Hello, I am new here and in this topic. I have two JBL ASB6125 (each with 2 x 15") and two JBL-2450H (2" compression driver) with JBL 2385A horns. Now I am unsure whether that is all I need to cover the full spectrum, especially for ambient lush electronic music mostly from analog synths and punchy kickdrum plus additional acoustic instruments for live jams. At the moment it sounds good but I dont have a direct commparison so cant really tell if something is missing.
Now someone mentioned I should get a 10 or 12 inch to cover the midrange better. But at least on paper the frequency overlap nicely and I dont want to muddy things up. I noticed a dip in the 400-700Hz range of the ASB6125 so I was looking to cover that area with the recommended additional driver. I found the Eighteensound 12ND710 would cover it well, at least on paper. Then I heard that perhaps the dip is there on purpose to bring out voices better. So im a bit confused right now 😕
JBL ASB6125 (left) -- JBL-2450H (middle) -- Eighteensound 12ND710 (right)
Now someone mentioned I should get a 10 or 12 inch to cover the midrange better. But at least on paper the frequency overlap nicely and I dont want to muddy things up. I noticed a dip in the 400-700Hz range of the ASB6125 so I was looking to cover that area with the recommended additional driver. I found the Eighteensound 12ND710 would cover it well, at least on paper. Then I heard that perhaps the dip is there on purpose to bring out voices better. So im a bit confused right now 😕
JBL ASB6125 (left) -- JBL-2450H (middle) -- Eighteensound 12ND710 (right)
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I am quite happy with 2 way 15" + 1.4" CD on horns. +- 3 db 54=17 khz. Sp2(2004). How deep it your 400-700 hz dip? It may be easily cancelled out by a DSP or graphic equalizer. Much lighter to carry around than another pair of boxes, plus another amp.
Much more likely to be +- 6 db or more dips or bumps 100-500 hz due to room effect. Those have to be equalized out for each setup. If you are picky. A crowd of cloth wrapped listeners breaks up the standing waves some. Electronic instruments, nobody but the musician knows what it was supposed to sound like in the first place.
Much more likely to be +- 6 db or more dips or bumps 100-500 hz due to room effect. Those have to be equalized out for each setup. If you are picky. A crowd of cloth wrapped listeners breaks up the standing waves some. Electronic instruments, nobody but the musician knows what it was supposed to sound like in the first place.
Thanks for your feedback! The dip of the ASB6125 can be seen on the attachment and is just 3-5 db or around 97 db between 400-700 hz after being on or above 100 hz. It almost looks as if it's there on purpose because at 1000 Hz it's back at 100 db and only after 1100 Hz falls off.
How are you going to use this gear? A home listening system or as an actual PA for live events?
Don't get too hung up on the published response graphs, everything changes with the cabs in a room and depending what horn the driver is mounted on. I have a similar system with double 15's and a 2" CD that is more or less flat from 30hz to about 17khz the only difference is there are double 18's covering 30-80hz. With these pro drivers DSP processing is not optional so figure out what you want to use. That big CD is like most in that it's capable of ripping your face clean off with ungodly midrange output, but it can also do surprisingly decent treble with a HF shelf filter, and the JBL horn itself may add an aggressive tone that will require some notching to tame. Part of getting a flat response from this kind of driver combo is time alignment.. my combo produced a response notch at the crossover that completely went away with alignment. I'd suggest starting with an 800hz 24db crossover and go from there, you want to cross from those 15's pretty low but too low often brings out the nasty in the CD so you have to strike a balance, I ended at at 1khz for example. If you need any more drivers it would most likely be a super tweeter to help with the very topend but you don't have to do that right away... first get the most from what you have.
