Using 2 JBL PRX835's (or other 3 ways) without a sub ?

Depends on venue size. I've filled in bass for my buddy's band with a small combo amp and he only ran 2 srx835p speakers setup in full range mode. For smaller indoor gigs, it was fine. Those speakers have nice lows as long as they are coupled to the ground.

 

My drummer has two PA: one set with a pair of Mackie 1530 (similar to the PRX835) and another set with a pair of Yorkville NX55 (12" top) and a Yorkville LS710 sub. I way prefer the second kit. I don't like PA with 15" speakers, much prefer 12" tops and a sub, more balanced.

 

Can you do it? Yes!
Should you is the real question.
For me, it would depend on the style of music. For rock stuff in smallish venues you should be fine. But if you are doing dub, hip-hop, anything with a lot of "thump", or mid-size+ venues, then I'd recommend subs.
Heck, try them out at a gig and see how they do.

 

I run sound professionally when I have the time. 12's are nice because they are lighter and a tad tighter. I have 2 PA systems. A full QSC and full JBL. My qsc is 2 k12.2 and 2 kw181 with a touchmix 16 mixer. This is my preferred system. I also have 2 jbl srx815p with 2 srx818sp subs. I prefer this setuo for DJ music.

For small indoor gigs, the prx835 will be fine. They have to be laying on floor for greater bass response. Medium indoor or outdoor gigs its best to have main/sub. I've ran sound with the srx835p speakers and no subs for smaller gigs. They are my buddys speakers when he plays and i run the sound for him. Bigger gigs he adds srx728 subs.

 

A couple of things to consider. Using the Boost mode applies EQ to extend the frequency response a bit lower, but it does not change the amount of output that is available. I would not use Boost with live music as it basically creates an artificially smiley-faced EQ curve with hyped highs and lows.

As @CBBass123 mentioned, speakers need to be ground stacked for max bass (half space loading). But main PA speaker need to be elevated above the crowd and ideally tilted forward to shoot the sound down into the crowd. If they are high enough you essentially consider them in full space instead of half space. At the very minimum, you will get low frequency boundary cancellation between the floor and the PRX835 where 1/4 wavelength is equal to the distance between the effective sound source and the floor.

 

Not every gig needs 2 subs... but if its questionable, i usually run two because they are fairly lightweight... roll pretty easy and i always stack them. One main reason i like to run 2 is, if it is a questionable sized gig... i don't have to push 2 subs hard vs 1 sub.

 

You can always turn the subs down if two is too much. If one is not enough, your just plain out of luck.

 

We use PRX 735's in a 300 seater room with no subs. I suppose it depends on the music you play and the levels you need but I actually prefer these without the sub. being a 3 way box they have a very smooth sound, near the back of the room the level is low but you would need a pair of speakers half way down on a delay to compensate.

 

Our music ranges from jazz to Latin to funk but we’re not a loud band. Have not used these outdoors but I think they would struggle in a full band setting outside unless it’s a sort of confined audience area.

 

M 835’s are kinda large for pole mounting. For safety and sonically I prefer having my 3 ways up on a sub, to 2 and short stick. Kw-153’s in my case. The 153’s will run away from k12’s volume and coverage wise. I've done Many shows on K12’s over 181’s and they are great up to a point. The 153’s will go way further. I would think the 835’s would do the same to 812’s.

Pic above is in a high wind environment. The strap is actually keeping the 153 from rotating ... band is High Pulp from Seattle, WA. Very nice set of instrumental, synth heavy groove music.