You need to wire Positive to 1+ and Negative to 2+ at the amp's SpeakOn connector. Doing it the way you describe will reverse phase.
The highpass filter should be 24dB/octave at 30Hz. 6dB/octave won't save the driver from a 10Hz thump at nearly full-power. It'll probably take it anyway because its a very good driver, but steeper slopes are better here.
I'd set the lowpass for 24dB LR. Personal preference. Same for the highpass on your tops. If both are pretty flat past the crossover point, this should give you a flat response through the crossover region.
I suspect that driver will handle things pretty well, but a -3dB limiter would probably save you from sine waves.
Chris
The highpass filter should be 24dB/octave at 30Hz. 6dB/octave won't save the driver from a 10Hz thump at nearly full-power. It'll probably take it anyway because its a very good driver, but steeper slopes are better here.
I'd set the lowpass for 24dB LR. Personal preference. Same for the highpass on your tops. If both are pretty flat past the crossover point, this should give you a flat response through the crossover region.
I suspect that driver will handle things pretty well, but a -3dB limiter would probably save you from sine waves.
Chris
Your two thoughts contradict each other. Only follow the former (+ve to +2) if you are looking for reversed polarity. The latter (+ve to +1) is what is recommended by the manufacturer and will push the speaker cone "forward" when positive voltage is applied.
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Baltic birch is cut and my b&c 18sw115-4 is ready to rumble. I have read every post on this thread. I wanted to give back a little to this great forum a little and add a post on amp setup. It seems that the behringer nu3000dsp's(6000) are probably one of the most common amps being used.
Im hoping the gurus like Walt will chime in.
1. You need speakon connectors. NL2MP, NL2FX, and NL4FX(for amp connection.
Fit the NL2MP into the sub box.
Wire the +ve terminal of your driver the +ve terminal of the NL2MP and the -ve terminal of your driver to the -ve terminal of the NL2MP.
Plug the NL2FX into the NL2MP in the sub.
At the sub end of the speaker cable wire the NL2FX, using the +ve and -ve screw down connections.
At the amp end of the speaker cable you need the 4 pole NL4FX. Wire the +ve terminal of the NL2FX to the +1 terminal of the NL4FX and the -ve terminal of the NL2FX to the +2 of the NL4FX.
(This is required because when in bridged mode the amp outputs the POS via 1+ and the NEG via the 2+).
Plug the NL4FX into Channel A.
2.Amp Software:
Download software, https://www.music-group.com/Categori...0AHO/downloads
(Took me a min to find this)
3. Amp setup: set amp to Bridge mode.
4.Crossover: Set High pass to 30 hz Butterworth (24db), set Low pass to 100 hz Linkwitz Riley (24db)
Looking for help here. I understand what the settings but dont have enough experience to know which one benefits me and protects the sub better. Guru help please.
5.Limiting: set load to 4ohm. Really need help here. Peak limiter, ??dBfs, ?? Vp, Load ??, Hold and Release. ( as applied to a 18sw115-4 running hard edm probably approach 3db crest factor as Art discussed.)
I wish i had more time to google these but i have to get everything running by the weekend. Stupid day job that pays money...Just looking for starting points so people like me dont have to reinvent the wheel. Love the forum and i owe Art for all of his hard work. Thank you Art. Simulation is great but real world results are a completely different thing.
Also if someone comes up with a more efficient assembly order that would be great. I sketched the profile on A and am using that as a jig to assemble the internal horn. Next i am going attach the horn to A and hope the sides and braces match up ok.
Im hoping the gurus like Walt will chime in.
1. You need speakon connectors. NL2MP, NL2FX, and NL4FX(for amp connection.
Fit the NL2MP into the sub box.
Wire the +ve terminal of your driver the +ve terminal of the NL2MP and the -ve terminal of your driver to the -ve terminal of the NL2MP.
Plug the NL2FX into the NL2MP in the sub.
At the sub end of the speaker cable wire the NL2FX, using the +ve and -ve screw down connections.
