Fostex-orama - Small Fostex driver / speaker comparisons PH1000, Blumenstein Orca, etc.

Not including the 6" Fostex for comparison, but focusing on the FE103En 4" drivers in the P1000 BH folded horn enclosures from Madisound (dark brown) and the Blumenstein Orca using the 3" Fe83En.

I'll take measurements a bit later. I might throw in the 4.5" Fostex drivers in some larger cabinets this weekend if I get a chance. The Flugelhorn flatpacks for the 4.5" drivers I ordered last year don't seem to be going anywhere - some story about the CNC software crashing. I guess I'll write that off on my taxes.

Quick impressions:

The P1000 likes to be placed further back to the wall to get low end reinforcement compared than the Orcas. This is not to say that the PH1000 are less bassy. The P1000 actually has better bass extension, albeit at a lower volume in relation to the mids. The P1000 mids have that typical full range midrange shout. The Orcas have less of that shout, but are also more rolled in the bass and highs. Neither have perfect tonality. With an EQ circuit or DEQ, the PH1000 would definitely have more potential because of better extension ....

The Orcas sound more congested and closed in. The difference is significant. Not really surprising since the Orca uses a much smaller 3" driver in a box (the box is ported). The P1000 4" driver just has an easier time pushing air, and the back loaded horn allows the driver to breath more - more lively, more open, soundstage is deeper past the window.

None of these drivers can be considered high efficiency. Moderate efficiency yes. High efficiency no. They do demand the highest quality amplification. Don't bother unless you have epic amps and sources. You will not understand their "magic" by using say a pedestrian Parasound P5 and A23 combo. That being said, most people are better off with an KEF LS50 or Q series speaker at around the same price or less. Although it should be mentioned that the complete P1000 kit is currently $235 at Madisound.

 

Yes, it's a huge diffusor on an otherwise flat glass table.

 

I don't like them that far from back wall. Too lean. Soundstage is not bad. Just PH1000 is much better, more open, more lively, less strained. BLH + larger driver > smaller driver in box. BLH is closer to an open baffle kind of sound.

 

Alpair have better frequency response, flatter, better bass extension, but need much more power. They love power IMO. The Fostex are more resolving and faster.

I haven't tried Seas and SS wide banders.

 

The 4" drivers as passable. 4.5" drivers are better. Larger the cabinet, longer horns, that is properly sized, the better. The 3" drivers are nonsense without a woofer.

I plan on experimenting with the 4" Fostex sigmas. Maybe some cardboard first to get the horn size right.

 

You mean like this? Although I'd probably do a two way to prevent the full ranger from having to strain. This project is on the backburner because I decided I didn't want the Fostex drivers in box. Will jigger a BLH for the Fostex and maybe put the woofer in a separate box.

 

Yes, because there are two drivers in that design, both drivers are reproducing the lows (one reproducing the lows and the other running full range).

As with all things, there are advantages and disadvantages with any approach. What the site neglected to say are the disadvantages of such a design: the mids and highs of a driver (small driver at that) running full range are still going to be polluted by distortion (harmonics) in the bass of that same driver, especially at higher SPL.

Also bass on small drivers means a lot of excursion, which means the voice coil will be farther away from rest position. This introduces massive non-linearities in the magnet strength curves, surround stiffness and damping, etc, which equates to more distortion.

Nothing wrong with this approach as I do the same thing with the 6.5" Fostex BLHs and a sub. But I've also incorporated a high-pass switch on the mains for music with more bass content. The high-pass makes the wide banders sound cleaner, but at a cost of slightly more grain (using large electrolytics) and small resolution loss.