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Q: mixing turbosound powered speaks w/eaw sb1000


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so,

 

we are having an easter sunrise service using our portable stereo PA system in our outdoor 1000+ seat amphitheater, featuring doyle dykes (solo gtr) and brenton brown (band)

 

4 x turbosound 445DP digital 3 way powered compact mains:

 

COMPONENTS

1 x co-axial 12

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Let the subs do their job...50Hz would render them almost useless.....try crossing at around 100Hz, with a 24dB slope, and experiment up and down a bit.

 

 

 

thanks for the reply!

 

pardon the misunderstanding-

i wasn't suggesting a crossover point per se, just adding a hi pass to the 445DPs

 

in my mind, raising the hi pass on the turbos would free up some headroom on the low freq amp built in to the speaker, allow the low freq driver to work less "incumbered", and reduce some potential phasing between the subs and lows on the mains

 

 

there is a mode switch on the turbosounds that i just found out that does roughly the same thing as i was suggesting---sets a hi pass internally at 125hz, designed to work in tandem with their subs recommended for use wth these mains.

 

but neither the speaker nor the included literature indicated where the frequency point was on the hi pass switch, so i had to contact the manufacturer.

 

 

 

any other suggestions?

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thanks for the reply!


pardon the misunderstanding-

i wasn't suggesting a crossover point per se, just adding a hi pass to the 445DPs


in my mind, raising the hi pass on the turbos would free up some headroom on the low freq amp built in to the speaker, allow the low freq driver to work less "incumbered", and reduce some potential phasing between the subs and lows on the mains



there is a mode switch on the turbosounds that i just found out that does roughly the same thing as i was suggesting---sets a hi pass internally at 125hz, designed to work in tandem with their subs recommended for use wth these mains.


but neither the speaker nor the included literature indicated where the frequency point was on the hi pass switch, so i had to contact the manufacturer.




any other suggestions?

 

 

I'm more confused now. What frequency range is going to the subs, and what frequency range is going to the mid-highs? As worded, it sounds as if you've got the mid-high's handling the the same LF signal as the subs. Phasing problems would not be a surprise if this was so, and indeed a lot of amp power is being 'wasted' on the mid-highs trying to handle that.

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In a nutshell, NO.

 

Looking at the power bandwidth product of the system, and the fact that you may not have enough PA for the job depending on the SPL needed towards the back of the audience area, I think you will need every bit of output the top boxes can provide. The 50Hz LF limit of the top boxes are most likely at least -6dB (and probably more like -10dB) lower sensitivity than the meat and potatoes bandwidth wher ethe bx is most sensitive. So, throwing scarce resources (power) to a boxes least efficient reproduction range is pretty much like throwing it away considering you have the subs which are most efficient/sensitive between about 40Hz and 100+Hz.

 

Cross the system over around 100-125Hz and be sure you have a HPF on the subs at about 35Hz and that's about all you can expect performance-wise from the system. Also watch the 9001 on those subs, certainly don't bridge it (impedance issues) and even one box per channel could cause damage under an unexpected accident of if you find yourself without enough sub for the job and in a fleeting moment of lacking judgement push the snot out of the cabinets.

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I'm more confused now. What frequency range is going to the subs, and what frequency range is going to the mid-highs? As worded, it sounds as if you've got the mid-high's handling the the same LF signal as the subs. Phasing problems would not be a surprise if this was so, and indeed a lot of amp power is being 'wasted' on the mid-highs trying to handle that.

 

 

thanks again, and i'm sorry for any vagueness on my part.

 

the system was purchased and set up by an a/v company, but i was not present for the fine tuning of the dsp for the amphitheater, and then the last time it was used, we had another engineer on board.

 

from what i can tell, the system is feeding main L/R out into channels 1 & 2 of the ashly 4.24C, and aux sub output is feeding input 3 of the ashly.

 

outputs 1 and 2 of the 4.24C feed the mains.

 

from memory, there was a 10:1 comp on the mains and a brickwall limit on the subs.

 

subs are being fed by the 9001, 1 side of the amp per cab, and there was a hi pass on the subs set at 29.? hz and a few para eq bumps in the 50 and 80 hz ranges, but i didn't find any setting limiting the mids/highs from feeding the subs.

 

there was a hi pass on the mains set low---35hz?---and a few para eq notches in the 400-500hz and in the 4k range.

 

my primary question was concerning the hi pass freq point.

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Sounds very wrong, perhaps you are missing the x-over filters location in the DSP. Often, translating the layout of a DSP signal flow can be confusing depending on the programmer's technique. There should be a 100Hz or so LPF on the sub outs and a corresponding 100Hz or so HPF on the top cabinet outs. This prevents build-up that would occur where the bands otherwise overlap. This would also cause some constructive/destructive interference and comb filtering where the two signals acoustically overlap.

