PX Configuration with JBL PRX700 Series - Idiot check!

Fondle

Hi all,

I've been DJing for almost 20 years and have decided to set up a small DJ & P.A. equipment rental business. Other than the odd fiddle around with P.A. gear whilst at gigs, I am new to this so learning all the time! I've read through the "Start Here" and F.A.Q. sections a couple of times and set my PX up based upon the information I found there, but wanted to run my various configurations past the experts in case I've misunderstood anything... your help and feedback are much appreciated! I haven't actually bought the speakers yet so have not run the wizards etc. but have set up the crossovers in the PX in a manner which I think makes sense...

The powered speakers I've settled on come from the new JBL PRX700 series:

2 x PRX718XLF Subs (Freq. Range -10dB 30Hz to 103Hz)
2 x PRX735 3 way full range speakers (Freq. Range -10dB 35Hz - 20kHz)
2 x PRX710 2 way speakers (Freq. Range -10dB 50Hz - 19.6kHz)

I'm assuming that I refer to the Freq. Range rather than the Freq. Response of the speakers in order to set the crossovers correctly... or have I got that the wrong way round?

The speakers will be offered as modular packages to suit the client's needs / space / situation. I've shown the packages and my configs below:

1.
2 x PRX718XLF Subs - HPF 40Hz BW18 - LPF 100Hz LR24
2 x PRX735 Tops - HPF 100Hz LR24

2.
2 x PRX735 Full Ranges - HPF 40Hz BW18

3.
2 x PRX718XLF - HPF 40Hz BW18 - LPF 118Hz LR24
2 x PRX710 - HPF 118Hz LR24

4.
1 x PRX718XLF - HPF 40Hz BW18 - LPF 118Hz LR24
2 x PRX710 - HPF 118Hz LR24

In all cases the Compressor & Limiter are disabled as the speakers themselves have dbx Type 4 limiters in them.

Have I got things about right? Any glaring errors?

Thanks in advance!
Dan.

Dra

Fondle wrote:

Hi all,

I've been DJing for almost 20 years and have decided to set up a small DJ & P.A. equipment rental business. Other than the odd fiddle around with P.A. gear whilst at gigs, I am new to this so learning all the time! I've read through the "Start Here" and F.A.Q. sections a couple of times and set my PX up based upon the information I found there, but wanted to run my various configurations past the experts in case I've misunderstood anything... your help and feedback are much appreciated! I haven't actually bought the speakers yet so have not run the wizards etc. but have set up the crossovers in the PX in a manner which I think makes sense...

The powered speakers I've settled on come from the new JBL PRX700 series:

2 x PRX718XLF Subs (Freq. Range -10dB 30Hz to 103Hz)
2 x PRX735 3 way full range speakers (Freq. Range -10dB 35Hz - 20kHz)
2 x PRX710 2 way speakers (Freq. Range -10dB 50Hz - 19.6kHz)

Use the response numbers. Filters (whether active or acoustical) should not be stacked.
The 718 is +/-3db at 87hz. I don't think these (710 & 718)combo very well. The 710 is responsed to 63hz, but I think the mid clarity will be diminished at higher volumes. The 712 would be a better choice, but even then a 12" crossing at 87hz is iffy, for the same reason. The 715 is more practical, but I assume size is a big concern for you. I am surprised that the 718 has such limited upper range. Now that I think about it, the 718 is applying a filter at 100hz. Apply no filter in the DRPX (raise to 300hz or higher)


I'm assuming that I refer to the Freq. Range rather than the Freq. Response of the speakers in order to set the crossovers correctly... or have I got that the wrong way round?

The speakers will be offered as modular packages to suit the client's needs / space / situation. I've shown the packages and my configs below:

1.
2 x PRX718XLF Subs - HPF 45Hz BW18 - LPF 300hzHz LR24
2 x PRX735 Tops - HPF 100Hz LR24

2.
2 x PRX735 Full Ranges - HPF 50Hz BW18

3. See above.
2 x PRX718XLF - HPF 45Hz BW18 - LPF 300Hz LR24
2 x PRX710 - HPF 118Hz LR24

4. See above.
1 x PRX718XLF - HPF 45Hz BW18 - LPF 300Hz LR24
2 x PRX710 - HPF 118Hz LR24

In all cases the Compressor & Limiter are disabled as the speakers themselves have dbx Type 4 limiters in them.

Have I got things about right? Any glaring errors?

Thanks in advance!
Dan.

Fondle

Thanks mate!

I'm buying the 710's primarily to be used as DJ monitors when the larger systems (718s & 735s / 735s no subs) are deployed, also as a mini-system for smaller house parties as and when required. The pairing of them with either stereo or mono subs was kind of an afterthought as to a possible alternative combination really... I guess I'll have a listen and see how they work out.

When you say stacking filters is bad, I guess you mean that if the subs / speakers are doing their own filtering, then let them do it not the PX? Hence the 300Hz or even OUT LPF?

Thanks again :-)

Dra

Fondle wrote:

Thanks mate!

When you say stacking filters is bad, I guess you mean that if the subs / speakers are doing their own filtering, then let them do it not the PX? Hence the 300Hz or even OUT LPF?

Thanks again :-)

Yes.
If the speaker has a natural roll-off (or DSP induced) of 12bd/octive starting at 50 hz, and you put 18db/octive filter at 50hz... who knows what it will do. Assumptions could lead to a 30db/octive slope. What about the "knee"? Who knows. What if the filter is moved up or down 10hz?

DRA

Fondle

Thank you very much for your help