keep_hope_alive Premium Member
Acoustics Engineer
Review of Ultra Subs A-12 Subwoofer
@Vertex Audio hooked me up with an Ultra Subs A-12. I have experience with the Ultra Subs LV10 subwoofer, which I absolutely love.
The A-12 is part of Ultra Subs entry level series. But this is far from "entry level". MSRP is $150.
The subwoofer is suitable for
- Sealed
- Vented (ported)
- Infinite Baffle
- Aperiodic
I ran the A-12 in a vented/aperiodic enclosure as part of my home theater. It replaced the Vega-124 that was using the same enclosure. The A-12 outperformed the Vega 124 in every way. A-12 sounded better, more natural. A-12 played lower. I was very pleased and will likely get another A-12 for this purpose. The HT application was mostly for break-in and also to get a feel for the musicality of the subwoofer. The enclosure was a front-facing slot ported enclosure with fiberglass insulation fill in the cavities as well as the port (creating an aperiodic effect). Amplifier was a plate amp rated 240W@4ohm and 1%THD. Mechanical excursion limits were not exceeded at any point. The A-12 blended flawlessly with the Boston Acoustics A40 speakers it was paired with. The sub was located directly below one of the speakers, pointed at the listeners. Even crossover points as high as 160Hz were fine, the A-12 sounds very nice.
I moved the A-12 into my 2001 Honda Accord. I placed it in the IB/TB wall that previously held a pair of Oz Audio 300H subwoofers (12" IB subs). I have been very happy with the Oz subs for both output and musical ability. I ran the A-12 from two different amplifiers. The first was an Xtant 3300c on the mono output (160W@4ohm .01%THD). The second was a Rockford Fosgate 500x with one channel bridged (200W@4ohm and .1%THD). While the RF should have "more power", the Xtant 3300c certainly provides more impact and overall output.
Listening impressions:
I listen to a fairly wide range of music.
Alice in Chains - Unplugged - the A-12 blended very well with my frontstage midbass. Upfront bass was maintained. Very natural.
Deadmou5 - 4x4=12 - Excellent output, good impact. Sounds great!
The Civil Wars - Barton Hollow - Blended well with the front midbass. Combination of chello and bass were very natural.
Slayer - Raining Blood - The A-12 did great keeping up with a fast double bass and is right at home with metal.
Jurassic 5 - Power In Numbers - Good bass impact, and it plays low effortlessly. It revealed that my car is sealed well enough that my drivers door seal will give under the pressure generated by this single sub with less than 200W.
Stephen Lynch - Lion - This album has a mix of a fairly mellow ensemble. Again, the A-12 did it's job by being invisible yet impactfull.
Build Quality
- The cone is a decently stiff poly.
- The surround is durable.
- The basket is stamped steel, but coated and shaped to look like cast. It certainly is more rigid than any other steel basket i've seen. They saved money but didn't forget the end goal of rigidity.
- Push-terminals seem to be more common these days - they work just fine.
- Cooling is adequate, both pole piece and also coil/spider venting.
- Cosmetics are simple. I like that in a sub.
next up - RTA measurements.
@Vertex Audio hooked me up with an Ultra Subs A-12. I have experience with the Ultra Subs LV10 subwoofer, which I absolutely love.
The A-12 is part of Ultra Subs entry level series. But this is far from "entry level". MSRP is $150.
The subwoofer is suitable for
- Sealed
- Vented (ported)
- Infinite Baffle
- Aperiodic
I ran the A-12 in a vented/aperiodic enclosure as part of my home theater. It replaced the Vega-124 that was using the same enclosure. The A-12 outperformed the Vega 124 in every way. A-12 sounded better, more natural. A-12 played lower. I was very pleased and will likely get another A-12 for this purpose. The HT application was mostly for break-in and also to get a feel for the musicality of the subwoofer. The enclosure was a front-facing slot ported enclosure with fiberglass insulation fill in the cavities as well as the port (creating an aperiodic effect). Amplifier was a plate amp rated 240W@4ohm and 1%THD. Mechanical excursion limits were not exceeded at any point. The A-12 blended flawlessly with the Boston Acoustics A40 speakers it was paired with. The sub was located directly below one of the speakers, pointed at the listeners. Even crossover points as high as 160Hz were fine, the A-12 sounds very nice.
I moved the A-12 into my 2001 Honda Accord. I placed it in the IB/TB wall that previously held a pair of Oz Audio 300H subwoofers (12" IB subs). I have been very happy with the Oz subs for both output and musical ability. I ran the A-12 from two different amplifiers. The first was an Xtant 3300c on the mono output (160W@4ohm .01%THD). The second was a Rockford Fosgate 500x with one channel bridged (200W@4ohm and .1%THD). While the RF should have "more power", the Xtant 3300c certainly provides more impact and overall output.
Listening impressions:
I listen to a fairly wide range of music.
Alice in Chains - Unplugged - the A-12 blended very well with my frontstage midbass. Upfront bass was maintained. Very natural.
Deadmou5 - 4x4=12 - Excellent output, good impact. Sounds great!
The Civil Wars - Barton Hollow - Blended well with the front midbass. Combination of chello and bass were very natural.
Slayer - Raining Blood - The A-12 did great keeping up with a fast double bass and is right at home with metal.
Jurassic 5 - Power In Numbers - Good bass impact, and it plays low effortlessly. It revealed that my car is sealed well enough that my drivers door seal will give under the pressure generated by this single sub with less than 200W.
Stephen Lynch - Lion - This album has a mix of a fairly mellow ensemble. Again, the A-12 did it's job by being invisible yet impactfull.
Build Quality
- The cone is a decently stiff poly.
- The surround is durable.
- The basket is stamped steel, but coated and shaped to look like cast. It certainly is more rigid than any other steel basket i've seen. They saved money but didn't forget the end goal of rigidity.
- Push-terminals seem to be more common these days - they work just fine.
- Cooling is adequate, both pole piece and also coil/spider venting.
- Cosmetics are simple. I like that in a sub.
next up - RTA measurements.
