Keystone Sub Using 18, 15, & 12 Inch Speakers

They did really well. We ran the 2 KS up front with the JBL mains on top and then a second delay about 30' back with 2 EV 18's and some MSR tops.

Honestly, considering that the EV's were half the size, half the weight, and had about half the RMS power in their built in amps, they were very impressive. I was hoping the KS would have tromped them a bit more. Sonically, the every DJ complimented just how great everything sounded. The end of the week we had a small party where only the KS and JBLs were playing so everyone really had a chance to hear the KS. The DJ's all praised the clarity. Output wise, I think they paid $600 each for the B stock EV subs. Each KS was around $500 without an amp (we used a 2500 watt amp on each KS). Once you factor in your time, the DIY approach really better be something you enjoy, because logistically those EVs impressed me. However it was Burning Man and the fact that the KS were hand built and brandless left everyone really happy. The veteran DJs all agreed the dance floor never sounded so good, and it was the first year we had to interrupt the parties on 3 different days to have people move their bikes from blocking the road it drew in so many Burners.
Glad to hear you and the DJs enjoyed yourself, you definitely put the blood, sweat and tears into the build!

The delayed EV sub cabinets are basically omnidirectional, if they were time aligned to the Keystones at 30 feet they would reinforce the sub SPL in front of them, but the rear wave would be progressively more out of phase with the Keystone output in the vicinity between them and the Keystones, which actually would reduce the low frequency SPL in the area between.

Art
 
Can anyone clarify the proper placement of "O" in the diagram from the plans? It appears "Q" runs the full length of the cabinet vertically with "R" across the bottom, and "P" across the top of the keystone panel. But the diagram appears "O" is in the middle of "Q" and overlapping "N". So does "O" sandwich between "Q" and "N"? any pics would help. thanks
 
Can anyone clarify the proper placement of "O" in the diagram from the plans? It appears "Q" runs the full length of the cabinet vertically with "R" across the bottom, and "P" across the top of the keystone panel. But the diagram appears "O" is in the middle of "Q" and overlapping "N". So does "O" sandwich between "Q" and "N"? any pics would help. thanks

"O" forms an L shape with "N" and braces either side of the Keystone exit.
You can see the screw position of "O" in the OP, post #23, and more clearly in post #628.

Art
 
Last edited:
Honestly, considering that the EV's were half the size, half the weight, and had about half the RMS power in their built in amps, they were very impressive.

Which model EVs were those? The ELX118Ps?

Your observations aren't unexpected - what most people consider as "bass" lives above 50 Hz, and if your EV sub is a "B6" alignment that basically boosts the low end around Fb a bit, the result can be a smaller box that gets low and actually sounds pretty good as well.

...until you hit lower frequencies and realise that where the EVs stop giving any more output, the KS just keep going and going :). And, you can probably try a "B6"-type EQ on the KS a little around Fb as well (last time I looked at the sim, Fb was below the passband) to further increase its LF output.

In addition to what Art said about the EVs being omnidirectional, being a completely different alignment, the phase response of those EVs was probably quite different to the KS as well. It's interesting that wasn't audibly noticeable.

Next time go with all KS... :)
 
In addition to what Art said about the EVs being omnidirectional, being a completely different alignment, the phase response of those EVs was probably quite different to the KS as well. It's interesting that wasn't audibly noticeable.

Next time go with all KS... :)
And don't use a delay ring of subs...

The phase response difference between the cabinet types would be minor compared to the comb filtered response resulting from the subs 30 feet apart, outer cabinets delayed.

Below is the phase and frequency response of the Keystone compared to a bass reflex with the same low corner and driver, both have BW24 filters at 25 & 125 Hz. As you mentioned the EV subs are probably tuned higher, the phase response would be even more divergent.
 

Attachments

  • TH, BR Phase.png
    TH, BR Phase.png
    179.3 KB · Views: 375
Last edited:
And don't use a delay ring of subs...

The phase response difference between the cabinet types would be minor compared to the comb filtered response resulting from the subs 30 feet apart, outer cabinets delayed.

Below is the phase and frequency response of the Keystone compared to a bass reflex with the same low corner and driver, both have BW24 filters at 25 & 125 Hz. As you mentioned the EV subs are probably tuned higher, the phase response would be even more divergent.

That looks like a pretty big phase difference. If I'm reading the graph right, it suggests that they're totally out of phase near 100 Hz?

I believe that the EV sub spec quotes -3dB @ 42Hz. I'll bet that's right where Fb is, if this is a powered sub.

BTW - the phase response of the KS in its passband looks impressive.
 
Is it acceptable practice in horn building to utilize kreg screws to mount the braces internally? Or will the screw slot have an ill effect like whistling or some odd sound? I usually come from the outside but figured the kreg screws on the braces may be easier and just as strong. What do you guys think?
 
Is it acceptable practice in horn building to utilize kreg screws to mount the braces internally? Or will the screw slot have an ill effect like whistling or some odd sound? I usually come from the outside but figured the kreg screws on the braces may be easier and just as strong. What do you guys think?
Kreg screws work fine, no ill effects, though screws from the outside have more area to grab, so will be a bit stronger.
 
Sorry to never have looked at more simulations but I figured I would just ask. Which 21" works in this design weltersys?
From the OP:
Using Hornresp simulations at rated Xmax values, (and impedance minima) average level from 35-100 Hz, the Keystone has these output levels:
BC21SW152-4 131.6 dB, 92 volts, 3.4 ohms, 2489 watts
BC18SW115-4 130.1 dB, 76v, 3.43 ohms, 1683 watts
BC18TBW100-4 127.8 dB, 59v, 3.32 ohms, 1048 watts
 
Glad to hear you and the DJs enjoyed yourself, you definitely put the blood, sweat and tears into the build!