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Sounds very wrong, perhaps you are missing the x-over filters location in the DSP. Often, translating the layout of a DSP signal flow can be confusing depending on the programmer's technique. There should be a 100Hz or so LPF on the sub outs and a corresponding 100Hz or so HPF on the top cabinet outs. This prevents build-up that would occur where the bands otherwise overlap. This would also cause some constructive/destructive interference and comb filtering where the two signals acoustically overlap.

 

 

exactly!!! so i'm not going nuts....

 

and that is exactly the info i was looking for in the ashley; low pass to limit the hi freqs from the subs at the upper limits of their reproductive range, and a corresponding hi pass on the mains that was relative to the low pass point on the subs. started to make me wonder if there was some new reason to stack low frequencies as indicated by the settings...

 

i swear i checked every possible angle on the ashly...looked through all the crossover/parametric eq/pass filter programming on each input/output...and no dice.

 

perhaps the last guy on the system did some *improvements*:freak:

 

then again, i recently went through our indoor system's soundweb dsp, tuned by the same a/v company, checking values and looking for tiny tweaks as the weather heats up, and i found a hi pass filter on our indoor SB 850 subs set to 100 hz as well as a subsequent L-R crossover on the subs set to hi pass at 35hz and low pass at 200 hz @24db slope...which didn't seem right to me so i bypassed the 100hz hi pass

 

i wish i had guys like you and craig on hand while i went through junk like this!

 

i'll start at a 100hz crossover point between subs and mains and scoot around from there

 

does the 10:1 comp on the mains and infinity to 1 on the subs seem right?

 

finally, any tips on more punch from the subs?

 

 

THANK YOU!

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i'll start at a 100hz crossover point between subs and mains and scoot around from there


does the 10:1 comp on the mains and infinity to 1 on the subs seem right?

 

I'd start at 90hz and then keep an eye on the amps to see how the power division is working out and walk out front to see how it sounds.

 

6:1 should do the job. I'd rather see that and pull your foot off the gas a little, rather than mash the throttle at 10:1 and squash the life out of the dynamics. It's not about how loud the system can be pushed, but more about getting impressive dynamics and clarity.

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I'd start at 90hz and then keep an eye on the amps to see how the power division is working out and walk out front to see how it sounds.


6:1 should do the job. I'd rather see that and pull your foot off the gas a little, rather than mash the throttle at 10:1 and squash the life out of the dynamics. It's not about how loud the system can be pushed, but more about getting impressive dynamics and clarity.

 

 

 

good points.

 

the turbosounds actually have built in protection limiters in them with a clip indicator on both the high and the low power amp, but i set a output limit of +5db on the ashly feeding the mains as well. so i think relaxing the ratio is a safe idea as well.

 

the subs thing is more touchy, especially because sometimes it seems much harder to hear slight fluctuations in the low frequency bands.

 

due to the configuration of our system, we have a swappable multipin drive cable at the amp rack to change the feed to the power amps, sourced from either our indoor FOH, or outdoor FOH, and a subsequent socapex cable from power amp outputs, feeding either the indoor subs and monitors, or outdoor subs and monitors.

 

kinda confusing...i might need to post some pictures, which might be kinda cool for folks looking in to this thread as well...

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this is exactly why DSP can be big problems. There are many places to screw up, and when programming you need to be very careful, almost anal.

 

 

i agree a million percent

 

i try to be as meticulous and methodical as sanity allows:D

 

the one drawback to the ashly is that we are not set up to run the software for it so i have to navigate through the unit's onboard menu screen, which is not that bad, but it does have some layered nooks and crannies that one could potentially skip over if not careful.

 

our indoor soundweb is linked to a pc so we have full visual confirmation of all matrix and control point info at a glance...way nicer.

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So the bottom line is that the subs should be handling somewhere in the range of 50Hz to 100Hz, and the mid-highs should see 100Hz and up. You can move the crossover point up or down 10Hz or so to determine if there's any improvement. The subs bandwidth would be relatively narrow but for live sound 50Hz is usually quite sufficient and will conserve power for the usable bandwidth.

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That is... when the Soundweb doesn't crash.

 

yikes!!!:eek:

 

yes, that is always a sobering thought. and yes it has happened, but not in a totally dramatic default reset...it manifests itself in a few random settings changing values...and frankly it's probably more difficult to troubleshoot when that happens because it is so subtle.

 

i have made it a point to periodically go down through the settings and check to make sure all systems are go.

 

we have backup disks of the settings, as well as the files loaded on other computers on site.