At the amp end of the speaker cable you need the 4 pole NL4FX. Wire the +ve terminal of the NL2FX to the +1 terminal of the NL4FX and the -ve terminal of the NL2FX to the +2 of the NL4FX.
(This is required because when in bridged mode the amp outputs the POS via 1+ and the NEG via the 2+).
Plug the NL4FX into Channel A.
2.Amp Software:
Download software, https://www.music-group.com/Categori...0AHO/downloads
(Took me a min to find this)
3. Amp setup: set amp to Bridge mode.
4.Crossover: Set High pass to 30 hz Butterworth (24db), set Low pass to 100 hz Linkwitz Riley (24db)
Looking for help here. I understand what the settings but dont have enough experience to know which one benefits me and protects the sub better. Guru help please.
5.Limiting: set load to 4ohm. Really need help here. Peak limiter, ??dBfs, ?? Vp, Load ??, Hold and Release. ( as applied to a 18sw115-4 running hard edm probably approach 3db crest factor as Art discussed.)
I wish i had more time to google these but i have to get everything running by the weekend. Stupid day job that pays money...Just looking for starting points so people like me dont have to reinvent the wheel. Love the forum and i owe Art for all of his hard work. Thank you Art. Simulation is great but real world results are a completely different thing.
Also if someone comes up with a more efficient assembly order that would be great. I sketched the profile on A and am using that as a jig to assemble the internal horn. Next i am going attach the horn to A and hope the sides and braces match up ok.
Treukauf,
3. Don't know any gurus named Walt, but maybe he will chime in.
4. 30 Hz BW is a good HP for the Keystone sub, the LP you choose is dependent on your top cabinet's response. The goal is smooth phase response through the crossover region, depending on the upper cabinet's design determines the proper polarity of it compared to the sub.
5. I have given my opinions here regarding what I consider "safe" limiting for the Keystone sub using a B&C18SW115-4, I'll repeat:
A) Use the DCR of the loudspeaker to determine the voltage setting, the DCR of the
B&C18SW115-4 is 3.3 ohms, the minimum impedance of it in the Keystone approaches that value at Fb/Fc, where cone movement (and forced air cooling) is also at minimum.
B) The manufacturer's "Continuous Program" rating of 3400 watts is OK for peak limiting, using short time constants of a few wavelengths duration.
C) Long term "RMS" limiting should be no more than half the "Nominal" rating of 1700 watts (850 watts), as that AES rating is conducted in free air, and the driver heats up more when loaded in the Keystone "tapped horn".
With the way I mix live music, I have never had a problem using no limiters at all, because the peak to average ratio is quite high. DJ's playing highly compressed EDM are often surprised when the "magic smoke" is released from their expensive drivers. If you follow my advice above, your drivers should be safe, as long as your amp does not dump DC current on the speaker outputs.
My 30+ year old Hafler DH-200 just burned up my 21 year old right Tannoy PBM 6.5 studio monitor yesterday, the amplifier's right output measured 5.3 volts DC, only about 6.85 watts into a woofer rated for around 60-100 watts (IIRC).
So now I'm using an NU4-6000 to power a pair of 4" speakers until I fix the Hafler and the Tannoy, but I'm not worried about blowing them, the NU4-6000 amp has output relays that disconnect the load if DC is detected. If I do get the Hafler repaired (it sounds just fine, so the DC is probably just from dried out capacitors) I will add an output relay circuit to the amp as an upgrade, I hate burning up speakers.
Art
Trekauf, I would limit the driver to around 55 volts. Use a multimeter on voltage setting on the outputs on the amp, put the amp on full volume(without speaker connected) and dial the gain on the x-over unit to around 55 volts out from the ampto then adjust the limiter to start around there.
I have 8 ohm 18sw 115, which I assumed has twice the zmin as the 4 ohm model and I give it 78 volts until the limiter kicks in, which would equal around what your should see and it works fine for me(very heavy techno)! I have a small hole in the front cloth cover to be able to feel the magnet and it was a little hot to the hand last time(far from burning me tho) which is within the 100°c safe limit I was informed from b&c.
