Attached for reference ... Note: vertical scale of the Keystone Z (left) isn't the same as the TH118XL (Right)
cheers
Martin
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Singtall,
The vertical scale is impedance in ohms.
Impedance in ohms, excursion in millimeters, phase in degrees and frequency response in decibels are all part of the "big picture".
The impedance curves are also indicative of excursion, minima and maxima match closely with the actual excursion measurements posted in the OP, indicating that the cabinet measured that Martin (Mars1234) posted was built "to plan".
In the charts below, comparing frequency response and impedance between the Keystone, the DSL TH118, and the DSL TH118XL, the penalty for extended low frequency response is evident in the 4-5dB sensitivity reduction shown in the larger "XL".
Also note, the sensitivity for both "4 ohm" DSL cabinets are derived from 28.3 volts into 4 ohms at 10 meters, they must be reduced by 3dB for a 1watt/1 meter equivalent sensitivity.
Art
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I got a chance to test the subs yesterday along with the carvin subs. The carvins have 2 Faital pro 18's and were the best subs I've heard to date. We put on some music with heavy kick drum, crossed over at 80hz and turned off the tops just to hear the subs. Starting with the carvins because we knew the sound of those. At some point we simply switched the cables to the keystones and stood there in amazement. Lower, louder, and tighter sounding! Everything you could want in a subwoofer.
Next we tried them with two carvin tcs210 tops per side. Using an RTA we played around with the crossover point until we arrived at 125hz on the subs and 150hz on the tops to get it flat sounding. Again the keystones didn't disappoint. Kick drum just pounded us in the chest.
My friend who helped me set everything up has a fairly large sound company and he is now wanting to retool using keystone subs. The absolute best bang for the buck if you can build it. Even with the current crazy prices of plywood.
Art, I can't thank you enough for the great design. If you ever find yourself near New Orleans Louisiana please give me a call so I can buy you a drink and dinner.
Next we tried them with two carvin tcs210 tops per side. Using an RTA we played around with the crossover point until we arrived at 125hz on the subs and 150hz on the tops to get it flat sounding. Again the keystones didn't disappoint. Kick drum just pounded us in the chest.
My friend who helped me set everything up has a fairly large sound company and he is now wanting to retool using keystone subs. The absolute best bang for the buck if you can build it. Even with the current crazy prices of plywood.
Art, I can't thank you enough for the great design. If you ever find yourself near New Orleans Louisiana please give me a call so I can buy you a drink and dinner.
Singtall,
Good to hear the comparison went well!
May be in your neighborhood next month, PM me with your phone & e-mail.
Faital Pro lists a dozen different 18", the 18HP1010 at 1000 watts, 100mm voice coil, and 9.75mm Xmax being a likely suspect.
Do you know the model number in the Carvin cabinet?
Art
Good to hear the comparison went well!
May be in your neighborhood next month, PM me with your phone & e-mail.
Faital Pro lists a dozen different 18", the 18HP1010 at 1000 watts, 100mm voice coil, and 9.75mm Xmax being a likely suspect.
Do you know the model number in the Carvin cabinet?
Art
This is the only speaker they show with the exact same Xmax
FaitalPRO | LF Loudspeakers | 18HP1010 (8Ω)
FaitalPRO | LF Loudspeakers | 18HP1010 (8Ω)
I had a chance to test my subs in a club and noticed that there is a ton of really low bass projected behind the speaker. I'm presuming it's because I used 7 ply home Depot birch instead of 13 ply birch. Is there a way to fix the situation short of building again from scratch. Like can I add another thinner sheet of wood to the back of the cabinet to stiffen it up?
Singtall,
No, the wood won't make a difference.
Tapped Horn Directivity
35 years ago, thinking the same as you, made a dozen horn cabinet compression chambers out of 1.125" MDF thinking it would reduce level behind, just ended up with very heavy cabinets.
Other than cardioid subs, any sub will be omnidirectional in the low bass, the level behind will be equal to that in front. In a small room, the modal response could even make the level louder behind at certain frequencies.
You can set up multiple subwoofers in a cardioid or end-fire array if you want to reduce level to the rear, though again, small room response dominates.
Simple "barn doors" or wave-guides can increase frontal output by 3dB while reducing the rear output by the same.
Horn Extender/Wave-guide for TH
Art
No, the wood won't make a difference.
Tapped Horn Directivity
35 years ago, thinking the same as you, made a dozen horn cabinet compression chambers out of 1.125" MDF thinking it would reduce level behind, just ended up with very heavy cabinets.
Other than cardioid subs, any sub will be omnidirectional in the low bass, the level behind will be equal to that in front. In a small room, the modal response could even make the level louder behind at certain frequencies.
You can set up multiple subwoofers in a cardioid or end-fire array if you want to reduce level to the rear, though again, small room response dominates.
Simple "barn doors" or wave-guides can increase frontal output by 3dB while reducing the rear output by the same.
Horn Extender/Wave-guide for TH
Art
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Thanks for the info. It was a small room that we tested in, so that makes sense. The drummer loved it though because he could feel the kick drum while using in ear monitors. Lol.
I also realized that I need some type of handles. Lifting it up a couple steps was difficult. Just need to figure out the best type of handles to use and where to install them.
I also realized that I need some type of handles. Lifting it up a couple steps was difficult. Just need to figure out the best type of handles to use and where to install them.
Nice! I need to build 2 more myself....just waiting on better lumber prices.
which speaker did you go with? I used the 3000Watt B&C instead of the more expensive 6000Watt version. I'm driving each speaker with a Behringer Inuke 3000, which they say puts out 3000 watts into 4 ohm bridged mono...but I'm thinking maybe 2400 or so realistically. but still, it's freaking earth shaking!
Last weekend I did live sound with a metal band and I have to say that I'm not used to having that much low end available. I'm running a driverack 2 using the reference mic to flatten the eq curve, and It's amazing to hear. I'm used to seeing an eq boost down low with other subs, but not the keystone.
which speaker did you go with? I used the 3000Watt B&C instead of the more expensive 6000Watt version. I'm driving each speaker with a Behringer Inuke 3000, which they say puts out 3000 watts into 4 ohm bridged mono...but I'm thinking maybe 2400 or so realistically. but still, it's freaking earth shaking!
Last weekend I did live sound with a metal band and I have to say that I'm not used to having that much low end available. I'm running a driverack 2 using the reference mic to flatten the eq curve, and It's amazing to hear. I'm used to seeing an eq boost down low with other subs, but not the keystone.
Most of the music I do shows for is very bass heavy EDM. I don't really like running my speakers very hard so instead of running the 4 harder I decided to just build 8. All of them are loaded with the B&C 18tbw100-8. Each set of 4 is powered by a CVR 2002-DSP which claims 3400 watts @ 4 ohms but I have not measured it. All I know is its more than enough power for how I run it. I also use the driverack with the rta mic, seems to work very well.
