Why 7pi? 7pi and listening room considerations [message #53231] |
Thu, 19 February 2009 01:22 |
Psychoacoustic
Messages: 75 Registered: May 2009
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Background- wanted to try horns and so constructed DIY speakers using Selenium 220Ti on JBL PT-F95HF waveguide paired with Pioneer HPM-100 woofers. Quite satisfactory, though not life-changing sound. However, discovered CD and now prefer it to much-loved Yamaha NS-1000M. Wishing to pursue the interest in DIY CD designs brought me to PiSpeakers- the Pi7 appears from an amateur perspective to be 'all CD' (in comparison to (e.g.) Pi4). This is the logic for choosing the Pi7 as the 'next step' on a CD journey. Comments? Constructed a dedicated listening room 6m (20’) X 3.8m (12.36’) X 2.3m (7.64’). Any considerations with Pi7 and these dimensions? Is 12 ft too narrow to take advantage of the Pi7 CD design on the horizontal plane? One end of the room has built-in bass-traps and mid-high absorptions panels from Ethan Winer's design www.ethanwiner.com/acoustics.html. As you can see in the photo, four bass traps (plain wood colour) meet in the corners (LH side wall partially obscured by curtain, RH back wall under C.D.s), with two absorbers (cotton covered) in the centre of the wall. Any issues with the Pi7 back-firing woofer and the bass traps of this design? Thanks.
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Re: Why 7pi? 7pi and listening room considerations [message #53240 is a reply to message #53239] |
Sun, 22 February 2009 19:35 |
PaulW
Messages: 71 Registered: May 2009 Location: UK
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I've no doubt the JBL unit is better, but I had to draw a line on the budget somewhere and it was more important for me to get the best treble, so the B&C DE250 was a must have. Now if I was going for the 4 Pi, then I suspect the JBL would really come into it's own as it is doing more work. All the problems I now have in the bass region I suspect will be sorted out with better output transformers in my Bottlehead amps which will provide better and tighter bass control. I've not started the re-build of the mid-horn yet (a project for this summer as I'm still using my outdoor workshop) but the main reason is to put together a slightly larger flair, but also have it completely exposed, with just the drive unit enclosed in a box (any thoughts Wayne?). Yes, satisfied enough to want to listen more than tweak or build or change or..... Paul
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Re: Thanks! [message #53241 is a reply to message #53234] |
Sun, 22 February 2009 19:54 |
Psychoacoustic
Messages: 75 Registered: May 2009
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Wayne, in response to jimbot enquiring the application of Delta 15, you wrote: Use the same midhorn, tweeter and crossover as the seven π cornerhorn but scale the bass bin larger, like the version for the JBL 2241, but tune it for 22Hz using a 4" long, 4" diameter port Some more questions to further clarify, if I may; In your testing and listening experience, would you consider the Delta Pro 15A model to be a performance compromise over the Omega Pro 15? (Purely budgetary motivated question, I can interpret the specs well enough). Regarding the larger cabs you suggested for the Delta 15- Presently I have 37" high bass bins- and they're TALL. Higher cabinets than this would put the mid/high drivers above seated ear level. With respect to the null axis, is this a problem? I presume the Omega Pro would also produce lower response in the bigger cabinet without changing the crossover- true?
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