I use 30 hz bw24 and 106 bw24(or maybe LR on top)
Good luck!
I have 8 ohm 18sw 115, which I assumed has twice the zmin as the 4 ohm model and I give it 78 volts until the limiter kicks in, which would equal around what your should see and it works fine for me(very heavy techno)! I have a small hole in the front cloth cover to be able to feel the magnet and it was a little hot to the hand last time(far from burning me tho) which is within the 100°c safe limit I was informed from b&c.
I use 30 hz bw24 and 106 bw24(or maybe LR on top)
Good luck!
Thanks for the advice. I thought in this thread Art was pushing his 18sw115 4 ohm to 82v? 55v seems early but im also not familiar with the voltage excursion relationship with this keystone. On the nu3000dsp i should just be able to set the Voltage peak to xx volts and prevent mechanical failure and monitor the voice coil temp to get a feel for thermal loading correct? Im currently reading powersofts article on attack, release and hold settings, but it seems very in depth. Hopefully keeping the gain around nominal will help. Lastly others who have built this model. Any tips on what you did to eq it or where it was lacking? I dont have a mic yet.
If I understood this correctly, 82 volts would yield about 2100w at impedance minima of 3.2 ohm(82x82/3.2) on the 4 ohm driver.I would not give the driver that related to how warm my magnet got from my settings. I'm not familiar with how to set up the limiter for or how sophisticated the iNukes dsp is so I'm a bit hesitant on commenting on it.
Voltage excursion I'm not sure what you mean about and as I have never used a dsp with peak limiting I've always only cared about long term limiting which means heat to the voice coil, which is probably gonna be the most important one for you as it is for me(with the music we both play)
I have gotten myself an ir termometer which is will monitor the magnet temperature from the small hole I was talking about in the earlier post, I've never cared about attack release(I think they are not editable on my drpa+) but only the total voltage before limiter kicks in.
I don't use any eq, they sound very good without.
Voltage excursion I'm not sure what you mean about and as I have never used a dsp with peak limiting I've always only cared about long term limiting which means heat to the voice coil, which is probably gonna be the most important one for you as it is for me(with the music we both play)
I have gotten myself an ir termometer which is will monitor the magnet temperature from the small hole I was talking about in the earlier post, I've never cared about attack release(I think they are not editable on my drpa+) but only the total voltage before limiter kicks in.
I don't use any eq, they sound very good without.
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Treukauf,
1) I'm a pro with over 40 years of experience, the 82 volt sine wave tests were very short to measure distortion. Longer duration 82 volt sine wave testing would likely burn the voice coil in short order.
2)All drivers in any cabinet design double excursion with each 6 dB increase in power.
3) Not correct, excursion is frequency related, the driver can (possibly) exceed Xlim/Xmech without exceeding it's thermal limits. That said, I've hit my 18SW115-4 with 120 volts at 60 Hz multiple times (pros make mistakes too
) with no harm, and 60 Hz is around one of the excursion maxima (IIRC)4) I equalized my Keystones for flat response from 32 Hz to 100 Hz, in addition taking out the upper out of band peak to smooth response in the crossover region. The EQ used to flatten the response is simply the inverse of the frequency response, the OP and several other posts show the measured response.
I will be simulating the Keystone B-Low tonight, but unfortunately have to start from scratch, somehow seem to have lost all my Hornresp files.
Got to work fast, my 10% Lowe's discount card expires tomorrow, so I have to finish the plan and layouts tonight to have time to purchase the wood for 6 Keystone B-Low, four SynTripP Too©, and eight SynTripP SSM© cabinets.
Going to be a long night...
Art
Hi Art,
How far out of band do you typically wander?
What are these variations of TripP de Syn all about!? Is that more candy in the shop a la Welter I'm seeing!? Excited and routing for you to get it done this eve. 10% is 10%!!
