Veepers Monitor | ||||||
|
||||||
|
||||||
Design Overview When somebody has been into this hobby as long as I have, it gets harder to come up with write ups. Eventually you run out of adjectives and justification for building new designs -- especially another 6.5 two way. Little boxes make sense, towers make sense. Stand mounted TM's seem like the least useful design format. They take up as much floor space as a tower, but aren't going to fit on anybody's desk top. So I went ahead and designed another one anyway. I got four of these Peerless awhile back as buyouts. By my recall, Peerless was changing factories for the cone material. So the old stock was sold out. If you read my site and posts on the forums, you know I'm a BIG fan of the Peerless Nomex line. Never heard one I didn't like. I was also enamored with the new Vifa NE neo tweeters when I used one in the Piccolatas. So I decided to try the 1" version. I loved the NE-19, but it takes some care to install -- not much margin for error. The NE 25 takes a 1-7/8 through hole and a 3/8 rabbet for countersinking. The box is about 14 liters (1/2 cu ft) tuned to 51 Hz. I used 3/4" Baltic for the baffle, 1/2" Baltic for all other panels. (If your calculated dimensions don't match up, you'll know why) I picked up a 7/8 roundover bit on clearance ($16 delivered) so I thought I'd try it out too. The day I measured these was windy and nasty, so I wound up with the box in the doorway facing out side. The swales in the 300-500 range correspond nicely to reflective surfaces from the setup. I more or less ignored them when designing the crossover -- assuming they were anomalies. I believe they were. One of the advantages to using better quality drivers is simpler crossovers. Not a lot of need for complicated filters, shelving and tank circuits. For the Veepers, I wound up with a pretty simple, asymmetric crossover. 2nd order on the woofer, 3rd order on the tweeter. Just a small shaping resistor on the tweeter shunt coil to smooth things out a bit. Crossover is about 2500. I'd safely call it an 8 ohm design. I no longer believe in boxes that double as jack stands for a deuce and a half truck. Loctite Power Grab construction adhesive is my go to product for bracing. There's always a lot of off cut strips. Glop them with Power Grab, stick randomly to the panels and let 'em dry. It's even water soluble. I lined the inside of the box with foam strips, added a fist full of loose Dacron batting. One PE #260-322 port tube and the box is ready. The veneer is 10 mil backed Red Oak. I have fallen in love with Titan DX Contact Cement from VeneerSupplies.com. It took me one afternoon to cut and apply the veneer. A single coat with a foam brush (both pieces) is enough. No stink, no fuss. Very thin too, so a quart will go a long way ( I think I did three pair with a single quart.) I sanded with 150, padded on a 1 lb cut of shellac, sprayed 3 coats of water based acrylic. Done. Listening Impressions I didn't include Frequency Response this time because of my measurement anomalies. I did do final impedance. When I measure again I'll do "as Built". Arizona DIY 2011 was the first time I really got to listen to these. I think the NE 25 is every bit as nice as the NE 19. It can definitely run "hotter" and cleaner than most 1" tweeters I've used. I think it's a bit more forgiving than the NE 19 for padding purposes. I wound up at 6.5 ohms, but both 6 & 7 were quite listenable. Like other Nomex woofers, this one is quite forgiving of crap mastered music. Not the ultimate in bass, but good meaty presentation. Very balanced and sweet throughout the spectrum. Nothing we played sounded bad. Nobody wanted to turn them down. One listener remarked that he couldn't locate the speakers -- even with his eyes open. Strong praise in my book. So why build the Veepers instead of the innumerable similar designs? I think of them as a Mazda 6 sedan. Extremely capable, dependable, reasonably priced, spunky, not mainstream, just about everybody will like them for a wide variety of musical tastes. |
||||||
|
||||||
Ground Plane Measurements of Final Veeper |
||||||