Some off-topic split to here - https://www.diyaudio.com/community/threads/cabs-ribbon-speaker-idea.401904/
OB update! My speakers from post 4160 got a bit of a refresh today. I took a bunch of new measurements of the drivers with and without the crossover, with and without the other drivers together, and then with my Flex Eight DSP.
The result of today’s tinkering is the attached picture (from my listening position). This is using the analog crossover I made, plus a few minor tweaks, and then a few PEQ tweaks to the input signal with the DSP.
This is sounding VERY good. A noticeable improvement from the previous iteration, which was a little boomy around 80-120 Hz, weak from 3-8K, and bright above 12K.
Earlier when I was using the full on multi-channel DSP crossover with three amps, the gain and noise was too high. Although that was likely due to beginner error and bravado, this setup is just as noise free (by my ears) as just using the analog crossover without the Flex Eight. Good thing, too, because this fancy piece of equipment was languishing for a while.
Happy weekend futzing to all!
The result of today’s tinkering is the attached picture (from my listening position). This is using the analog crossover I made, plus a few minor tweaks, and then a few PEQ tweaks to the input signal with the DSP.
This is sounding VERY good. A noticeable improvement from the previous iteration, which was a little boomy around 80-120 Hz, weak from 3-8K, and bright above 12K.
Earlier when I was using the full on multi-channel DSP crossover with three amps, the gain and noise was too high. Although that was likely due to beginner error and bravado, this setup is just as noise free (by my ears) as just using the analog crossover without the Flex Eight. Good thing, too, because this fancy piece of equipment was languishing for a while.
Happy weekend futzing to all!
Attachments
Look at these eminence. I might try them someday
http://www.loudspeakerdatabase.com/Eminence/LEGEND_BP1525
I tried them and they are working really well above 70hz. below there is no enough cone travel for high SPL. Problem solved with two RSS390HF.
https://www.diyaudio.com/community/threads/ultimate-open-baffle-gallery.123512/post-6669937
https://www.diyaudio.com/community/threads/ultimate-open-baffle-gallery.123512/post-6669937
If we look at the frequency response and impedance of the Eminence Alpha 15A and BP 1525, we see that the latter has some cone breakup around 3-400 Hz which the Alpha 15A doesn't have. This, and slightly lower Mms is why I like the Alpha 15A better for mid bass, where it's low Xmax is not a problem.
BP 1525
Alpha 15A - smoother impedance indicating less cone breakup.
BP 1525
Alpha 15A - smoother impedance indicating less cone breakup.
I would normally not use 15 inch above 200 hertz. I think I would prefer the much better efficiency. But, I also stumbled over the MTX RT15-04 which also seems a good price worthy candidate (but a high mms woofer)
bp1525 are high passed at 220 Hz, so no problem for me.
they are giving better punch filling, probably due to stronger motor and lowr Qts
they are giving better punch filling, probably due to stronger motor and lowr Qts
A 15" driver can in many cases work well up to 1 kHz. There are many examples of such designs.
I did test a single Eminence Alpha 15A in dipole as midbass up to 500 Hz. Can't say that I lacked any "punch" or transient impact compared to my current dipoles using four Eminence Delta 12A, which have higher sensitivity and lower Qts. I'm not at all so sure that Qts has anything to do with the subjective impression of transient response when its not being used down to Fs.
I did test a single Eminence Alpha 15A in dipole as midbass up to 500 Hz. Can't say that I lacked any "punch" or transient impact compared to my current dipoles using four Eminence Delta 12A, which have higher sensitivity and lower Qts. I'm not at all so sure that Qts has anything to do with the subjective impression of transient response when its not being used down to Fs.
And, as Kjeldsen said, there is quite a jump in directivity between 500 Hz and 800 Hz. Is it audible is different matter
I don't think graph shows directivity. Measurements need to be 0 to 90 degrees with 10 degrees interval. Those graphs will show significant beaming
https://www.erinsaudiocorner.com/loudspeakers/jbl_m2/
https://www.erinsaudiocorner.com/loudspeakers/jbl_m2/
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And in some rooms that are lively, small or completely untreated, beaming works for the listener. Remember folks…..more than half of your experience isn‘t the gear….it’s the acoustic space
I am currently re-jigging my P17s that were built by someone else. I am having difficulty with the crossover for the woofer due to what has been done before. Fikus's drawing for the crossover (woofer) has both terminals shown as + yet he says bass is in opposite polarity. One of them must be - but I am not sure which one.
http://lampizator.eu/speakers/projects/P17/Endorphine from Kingston Kitchen.html