P9 - Chasse - Peerless 850122 / LPG26T - MT - converted to Seas H400 tweeter

Chasse: [sha-SAY] Chased. A step in which one foot literally chases the other foot out of its position; done in a series.

Update 1/2005: I never got the repaired LPG to sound right, everyone could hear it. I recut the walnut donut to fit a Seas H400 I had from the Madisound sale. They are a much higher quality tweeter as far as build quality. Much to my surprise, the Seas were a drop in, the speakers still measure flat, so no crossover change. Here is the new MLS with SEAS tweeter, 1/3 smoothing, 400-20000hz because my room suddenly decided not to behave. I really have to set up something outside, although it is 11o and snowing right now.

Peerless 850122 Seas H400

I learned these:

1. For the thousandth time, do not buy one-off drivers. I almost messed one up during soldering and if I had, the whole cut-out thing would have been wasted as I could not find a replacement tweeter.

2. The LPG tweeter is pretty cheaply made. The cheap aluminum face plate was easy to scratch (this may not be the standard plate), the dome is like 2 micron aluminum. I pulled on apart to fix it when I blew the solder and the plate assembly had enough play to mess up the dome alignment. I had to try two or three times to remount it to get it to act like the other tweeter. The coil wires are like 100 gauge. I did end up with a decent response but I am done with this tweeter. Too many good cheap tweeters from Seas and Vifa to play with this.

3. The wood inlays are not that hard. The inlays are really what this speaker was about. I will do the baffle edge thing again. I veneered the box, cut a slot for the walnut, glued an oversized piece of walnut in, then use a trim bit on the router to match it with the veneer. Run the ball bearing up close to the walnut so you don't take any veneer off.

4. Never do poly coating in the spring during pollen time. I had to do maybe 12 coats before I got a decent one without lumps of pollen.

5. The Peerless drivers look pretty good quality but the basket lip is very thin. I bought these used and the previous owner screwed in the screws too tight and bent both baskets a little. I have never had this problem before. These are surface mounted, I figured the baskets are so thin I could to it.

Peerless / LPG box
Interior of box and bracing. Here you can see I really come close the Amati factory in quality. :) . . . Actually I just glued it and wiped it out later. I do over glue things as I figure better bonded than not, it is inside and who cares what is looks like. I usually put the center brace off kilter a little to make sure there is no accidental bell effect on the box and to try to deflect back waves. I have no idea if this works, but it is a theory.



Peerless LPG baffle mounting
This is how I glue the baffles. Note how they are hanging out all over the place. I cut them oversize and then use the trim blade on the router to get the nice edge. Saves a lot of finish work. At this point, there is no front or rear.

finished box

The finished product. The LPG tweeters are chopped so I had to figure out how to mount them. I used the router to cut a rabbet in a piece of walnut. Then I used the Jasper Jig to cut a doughnut that fit into the tweeter hole. The walnut fills in the chopped part of the tweeter. Worked reasonably well. I should have made the walnut part vertical rather than horizontal as it was hard to make the strokes of poly match the grain direction. The rounded walnut baffle was easy and worked well. Install the wood oversize and trim with the router. I was supposed to do a walnut port opening on this but I could not find 2.5" port tubing.

Chasse MLS

MLS looks OK. The variation at 300 is the floor and at 500 is the ceiling. There is a small hump at 800 I just don't want to deal with. I will update later after some listening.

Chasse IMP

I took these to DIY2004 and a lot of people liked them so here is the crossover. They also measured a lot flatter at the event. maybe my measurement system is just a little off. Note that a lot of people think flat measuring speakers sound bright, so be prepared. Also, I am 90% sure this is the final crossover. I am not pulling them apart to check unless someone tells me they are wrong.

LPG 26t crossover

Peerless 850122 crossover

speaker icon

Copyright Peter Jay Smith 2005 Return to helarc.com