O Audio subwoofer plate amp and JL W3 vs SVS.

O Audio subwoofer plate amp combined with JLW3. Excellent.

I am very pleased with the recent acquisition of an O Audio 300 Watt subwoofer plate amplifier.

I have mounted this amp into a custom slot ported box tuned according to JL Audio’s recommended enclosure specifications. The chosen driver was the JL audio 12W3 D2.

I did some research on other plate amps before I went with the O Audio. The Dayton products I read about lacked some of the features of the O Audio unit. The Dayton had two models of the same 240 watt amp. One has a bass eq that is always on. The other model lacks the feature entirely. I would prefer a switch so I could turn it on or off. I also read some complaints that the Daytons have shutdown problems. I considered the BASH amps. They seemed to be more flexible than the Daytons. They arent getting the shutdown complaints. I chose not to go with the BASH due to 2 factors. Lack of availability and long term reliability. I was advised by a reseller that BASH amps are excellent for a year and then usually fail. I hate end of warranty self destruct timers.

Initial impression:

When the O Audio arrived it was sealed in plastic contained in a cardboard box. No manual or spec sheet. Nothing. I disconcerted over this. It seemed like a cheap shortcut to me. The knobs and switches were rugged and intuitive. The internals were well assembled high grade components. The electronics side of the amp was not covered as is the Dayton. I would have preferred to see a cover over the electronics. Oh well sometimes you can have most but not all. The amp was manufactured in Canada. I did not see anything referring to China on it. To me this is a plus. Sometimes Chinese outsourcing tends to reduce quality in my opinion. PSB and Martin Logan are both victims of this.

Performance and Operation.

Once the amp was mounted in the box. I set the Xover to 80Hz. Everything else flat or 0. volume set at 40%. I began putting the unit through its paces. A red LED indicated the amp was in standby. As soon as I started music the red light turned green. Bamboo by Nicholas Gunn was the chosen source material. The bass was tight and well controlled. Each octave was easily discernable. This box is definitely not a one note wonder. The frequency response appeared to be very smooth. The extension was deep. As I forced the volume higher neither the amp nor driver lost composure. Everything was full bodied, well extended, and maintained under tight control. I ran the amp for extended periods of time and it never shut down or went into protection. This performance greatly exceeded the PSB subsonic 2 which it replaced. The O Audio/JL played deeper, was more musical, and had significantly more output than the PSB. I then tested the amp using the movie War of the Worlds. I enjoy the scene where the tripods become active and crawl out of the ground. The O Audio/JL became frightening. No port noise. Deep scary bass. This single 12 driven by the O Audio made us feel that the aliens were getting ready to come up through the floor. Impressive. This particular scene caused much port huffing with the PSB sub. I then forced the amp to clip but the result was not too terribly offending. It almost reminded me of an NAD soft clip. Consider that things were falling off of shelves and windows were rattling open at this point.

In comparison with one of my other favorite subwoofers, the SVS PC25/31 The custom box had one significant advantage over the SVS. The complete lack of port noise. I love the SVS but when it plays certain octaves it has port noise and a rattling wire screen on top of it. This can be distracting. Let me clarify -the SVS is not an evil offender of noises and rattles. It is quieter than most. I have heard Sunfire subs sound like they are going to explode at certain levels and frequencies. Sunfires can exhibit Passive Radiator slap. The SVS is quieter and superior to the Sunfire.

LFE was similar with SVS / O Audio-JL. Svs offers a port plug to tune the sub lower. I must speculate that if the port foam were added to the SVS it may play deeper. This would of course penalize its musicality and articulation.

Both were very musical. I give the nod to O Audio/JL for articulation.

SPL/output seemed to be very similar even though the SVS had a higher power amplifier.

The SVS was far superior in one area. Ease of placement. The down firing sub sounded very similar no matter where you put it. As you move around the room the SVS remained optimal. The custom O Audio JL suffered in this respect. It has a sweet spot. This is a common trait among most subwoofers. It is not a problem if you stay near your listening position. I experimented with a rear firing configuration. This did not work well. It increased the already strong output but hurt its musicality. I intend to experiment with down firing. This will require cabinet modification so that test will be a while.

The positives:

Strong Output
No port noise or any noise that wasn’t music.
The satisfaction of doing a custom build.
Price $500.00 total.
Competitive against home subs that cost much more. Shipping time was fast.
The overall refinement of the O Audio and JL are superb.

The cons.
It’s custom. You have to build it. It is a time investment.
Challenging to find optimal placement.
The amps output power is rated at 4 Ohms.
Amp Not stable below 4 Ohms. A 2 Ohm load may cause damage.
The volume had to be turned up a little higher than I like to trip the auto on.
1 year warranty seems a little short.
No Manual came with this unit.
No port noise but lots of wind. It will send a strong breeze your way.
Unknown long term reliability.

I don’t work for O Audio. I don’t work for JL. I am very fond of both. Both are easy to recommend. I also recommend SVS. If I were buying a new sub without building it-SVS is preferred.

If you want a DYI project combine a JL subwoofer with an O Audio amplifier. The Use the JL audio box dimensions on their web site. The result is impressive.
Thanks for your post. I am considering o audio 500watt plate amp for a sub project and the information you provided was helpful to me. Can you please tell me where you purchased your amp? O audios web site does not give me a very secure feeling. Thanks
Ordered direct from O Audio. Didnt have any problems at all. They also responded to my emails in a timely manner. Good Luck.