B&C 8CXT.
Augerpro subsequently measured them:
http://sites.google.com/site/drivervault/driver-measurements/faitalpro-12pr300/b-c-8cxt
I thought we might have been unfair to APT-50, measuring with a filter, so I redid two samples with none, below.
Familiar....
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With Selenium D220Ti, we tried several EconoWave filter combinations, ending up with additional BSC for use outdoors in the lowpass, and the standard low-sensitivity highpass running full on. The acoustic crossover frequency is presently at 1.436 kHz:
Yes, it has 5 dB of extra "sizzle" on axis, but we opted to leave that there in favor of better spectral balance out to 30°, i.e., 60° beamwidth. Kent is adding fiberglass damping and completing the second unit for listening tests outside. If we have an opportunity before they are "deployed," we'll measure to determine where these are tuned, and maybe tweak that a bit, but we're getting surprisingly good bass extension presently....
Yes, it has 5 dB of extra "sizzle" on axis, but we opted to leave that there in favor of better spectral balance out to 30°, i.e., 60° beamwidth. Kent is adding fiberglass damping and completing the second unit for listening tests outside. If we have an opportunity before they are "deployed," we'll measure to determine where these are tuned, and maybe tweak that a bit, but we're getting surprisingly good bass extension presently....
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With Selenium D220Ti, we tried several EconoWave filter combinations, ending up with additional BSC for use outdoors in the lowpass, and the standard low-sensitivity highpass running full on. The acoustic crossover frequency ended up at 1.436 kHz:
but we're getting surprisingly good bass extension presently....
Hi Zilch
Back at the honing grind stone I see.
Interesting there is that 10" woofer midrange suckout again. As seen on the US speaker Eminence chart, wondering if that was real before...guess so. Not too much help with using a passive Xover for that.
FWIW What was the rational for all the changes ie more BSC and reverting to the low eff Xover version, Considering 1) you got good/better bass. 2) IMO lower crossover may measure better but a trade off sound wise (music) at higher SPL? Not questioning any judgement just wanting to know your thought processes
. edit>The woofer at 95dB eff is just at the eff cut off and with the mid suck out and extra BSC (tiny baffle) you will need to use the low eff Xover.BTW Good work you guys!
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The high-efficiency variant would require an L-Pad to balance; I wanted to avoid having one at all in the hostile environment of the intended use. I could set the attenuation almost anywhere desired by varying the values in Wayne Parham's HF comp filter, so I tried to bracket the range by running on the <95 dB version, which balanced well with the L-pad bypassed. In the previous testing, ~5 dB "hotter," we ignored this element entirely.FWIW What was the rational for all the changes ie more BSC and reverting to the low eff Xover version, Considering 1) you got good/better bass. 2) IMO lower crossover may measure better but a trade off sound wise (music) at higher SPL? Not questioning any judgement just wanting to know your thought processes
Baffle step, we shot from the hip, trying different lowpass values, measuring, and listening, because 200 Hz is as low as I go with MLS indoors. I acknowledge that we may have overshot it, as the acoustic crossover frequency came out a bit lower than I was anticipating, and you suggested maybe a bit higher, instead, but we did crank it and heard no distress. I wasn't watching the cone excursion, but perhaps Kent might pay particular attention to that when he runs his listening tests outdoors. Can we talk you into modeling the filter for us? Here's the circuit, except L2 is 3.5 mH, DCR 0.36 Ohms:
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Highpass is as shown, but with the L-pad bypassed. Lowpass is 2nd order; the 12 uF remains. You can see they are summing reasonably, but there's still time to tweak. We may have kicked up the VLF too much is the concern. Kent can tell us if the amp he'll be using has a highpass filter to protect the woofer when they start bumping on the Playa....I'll model it fer sure, just not sure when. It might be OK for BSC 1st order if woofer doesn't breakup high?
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Highpass is as shown, but with the L-pad bypassed. Lowpass is 2nd order; the 12 uF remains. You can see they are summing reasonably, but there's still time to tweak. We may have kicked up the VLF too much is the concern. Kent can tell us if the amp he'll be using has a highpass filter to protect the woofer when they start bumping on the Playa....
