First Order Crossovers: Pros and Cons
As per Skrivis, my own (unsollicited) opinion would be slightly in favour of a series -- IF you can easily get the drivers' electrical parametres VERY close (or near identical). Again, I'm just a hobbyist -- not a professional. As to the Heil, 3kHz seems quite high -- which model are you using? As I know nothing about the Peerless, I really can't offer an opinion as to that particular match. However, the Heil is dipole, so are you considering a 3-way with an open baffle mid -- or are you going closed cab after the Heil? If so, getting your system radiation pattern acceptable 3kHz downward could be a bit tricky! ASAIK, the guy who makes "Heil" speakers crosses his AMT's about two octaves lower onto an upward firing peerless (quite a big unit if I remember correctly...). Frankly speaking the result is excellent down to the peerless: then things get a bit messy BUT that's just my opinion. Cheers Cheers |
Some series xover related pages: Graddon, Murray H, K Lehma, Jon Risch. Of course, any ref list on xovers would be incomplete without the frd consortium. Cheers |
Cdc -- there may be numerous advantages to multi-driver spkrs but spl is not necessarily one of them (think of those 22.000 gauss Lowthers with a front horn). I love wide-range drivers. Single wide-range drivers are actually rare; remember the whizzers on most such drive units. Limited frequency range, beaming, dispersion, IM, (response peaks & valleys)... are some of the most annoying (to me) problems. {BTW, you DO use a circuit on the Jordan & it actually sounds good}. BUT, a single wide-range unit has immediacy, reasonable response in a critical region (200-4kHz, most will do 8kHz for you, some will actually hit F6 @ 20kHz withOUT a whizzer!!), phase & the like are out... it's marvellous. Extension can be had using a supertweet (not easy to match) and, better still, using a stereo subwoof. Tough to beat. Ultimately though, these are EXPENSIVE spkrs. Driver cost alone for a high level full-range biamped design can easily top $6k (that's $35-50k in commercial equivalent). |
Cdc-- I only dimly remember the Jordan circuit, but it looked like a contour rather than BSC (it was across the driver -- but don't hold me on this!). Skrivis: Re: first order+ drivers. Why not use a wide-range drivers -- i.e. a 8" + supertweet, then a hefty subwoof. You'd have to biamp (at least) but, as you note, there's no free lunch! |
Cdc: forget the perfect piston. It'd be nice to have -- but let's just dream for now:) An 8" driver has the advantage of being able to cope with mid & low-mid frequencies w/out extreme excursion. A smaller driver would be straining. OTOH, it WILL beam, as you hint, higher up. That'll narrow the sweet spot but, on the brighter side, IF the dispersion changes in a reasonably controlled manner, you reduce reflections... (at least that's s/thing). If the full-range can take it elegantly, I would try cutting in the tweet, 1st order, higher around 8kHz. It's a pain to align the drivers -- but once it's done, it sounds good. Cheers |
Driver aligment isn;t easy to do well (wavelengths are so short up there). A Supravox 215 fron mounted on the baffle and a tweet back mounted with a makeshift waveguide, blended quite well at ~8-9kHz. All open baffle. bastanissells an open baffle kit called "prometheus airforce" that's reputedly very good (someone does sell import it in the US). Do check the Tangbang's excursion capabilities -- I think you'd need to cross the Tang to a woof quite high up to avoid hitting xmax too soon. Also run a quick test to see if a small contour wouldn't be indicated (quite a few people at diyaudio have worked with the Tang). As to the Hammer, I haven't heard it but given the many accolades (esp with a fostex supertweet) it may be an option. Good discussion at melhuish's site (super 12. Cheers |
