![]() ![]() ![]() ![]() ![]() |
| Value | ![]() ![]() ![]() ![]() ![]() |
At first I ran it with my dual F113s placed front right (the Fathoms are on the left side wall) and felt it blended very well with the Fathoms. Then, I turned the Fathoms off and ran it alone and then did a brief A/B with a single F113. It really is a very nice little sub for the money. Build quality and finish are good and it plays clean and loud down to the low 20Hz region. It handled music and movies very well clean output that was almost Fathom like. At its street price, two or even four of these would make for a very nice HT implementation and the small form factor is a big plus for flexible positioning and hence bass optimization.
I have returned this demo model to my dealer but I am thinking of going to quad subs in my HT room and this little sub (it makes the small Fathoms look huge) is on the short list for that duty.
One side note, the packaging is incredible triple boxed with a velvet sock cover on the sub. Nice job Sunfire!
Will 1 HRS-12 be enough to fill a 3000 cubic feet room?
Thanks.
Aaaaaa sorry, you already stated that
I'm considering going all the way from Norway to CE state of the Union, do you think, that'll be worth it?
Wow you would probably qualify as the longest traveler to our event in its history if you come! Its definately worth and I am not just saying that because I am hosting it
- 2 days of great product demos
- Debut of new products from Yamaha, EMP, Pioneer, Emotiva and others
- Great food! (breakfast for 2 days, formal dining event)
- Costume party, dance and entertainment
- free educational seminars
- chance to hang with Audioholics staff
- Disney access
- tons of free party swag and product giveaways
- a nice week of warm weather
Check out our video from last years event which was only about 1/2 the size of this one:
http://www.audioholics.com/news/trade-show-coverage/videos/2007-ce-union-overview-video [audioholics.com]

