Velodyne ULD-15 troubles

[nate86]

The amp/controller can be fixed fairly easily by a competent tech.
It’s the subwoofer itself that gets very tricky to repair.
If the foam surround rots you can’t just do a simple refoam. The sub and servo controller need to be calibrated together to get the servo controller to operate the woofer without distortion. This is where I was very unhappy with velodyne for not supporting their product.
This is not something any tech can do without experience with servo subwoofers.

Hmm- This is a very, very interesting idea. Does anyone know how one would calibrate the sub and servo after a refoam? I recently refoamed my ULD-12 and would be very, very grateful for this kind of info...

EDIT- reading the ULD-15 schematic/service manual now and it tells you how to do the calibration. I'm guessing this process is similar for the ULD-12, but man, a ULD-12 service manual would be REALLY handy right now.

 

[dc270]

Hmm- This is a very, very interesting idea. Does anyone know how one would calibrate the sub and servo after a refoam? I recently refoamed my ULD-12 and would be very, very grateful for this kind of info...

EDIT- reading the ULD-15 schematic/service manual now and it tells you how to do the calibration. I'm guessing this process is similar for the ULD-12, but man, a ULD-12 service manual would be REALLY handy right now.

read the link I sen- calibration is in there!
DC

 

[brad1138]

Sorry to resurrect this ancient thread, but I wanted to add and (IMHO) correct some of the info in it.

I have 2 ULD 15 Series IIs. Both have been refoamed and both work great, without any "recalibration". The PDF service manual is readily available now.

I also had both of mine modified to (effectively) remove the internal 85Hz X-over, as per the svc manual, so that it is entirely handled by my PrePro.

The sensor is just a motion sensor, sensing when it changes direction. The new surround could (very) slightly change the default position of the sub, but when it is turned on, that placement will be completely controlled by the massive magnet, the new surround will make no difference.

I had one of the surrounds replaced by Ja Mac's in Portland, OR. they are highly reputable and have been doing it for decades, and said nothing about needing to recalibrate. The other one was refoamed shortly before I bought it by a place in Seattle, and likewise, no mention of that. And again, the proof is in the pudding, they both work awesome (really awesome )

 

[capacitor2]

Just a quick comment on the ULD-12 external controller box, vs the one that comes with the ULD-15/18 units. It looks like the ULD-12 has a power amp built into the sub cabinet, whereas the ULD-15/18's power amp is external. This would explain the relative simplicity of the ULD-12's controller. Disclaimer: I have a ULD-15 with two power amps that both blow fuses, and I have a ULD-12 coming (so gathering as much info as I can find, in preparation to performing repairs).

 

[egellings]

Maybe the accelerometer on the driver is bad.

 

[northlander]

If you need a schematic PM me, I have been offering schematics for these for a good while now. Velodyne is NONE to happy about it but I would rather support their old, better products than their newer subs that typically break down inside a year of so. They were a great sub company at one time- IMHO not so much any more....
DC

Can I request a schematic? TIA!!