Welcome! Need support, you got it. Or share you ideas and experiences.
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In Reply to: All kinds of music posted by JBasham on June 20, 2006 at 10:56:31:
Do you really mean 5-10db more at the 3 sets of frequencies? No speaker is flat but if I had 5-10db more from 8kHz to 18kHz I'd have blood pouring from my ears when I listen at high levels. (alright maybe not but 5-10db?)
Follow Ups:
This is what I'm talking about:http://www.audioasylum.com/forums/bastanis/messages/551.html
I don't have the parallel cap Robert suggests, and I should (my bad.) I'll try it pronto.
OK, I see where your 5 to 10db came from.For sure the setup of my Proms is different.
1) I have the widebands 1.3 meters from the back wall - this must give a very different frequency response.2) I have the subs in the rear corners - I did originally find I was missing the very deepest bass for sometime compared to REL Storm that go down to 18/20Hz. With careful tuning and mainly very extended run-in time I've got most of the deep bass back.
3) I run the tweeters run as dipoles - this seems to release extra treble energy and "air".
When I had a few hundred hour on the speakers I was still messing around with the bass settings. I now realise it was still changing considerably. After a year (!) I now have stability. I should add that I travel a lot with work so maybe I'm only up to 1,000 or 1,500 hours or so.
I had a problem with my phono stage at one point, I added 0.22uF to the xover cap, it brought the treble up a lot. Now that I've fixed the phono stage I'm back to 1.01uF. If your room is causing a treble roll-off then it seems reasonable to increase the xover cap. 0.22uF might be too much so be ready with a smaller cap.
Things are broken in at this point. I recently tried feeding signal to the subs off the amp terminals instead of the preamp, based on the 6Moons thread, to see if it would fill the midrange dip any. When I set the analyzer up and ran the new response up against my stored scan for the previous setup taken several months ago, they tracked exactly.Robert has suggested the midrange dip is from sidewall reflections cancelling out wavelenghts from the wideband unit. I measure the same roll-off no matter where I put the wideband unit in the room, and regardless of whether I'm using one or two widebands in the test.
Hi,when you can measure the same behaviour doesn`t matter where the speakers are placed something is wrong. Prometheus doesn`t show this behaviour to my measurements and also to the independent measurements of the German Klang & Ton diy- magazine from the review of the MKI (same widebands) in the issue 6/2002 (you can find the graph on my website under "press").
Do you get the same results when you measure the drivers nearfield (microfone very close to the cone)? Is there an imbalance in this frequency- range audible?
When you measure the same behaviour nearfield and you have the feeling that male voices or instruments like Cello are fine it is also possible that there is a failure in the measuring setup.Regards
Robert Bastani
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