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FDP Forum / Performer's Corner / Need PA help fromTony and the other FDP experts.
(This message was last edited by 3putt at 07:23 PM, Jul 27th, 2010)
(This message was last edited by DiploStrat at 02:49 AM, Jul 28th, 2010)
(This message was last edited by Tony Wright at 10:37 AM, Jul 28th, 2010)
FDP Forum / Performer's Corner / Need PA help fromTony and the other FDP experts.
3putt
Contributing Member
***
Mid-Mo.
One note short of a chordJul 27th, 2010 06:21 PM Edit Profile Print Topic Search
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Thanks in advance!
2 questions first, what watt power amps will we need to drive the following 6 cabs. We plan on using our 4 powered speakers (if feasible) for monitors. (Also, any brands to avoing)
OUR SPEAKERS and the back panel instructions:
Peavy Specs
PV 2x15 - 700W program 1400W peak
Nominal Impedence 4 Ohms
PV 115 - 400 Watts program/800 Peak
Impedence 8 ohms.
Both have built in crossovers according to the manuals
SUBS PV 118’s - 400W program
8 ohms
Second ?: We know we need effects, crossover (?), power conditioner, compressor/limiter, EQ, mixing board (prolly 16 channel) What would brands would be an economical solution to build this and what should we look for or avoid?
thanks again!
Tony Wright
Contributing Member
****
Stillwater, OK
Built for comfort, not for speed.Jul 28th, 2010 12:17 AM Edit Profile Print Topic Search
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Before we start on your specific questions...
NOTE: Most commercially manufactured speakers have an internal crossover. They split one side for the horn and the other side for the woofer.
Some subwoofers have a "low pass filter" which allows low frequencies to go into the subwoofer, but does not limit the frequencies sent to the mains (mid/high/low all in one speaker). That is not the end of the world, but the more efficient approach is to let the subs carry the lows with an appropriate set of speakers and matching power amps...and let the mains carry the mids and highs with a matching power amp.
Running everything in the mains will not necessarily "damage" the speakers but you will get a more "muddy" sound with the low frequencies coming out of the mains AND the subs. I would encourage you to check the various power amps to see which ones have an internal crossover or filter so you can run a cleaner signal.
For instance, I suggest the QSC GX-5 for the PV115 and for the PV118. The GX-5 has an internal filter/crossover that splits the signal and sends the lows to the "A' side and the mids/highs to the "B" side of the same power amp. Thus you could use two GX-5 with one PV118 and one PV115 on each of the two GX-5.
It would not surprise me to learn other amps such as the new Crown XLS DriveCore series has a similar feature.
Do your own research and decide where you want to spend your money.
=======================================
Question 1:
"...what watt power amps will we need to drive the following 6 cabs..."
"Peavy Specs
PV 2x15 - 700W program 1400W peak
Nominal Impedence 4 Ohms
PV 115 - 400 Watts program/800 Peak
Impedence 8 ohms.
Both have built in crossovers according to the manuals
SUBS PV 118’s - 400W program
8 ohms"
Response:
Always try to target the power amp to match the Program Rating...NEVER the Peak Rating which will cause damage to speakers.
So...
PV215, 700 Watts, 4 Ohms.
QSC GX-5 (700 Watts at 4 Ohms stereo) $400
or the "close out"
Crown XLS602 (600 Watts at 4 Ohms stereo) $250
or the "close out:
Crown XLS802 (800 Watts at 4 Ohms stereo) $300
(NOTE: GX-5 and the XLS602 and the XLS802 cannot operate at 2 Ohms per side.)
The Crown amps are on close out because the new "lightweight XLS "DriveCore" models are on the market...
The new Crown XLS2000 (DriveCore model), $500, would be a good match to the PV215 at 650 Watts at 4 Ohms stereo and only 11 pounds.
=======
PV115, 400 Watts Program at 8 Ohms.
PV118, 400 Watts Program at 8 Ohms.
Both of these speaker cabinets have the same power rating and same Ohm rating. Therefore, the same brand and model would match "both" speakers...
(prices on amps listed above)
QSC GX-5 which is 350 Watts at 8 Ohms stereo
Crown XLS602 is 380 Watts at 8 Ohms stereo.
Crown XLS1500 is 300 Watts at 8 Ohms stereo
NOTE: The above are just "some" of dozens of power amps that would meet your needs. An example would be the QSC RMX1850HD and the QSC RMX2450 to match either/both the PV115 and PV118. The RMX2450 would also be very close to the PV215. And the list goes on and on...
==================
Question 2:
"...Also, any brands to avoing..."
Response:
Well, I would avoid the bargain basement, brands simply as a matter of "gear snobbery"...
Look, seriously, you know what brand name guitars and brand names amps are "good"...well, do a little research of what the locals in your neck of the woods use...why reinvent the wheel.
Personally, I have owned a Behringer powered mixer for years and I am very happy...but I sold the Behringer EP1500 I acquired in a trade. The guy who got it has used it for about 3 years with his gospel group. But at the same time, I would avoid American Audio and Galaxy and Nady and Carvin...why? Lack of respect for the gear.
In reality, the Crown XLS series that is being discontinued/closed out because they have released an improved model that weighs less and has more power at similar market prices. Thus the older, lower powered, heavier XLS series is on the chopping block. since you are a young, healthy musician, I am sure weight is not an issue for you like it is me. (I got more money than strength and stamina...)
