Nice Chris ,as always I am sure it will smoke the competition....
What competition? Unless Matt has a pair of Revel Salon 2's laying around, which this was specifically designed to equal or better in all respects except bass SPL(
the Salon2 w/3 x 8" units ported in each, will likely have a bit more bass output under 43Hz even though I'm using the best of the best in 8" drivers here (8" JL Audio W7) with this project...). This will have radically superior off axis, this will have substantially lower cabinet resonance, equal driver resolution(
the MMD mid-range in the Primus 360/362 is good enough for any caliber of speaker - it's potential is simply lowered radically in it's USE in the stock Primus due to the incredibly resonant cabinet system and of course, very poor midbass response with the huge midbass hump in the OEM response curve), though I know a lot of people would will refuse to believe that such a cheap speaker would come with a mid-range of that caliber. The Salon 2 will have slightly flatter response through the treble, as the ribbon tweeter I am using has some deviation between on and off axis due to a small waveguide on it, but that is not substantial, and the off axis linearity provided by this tweeter more than makes up for the little bit of deviation. Much wider and more realistic soundstage will be possible with correct room placement and acoustics because of the much wider dispersion this tweeter provides. This is a 4 way fully active system. It will have the ability to of course let Matt adjust baffle step compensation to the exact amount needed for his room to get neutral mid-range balance - a feature that virtually no passive xover speaker offers - and this is a big deal as the exact amount of compensation that is ideal depends on distance from walls, room size, etc.. Also, he has the ability adjust treble tilt for ideal overall treble energy output. In addition, he can choose the LF safety roll off point. If he wanted to use the unit only down to about 43 Hz, it could easily have the dynamic range of the Salon 2 with the single W7 8". But he can have it go down to 30Hz, but some compromise in output will be had, as that 8" has to go to extreme stroke levels to get high output now, and it has no port to help out like the Salon 2 has. Adding port would have added a couple of hundred dollars or more to the construction cost of Matt's speakers due to the expansion of the back and complex assembly to remain resonance free, and incorporating a proper folded slot port. Please realize, it would not simply be a folded port added to the cabinet with a solid connection; it would have to be added with a floating suspension to prevent the large spanning non braced slot areas from becoming resonant, or other complex building to prevent resonance. But, with the port, it could have extension down to 23-24Hz with no compromise in distortion or SPL output due to this extraordinary driver technology, even though it's only an 8" driver. The only comparable(or perhaps even superior) 8" driver, that would have been my choice, was made by TC Sounds, but it has not been available for a long time since the company is currently not producing anything and may not ever produce anything again, though it is said they are trying very hard to re-structure and get back into business. The crossover on this speaker is fully active 4 way. It uses a DCX2496. In order to get the LF active and extending the 3 way DCX to 4 way with minimal cost, a Behringer CX2310 is being utilized. The mid and high outputs from the DCX will be used normally, feeding the 4" mid and ribbon tweeter amps directly. The LF output from the DCX, however, will be routed to a CX2310. The DCX will be set to cross the LF from the midbasses to mids, around 500Hz. Then the signal fed to the CX2310 will be further split at 80Hz to feed the 8" W7 LF driver amp and the mid-bass driver amp. This will allow 4 way split, while still having full control over all drivers by the DCX, without having the expense of paying for a 2nd DCX. The CX2310 is only $80, as compared to $275 for another DCX2496.
I think I saw Matt mention something about the passive crossovers still being usable in a prior post or thread. I want to make it clear that the old passive crossover board can still be used in the speaker, but Matt will have to swap out the ribbon tweeter for the original Primus tweeter and remove the safety capacitor from the tweeter circuit inside the cabinet. Also, the 8W7 would not be usable unless an active crossover was used, of course. A parametric EQ would be needed to compensate for the roll off in the small sealed cabinet section that the 8W7 resides within. Though, I could not imagine anyone wanting to use the original passive xover; the overall result would be significantly decreased sound quality.
-Chris
