DESIGN PRINCIPLES
DDQ is the acronym of Chinese Pinyin 'Duolian Duichen Qudong', which means 'Multi-folded Symmetrical Driving Technology'. Its structure is totally different from the traditional woofers.
DDQ's patented and unique design mainly comprises of these parts below:
1. several 'V' type sub-structures which mainly comprises of two cone frames and two cones;
2. two symmetrical driving unit installed on its two ends;
3. two specially designed high rigidity transmission poles go through each 'V' sub-structures' center;
4.two transmission poles are drove separately by one driving unit;
5.each transmission pole drives one cone in every 'V' sub-structures it goes through, it means, if DDQ has two 'V' sub-structures, each one transmission pole will drive two cones at the same time;
When the DDQ works, two symmetrical driver units push and pull the two cones in every 'V' type sub-structures' by the transmission poles, and then the two cones in every 'V' type sub-structure move in opposite direction. Through this motion, the air just pulled in or pushed out to produce sound. Compared with traditional cone-type woofers , the DDQ has specific compression-ratio. Under the same output area, the DDQ features much better driving performance, much greater dynamic range!!
STRUCTURE FEATURES
PERFORMANCE FEATURES
1. DDQ's low end limit is F0, please notice that its SPL has no roll-off on its F0 point. Usually, a traditional woofer will has a typical 3~6 dB roll-off at its F0. With smaller caliber, the roll-off gets sharper! Our model 'DDQ5-2' has a F0 at 60Hz, its SPL has no roll-off at 60Hz, and -3dB at 42Hz. And model 'DDQ6-2' has a F0 at 55Hz, its SPL has no roll-off at 55Hz, and -3dB at 34Hz.
2. DDQ adopts a symmetrical driving structure. So the motion direction between the adjacent cone is opposite thus has a nearly zero resultant forces. When installed in the speaker box, it brings very slight vibration, so the bass quality is much purer!
3. DDQ has several 'V' type sub-structures and each 'V' type sub-structure acts as a sound source when it works. In each 'V' type sub-structure, it has two cones that driven by separate transmission poles. When it works, these two cones will pull-in or push-out the air to produce sound. Because this 'V' type structure has particular compression ratio, so the DDQ nearly has no power compression in its low end.
NOTICE
After reading all the info we described above, an experienced speaker designer must have a question -- 'The depth of the DDQ's "V"-type structure would cause severe front-chamber-effect thus results in big fluctuation in response(especially in high frequency range), how do you fix this problem?'
Yes! The 'front-chamber' effect really exist in the early prototypes of DDQ and gave a bad impact on the response. After many analysis and experiments we successfully solve this problem by adding arrays of regular and optimized rectangular holes(we called these holes as 'Q-damping' hole) in every side plate of the 'V'-type structure. This measurement makes the response more flat.
Currently DDQ series has three models:
- DDQ5-2:2 sets of 'V' sub-structures with two 5-inch cones in each 'V' sub-structures(frequency limit:42Hz(-3dB) Power: 50W).
- DDQ6-2:2 sets of 'V' sub-structures with two 6-inch cones in each 'V' sub-structures(frequency limit:34Hz(-3dB) Power: 50W).
- DDQ8-2:2 sets of 'V' sub-structures with two 8-inch cones in each 'V' sub-structures(frequency limit:27Hz(-3dB) Power: 100W).