Many cheers,
Justin
Justin,
How far out of band that EQ correction is needed depends on the crossover slope and amplitude of what needs to be fixed, and how many bands of PEQ you have to play with. When I owned the original Keystones, I was using a DBX DriverackPA, so was limited to only 2 PEQ points in the LF band, so IIRC I used one to remove the peaks at 133 and 166 Hz, then a low shelf to bring up the 40-60Hz range up to the upper level.
Now that I have a BSS Blue 100, I can add PEQ till the cows come home
.I finished the Hornresp sim on the Keystone B-Low (but lost it, and found my other old files...), the extra 5" of height will make it hit the Low B (31 Hz) with ease, the Fb (minimum excursion) is at 29.65 Hz.
According to the sims, the taller cabinet extra volume does not quite make up for Hoffman's Iron Law, the standard Keystone with BC18SW115-4 averages 134.3 dB SPL at Xvar from 40-80 Hz using 1939 watts at the impedance minima, 131.4 dB loaded with the BC18TBW100-4 with only 1202 watts.
The difference between the driver's output will probably be less than the simulation due to the SW115 requiring almost 3 dB more power, which will increase power compression, "thermal limiting" due to increased impedance.
The "B-Low" version will average 129.25 dB from 30-80 Hz using 2062 watts at Xvar with the BC18SW115-4, 126.8 dB with the BC18TBW100-4 with only 1200 watts.
So the BC18SW115-4 will take a 5.05 dB hit for 10 Hz lower extension, the BC18TBW100-4 (which I will be using) a 4.6 dB drop. However, in the B-Low version, the difference between the two drivers is less, only 2.45 dB, I expect given 3000 watts peak the TBW100-4 may actually be a bit louder than the SW115 due to it's higher sensitivity.
Considering I'm building six Keystones rather than a pair, they will give considerably more output potential and sensitivity than I had, and 10 Hz lower extension!
The SynTripP Too© design is a two-way,* two-part,* two cabinet, latch together, infinitely adjustable angle virtual point source center fill/lip fill/stage monitor 25 x 25 degree cabinet using a*3.5" "full range" driver and 8" woofer. The pair of cabinets can share the same pole as the SynTripP cabinet, and be put on after the pole goes up.
The SynTripP SSM© design is a 45 x 45 degree two-way, virtual point source Stage/Studio monitor cabinet, it features the same adjustable pole mount as the SynTripP, and a wedge shape for floor monitor use.
I'm going to continue to be quite busy for some time...
Art
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Thanks Art. I do understant that frequency dictates the physical air pressure loading of the woofer ie at certain freqs a small voltage can cause a lot of excursion. I was just looking for some starting points on amp settings for the weekend. I will use the recomended crossovers and watch the temp very closely. Hopefully later i can start tuning. Good luck with your next project. I was also up till 1 am working on the keystone haha but im +- 1/16th on dims so that was nice.
Art , how does the max spl of your B low design compare to the keystone 18? Wasnt sure how much peak you lost extending to lower freqs.
Art , how does the max spl of your B low design compare to the keystone 18? Wasnt sure how much peak you lost extending to lower freqs.
I finished my first keystone 18sw115 build. Went great box turned out dead on. Note to people that the N braces need to be wider than the keystone opening haha. Anyways sound quality is good but i have very little volume unless the gain and front attenuator nob are all the way cranked on my nu3000dsp. I used bridge mode with Output A +1 and +2. ( im used to bridging with outputs from A and B but +2 and internal switching must incorporate B). It kinda seems like im only getting half power like 700watts rms. I switched back and forth with my qsc 181 to eliminate the input signal variable. I will do some more amp research.
The second to the last led light is -6dB, one quarter power.
You need a line driver or mixer that is capable of line level to drive the amp to full power.
Treukauf,
You are welcome, stay tuned for the next generation, the B-Low Keystone.
Cheers,
Art
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I miss the days when 3/4" ply was 3/4" thick...
The thicker plywood in the photo is nominally .71 inch, it measures 18.25mm thick, the thinner stuff for small top cabinets and some shelving is 12.25mm.
Art