Velodyne woofer driver replacement/ change help

[skdas]

Dear Forum members,

I have a Velodyne woofer with following specification.


Woofer 8” forward firing (6.5” piston diameter)

Amplifier (Class D) 2000 watts Dynamic 1000 watts RMS Power

High Pass Crossover 80 Hz (6 dB/octave)

Low Pass Crossover 40 Hz-120 Hz 12 dB octave initial, 48 dB octave ultimate

Frequency Response 28-120 Hz (+/-3 dB)

Harmonic Distortion <5% (typical)

Magnet Structure 204 oz. (12.7 lbs)

Voice Coil 2.5” Dual Layer inner/outer wind

Inputs Line and Speaker Level

Outputs Line-level, 80 Hz up

Phase 0° or 180°

Video Shielded No

Dimensions (H/W/D) (inc. feet, grill and knobs) 10.063” x 10.375” x 12.75” (27 x 26 x 33 cm)

Cabinet Sealed enclosure



As I use it in my L shape room with sides dimension of 5m*4m*7m. The unit is unable to fill the room. Is it possible to change the 8” woofer driver with a 12” or 15” driver single / pair!

I want to use the entire electronics component with separate enclosure. Please let me know if it is possible at all? If so what drive I should you and where to source it.

The unit is intended to use for Music purpose only accompanying with a floor standing speaker having a 6.5” woofer & horn tweeter. (I want to avoid bellow 40 Hz sub woofer effect)


What is the disadvantage of using high efficiency driver like 12”/ 15”/ 18”over a specially designed sub woofer driver which normally has a low efficiency? (For Music purpose only)

 

[diyaudio]

So you want to re-use the high powered amp. Take two of 12" car sub (JBL or something better) and put on opposite side of a cube enclosure. Take two of 15" passive radiators (you can make them) and put on the remaining two opposite sides. Tune to about 20hz or 25 hz. The poserful electronics are put to good use. Cant better this system.

Pro audio (sub)woofers need bigger box due to large Vas parameter and lighter cones. Car subs are opposite, comparatively lower Vas and heavier cones.

 

[shankara.kris]

Its mostly a reverse engineering project where we need to work it out from backwards based on the amp's power.
Firstly you need to choose the drivers that can sustain amp's power (RMS)
Secondly, if you are designing it to include passive/bass radiators, then it needs to have its own measurement which will be factored in when tuning and determining F3 numbers. This requires a enclosure tuning software where we put the woofer plus radiator parameters to determine the box and tuning frequency.
Mostly, if the bass/passive radiators are unknown or mismatching them with woofers, it wont give us the good results.
Also if woofer parameters are unknown too, then you are likely blow off the woofer at a given frequency/volume combination when it can't handle it.

Lot of things to consider. My suggestion would be to select the drivers / radiators with TS parameters or get radiators of the same brand as the woofer and measure it out.

 

[diyaudio]

Car subs are designed for sealed/ported application and they can take about 200 watts RMS. They all have Qts lesser than 0.5, so they can be easily used. Passives are just a cone with added mass. A frequency sweep could be used to tune it in the ballpark. during sweep just note PR excursion and active driver excursion. At tuning, the sealed does not move (very little movement) and PR moves a lot. Not difficult to do considering the gain.