Yup SPL vs SQ/BSC outdoors... my concern from the git go. Try and get a little more SPLs with 1st order and then you can adjust the HPF to match the natural woofer rolloff, say 30 degrees or so (horn directivity up high). But Kent knows the application best, so a tradeoff decision is his ultimately, with your sweat and good will of course. Id say you got it pretty good so far as SQ, but will it be loud enough? SQ bass bump maybe best with amp tone controls YMMV.
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I haven't got both set-up yet, but I've been listening to one. I did the insulation which helped the bass clarity, less boxy sound. There is a fair amount of bass. This was in the garage, so not a true 'playa' test. Will prob. do that monday.
The intended amp does have simple tone controls.
A big thank you to you, Zilch; seeing the test results as we tweaked was really informative. I could see how one can play with that for hours! Hat's off to you!
-Kent
The intended amp does have simple tone controls.
A big thank you to you, Zilch; seeing the test results as we tweaked was really informative. I could see how one can play with that for hours! Hat's off to you!
-Kent
You are very welcome, of course.
A quick check of the time stamps says we did, actually.I could see how one can play with that for hours! Hat's off to you!
[Time flies when yer havin' fun....
]
Thanks, guys! Both speakers are operational, finally. I did an outside sound test. They sound very good- perfect for the application!
Yes, they give a bass thump. The LF drivers are moving quite a bit at high levels. Travel ~8mm on the thumps- above the rated xmax. How unsafe is that?
Hard to est. the power into them. With the ipod at full, the amp volume was at ~20db attenuation, the speakers get plenty loud at that level.. It is a 100w per channel amp.
I leave in 2 days....yikes!
Yes, they give a bass thump. The LF drivers are moving quite a bit at high levels. Travel ~8mm on the thumps- above the rated xmax. How unsafe is that?
Hard to est. the power into them. With the ipod at full, the amp volume was at ~20db attenuation, the speakers get plenty loud at that level.. It is a 100w per channel amp.
I leave in 2 days....yikes!
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Xmax and Xlm are one-way, unless stated otherwise, 5.0 and 7.6 mm, respectively. You may want trim the bass control down 2 - 3 dB when playing at high levels if you think it's excessive, or you hear distortion.
They look very cool with their snazzy grilles, and I'm guessing, with both running, they sound outstanding. If you feel it's necessary to tweak them more before you go, I'm here the next couple of days to do it.
Trying my upload again, and it worked this time. We're running violet and cyan:
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Copper speakers have survived BM09!
Hi folks-
just a quick note to say the copper speakers performed flawlessly and have been unpacked in their dusty state into my garage.
Our sound never got real high. A few times it got a bit loud for the public I noticed the woofers moving a fair bit, but not excessive. We always kept it to a lower level and I observed no over diving. I did have the speakers hooked up to a receiver with a crude 5-band EQ. I raised the 5kHz some 5 db and lowered the 60Hz band about the same.
Lot of pics were taken by others; I was too busy to get good shots. Attached is one of the few I took with the speakers around mid-event facing into our bike-decoration courtyard.
They were stable, robust and appreciated. I will try to bring them to Burning Amp in October. I'm thinking on leaving them in their dusty state; though an examination of dust penetration into the HF driver is in order.
Thanks again to all, and especially Zilch for all the help and knowledge to make these possible!
More pics soon!
Cheers- Kent
Hi folks-
just a quick note to say the copper speakers performed flawlessly and have been unpacked in their dusty state into my garage.
Our sound never got real high. A few times it got a bit loud for the public I noticed the woofers moving a fair bit, but not excessive. We always kept it to a lower level and I observed no over diving. I did have the speakers hooked up to a receiver with a crude 5-band EQ. I raised the 5kHz some 5 db and lowered the 60Hz band about the same.
Lot of pics were taken by others; I was too busy to get good shots. Attached is one of the few I took with the speakers around mid-event facing into our bike-decoration courtyard.
They were stable, robust and appreciated. I will try to bring them to Burning Amp in October. I'm thinking on leaving them in their dusty state; though an examination of dust penetration into the HF driver is in order.
Thanks again to all, and especially Zilch for all the help and knowledge to make these possible!
More pics soon!