Don't get too hung up on the published response graphs, everything changes with the cabs in a room and depending what horn the driver is mounted on. I have a similar system with double 15's and a 2" CD that is more or less flat from 30hz to about 17khz the only difference is there are double 18's covering 30-80hz. With these pro drivers DSP processing is not optional so figure out what you want to use. That big CD is like most in that it's capable of ripping your face clean off with ungodly midrange output, but it can also do surprisingly decent treble with a HF shelf filter, and the JBL horn itself may add an aggressive tone that will require some notching to tame. Part of getting a flat response from this kind of driver combo is time alignment.. my combo produced a response notch at the crossover that completely went away with alignment. I'd suggest starting with an 800hz 24db crossover and go from there, you want to cross from those 15's pretty low but too low often brings out the nasty in the CD so you have to strike a balance, I ended at at 1khz for example. If you need any more drivers it would most likely be a super tweeter to help with the very topend but you don't have to do that right away... first get the most from what you have.
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True if the 15’s were actual *sub*woofers. My guess is they weren’t meant for a lot of LF extension if they actually work reasonably well directly paired with a 2”. Using 12’s in place of the 15’s and adding subs it the best way to go - but that’s a whole new system from the ground up. Are the 15’s providing enough bass, can it do it without strain or overload, and will more be wanted in the future?
Yea thats a good question. There's lots of punch and someone said 15" can be punchier than 18". I plotted the frequency response graphs of a JBL ASB6125 dual 15" sub and of a JBL 2450H compression driver. At least in theory, I wouldn't need anything in the mids and even a dual 18" sub like the JBL SRX828S wouldn't add much.
Don't listen to "someone".
Listen to your system and add some dB in the ~ 100 Hz range and adjust to get punch!
(Edit: and welcome to the world's best forum!)
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Thanks thats very helpful re DSP and time alignment. I have to look into it. Re "the nasty in the CD" there will be moment where it may fit but definetly not always. So I thought a midrange driver would help and bring more warmth into it when needed. But your suggestion to rather cover the high-end is new. Do you think its needed given the graph above?
Mike,
You have not mentioned what you are presently using for a crossover and equalization, which are of equal importance as the drivers, enclosure, and horn.
The crossover frequencies, filter type and driver polarity can easily affect response by as much +/-12dB in the overlap region.
Your vertical and horizontal listening position relative to the HF/LF can make another +/-6dB difference over almost half the audio spectrum.
The horn/driver requires ~+/- 6dB equalization to even be in the ballpark of sounding as good as it can.
Like Conaski said, before considering adding components, optimize what you have.
To give any optimization advice, we need to know what other components you have in the system- mixer, amplifiers, crossover, EQ, DSP..
Art
So our goal is to power a large garden area for 100-200 people. There will be times with DJs and times with live acts both electronic and acoustic.
Here's what I got so far:
- Highs: two JBL 2450H 2" (all looks relatively new) with two 2385A horns (I'm planning to build a wooden box around with speakon plug)
- Subs: two ASB6125 dual 15" (all looks relatively new)
- Amp for highs: QSC PLX 1104 (from 2013, looks like new, sounds awesome, I returned the newly ordered Behringer NX-6000D after direct comparison)
- Amp for subs: Behringer NX-6000 (newly ordered but returned within 30 days after direct comparison with the QSC, which is sooo much warmer and precise and just right but too little power for the subs)
- Crossover: ASHLY XR77/12 Stereo Three Way Crossover ($150, mostly chosen for its analog feel but not yet tested)
- Mixer: SSL Six 6-channel SuperAnalogue (picking it up as we speak)
- Amp for subs (option A): LAB Gruppen FP 10000Q ($1900, from 2008, looks good, they used for their band gigs, but seller prefers selling it with his Martin Audio 18" subs and 15" speakers).
- Amp for subs (option B): LAB.Gruppen FP7000 ($2500, new but opened, with full warranty, must be shipped and imported)
- Amp for subs (option C): QSC PL380 Non-DSP ($1300-1500, must be shipped and imported or brandnew for $2900)
- Crossover (option): Martin Audio Blackline M3 - Electronic System Controller ($350, same person as LAB Gruppen FP 10000Q)
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You could have purchased a new DSP crossover for little more, and have the tool needed for what you want to accomplish.
If you haven't tested it, you have been listening with no crossovers, you may destroy the JBL 2450H diaphragms.
