B&C frequency response?

[Daniel lussier]

I have two 18inch custom built subwoofers using B&C 18sp76s. One in each of their own enclosures. It’s just a box with the speakers mounted on top at a bit of an angle and then it’s just a grill. Nothing fancy. He owns a full production company so I trust the enclosure is fine but my question is the frequency response of this particular speaker is 40hz-2000hz, if sub woofers are generally 25hz-150hz than would this be more of a mid bass speaker?

Why does the frequency go so high up? I’ve seen this with a lot of other subwoofers too

I currently do live sound for metal/hardcore punk bands so I always take these with me to take the load off my new jbl eon 715s

I use a behringer xpro crossover with the mono summed sub out going to a qsc plx 3402 power amp then each chanel is sent to a sun giving it 700 watts to each at 8ohms. I do have two Mackie fr2500s I could use for an extra 50watts a channel but I don’t see the point in that at all lol.

I want to buy the new jbl eon 718s to pair with my tops anyway but I eventually wanna do edm/rave shows, so everything needs to remain portable. I’d love some Hennessy sound design subs but thoes are way better for permanent install cause I’m just one guy doing this.

I recently got an absolute steal on some gear that never left a guys basment (dead head with some money) but I won’t go into that but I got two jbl jrx 125 quasi 3 way speakers and a behringer 18” xpro 1800 passive subwoofer a Mackie cfx16 with the sun out 75hz output that I’m going to start usuing instead of my Yamaha emx1604 (I could be butchering some of these sorry) the powered mixing board. And two of the Mackie fr 2500s I was talking about.

I want to use everything I’ve mentioned for running a rave/edm show at function halls, venues with out PA systems. And my idea so far is to use the 2 jbl jrx 125s ran on one Mackie fr 2500 (750w each channel @4ohms since both jrx’s are 4ohms), my two B&C 18sp76 subs ran on my qsc plx 3402 (700watts each channel @8ohms. Each b&c is 8 ohms 600 watt nominal 1200 continuous) and when I buy them the jbl eon 718 powered subs and my current jbl eon 715s would maybe be front fills? All of this plus maybe the Yamaha club v 218 dual 18inch speaker cab?

I’d arrange it so all the subs are right in front of the Dj right in front of the dance floor going Yamaha club v 218s center. My B&c subs left and right of that and the eon 718s left and right of thoes with the jbl vrx 125 on top of the 718s far left and right with the 715s as possible front fills.

So, are my b&c’s better used as mid bass speakers? Say I had the eon 718s covering up to 80hz and my b&c’s covering 80-250hz? Maybe even 120hz-500hz? I only ask because every subwoofer frequency response ends at like 150hz so if the B&c ends at 2000hz what is their best application. Always indoors too I don’t think I could cover an outdoor show even with what I just mentioned. If they would be best used as mid bass (120hz-500hz or whatever) where is the best placement for them. Both side by side dead center? Or under the mains far left and right with the powered subs center on the dance floor side by side.

I apologize for the rambling over such a basic question. I’m just learning all this stuff with a pretty basic back ground in stage handing and tech stuff. I’m no audio engineer but I can run a hardcore/metal/punk show alone pretty good.

I’d love some suggestions on some ideal equipment for doing indoor raves at a max 500 person event hall. I’m trying to use what I have and to not have to buy another thing again other than to replace it. Assume I already have the eon 718s cause I’m buying thoes no matter what my subs don’t have handles and are so awkward to carry and ya know. Active subs to active tops are so much easier.

Thanks y’all!

 

[Carl Klinkenborg]

Long story short, an 18" can certainly produce healthy output up to about 2kHz but you wouldn't want to because it will beam the higher frequencies over a narrow angle, so a few hundred Hz is a reasonable limit. Very few subs are flat to 25Hz, and without an actual response plot of your particular speaker the discussion is moot. There is usually not a great deal of worthwhile content below 40Hz and it simply eats up power and excursion, so even if this was the lower limit you should still treat it as a sub. If you have actually tried the setup, what did you feel was lacking?

 

[Daniel lussier]

Long story short, an 18" can certainly produce healthy output up to about 2kHz but you wouldn't want to because it will beam the higher frequencies over a narrow angle, so a few hundred Hz is a reasonable limit. Very few subs are flat to 25Hz, and without an actual response plot of your particular speaker the discussion is moot. There is usually not a great deal of worthwhile content below 40Hz and it simply eats up power and excursion, so even if this was the lower limit you should still treat it as a sub. If you have actually tried the setup, what did you feel was lacking?

It sounds good honestly but I must of been looking to hard into the numbers. I haven’t yet been able to use the jrx’s with my subs in a live setting only the eon715s and they sound great. I wasn’t sure if their was a better application for them, I other wise have no complaints. Testing the jrx’s in my basement and with the cfx16mk2 board I have one thing I noticed was playing music through the board in a mic input sounds not great but playing music through the tape in sounds perfect. I thought it might be because the speakers are up in the air and the sound reflection. Idk how to explain it. But as for now I’m gunna use the cfx’s internal crossover sub out to my qsc to drive the subs up to 75hz and use the crossover settings on the eon 715s at 80. Only thing that blows is that missing frequency gap lol