That's where I'm leaning at this point, but the Radian 5312 might have a better CD, the Faital has a real dip from 10-15K, and will drop even a bit lower with crossover attenuation. It's a tough call.
You're welcome! Well, if you play with an EQ you'll find that down low +/-3 dB is hard to hear unless it's very loud and/or sums with any room modes.
Well then this is good enough justification to push the bass extension to the lowest point while watching that sag and keeping it within 1.5-2db. Puts me in roughly 75-95L box depending on the driver, I'd like to keep it to 80-85 and will play with that number. This is just for a test cab mind you, I don't know how my outdoor measurements will stack up but I guess there's only one way to find out.
I'm still not completely clear about the balance between baffle diffraction losses while measuring quasi-anechoic, baffle step compensation, and room gain. Seems to me it could be a wash sometimes.
I'm still not completely clear about the balance between baffle diffraction losses while measuring quasi-anechoic, baffle step compensation, and room gain. Seems to me it could be a wash sometimes.
Well, keep in mind the differing pi space loadings, i.e. if designing for spaced up off the floor, in a corner, etc., whereas outdoors one is normally doing either nearfield or ground plane unless you're serious like Altec was that measured at a 24 ft? height to accurately measure free space (horn cab is 108.5" x 80.5" x 39.5"!), so required a large mobile crane to hoist into position).
Yeah, never had the benefit of any accurate measurements, so mostly did EBS alignments for small rooms and max flat or prosound alignments (sealed size cabs tuned > Fs) for larger ones and let them use their tone controls/EQs to dial them in.
Yeah, never had the benefit of any accurate measurements, so mostly did EBS alignments for small rooms and max flat or prosound alignments (sealed size cabs tuned > Fs) for larger ones and let them use their tone controls/EQs to dial them in.
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I don't see excursion graphs w/frequency.....i believe you can plot that in WinIsd no?
So you have a mic and the ability to measure then...........if you still have this old box, measure your free air F3 and then measure inside at your intended LP........you'll know what your room gain profile looks like.......tune the new system accordingly. The room is a constant if the height of diver is fairly consistent
Yeah they're in the file for each 'project'. For all these drivers it's ridiculously flat and well below the line, showing 1mm or less. Especially at the levels I intend to listen, 75db or even less, with a tiny SET amp, it doesn't seem like it should be a concern at all, no?
I actually used the parts from the 84L box to make the 40L box, didn't have any other 3/4" scrap around and it was a Sunday! But with the alignments I'm doing I figure I can build one based on the driver/alignment I like, and see how it compares to what WinISD says, then the battle begins.......I'll build the enclosure at the max volume that looks good, and be able to shrink it down, no more bricks,, that was a fiasco.
I'll do as you say, it would be very informative to see how the room affects things compared to my outdoor measurements. Should I just to 1m measurements, same as outside?
Not at 1 or 2 watts. I ripped the internal ribbons on a 10" KLH woofer by walking across a wood floor with the needle on the turntable, powered by a 35 w/ch tube amp. No high pass subsonic filter in a PAS2 preamp. If you don't have a record player, unlikely to encounter that kind of subsonic frequency.
Eminence is strident about the need for 24 db/octave high pass filters at 100 hz or so, since they have to warranty the drivers. Mostly in their vented box designs. See their cabinet drawings, linked to from the driver page.
Ouch, that must have been a sad day and a bad sound!
I may just low pass but not above 50hz, but it depends on where I settle with the alignment. I don't want to throw away anything useful down there and even with my bigger tube amp I'm not too worried about frying these drivers.
I may just low pass but not above 50hz, but it depends on where I settle with the alignment. I don't want to throw away anything useful down there and even with my bigger tube amp I'm not too worried about frying these drivers.
There is no sound at all from the woofer once the ribbon (wire) is ripped.
I've got speakers that perform down to 54 hz, but I still play LP's o a turntable. I still live on a wood floor. Cheapest high pass filter was a Nady sub crossover used for $60. Goes between the mixer & power amp. Low cutoff frequency is a knob you adjust. I don't have a sub, but I don't want to rip $320 each Peavey 1505-8kadt 15" woofers. Most mixers (like my PV8) also have an internal below 40 hz cutoff filter. Not my RA-88a disco mixer, it has a 6 db octave high pass which is audible & annoying.
I've got speakers that perform down to 54 hz, but I still play LP's o a turntable. I still live on a wood floor. Cheapest high pass filter was a Nady sub crossover used for $60. Goes between the mixer & power amp. Low cutoff frequency is a knob you adjust. I don't have a sub, but I don't want to rip $320 each Peavey 1505-8kadt 15" woofers. Most mixers (like my PV8) also have an internal below 40 hz cutoff filter. Not my RA-88a disco mixer, it has a 6 db octave high pass which is audible & annoying.