The ASHLY XR77/12 (a black-face version of the Blue 1970's era SC-77) flexibility ("infinitely-variable controls") made it grossly inaccurate ("typically within 1/3 octave").
You probably would not want to play with a musician who was "typically within four semitones" of the correct note
Identical settings result in different crossover frequencies and levels L/R.
What was called a "rolloff control" is labeled "dB":
24dB per octave filters became the de-facto choice for PA speakers by the late 1970's, the ASHLY XR77/12 brings back memories of replacing dozens of shattered or burnt diaphragms back then.
It has no EQ compensation for your JBL 2450H/2385 horn's 60x40 degree constant directivity -10dB high frequency rolloff.
The ASHLY XR77/12 has no polarity reversal switches, though it (probably) reverses polarity between low/high, and mid/hi, as required for a 12dB/octave IIR filter.
JBL has had odd polarity conventions on many of their drivers compared to the usual..
An inverted low/high polarity will cause a huge response dip in the crossover region.
As a two way, your LF should be set up in one of two ways- cut (high-pass) the bass response off at 48Hz (~an octave higher than you want) or cut the HF at 24kHz..
Nice for recording, but lacks the input channels, EQ, effects, and dynamic processing desired in a live band setting.
The Behringer NX-6000 would have been OK and plenty of power for your bass speakers.
That said, LAB Gruppen is a higher grade amp, though FP 10000Q is way overkill, set the limiters with care.
You have not even thought about EQ, one of the basic tools required, which is built in to most any DSP. DSP is available in many amplifiers.
To create a good sounding system from raw components requires a lot of audio knowledge and skill sets you do not appear to currently have.
Purchasing powered speakers would have eliminated the very steep learning curve required.
Any way, start with reading the ASHLY SC-77 (or XR77/12 if you can find one) manual.
https://ashly.com/wp-content/uploads/2015/08/sc-series-crossovers-r01.pdf
Cheers,
Art
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Hi Art
Thanks for your valued feedback.
Cheers
Mike
Thanks for your valued feedback.
It all started with the JBL ASB6125 subs which we both got for 800 and have retailed for 7000 and used are still around 3-4000. So now I'm in the rabbit hole of PA systems 😊
We used them with the Behringer NX-6000D and I set the crossover at 1kHz. But connecting the only subs and comparing with the QSC, the Behringer sounded like metallic cookie box. So it went back right away.
I guess it will also go back. Bought it used online with 14-day return policy.
The analogue amp is amazing. I compared a synth directly and via SSL Six, it just sounds well-rounded coming out of it. It has some EQ, re effects I have a Microcosm Hologram. So what seems lacking is a "better" EQ? and dynamic processing. Can you recommend something that sounds warm and analog? With the digital qualities of the NX-6000D I was not impressed at all. I probably have to dive deeper into this topic 😉
Cheers
Mike
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I guess all that’s is needed is a sub amp and some 12’s. If those 15’s are true subs, they were never meant to go to 700Hz but should have plenty of bass. I had this pegged as a typical 2x15/2” rig - which was a de-facto standard back when heavy was acceptable and bass requirements were not severe. Adding 12’s to something that would need 18” subs later doesn’t make any sense at all, but using one or two per side as proper mid/bass drivers when sub duty down to 40 is properly covered does. If your bass requirements go up in the future one can add more reflex 15’s (or 18’s) provided they are similarly tuned - so no money wasted. Nice 12” drivers start a little over $200, and flamethrowers run 300+. Bigger coil is better, and 6-8mm of x-max is enough here. Crossover at 100 and 1200, then tune it in.
The inuke may be acceptable for 100 Hz and down duty - but playing raw 15’s through them full range was certainly telling. Probably brought out every resonance and box mode in the mid range and stuck them all in your face (metallic cookie box effect). True subs are not going to have a lot of damping material added, as you would in a mid/high box. The mids bounce off the walls, and come out the port - - and that response is anything but flat. Add that to an amp with coloration or not well behaved, and prepare to run from the room screaming. The resonances are high Q and with sparsely taken discrete points or a lot of data smoothing they are “invisible” on a graph. The inuke’s are not long term reliable, and if there is funding for a Labgruppen or old Powerlight there’s no contest.
