January 2011

Dayton SA1000 Subwoofer Amplifier
A truly fine subwoofer amplifier.
Review By Jeff Poth

  Subwoofers... if there is a rarer phrase than "I have too much subwoofer" in audiophilia, I have not heard it. It ranks up there with "That kangaroo has my blender again". There's a very good reason for this exceptional rarity- you can never have too much sub. Accordingly. I submit for your perusal the (almost) 1 kilowatt, Dayton SA1000 stand-alone subwoofer amplifier

Just The Facts, Kangaroo Man, Just The Facts
There are many subwoofer amplifiers available, but only a few standalone (as opposed to "plate" style, which mount into the subwoofer enclosure) amps for home use. I am a fan of a standalone amplifier for subwoofers, since plate amps tend to mean you need to add a sealed section to the subwoofer box, for best performance. Otherwise, they can be shaken to death, or air pressure can be forced out of the switches and whatnot, making spurious noise. In addition, the superior real-estate allows the Dayton to be loaded with features. In addition to the standard phase, level, and crossover frequency controls (which essentially all subwoofer amplifiers have), it has some very handy additional features.

Bass Boost Function: This is sometimes built-into the circuitry of plate amps, but is rare to see a user control for it, typically this feature is fixed and cannot be changed without hacking the amp. It applies a 3dB bump at 25Hz with a Q of 1.4 (boost starts at about 40 and goes to about 15).

Defeatable High-Pass Filter: This is a rumble filter to prevent over excursion at frequencies too deep for the sub. This is very useful when you have a modest sized sub, or have rumble from a turntable, or just want to maximize how loud you can go. Most plate amps have this too, and again, is not user-controllable.

Parametric Filter: This allows a frequency specific equalization function, either a boost or a cut, with controls for frequency, gain (-14 to +6), and Q (bandwidth of the equalization function). This function is not implemented in a typical plate amplifier, and is incredibly handy for managing room modes, or contouring the bottom end somewhat.

The SA1000 is a very powerful amplifier with just shy of 1,000W into 4 ohms, with typical content (one third duty cycle, meaning, it won't do a continual sine wave, but will whump along with music plenty well). While we normally might see this specification as a bad thing, it's really not a major limitation- bass tends to come in short bursts. Power consumption is minimal due to a sliding rail power supply scheme, it's only 24W at idle. I have not yet been able to make it get hot (which it most certainly would, if you were driving a few hundred watts RMS). Build quality is excellent, and its black minimalist styling with internal heatsinks suits most systems fairly well, it's not an eyesore nor a work of art. Packaging was very good, with large foam spacers inside the shipping box. It has 2 pairs of high quality insulated binding posts, small pop-out knobs and switches for adjustments, and RCA in and out (with a 12dB/80Hz highpass on the output).

For Those About To Thump: We Salute You!
It is a well-kept secret that I am something of a bass fiend. Well, maybe not so well kept. The Trio12 subwoofers (reviewed here) are the first full and proper "Super Subs" I've had the pleasure of owning. I've had big subs before, I'm on my second Adire Tempest based unit (both mid-q sealed boxes), but the Trio 12s have the XBL^2 motor and the pair of them is really in a different class than the Tempest. Between the 2 units, I get quite a bit more output, and it's much cleaner. I never noticed a problem with the Tempest, it wouldn't overtly distort until things were falling off the shelves. But the Trios take it another notch up, having more power handling, more Xmax, more surface area, and much nicer motors.

Of course, that much sub deserves a lot of amp. I tried a few smallish amps, as well as a Reckhorn A403. The smallish amps (150W range) didn't have the cojones, and the Reckhorn was a disappointment- somewhat timid sound, and 2 units I had both developed a fuse blowing problem. The Dayton SA1000 is not timid. It has not given me any trouble in the couple months I've had it. The feature set is impressive and useful and I have no complaints thus far. In short, this is the finest sub amplifier I've had the pleasure of working with.

The SA1000 is in control of the woofers. It's a good match from an output perspective, as it can squeeze everything the trio12s have out, before running out of power. This is an issue because the trios, as with the overwhelming majority of sub drivers, are not very sensitive. I can readily achieve unhealthy SPLs with both the amp and the woofers loafing along. The performance of this combo is amongst the finest bass I've ever heard. Other contenders would be one of the older Gradient models I heard at a show (dipole 10"s, it was exceptionally clean and well defined), Edgarhorn Titans with Seismic sub (GOOD stuff), and my own minimal baffle dipoles (old, undocumented project) which had a quad of peerless 8" woofers per side, and 10" vented sonosubs (one per side) backing them up.

I expect a great deal of clean, well defined bass from a subwoofer. Thumpy one-note nonsense need not apply, nor should tiny woofers be used with huge amps (a la Sunfire). The SA1000 driving my pair of Trios does not disappoint- pitch definition and the ability to follow the instruments playing in the sub range are both excellent, to go along with truly massive dynamics. This combo is equally at home adding spaciousness to a harpsichord recording or providing explosions and bone crunching sound effects for HT applications.

The Important Paragraph
In short, this is the finest subwoofer amplifier I know of for home builders, or users of passive subwoofers. The feature set gives a tremendous amount of flexibility for integration and optimization, the amp is as transparent sonically as I have heard (for subs), which is likely due to its substantial power reserves. I give this the highest recommendation I can. If it meets your needs, go buy this amp. I've removed half a note on each of the appropo sonic categories just to allow for something better, somehow, some way, some day, and one ding off the value scale just because it's a relatively pricey amplifier for a sub, and there are some solid (but less powerful and fewer features) amplifiers at less than half as much.

Specifications
Type: Stereo solid-state subwoofer amplifier
Rated Power Output (0.92% THD): 497 watts into 8 ohms, 950 watts into 4 ohms
Signal to Noise Ratio: 98 dB A-weighted
Efficiency: 86%
Input Impedance: 12 kOhms
Subsonic Filter: -3 dB @ 18 Hz, Q=0.8
Bass Boost: +3 dB @ 25 Hz, Q=1.4
High Pass Output: -3 dB @ 80 Hz, 12 dB/octave
Low Pass Adjustment: 30-200 Hz
Phase Adjustment: 0°–180°
Parametric EQ Frequency: 18 to 80 Hz
Bandwidth: 0.1–1.0 Q
Level: -14.5 dB to +6 dB
Dimensions: 17.5 x 4 x 13 (WxHxD in inches)
Weight: 20 lbs.
Price: 549.99 (425.80 street).