Even most 18” PA subs have a footnote that the power rating is only applicable using a 30-40hz subsonic filter. I ripped a 15” cerwin vega stroker back in the day which was told to be indestructible. The cone almost hit the metal grill at the moment. I managed to solder the wire again and saved the day.
Sim your desired 75db and that’s at what?……..1m?………..figure on your typical listening distance and for a point source, use the inverse square law Lp(R2) = Lp(R1) - 20·Log10(R2/R1)………so if your listening at 2m then the 75db becomes 69db. At 3m which is where I like to listen we’re now down to 63db five or take
Here you go fabricade, this is a SBB4 alignment, maxed out at 106L/43Hz. I'm impressed by how far this driver can stretch, F3 42hz, you can see it next to my other top choices at the moment, FaitalPro 12HX500 and Radian 5312. I'll post a second screen shot with slightly different tuning, closer to flat.
At $300US that Celestion is pretty cheap, but take a look at the CD response, pretty funky.
So now that I'm getting to understand how to manipulate the box tunings, I'm curious which of the above curves people would shoot for. I can extend F3 and rolloff point by quite a bit if I'm willing to sag by a db or two in the midbass, is it a good tradeoff? As GM said, we really aren't that sensitive to a drop of a couple of db in these regions, so it seems like having useable bass into the mid 40s is a great thing. Excursion graphs are fine even with my bigger 35w tubie, but I guess the only thing I wonder about is if I'm actually going to get much power into that extended FR, so it might be better to make a higher alignment with a smaller enclosure? Is that a reasonable assumption? Preserving sensitivity is priority number 1, but the two drivers I've narrowed down to are also there because the CD response is much smoother, and I know the Radian CDs have a good rep and may be hard to beat. Assuming I choose the Radian 5312 or the Faital 12HX500 (less likely due to cost), I'm faced with sensitivity between 95-96db, before I have to lose some of that to the crossover and other losses. Another key reason to have a well behaved CD, so I don't need to step all over it with correction networks. Either way I'm going to be squashing the CD down. I know I can probably keep the woofer to a simple LC second order, so hopefully won't lose too much there.
As you can see my lady is out of the country and I'm free to obsess all day on this 😳
So now that I'm getting to understand how to manipulate the box tunings, I'm curious which of the above curves people would shoot for. I can extend F3 and rolloff point by quite a bit if I'm willing to sag by a db or two in the midbass, is it a good tradeoff? As GM said, we really aren't that sensitive to a drop of a couple of db in these regions, so it seems like having useable bass into the mid 40s is a great thing. Excursion graphs are fine even with my bigger 35w tubie, but I guess the only thing I wonder about is if I'm actually going to get much power into that extended FR, so it might be better to make a higher alignment with a smaller enclosure? Is that a reasonable assumption? Preserving sensitivity is priority number 1, but the two drivers I've narrowed down to are also there because the CD response is much smoother, and I know the Radian CDs have a good rep and may be hard to beat. Assuming I choose the Radian 5312 or the Faital 12HX500 (less likely due to cost), I'm faced with sensitivity between 95-96db, before I have to lose some of that to the crossover and other losses. Another key reason to have a well behaved CD, so I don't need to step all over it with correction networks. Either way I'm going to be squashing the CD down. I know I can probably keep the woofer to a simple LC second order, so hopefully won't lose too much there.
As you can see my lady is out of the country and I'm free to obsess all day on this 😳
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TBH I don't think you'll notice a big difference in the bass alignment, it's a handful of dB. You'll place them in the room to get the sound you want and that will over-rule the difference. Commit to something and focus your efforts on designing a good crossover.
Point well taken Tenson, and just like what GM told me. So to reiterate my concerns about flea watt power, I'm going to paste a shot with two alignments of the same driver, the Radian 5312. Would one be better with low watts, or am I mistaken about this? Seems like I should be thinking more conservatively about the use of those tiny watts. Maybe this is out of reach even, and I need to go full horn, God help me.
It's not a significant consideration, this graphs only shows a difference <200hz which will not affect your perception of loudness much. Everything that happens in the real life box and room will matter 10x more.
I've got to ask a serious question: why are you designing the most compromised audio component; the loudspeaker, around the amplifier which can be designed with minimal compromises? This is probably a taboo question and I should know better than to start a holy war.
I've got to ask a serious question: why are you designing the most compromised audio component; the loudspeaker, around the amplifier which can be designed with minimal compromises? This is probably a taboo question and I should know better than to start a holy war.
Not sure I really understand your question. I own a lovely little SET amp, and thought it would be possible to design and build a pair of speakers for it. I didn't know 4-5 months ago as much as I know now, and figured this was entirely possible without going to a giant BLH or some other crazy old school refrigerator. Maybe I was wrong, and that's what I'm exploring. I don't think it's unreasonable and this still may just work out great. Oh, I have to add, one of the reasons I can't build huge enclosures is because my room won't accomodate them, otherwise I'd have done that already.