The OB (Open Baffle) series of speakers feature mid-bass drivers mounted in an open baffle and covering ranges from 200Hz to 2kHz.
The OB-5 is the shorter, smaller, and less expensive version of the OB-7 Plus. It only uses two M-130/16's in a ported enclosure covering from 200Hz and down instead of the four M-130's and built in powered sub used in the OB-7 Plus.
The driver complement uses the BG Neo 3 pdr covering the range from 1,800Hz and up. From there it hands off to a pair of M-130/16's mounted in an open baffle and covering from there down to a crossover point of 200Hz using a first order electrical slope. It then hands off to another pair of M-130/16 woofers wired in a parallel configuration and in a ported enclosure. The lower pair of M-130/16's are tuned to reach a -3db down point in the 45Hz range. This may be lower due to room gain of a typical room.
The open baffle area to the sides of the M-130/16 woofers are covered in grill cloth but can be left completely open. It can also be built with no top or back behind the upper drivers.
These speakers have 91db sensitivity with 1 watt/1 meter and have about a 6 ohm average impedance load with a minimum impedance that drops to 4 ohms in the 4 to 5kHz range. They are fairly easy to drive and easy to get good output levels without tons of power.
This is an incredible sounding design that I am quite proud of. The clean and open sound of this speaker is very addicting and a pleasure to listen to. It is an emotionally involving speaker.
Check out the kit. It comes with everything but the tools needed to assemble it.
Everything is now in stock and ready to ship. Crossover components include Erse XQ inductors for everything except the low pass on the lower M-130/16 woofers. It uses a laminated Erse Super Q coil. Caps are a combination of Erse poly caps and Sonicaps. The larger Erse caps are all by-passed with Gen.2 Sonicap by-pass caps. Resistors are Mills and Lynk. The kit also comes with eight good looking, solid Brass floor spikes, OFC wire, screws, solder, and heat shrink are also included.
We now offer the new patent pending Electra Tube Connectorsas the standard speaker wire connectors for all of our kits as they are superior to all current binding posts. These have a $59 a set retail value. The standard internal wire is a high purity solid core 16 gauge with a polyethylene jacket.
For reference, our A/V series kits and enclosures are considered entry level to novice level in difficulty. The OB-5 kit and enclosures would clearly be considered novice level in difficulty.
For this build we recommend 4 sheets of No Rez.
See Carlos's build: http://www.audiocircle.com/index.php?topic=59326.0
This one was built out by one of our customers.
Prices are per pair. Click here for enclosure plans.