I don’t know what DSP I’d buy these days -been too long since I looked into it. My old Driverack is obsolete and 20 years old but still runs. The Behringer is noisier and runs out of processing power on me, but is quicker and simpler to set up.
The inuke may be acceptable for 100 Hz and down duty - but playing raw 15’s through them full range was certainly telling. Probably brought out every resonance and box mode in the mid range and stuck them all in your face (metallic cookie box effect). True subs are not going to have a lot of damping material added, as you would in a mid/high box. The mids bounce off the walls, and come out the port - - and that response is anything but flat. Add that to an amp with coloration or not well behaved, and prepare to run from the room screaming. The resonances are high Q and with sparsely taken discrete points or a lot of data smoothing they are “invisible” on a graph. The inuke’s are not long term reliable, and if there is funding for a Labgruppen or old Powerlight there’s no contest.
I don’t know what DSP I’d buy these days -been too long since I looked into it. My old Driverack is obsolete and 20 years old but still runs. The Behringer is noisier and runs out of processing power on me, but is quicker and simpler to set up.
The same 15" driver (2265H) is used in JBLs AE lineup where it is crossed directly to HF horns in the fullrange cabinets, so I don't see that being a problem here. If the cab needs some internal damping that is relatively easy to add. The XTA loudspeaker processors get good reviews.. https://www.xta.co.uk/products/4-series/
There are a number of things that could have been wrong with your set up that could result in "a metallic cookie box" sound, but I would doubt the amplifier would be at fault.
I can't tell the difference between good analog or digital mixers until they are driven into distortion.
Midas digital consoles retained the sound associated with analog "warmth".
Thank you for the feedback which is highly appreciated 🙏
and
Good point, the bass we get out the ASB6125 is great and sufficient for now. So thank you all for the advice. We wont add more drivers for now.
Yes thats the plan. Keep looking for well maintained Labgruppen or Powerlight at good prices or the brand new PL380 for 2900.
Looking for used active analog crossovers like Ashly XR2001 or BSS FDS-360. Don't see the need for digital in our simple setup. Perhaps adding a parametric EQ like Klark Teknik DN3x0 would make sense.
Just unpacked the ASHLY XR77/12 and will test it once I get the XLR to TRS cables. If all goes well I can get a BSS FDS-360 for 200 and compare both
Haha, looking forward to that moment. So what you think? Adding parametric EQ like Klark Teknik DN3x0 would round it up? I try to avoid digital with screens unless it's absolutely needed 😉
The LR24dB/oct BSS FDS-360 sounds far better than the ASHLY XR77/12, is dead on accurate and has (peak) limiters. It's peak limiters are pretty obvious when they kick in..
The FDS-360 crossover points are fixed, you have to re-wire circuit boards to change frequencies.
800, 1K0, 1K2 would work OK:
It's HP filter card (low cut) is normally set at 30Hz, a bit low for your box tuning frequency (Fb) of ~40Hz, near the low E1 frequency.
Below Fb, the output of the ports and drivers go out of phase, the driver "unloads".
A 35Hz HP would be better to keep your lush analog synth patches from uselessly flapping the cones.
The low B (~32 Hz) is several notes below your cabinet's tuning.
You could lower Fb by extending the ports, put output would be reduced. As a two way, 40Hz is a good compromise Fb.
The KT DN300 is good, but mono.
I would assume you want a stereo system, the BSS FCS 966 would be the best of those selections. It's separate HF contour filters could be used to (partially..) compensate for the HF rolloff of your HF/horn driver.
That said, having extensively used the analog KT, BSS, DBX products for decades, I can say without qualification their DSP options are a better choice for speaker processing.
DSP offers separate filter frequency choice and EQ, delay, compression, limiting for each output.
That flexibility is game changing, kind of the equivalent from going from a monophonic to a polyphonic synth.
Art
