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  1. Curiously, to use some 'more-open' mesh on the back of the drivers, the black painted metal flyscreen mesh from Bunnings is ideal and I think, if you ask, you can just buy 1/2 metre of it - you can cut it with scissors. I did get an upmarket cable for it but didn't change the earpads - excellent 'bang-for-the-buck' - mates up well with the Massdrop CTH amplifier
  2. You might try some diffusion, perhaps behind the listening position for a start, where the sofa is at present, and/or in front of the blue curtain - see if you can borrow some panels to start with as they're not cheap.
  3. Mouser is an big electronics supply house like Farnell, RS, Elfa, Digikey, etc - Mouser Electronics Australia - specializing in a very wide range of genuine electronic components.
  4. Hi ALF< It was a real surprise when we tested these little things just how well they performed once the bass was restricted so it's no surprise that they'll match up not only with a 80Hz sub but also running nearly unrestricted with the 15" bass drivers - those Augie's were a pretty good driver too. I'm with Matt here in looking for a spare pair of the Betsy's - I was thinking about adding a partial EnABL pattern to the cone to further reduce the low cone resonance and would like another pair to experiment with - if you do get around to parting with them
  5. I missed that bit about your 6as7 amp being an integrated unit with the preamp/volume control inbuilt and you probably can't separate the pre-amp section from the amplifier so that makes it a bit different If I remember, you have the Betsy in a small baffle, yes? And this will rolloff the bass because of the baffle size but adding another 6dB via a series capacitor is fairly straight-forward - I have plenty of reasonable film caps to get you started on this even if looking at an 80Hz rolloff. The room size is going to be a bit of a challenge for bass (3.5 x 2.5 x 2.5high = 22m3 or about 600ft3) - it might be worth the time/expense of getting Paul over to measure your room and see some options on how to control the room sound ( I have plenty of absorber panels to help if/when you go this way plus the diffusers.) Those Alpha's are the OB 15" drivers, yes? These might be too big in that room to just let run without a sharp high freq rolloff - this is just a stray thought, just an opinion only, as I've no actual experience on this There's a guy here called "snoopy8" that's pretty good with all these Berhingers and such computer things and pretty sure he could be a source of help here too - it might be a simple way forward to see just what that room of yours is doing with the music and narrow the options for integrating the bass with the OBs My room is a reasonable 6 x 5.5 x 2.5m and has a lot of window area with heavy drapes so not too bad, but even with a the 15" bass driver in a closed box, there's bound to be some problems especially as the higher Xover freq (120 - 150Hz) means the bass driver has to be in physically located next to/under the Betsy and it's baffle - this will limit the options. I'll keep my eye on that diyA Xover thread and we'll see how it develops - it could be an easy, simple way to run these OBs and it seems there are a few other posters that are looking at a similar setup. I noticed that there appears to be a more universal Xover in the works that looks a bit easier to alter the filter parameters without the high price tag so this is another possible simple-to-follow option too. I finally got the required passwords and some of the numbers right for this bloody great slab of a phone (Samsung Galaxy8 ) and it appears that I can now turn the complicated thing 'on' and receive phone calls at least! Looking up 'how to read messages' is next! …, and I had just got used to my $50 little 'thing' from the Post Office with the Amaysim pay-as-you-go setup for just talking to people - it seems that simple thing is a thing of the past.
  6. Yes, that's the attraction of both the OB idea and the planar speakers - all that indirect sound that increases the stereo image effect. One suggestion about your sub (single driver?) is to move it to the most ridiculous position you can manage with the available wiring - I've found that one of the better setups has the subs well away from any corners and up off the floor, even if just tilted up with a book or something under the front edge - you can try it under a coffee table in the middle, for example, pointing sidewards, upwards, etc You might think it should be next to the OBs but this isn't a common good place - you might think that the corner gives you that extra volume, and it does, but the sound is nearly always garbled in the extreme - try it in the middle of a sidewall up off the floor and maybe even pointing up to the ceiling, ridiculous as this may seem. Oh yeah, some subs have a reversing phase switch - try that too. Generally, most subs generate up to 100% distortion and many manufacturers count on their customers accepting this crap as acceptable - there are a number of information papers on the Harmon website about subs and the benefits of multiple subs that's worth a visit. There is so much rubbish written and pontificated about subs that it's extremely frustrating to see such problems these days. I'm over in Mt Waverley if you want to try some of the diffusers, etc
  7. I'm not sure about this so be prepared to disagree As I see it, the 6as7 amp will be a good match with the Betsy on the OB - the speaker will have a low freq rolloff depending on the baffle size so you probably won't need a filter, or if so, a simple series capacitor will add a 6dB extra rolloff and that'll possibly be enough to get you operating. There are a lot of good film caps of sufficient size to not lose signal quality for this without breaking the bank. Now, the bass - if you're going for OB bass drivers, you will need some extra freq adjustment (bass boost) - if using a 'more standard' bass, you can just use a simple rolloff filter (a low pass filter) on a second, higher power amplifier and feed it the same signal as your 6as7 amp (in parallel) - with a bit of luck, this second amp will have it's own volume control so you could set the volume of this bass amp in relation to the 6as7 amp and then have a method of controlling the volume out of your preamp (assume this contains the phono preamp too and the master control?) Now, the sticking point is that low pass filter and there are quite a few respectable circuits from China using reasonable ICs that'll do this - I was perusing Jim's Audio awhile back and there's a few there with options of upgrading both the power supplies and the ICs too so it's within reach without major project. But it's still a bit of 'stuffing around'! I read the thread on that Xover of NPs on diyA and it's dedicated to the Linkwitz LX speaker design but just a few days ago, one of the guys has modded the circuit to do a similar response that we might use for our OB Betsy drivers, so it's quite flexible Let's see what others have to say about this as my opinion is quite limited here - I do have the Berhinger and the Minidsp that I have yet to get working properly, the electronic DBX (balanced only unfortunately), an old LCR Xovers, so have a few options here but progress is woefully slow. Yes, the diffusers are excellent behind the OB speakers but are best spaced over 5ft behind the speakers for best results - this is added to reducing the early reflected sound off the side-walls with simple filter pads - I've got plenty of these too if you want to play with them I
