On the Down Low

[tulk1]

After years of using our analog subs, I bit the bullet today and bought 2 JBL PRX618-XLF subs. These are powered, 1000w, built in crossovers, yada yada. Nice looking, tho'. Should actually help with tear down at 1:00BFE in the morning. Might help with set up times, too. XLR to the sub, XLR to the top, XLR out of the sub to the other sub, XLR out of that to the tops. Power up, let the bottom do its thang!! Actually, this will allow us to drop the current JBL subs, and two racks with crown amps and dbx crossovers in each. Will lighten the trailer load a bit, as these only weigh about 10lbs more than the JRXs. Which, btw, anyone want a couple of subs, power amp, crossovers and racks?

[Billgelder]

Nice, We are thinking of get them also, let us know how they workout.

[grubber]

Beauties, have been using our Mackie powered subs for 4-5 years now. very easy setup with the tops. A DBX Power speaker rack effect makes them sound fantastic. the only outboard effect we use, sweetens them up and eliminates any potential feedback.

[FredZepp]

Impressive... that seems like a smart purchase.

 

and 133 db should be enough..

• Maximum SPL 133db peak
• 460mm (18") Differential Drive dual voice-coil and magnetic gap, neodymium woofer
• 1000W (2 x 500W) Class-D, Crown digital amplifier
• DSP input section with dbx Type IV limiter circuit, crossover, dynamic limiting, component optimization, selectable system EQ

[bolero]

what's the difference between a digital & analog amplifier?

[tulk1]

what's the difference between a digital & analog amplifier?

Well, that may be a misnomer on my part. What I meant was passive speakers with components (Sub, amp, x-over) vs a built in system like a powered unit - all in one. However, the new light weight amps are actually more digital than their older counterparts. We've been using Crown 402XLS amps, bridged to 4 ohms to give us about 1100w. The new Crown amps (and most others) use a switch mode power supply, which is not unlike the guts in a cell phone. Plus all the built-in DSP for crossovers, feedback control, etc. Lots of digital stuff going on behind the scenes. And not so much with the older, heavier power supplies and such. Thats why I can get better speakers with built-in power that weigh just a fraction more than the passive speakers alone.

[tulk1]

Thought I'd do a follow up to this post.

 

We had some weird goings on with the JBL PRX618s. First time out they seemed to be working. But after that we could not get a sound from these subs. Talked to several engineers about the issue, none could help me resolve it. I could get signal to the subs, but no sound. I know we had signal because the chain is: Mixer > Sub > Top. Tops worked, subs didn't. Sent one back and got a newer JBL PRX718XLF. Same scenario - no sound. We pulled the mixer, tops and subs into the rehearsal room to do a controlled test. Same thing - signal to subs (lights showed signal) but no sound, tops worked fine. We even had a local sound guy drop by (coincidentally) on the day we were testing. He put the system thru a good check and made the same determination that we did: WTF, it shouldn't do this!! Our KW152s in deep mode out did them as subs. So, back went the JBLs.

 

Enter - QSC KW181s. And let me say I wish now that I had just gone this way from day one. Maybe it's a matching thing, kinda like mixing skim milk with whole milk - it's gonna explode! But once we matched up the KW181s with the KW152s we suddenly had that complete sound we'd been missing. They are very musical, very articulate for sub frequencies. And, if you stand close to them in just the right spot you might have an unexpected need to hit the john ... fast!! ....

 

So, there we are. And for now, my search for the perfect bottom end had ended .............. music gear-wise, that is!!

[Keith7940236]

Congratulations! Glad to hear that it worked out!

[fxdx99]

Nice. For our company picnic, the sound guy had 4 KW181s and 4 (2 pair) KLA12s. Great great sound. Very clear and musical as you said.

 

Glad that your perfect bottom end search is cut in half. Good luck on the balance...

[TalismanRich]

Subs? We don't need no stinkin' SUBS!

 

... and to think that we used to have what we thought was a kick ass PA system so many years ago. 4 channels, 100 watts, reverb, 4x8 columns on each side. Cost the band about $800 around 1970!