View Full Version : RDAudio Alpha review

08-16-2009, 04:42 PM
RDAudio Alpha review:
Driver overview:
Based on a standard 12 spoke basket with a nice matt grey powder coat finish. Motor is a dual stack with 1”slugs with a well vented back plate with plenty of rearward travel built into it. Top plate has a generous thickness and should provide a nice focused motor force. Coil is a 3” alum. flat wire design. Spider is clamed with a nice ring and not just glued directly to the spider landing. Leads are nice heavy gauge and sewn to the spider to prevent lead wire slap. Cone is very thick and also very strong. Should resist flex easily. Surround is a medium sized foam roll design and also stiff even after break in.
Test System overview:
Car: 2005 Ford Focus hatchback
Electrical: Stock alt with big 3 upgrade. Kinetic 1800 under the hood, All Knu Konceptz wiring/fusing throughout. Dual 1/0 runs from front to back. 2 more 1800 in the rear spare tire well.
Head Unit: Pioneer 800prs
Processors: none
Amps: Sundown 3000D, 100.4, and 125.2(not used currently)
Front Speakers: Pioneer 720prs, 6.75 components with mid in factory door location and tweeters mounted in the A-pillars. Ran by-amped by the Sundown 100.4
Rear Speakers: none
Subwoofer: RDAudio Alpha V.3, D1 coils wired in series to the 3000D for a 2ohm load
Subwoofer Enclosure: BJ Fisher 4cft box with multiple port options. Tested with 4 different ports (26hz, 32hz, 40hz, 50hz) and sealed
First impressions: Sub arrived very well packed. Lacked a owner’s manual or driver speck sheet. Driver itself is a very well presented affair. Defiantly liked the simple RD dust cap. Another little quip is the dust cap is not orientated with the mounting holes. So if you mount the top mounting hole vertical the dust cap id slightly off- kilter. Turning the driver over presents a large motor structure with nicely machined bottom plate with pole and gap venting. A large double stack of ferret slugs provide the motivating force. They are covered in a large magnet boot. A very nicely built driver that exceeded my expectations for this price point.

Listening impressions: I received the driver right before leaving on a weekend trip to Indianapolis, about a 8hr drive each way. I loaded the sub in its new home, set the gains by ear, added a couple extra ports and a sealed baffle for the enclosure and away we went. Started out with Gorillaz: Clint Eastwood and my daily port tuned to 26hz. Driver defiantly needs broke in. Was not playing the low notes with much authority. Pulled over and switched to the 40hz port to give it a little more breathing room and give the suspension a little more work out. After a couple hours of wailing on it with Nickleback, Theory of a Deadman, and Deaftones she was starting to open up. Outside St. Louise I stopped and switched to the 32hz port and adjusted the 3000D. This seemed to be the best tuning for the sub in my car. Sub still had trouble reaching real deep on the Pans Labyrinth soundtrack but it really shinned on Lady Gaga’s and Pink’s newest releases. Found a couple new rattle in my car! Seems to like the 40-50hz range. Never showed any signs of stress, no funny smells, or funny noises. After about 5hrs tough the dust cap was quite warm. Will say in its defense I was over powering it a little. Sub did improve with more time on it and was getting noticeably louder as it broke in. After the first days pull (Indy Super Pull) we decided to have a little fun with it. I pulled the sub and wired the coils parallel for a .5 load on the 3000D, dropped the 50hz port in, ran a set of jumper cables from our haulers large batteries and burped it a couple times with a 55hz tone. Way above its rated power would guess around 4000w @ 10sec tone burst. Sub defiantly got a work out and really impressed me. Only signs of stress were a slight smell of hot glue coming from the port and a very hot dust cap. This was after around 10 burps in a half hour.
For the ride home I decided to try it sealed for a bit; From Indianapolis In. back to Effingham Il about 4hrs. Sub did amazingly well in this set-up. 4cft was a touch large and would venture to guess in a 2-2.5cft sealed box and 1500w would really suit it if space was limited. Switched back to the 32hz port for the remainder of the trip. Again seems to be this subs sweet spot for my car. Have yet to get the sub metered due to it still needing broke in and job causing me to miss the last Midwest SPL finals in Springfield, Mo.

Overall Impressions: Even after having it installed for a little over a week and having put close to 60hrs on the driver it still has trouble playing below 30hz with authority. Where the sub really shines is the mid 30-40hz range up to 60hz. If you listen to hip hop, rap, dance, or most rock. Sub stays nice and tight on rock tracks but will fatten up for bass heavy hip hop tracks. Defiantly a well designed suspension to handle vastly different music well. Sub would make a great daily ground pounder. It also can absorb copious amounts of power with very very few signs of stress. I would recommend between 800-1500w per sub in a daily driver with a enclosure with 3-4cft tuned in the mid 30hz range.
I will update this as time goes on. Plan on having the sub installed for a month or so. Will get a Termlab reading in the next week or so to see what kind of numbers it will do.
Overall the sub was extremely impressive for its price. For once you get way more than you pay for in my opinion. RD should be very pleased with what they have accomplished with this sub!!

Here is a short vid. Ignore the buzz, still trying to get rid of the hatch rattles.
speaker 4 video by orangelss - Photobucket

08-17-2009, 10:21 PM