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Finally just bit the bullet and bought my new rig...


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After going back and forth the last couple of months debating whether to go active or passive, I finally narrowed it down pair of yorkville ls800p and a pair of ef500p for active, and a pair of SRX718S and a pair of SRX712m for passive. I would need amps also for the SRX's. I decided that they would be powered by Crown XTi4002's.

 

Well, I came across a deal I could not refuse. A guy had 4 SRX712M and he was asking $2600 for them. I pulled the ropes a little bit and he was willing to let them go for $2400. I bought the SRX718S brand new along with three XTi4002.

 

The subs and amps came in yesterday. The subs are more compact than I thought. The amps are pretty light too. Not quite as light as the Peavey IPR but still light. They do seem a lot more durable.

 

Anyway, with the built in DSP, would any of you recommend to use onboard crossover and EQ or would you recommend external crossover and EQ. I was thinking maybe a driverack PA plus.

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Congrats! The SRX subs are compact. We play a venue with a big stage and they have niches in the front of the stage where the house subs sit on the floor flush with the front of the stage. The club has two SRX718's and 2 of the Mackie HD 1801's. I realized after I set up my rig with 2 QSC HPR181's the other night I could get a good view of the different dimensions of each sub from out front. I was surprised how much larger the QSC's are than the Mackie's but the SRX's look tiny compared to both the others. It's amazing how compact they made that speaker and yet how great it sounds. Enjoy!

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Thanks for the confirmation guys! I was kind of doubting my decisions. These subs are indeed compact. I saw the UPS guy carry them (one at a time) from the truck to my doorstep and I thought "Man, that guy is strong!" When I unboxed it, I realized how light they were.

 

And thanks for the link to the post with the settings.

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Thanks for the confirmation guys! I was kind of doubting my decisions. These subs are indeed compact. I saw the UPS guy carry them (one at a time) from the truck to my doorstep and I thought "Man, that guy is strong!" When I unboxed it, I realized how light they were.


And thanks for the link to the post with the settings.

 

Did you see the magnetic channel stickers for your StudioLive?

 

 

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Very Nice! A good friend a forum poster Don Davis uses 4 712's over 4718's and the sound quality out of that system is amazing. I have a pair of 718's myself, great little subs and looking for some 712's.

 

 

Hey Bob, I pulled the trigger and upgraded to 4 - 718's and they are the bomb! Used them in a 2000 seat theater this past Sunday and they rocked it.

 

Tomis17, thats going to be a very nice rig, congrats!

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Thanks! I hope the buy once cry once philosophy works out to my favor even though it dug a deeper hole in my wallet than what I expected.

 

It will. I bought my Unity15/LS800p rig in 03. It's almost 10 years later. Never had to upgrade, it's just sounded great this whole time. I'm sure in a couple years you will wonder how you ever got by without the rig!!!

 

If not sooner.

 

 

:thu:

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These are the mains points from Agedhorse's post in case anyone is feeling lazy:

 

 

As I promised a while back, I am sharing a set of parameters that I generated while developing a tuning for SRX-712M's used in Biamp mode for stage wedges, While I know this is a bit excessive of an application of this box for most of you, it's a pretty common box on the higher level systems and these tunings will work well for speaker on a stick WITHOUT SUB. If I get some time, I have an SRX-718M sitting in the shop and I'll try to run it.


This was developed while testing a (replacement) BBE DS-48 which I had to fix before programming. Microscopic solder bridge on the DSP causing intermittent operation. Turns out their PCB hygine is not as good as it should be. With lead free solder chemistry, cleanliness is absolutely critical as dross captured in the surface flux/oil in the solder bath (it's not purely reflowed) can easily contaminate the top surface. Grrr.


Lows

HPF = 49.6Hz, 24dB, BW

LPF = 1.21kHz, 24dB, LR

Gain = +3dB

Polarity = +

Delay = 0.50msec

PEQ:

315Hz, Q=2, G=-3.9dB

231Hz, Q=2, G=+3.0dB

600Hz, Q=3, G=+1.6dB

72.9Hz, Q=1, G=+5.0dB

105Hz, Q=3, G=-2.0dB


Highs

HPF = 1.21kHz, 24dB, LR

LPF = thru

Gain = -7dB

Polarity = +

Delay = 0

PEQ:

2.16kHz, Q=3.8, G=+2.4dB

2.88kHz, Q=3.0, G=-3.0dB

15.4kHz, HF shelf, G=+4dB


There are some tricks I specifically used with cascaded filters modifying each other's response at their margins (I use this technique in my analog filter design in some pretty popular products as well, so it's not something unique to DSP) to gain performance improvements not available by using a single filter section. This is generally used to overcome a mechanically induced response anomoly.


There is an intentional gentle rolloff from flat starting about 2kHz and ends up -2dB at about 15kHz where the HF lift filter transitions. This is also common, especially in near-field applications where you may get loud. There is compound filtering on the LF section to improve performance without a sub while still maintaining reasonable protections under high drive conditions. I would not power this box at more than 800 watts RMS, this is my disclaimer and my linearity testing confirmed this.


This is good palce to start, then add a little 1/3 octave to touch up for room conditions (if needed). It also reinforces my experience that this is one heck of a nice box with an outstanding HF section.