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So the bottom line is that the subs should be handling somewhere in the range of 50Hz to 100Hz, and the mid-highs should see 100Hz and up. You can move the crossover point up or down 10Hz or so to determine if there's any improvement. The subs bandwidth would be relatively narrow but for live sound 50Hz is usually quite sufficient and will conserve power for the usable bandwidth.

 

 

sounds most excellent!

 

my webpage has run into it's monthly data flow limit, so i can't post any pics until the 1st of the month. i'll resurrect the thread at that time, and bump with my observations on how the settings sound/perform as well, and maybe a pic or two of the event....

 

thank you guys very much!

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Start with 100Hz, you won't gain much by going up. If you do, limit yourself to about 125Hz to keep the subs from getting too woofy, most have a pretty good bump around 125Hz due to box geometry which will not show up on most modeling programs.

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Start with 100Hz, you won't gain much by going up. If you do, limit yourself to about 125Hz to keep the subs from getting too woofy, most have a pretty good bump around 125Hz due to box geometry which will not show up on most modeling programs.

 

update--

after considering your very astute "anal" advice to dig deeper, (wow did that come out WRONG :D )

 

i found out something new about the ashly

(it's a 3.24CL actually, not the big brother 4.24C we have in another bldg)

 

 

in every other instance, when the function currently being edited is more than one item deep in the onboard menu, there is an accompanying number with a flashing curser under the item being edited

 

(for instance, there are 4 eqs available per output, so when working on the specific eq, it flashes "PE1" for parametric eq #1, or "HS2" for high shelf eq 2, and so on...)

 

but for the crossover section, this protocol is not consistent, so when i looked at the crossover page, it showed me a High Pass control with it's corresponding controls

(frequency, type selection [likwitz-riley, butterworth, or bessel], and bandwith),

 

but no flashing number, or indication that this worked in tandem with any other crossover function/page

 

so in my mind when i scrolled from that initial page to the next item and found a Low Pass filter, it appeared that it was a one or the other kinda thing.

 

particularly since there was nothing set for the Low Pass filter when I checked that page, for the sub outputs...meaning the tech who set up the system may have made the same mistake I did.

 

now i'm off to recheck the old system in the church school using the 4.24C....

 

thanks again for the prodding aged horse!

 

pictures to come at the 1st of the month.....

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It is utterly frustrating how difficult the navigation of the menus and syntax can be, and how easy it is for un-anticipated results to creep into the programming. I edited a MediaMatrix job that a "competitor" finished up and found so many errors that the ned user had us do a follow-up service call to comb through the rest of the system. Found a lot of small problems (connector polarity reversal, unintended grounding paths, poor choices in parameter programming etc) with the end result that the system performance improved significantly (noise improved by a whopping 8dBv!!!) on a system where they spent probably $20k additional for low noise solutions, then pissed the benefits away in lack of attention to detail. This was a $500k-ish installation, no expense spared.

 

(Take note Don, DSP may seem simple to you and me, but thse were guys who spent plenty of time going through the Media Matrix school and it was riddled with errors.)

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nice!

 

so, armed with my newfound knowledge, i rolled over to the former church system armed with a soundcraft K2 board, ashly 4.24C, various yamaha and crest amps, and EAW AS592ix bi-amped 3-way speakers (now currently the school's sound system for chapel, plays, awards, etc)

 

and EUREKA!!

 

once again, the same types of errors on the crossovers were evident, and this was a system tuned by yet another pro AV company.

 

so after checking all 8 outputs and retweaking every parameter, based on info i accumulated from EAW specs and reps, as i'm finishing the last output channel, the principle of the school staggers in looking for their student AV team...they are playing a movie for the K-4th grade kids and need video/audio NOW. perfect for checking my work.

 

A/V team is MIA so i get the honor of making DVD player talk to cheezo video switcher and the projector screen, and get audio to the PA, in 2 minutes....just call me clutch.

 

the verdict.....WOW!

 

as the THX ad at the head of the DVD pours out of the system, i'm thrilled at the improvements!

 

the kids hoot and holler as the subs rattle the room, the teachers thank me for being there and quelling their antsy rugrats....

 

tune in next time for more adventures with

 

S O U N D M A N

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Welcome to the world of correcting the plethora of errors that easily creep into the layerd menu realm of DSP.

 

Nothing wrong with the process, but hardly user friendly for someone who knows what they are doing... imagine the damage that can result from somebody who THINKS they know what they are doing.

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Welcome to the world of correcting the plethora of errors that easily creep into the layerd menu realm of DSP.


Nothing wrong with the process, but hardly user friendly for someone who knows what they are doing... imagine the damage that can result from somebody who THINKS they know what they are doing.

 

 

Yeah, kind of like the guy who sets a graphic eq as a smiley face!

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