The delayed EV sub cabinets are basically omnidirectional, if they were time aligned to the Keystones at 30 feet they would reinforce the sub SPL in front of them, but the rear wave would be progressively more out of phase with the Keystone output in the vicinity between them and the Keystones, which actually would reduce the low frequency SPL in the area between.

Art

Ha! Art you just really impressed me. I didn't go into the detail, but you just laid out the phase issues and it was exactly the omnidirectional effect that was causing stacks of high spl waves and cavities with lower output.

The conditions we were in were....well it was a dust storm in the desert. We lost a CDJ, a booth monitor, an MSR and an XLR jack on one amp became one with the cable as the dust turned to concrete in it.

The winds were so strong at times it was effecting the sound too. What happened? Everyone had a blast and found a spot they wanted to dance.

FYI Burning Man is the greatest place on the planet, and if you want to see what the human spirit is capable of without the damn ego in the way, treat yourself to this escape where you can see us evolve past ourselves. It's pretty tough coming back to this default world, but I feel quite energized and I have certainly burned down a past me.

I have a year now to relax and come up with solutions for all the little issues I hadn't planned on. I think we are going to be rebuilding our art car for next year and really decking out the sound.
 
Which model EVs were those? The ELX118Ps?

Your observations aren't unexpected - what most people consider as "bass" lives above 50 Hz, and if your EV sub is a "B6" alignment that basically boosts the low end around Fb a bit, the result can be a smaller box that gets low and actually sounds pretty good as well.

...until you hit lower frequencies and realise that where the EVs stop giving any more output, the KS just keep going and going :). And, you can probably try a "B6"-type EQ on the KS a little around Fb as well (last time I looked at the sim, Fb was below the passband) to further increase its LF output.

In addition to what Art said about the EVs being omnidirectional, being a completely different alignment, the phase response of those EVs was probably quite different to the KS as well. It's interesting that wasn't audibly noticeable.

Next time go with all KS... :)

Electro-Voice EKX-18SP 18? Powered Subwoofer | Used | IDJNOW
 
FYI Burning Man is the greatest place on the planet, and if you want to see what the human spirit is capable of without the damn ego in the way, treat yourself to this escape where you can see us evolve past ourselves. It's pretty tough coming back to this default world, but I feel quite energized and I have certainly burned down a past me.

Pics or it didn't happen :)

Sounds different to what the media seems to be suggesting that it is now - a hangout for hipsters, posers and the elite :).
 
Pics or it didn't happen :)

Sounds different to what the media seems to be suggesting that it is now - a hangout for hipsters, posers and the elite :).

For the love of anything worthwhile, if you form your perceptions from the media, you will be the lemming they require to justify their own means.

I am 34 years old. I have been on tropical vacations with the love of my life who I later married (and now divorced). I have amazing parents. I have shared memories with friends I would break down walls to be there for.

I have never had a greater or more influational week ever.

There are over 70,000 people there. Most of us have probably sat in meetings with about 10 that we couldn't figure out how to communicate with or see eye to eye. Create your own reality. I chose to align myself with the ones who share similar passions and understandings.

I was there 10 days. I partied harder than ever, laughed more than I can remember, I felt loved, I felt alone, I felt successful, I felt defeated. I picked others up and I fell down myself. When I fell, I was lifted by men and women who love fearlessly.

Ya Pascal and all the rich boys want to capitalize on those masses, but that's why they made the changes they made this year to make it harder and harder. I saw 2 DJ's that were mainstream...Diplo and Major Lazor and guess what - 2 worst sets of the week.

I ran out of warm clothes and strangers literally gave me theirs, when our diesel company flaked, neighbors we didn't know brought us extra of theirs.

You can go to Burning Man with different goals, it's radical inclusion. If you want to go as a tourist and fly in, then ride a segway around, and stay in your class A pusher, you sure can. If you want to throw a bunch of blinky lights on your credit card and indulge in yourself and try to look good and get laid, you sure can do that too. You can also walk in there with an open mind an open heart and open arms, and you will most likely experience something that you can't believe is possible without magic. The playa provides.
 
12004815_10105678182269033_7395129023585161078_n.jpg

While this picture doesn't really show BM, it shows what it meant to me.

This phenomenal DJ and went from acquaintances to friends to brothers through this.

In the middle of his set, one of our lovely bar fluffers tripped on a junction box that took the amp rack out. I was in a different place mentally and had just started to let loose and enjoy the music when it happened. I ran through the crowd of people into the trailer took a deep breath, and reset everything as quickly as possible. I had just completed a walk through on all the speakers to assure everything was back online and performing. What you can't see is the look on his face of appreciation. This connection really meant everything to me. This picture reminds me that even though I put my thumb through a table saw over a month ago, that we all still made it, and we made it together. We gave a lot of people exactly the medicine they came looking for and had such a great party.
 
A cabinet that drops off below 50 Hz can be a lot smaller than one that drops off at 35 Hz, Hoffman's iron law..

100% alines with what was audible.

The EVs were load, very, but reminded me if trying to get different tones by hitting a kick drum. You can only create so much variation and all the output seems boomy and similar.

The KS had fidelity in truckloads and sounded like music...not a subwoofer.

Art I cannot thank you enough for all the help.
 
From the OP:
Using Hornresp simulations at rated Xmax values, (and impedance minima) average level from 35-100 Hz, the Keystone has these output levels:
BC21SW152-4 131.6 dB, 92 volts, 3.4 ohms, 2489 watts
BC18SW115-4 130.1 dB, 76v, 3.43 ohms, 1683 watts
BC18TBW100-4 127.8 dB, 59v, 3.32 ohms, 1048 watts
Thanks.

I have a BC21SW152 that I will be building a few cabinets for. I was hoping that maybe this design would work but not this time. :(