I think my tunings for THIS box is better than Harman's, there is something goofy with the 712 model that the 722 tuning does not share. I don't know why they underlapped and used such disparate crossover frequencies. There was NOTHING in the basic response that would even begin to indicate that it was necessary.


Anybody biamping this box, give it a try and report back. This is the sort of stuff I do as my day job, it's not quite as easy as it seems from the above numbers. There is quite a bit of interpretation of the data that's required to make good decisions as to what's good data, what's the best and most practical way to proceed, and when do the solutions start getting in the way of the problems.


Here's what I got using a DR-260 and triamp w/ 718 on the bottom and 712M on the top. Using QSC PLX-3402 on subs and lows, PLX-1202 on highs.


Subs

HPF = 31.3Hz, 24dB, BW

LPF = 91Hz, 48dB, LR

Gain = +3dB

Polarity = +

Delay = 0.00msec

PEQ:

41.7Hz, Q=5.01, G=+1.5dB

66Hz, Q=7.83, G=-2dB

Easyover off, threshold=+6dB



Lows

HPF = 91.3Hz, 48dB, LR

LPF = 1.22kHz, 24dB, LR

Gain = 0dB

Polarity = +

Delay = 0.00msec

PEQ:

648Hz, Q=3.876, G=+2.5dB

1kHz, Q=1.573, G=+2.5dB

354Hz, Q=1.382, G=-2.5dB

Easyover off, threshold=+3dB


Highs

HPF = 1.21kHz, 24dB, LR

LPF = thru

Gain = -15dB

Polarity = -

Delay = 0

PEQ:

3kHz, Q=2.996, G=-1.5dB

2kHz, Q=5.706, G=-2.0dB

5.04kHz, Q=4.41, G=-1.5dB

11.6kHz, Slope=9, G=-5.5dB (hf lift)

Easyover off, threshold=-16dB


As you can see, a different set of parameters that maintain quite a bit of similarity are present, I preferred the HF horn down a few dB more on this set-up, perhaps it's a slightly different environment or just a different preference day for me. I generally do not like a flat HF response all the way out, I like a gradual rolloff of a couple of dB from about 2.5k-15k, just is a little more forgiving and my ears don't do the rolloff for me


Since this is a different environment with some significant bounderies, I had identified the bounderies and their effects the best I could so the results are reasonable and corrolate reasonable well. It's interesting that in this case I found that inverting the HF driver worked better (actually a lot better) than the delay, and there was no meaningful difference delaying the HF driver here... and I don't know why, but both methods are reasonable but like I have always said, changing the measurement environment (including mic position by a little bit) can totally change the results, so there is considerable latitude in the interpretation and application of the basic measurement/correction techniques. There are some differences in measurement mics, testset calibration, mic calibration, etc. There are also major boners out there that are just goofy and wrong when looking at the overall solution. Exact is not necessary, close is good enough in 99.9% of the cases because exact changes with many ofthe variables and if you don't have control of things like room acoustics, it doesn't matter what you would like to do, it is what it is.


Now that I have my universal test system set up, I'll see if I can run a passive 712 test, that would be on top of a sub since that's how most are run. That also means that there will be a significant boundery event around 150-ish Hz which I will ignore with my parameters since that will be different depending on the surface boundery material.


Here's the best I can do with a passive 712M. The out of the box flat eq has a fair amount of 11-15kHz going on, kind of the bright JBL thing which I do not care for myself. The biggest improvement here is the reduction of this. For biamped w/ subs, ignore the lowest band, that's a LF extension. I used a HPF of about 62Hz, BW-24 because these boxes don't excel at LF reproduction, but would kill for acoustic and jazz without subs if that's the style.


PEQ:

81Hz, Q=5.706, G=+4.5dB (note this works in conjunction with the HPF)

225Hz, Q=4.41, G=+4dB (note some of this is boundery cancellation so flavor gently)

500Hz, Q=6.491, G=-3dB

1.68kHz, Q=2.035, G=+3dB

14.7kHz, Q=5.706, G=-5.5dB (HF response taming, they use a passibe lift network that's excessive IMO)


Also, I used borrowed PEQ band to achieve the fifth band. Most of you using subs will not need band 1, it's mostly for informational purposes.


Gotta get back to work!!!


Either 24 or 48dB/octave is viable, JBL recommends on the PRX-618XLF and the transition within the crossover area is a bit better IMO w/ 48dB/octave but either is acceptable.


There are no exacts but a range of acceptable solutions. This is what I was trying to say, AND there are a range of poor solutions as well. Sometimes anechoic flat is not ideal because it does not represent how the product will end up being used 99% of the time BUT it's a good start. I went ahead and let some typical room interactions enter my solution because it's what most of you will see. I also find a pure flat response at the very high frequency band a little too much for most applications, over the years I have found most folks to prefer a gentle coupld of dB rolloff but if you have hearing challenges, this may not be either audible or desired but I am looking at the general audience type population not somebody who has hearing damage.

 

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Did you see the magnetic channel stickers

 

 

I have been using magnetic channel strips for years. Stop by your local sign shop and get some magnetic sheeting that they use for magnetic truck signs. They usually have scraps that can be had for cheap or even free. I cut it into narrow strips with a utility knife and straight edge. You can write on them with a dry erase marker, sharpie, or even ball point pen or pencil.

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Try it without biamping the 712's first. For many applications it's probably not justified.

 

 

I will try that out first. Sometimes it's just having it just to have and not because I need...sad but true.

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