  8. Hi Mullet, I finally got off my "A" and ordered the basic Betsy (not the Alnico) so can 'get with the flow' with everyone else and not use the BetsyK with the series resistor on the OB anymore - might get the Alnico version later on. Cost including freight is total US$171! About A$250 - have to add the gst too when it gets here - crazy cheap little driver of this quality Having a 'proper read' about the electronic Xover on diyA - it looks quite interesting indeed - thanks for the info A while back, I had the "styro foam guys" out in Rowville cut some foam into the Tim Perry version of the 1D Schroeder diffusers called "Leanfusers" - there's plenty of info on the Arqen.com website - I have quite a few spare panels if you want to play around with them - they're the plain white foam with an off-white paint on them
  9. In my opinion, (and remember this), I think you'll get a very clean, higher quality signal via the Diya-Store Xover with it's flexibility for later variations in the drivers, etc - one of the specific jobs it was designed for is the high efficiency 2 way systems and the 6as7 will be a good match for the Betsy in the OB and (hopefully) a large room. If you just purchase the pcb and initial components, you can assemble the case, etc at home and it's a bit of a steal at that price. You can use all sorts of amps for the bass (even a 2nd hand hifi amp) and also use the bass boost facility in the Xover if you want to use the Closed box (B2) for the bass drivers, or possibly a couple of subs - it's pretty flexible.
  10. Very helpful info, Wimbo - thanks
  11. I'm putting together a list of components from Mouser and if anyone wants some, just let me know - if curious, these are for 2 current projects from diyA - the new Active Bridge one uses fets instead of diodes on the power supply (tiny board, no heatsink required) and the new dc/ac amplifier protection boards (with SSR fets instead of relays) Intend to send in the order on Monday - short notice, I know but ...
  12. No it'sot a passive switch but you can use a simple switch and a basic cheap 'wall-wart' 12v dc power supply to operate the 2 relays to switch either of the amplifier's 2 wires channels to the one speaker - a 2 pole switch has 2 independent relays contact sets - one set selects either amplifiers output 'positive' and the other side of the same relay switches the same amplifiers 'negative' or 'ground' return conductor hence no need 2 separate relays - that's about as simple as it gets. For a high quality 4 pole 2 position switch, you need to look towards the industrial sector and there's hundreds of them to choose from but they're not cheap. All the best with your project - I suggest you keep it as simple as you can
  13. Just try a couple of double pole good quality 2 position 12v relays to switch the actives and the grounds, 1 relay per channel - best to keep all amp outputs as separate as possible.
  14. I tried various types of the passive XOvers but the size of the chokes at this freq produces so many problems that I gave the idea away, even the monster #16 bifilar ( 2 wires in parallel) ones. So, onto the electronic Xovers (with and without ICs), that have much more flexibility but the compromises are just different and produce their own limitations, mainly in the high pass, higher freq area - in the bass, it's not as critical and you don't notice deficiencies as much. Getting the 2 drivers to 'marry-up' is much harder now as the clarity improves (IMO anyway!) If you're using different amps and different type of speakers (like I'm attempting), sometimes the compromises are balanced out but this also limits the arrangement too, so looking for a better alternative and this brings the idea of the dsp into focus and we are now seeing quite a few more designed for the home use rather than just pro-audio. There are 2 local products too, the Lucy Audio is now available and the Analog Precision is going thru final design, plus quite a few others in hifi stores - a changing world of audio, despite the resurgence of the vinyl TT systems. I like the sound of the Ayre Acoustic dac and want to see this matched by the dsp units, and because I'm an amateur at these things, the simpler approach appeals more, but a lot of this depends on how you use them in practice - some of them are not at all easy to use unless you're a 'computer person' and it seems to be 'the norm' to misuse them in the attempt to get this supposedly ideal flat freq response and this frustrates the efforts of a 'better sound' and many of us just give the whole idea away and go back to simple analog filters with all their 'warts and all' Anyway, back on topic - IMO, using a separate bass driver (either OB or 'normal' cabinet) offers an excellent simple way of a 'great sound' in the room with less room acoustical difficulties. The Betsy's are quite robust and produce a rather uncoloured sound above the bass response in an OB. Curiously, with a reasonably sized baffle and sharp filters, I think it's quite possible to run these drivers down to about the 80Hz area and complete the bass range with high quality subs, but I haven't actually heard this so this is just an opinion based on A/Circle comments. I now use Uriah Daley's "the Clone Note" version of the Lightspeed Vol Control - to me, this is a more transparent sound and has the ability to alter the impedances, but any of the LightSpeed Vol Controls are worth a good listen, IMO. George wasn't at all happy about using an input selector or relays, but if you can get a good switch it's a quite reasonable compromise that I use and no problems so far - I have been chasing a high quality reasonably priced 4 pole 3 position switch for quite awhile now to isolate the ground connections too but they're not common, or cheap. All the best ...
  15. I'm just about ready to order a pair of the Alnico Betsy's if anyone wants to join - maybe combine postage? The cost of these will be about A$650 with the gst, I think. 'Normal' Betsy's (and Betsy K's too) are a bit less than A$300, I think. There are a few different reasonable quality electronic Xovers that'll be okay for a 2 way, particularly if looking around the 120 - 150Hz FAST setup - plenty of good bass drivers in both B2 and B4 boxes.
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