Cheers- Kent
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Stockpot enclosure and guerrilla music at burningman
Using the advice from the people here, I made a small speaker in an industrial 16 quart cooking pot, using the eminence 8cx, Selenium horn driver and old t-amp. It was a 22 lb battery operated PA speaker that got quite loud! The easy part was finding the right sized enclosure. Harder was the cross-bracing, damping spray, pink insulation, and Swiffer covered grill.
My friend created the sound using electric guitar peddles feeding back on themselves. He is pictured below.
We went to several art installations and played some music, getting a few complements.
Thanks for all the help from this forum. The sound was really crisp and loud...next time it will be more portable, more directional, and much louder. Maybe 12 lbs and twice as loud. There was plenty of competition from other sound sources.
Using the advice from the people here, I made a small speaker in an industrial 16 quart cooking pot, using the eminence 8cx, Selenium horn driver and old t-amp. It was a 22 lb battery operated PA speaker that got quite loud! The easy part was finding the right sized enclosure. Harder was the cross-bracing, damping spray, pink insulation, and Swiffer covered grill.
My friend created the sound using electric guitar peddles feeding back on themselves. He is pictured below.
We went to several art installations and played some music, getting a few complements.
Thanks for all the help from this forum. The sound was really crisp and loud...next time it will be more portable, more directional, and much louder. Maybe 12 lbs and twice as loud. There was plenty of competition from other sound sources.
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Hey Bluewhale-
Your system sounded great! Thanks for stopping by our camp; sorry about not visiting more- I was too busy helping cute girls with bike decoration!
Seems the eminance/selenium combo worked well for us. I really liked your set-up and was impressed with the t-amp performance. I look forward to see if the swiffer cloth helped keep the dust down, as mine for the most part was exposed.
-Kent
-Kent
Your system sounded great! Thanks for stopping by our camp; sorry about not visiting more- I was too busy helping cute girls with bike decoration!
Seems the eminance/selenium combo worked well for us. I really liked your set-up and was impressed with the t-amp performance. I look forward to see if the swiffer cloth helped keep the dust down, as mine for the most part was exposed.
-Kent
-Kent
Yeah, I want to return to your camp again and would of, if it were not for the plethora of distractions. I never heard your setup!
The swiffers were partly successful. They were very sonically transparent but the dust was so fine and blown with such velocity that it eventually made its way through to the inside. The speaker still works fine, though an upward facing speaker would be in danger!
The t-amp was surprisingly loud, and worked fine in the camp. It could of been louder during our guerrilla music routine. So, next time I'm going to be using two battery packs (two of the iSun battpacks, see http://shop2.frys.com/product/3572644 ) wired in series for 24 volts with a 100 watt t-amp from Sure electronics (2050). Each battery provides 24 watt hours (2 amps * 12 volts), which lasted more than it should at near full volume levels.
Its amazing how loud and small and efficient a PA system can get!!
The swiffers were partly successful. They were very sonically transparent but the dust was so fine and blown with such velocity that it eventually made its way through to the inside. The speaker still works fine, though an upward facing speaker would be in danger!
The t-amp was surprisingly loud, and worked fine in the camp. It could of been louder during our guerrilla music routine. So, next time I'm going to be using two battery packs (two of the iSun battpacks, see http://shop2.frys.com/product/3572644 ) wired in series for 24 volts with a 100 watt t-amp from Sure electronics (2050). Each battery provides 24 watt hours (2 amps * 12 volts), which lasted more than it should at near full volume levels.
Its amazing how loud and small and efficient a PA system can get!!
But aren't those notches just because of the time-misalignment of the drivers? Surely the woofer needs delaying.
Let's see: wavelength at 6kHz is a tad over 2 inches, or just over 1" for 180 degree phase shift... and how far behind the cone is the D220i diaphragm? I bet it's a little over an inch. I'll try and measure how well delay cleans this up after I assemble my 10cx/220ti vocal wedges in a few weeks...
AF
Let's see: wavelength at 6kHz is a tad over 2 inches, or just over 1" for 180 degree phase shift... and how far behind the cone is the D220i diaphragm? I bet it's a little over an inch. I'll try and measure how well delay cleans this up after I assemble my 10cx/220ti vocal wedges in a few weeks...
AF
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