Lessons learned building a Peerless XLS 12 + PR Sub (bit long)

Status
Not open for further replies.
Brief description of the project:

1.35 cu. ft box – 26 x 14.5 x 10 inches H x W x D; Peerless XLS 12 + XLS PR; 175g added mass to the PR. No plate amp in the box. The cabinet has ¾ inch MDF sides + back + full height cross brace + 3 inch long brace across back. Baffle is 1 ¼ inch MDF. Modeled with BassBox.

1. The XLS 12 + XLS PR works very well. It not only extends well and plays loud, but it exposes low frequency detail I missed in my old sub (10 inch vented Peerless 831727). Have not heard any signs of excursion limits for the driver or PR. I have not measured it – but plan to retrieve my Richter Scale from storage to do so.
2. The sub is approximately 6 db less efficient than my old sub (based on new sub level calibration).
3. It is interesting to watch the excursion change from the driver to the PR as frequency changes. During the helicopter take off scenes of Black Hawk Down the PR looks like it is moving twice as much as the driver.
4. My 150W Keiga sub amp seems to be sufficient for now. No obvious sign of clipping or lack of headroom. My amp is not mounted in the sub box so I can change it later.
5. Peak loudness of 100db so far as per RS meter is very loud in my living room. No one in my family wants to watch movies any louder than that.
6. The cabinet doesn’t vibrate, but it “moves” a lot when low bass is present. Not using spikes (see #7 next) at the moment but this cabinet is relatively slim and tall for a sub and tends to rock back and forth. Now I understand why some subs might walk across the floor. Downfiring might make sense next time.
7. I bought some two-piece cones (bought from Madisound but PE has the same) but I think the two piece design is stupid. It is supposed to allow micro adjustment of height but the screw threads are loose so the cone tip has too much play. The cones don’t have a jam nut either so there is no way they will stay tight.
8. The Jasper circle jig works very well but the cut through 1 ¼ inch material had to be done on both sides. A longer bit would make this much easier.
9. Polyurethane glue (e.g. “Gorilla glue”) does indeed fill small gaps well but it foams out of joints; requires extra work later.
10. Gloss black is not easy to achieve with cans of spray paint. Flat black is much easier!
11. Flexible veneer works well. I’ve used it before and continue to recommend it.
12. Water based contact cement works well with flexible veneer even though Constantines says never to use it for veneer.
13. Madisound’s hex head 10-24 screws (with T-nuts) are great for driver mounting.
14. I was worried about minor air leaks through the T-nuts and screws so I used small o-rings under the screw heads. They work.
15. Lead sheet (used for roofing flashing material) cut into disks works very well as passive radiator weight. Because of density it is thinner than steel fender washers and fits closer to the PR. Less cantilever effect.
16. I still like rope putty as a gasket for driver mounting because it has no seams
17. Quarter sheet finishing sander (Rigid brand) with vacuum attachment works well.
 
Status
Not open for further replies.