vrx928 and 915subs

jo

hello all
I am running a vrx system with the drive rack 260
vrx928la 1 per side
vrx915s 1 per side
crown 602 for highs
crown xti 4000 mids/low
yorkville 4040

do the presets for speakers mean perside ex. vrx928la 1 / vrx928la 2 / 3,4 ect?
is there any1 in the jacksonville fl area that can help me I've been tweaking system for 3 weeks now and feel it should be more powerful
joelafrance@bellsouth.net please drop me anote if you can help thx
jo
my main problem is familiarity with the driveracks in general

Gadget

Man, I just looked those up and @ only 90 DBSPL @ 1 meter those things are VERY inefficient. We have experienced the VRX series on several occasions doing national acts in smaller clubs (TOTO not too long ago) and I have to say I really don't like those boxes... They are difficult at best to EQ the settings JBL gives are less than spectacular and we have found that the 260 doesn't have enough PEQ's to fix all the problems associated with those boxes...Since those are a ~quasi~line array speaker( a line array characteristics are such that the length of the array determines the frequency response of the directivity of the array) they are treated differently than conventional horizontal arrays, but the number of boxes doesn't really change the settings .. except in terms of delay and power shading. I say Quasi because the line array is typically made up of long throw speakers (which the VRX are NOT) and the top most boxes are sent out to the farthest reaches/upper seating, the next lower boxes are aimed and delayed to reach lower, closer audience, and so on till it's usually terminated in a more nearfield type speaker for underhang and front rows coverages...

With 15 degree vertical coverage and 8\" woofer and 1 \" 20 watt tweeters I'm not surprised it's not very loud.. especially with disappointingly low 90 db spl output... Typical line arrays are usually closer to 105 - 107 db spl@ 1 meter...thats a whopping 15-17 db difference... even the JRX are 99 db spl. Between 6 dB and 10 dB is double the volume level, where 6 dB is four times the power and 10 dB is 10 times the power necessary to achieve equivalent volume.

Likewise, your subs are @ 91 db spl 1 meter one watt.. and @ 3200 watts peak power your amp in stereo is putting out a paltry 750 watts and bridged mono 1088 watts per speaker, thats a full third under program rating...

I'm not sure what to tell you, I think you will very probably have trouble getting a ton of volume out of that system for any but the smaller rooms..What is the system used for?

Sorry to be so negative I just can't figure out what JBL is doing these days? The SRX 700 series are not even able to reproduce 12K ? whats THAT about, and they will NOT respond to any inquiries about this ... Mikey Kovach found brand new speakers with two different drivers in them :shock: .

Good luck
Gadget

Dra

I would assume that the presets are \"per side\" because no one would have 1 speaker only. I have opened all of them and there are some PEQ and crossover gain differences. Must be some summing / cancelling going on.
I have in-laws in Jax. Next time I'm in town I may look you up (to get away).

Have you done a manual gain structure for all the amps?
Have you tried running the tops full range straight from the board to see how they sound?
Where do you think that they are deficient? Or do they sound good, just not enough of it?

DRA

jo

small club use mostly they do sound good however the power is disappointing for the money I'm starting to dislike the newer jbl designs they are screwing themselves I've been doing sound for many years since the 70's lol and thought it was just me not being familiar with the driverack series the more i get into these things the less difficult setup are however its still a good thing when you can reach for a knob and turn it instead of paging through a bunch o crap thanks again
someone ought to sue jbl for screwing up a great reputation

jo

You'd be welcome Dra would love to talk shop with you and network in general thx for chiming in lol joe

Gadget

Joe,

If you were using 4 or more cabs per side you MIGHT get usable performance...JBL isn't the only one out there fudging the figures to SELL the junk... There ARE still reputable MFG'rs doing good work out there.. Tom Danley is one. Without some standardization in the speaker industry speaker spec's don't mean squat...Some speaker MFG's actually surpass JBL's faux paws, or are at least as guilty (actually most are) as JBL for overstating a speakers capabilities... I might say that my speakers have response clear down to 20 hz.... without ever having to reveal that the 20 hz response is actually 10-20 db down...or more ( I have LABsubs...). Actually most double 18\" 15\" cabs don't have much usable info below 40 hz... Horn subs are far superior in output usually at the cost of size and weight... but the EFFICIENCY and the LF EXTENSION to the 30's and upper 20's in groups of more than 6... absolutely unbelievable...

12\" speakers make a much better low end speaker than 15 and 18\" drivers.... Imagine a dump truck with a Ferrari engine...how fast can you accelerate and slow down to reverse direction? now imagine the same engine in a Ferrari body...NOW how fast can you start and stop? Reverse direction...Obviously The car can maneuver with great ease versus the truck. Thats the baggage the 18\" driver carries...

Weight (cone/spider/voice coil) cone mass
Air mass(air displaced by the cone as it travels)
frequency response ( more air mass per stroke but limited frequency capability... the lower the frequency the longer the wave form the more power it takes to reproduce.

I also couple the sub speakers in a \"mono\" block configuration, utilizing the free power when speakers couple. Dis-similar speakers or multiple cabinets can cause lobing, phasing or other undesirable effects

gadget

jo

thx gadget
the more I begin to get into these new age systems the more I'm convinced to go back to old school days and equipment. what you say has ben true for over 30 years I think the industry as a whole needs to look at what there doing lol it makes me more in demand today than ever before, for me Im gonna stick with the old school way till all the bugs are worked out. folded horns were the rage in the 70's and 80's and I still belive in them today. thanks for the input you guys I just wanted to justify the money I spent I guess I was foolish to belive a factory rep
jo