=========================
=========================
Question:
"...We know we need effects, crossover (?), power conditioner, compressor/limiter, EQ, mixing board (prolly 16 channel) What would brands would be an economical solution to build this and what should we look for or avoid?"
Well, is this about "quality" or about "budget"?
Behringer is always an option. I used a B'ger unpowered mixer for a while but sold it...I got it for a specific purpose and that was "done". It was one of the cheaper B'gers but did adequate for the assignment I had bought it for. The one nice thing about B'ger is you can buy everything from one manufacturer. Personally, that does not matter to me. Although I am pretty brand loyal...some companies do specific things better than others.
I would prefer a Yamaha unpowered mixer if you are looking for budget. Yamaha is normally cheaper than Mackie. The Yamaha MG206C is a very nice mixer.
The mixers that come with all sorts of on board processing (digital effects/reverb or graphic EQ, etc) often provide a little more features but they raise the price far more than the "small" feature they offer...such as a 9 or 15 band graphic EQ and reverb which could raise the mixer price by as much as $150.
Unless you MUST buy with a proprietary credit card from a specific online dealer to afford all this...I suggest looking local for used gear.
For instance, a used Allen and Heath MixWizard could be a better mixer than a new Yamaha MG206C. But ALWAYS look carefully at the used gear. Make sure everything functions. Make sure all the knobs and fader caps are still on the mixer. If it looks good and sounds good, then it probably "is" good. But ask lots of questions. Use your common sense.
The above holds true for any and all rack gear.
If you want "everything in one box" then get a Presonus StudioLive 16:4:2 digital mixer which has internal graphic EQ and internal compressor and internal digital effects. All you need is a crossover and graphic EQ for your monitors. WARNING, it won't be cheap.
So, what do you really need?
A mixer. Personally, I would opt for a 31 band graphic EQ on every monitor mix and I would "get by" with a dual 15 band graphic EQ for the mains...or I would dump the money into buying a DriveRackPA for the mains...that DRPA also covers the crossover and limiter functions.
If you buy a power amp with an internal filter or crossover function, then you DON'T need a DRPA.
You need some form of crossover or "filter" so you can split the frequencies.
And the three devices that are less critical are:
* Power Conditioner...in most cases they are just a fancy power strip.
* Compressor...I do not own one any more. But some bands and some soundco's think the compressor is a vital piece of equipment.
* Effects unit...yeah, really, it is an optional piece of equipment. I prefer "dry" but will use a "slight" amount of basic reverb to "warm up" a singer's voice...rarely on an instrument...(well, on occasion on acoustic instruments like mandolin or guitar or fiddle).
One last "mixer" observation...you might look at a 12 channel mixer (perhaps "10" mic channels with two stereo pair channels). First they are cheaper...add a pair of 1/4 to XLR adapters and you have another "mic" channel. Of course, if you mix from on stage, you could just plug the keyboards in directly to the mixer without a DI (remember the 20 ft guideline). Why 12 channels? Think about the typical club band: 3 or 4 vocals, 2 guitars, keys, bass, 4 drum mics. That would handle nearly any club.
=======================================
=======================================
And now, a question for you:
"Why so many PA cabinets?"
Discussion:
The PV215 (2-15s) cabinets are quasi 3 way cabinets. The lows go only to the bottom woofer, the highs only go to the horn and the top woofer gets all content not sent to the horn...basically mids and lows. Nothing wrong with that, but you are also getting a pair of full range cabinets (the PV115) and a pair of subs (PV118)...so we are back to that "lows from multiple sources" which creates a muddy sound.
So, "IF" you have not purchased all those speakers yet, I would respectfully suggest you not buy the PV215...in fact, if you will be spending nearly $1500 for those six cabinets AND you will need to buy at least three power amps to properly power those cabinets.
I have no idea exactly where "Mid-MO" is but surely you are close to a Craigslist or other classified to look for used gear. If you are buying with cash, you can stretch your dollar a lot farther buying used gear.
Do not misunderstand...the PV115 is a decent cabinet. I own a pair of Peavey PR15 and love them for their weight and sound quality for the money invested. I had an occasion to help a guy set up his system about 5 weeks ago...he was setting up a rehearsal space in the basement of his home. I told him I doubted the PV118 would make much difference...BOY was I wrong. We used a DBX crossover and split at 90 Hz. Then we connected the subs to his Crown CE2000 amp and it sounded pretty good...
Finally...
I am sorry if this rambled on. I was working on this while watching a couple of good movies and the time got away from me...as did my train of thought. I hope this helps more than it confuses.
DiploStrat
Contributing Member
**********
*******
Bangui, CAR
Down by the (Oubangui) RiverJul 28th, 2010 01:38 AM Edit Profile Print Topic Search
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One small point to add to Tony's tome:
-- Remember that the "rating" on the back of a speaker has nothing to do with sound level. The 700w/1400w peak merely means that 700w, un-clipped, will probably not melt the voice coils long term. Probably is the key word here.
-- Similarly, the "output" on the back of an amp merely indicates how much voltage it can provide before it blows something. (Assuming that you are not running on a hot day in Florida.)
So what? So a speaker rating tells you nothing about how much power it needs to be loud enough. (That's called efficiency and is another can of worms.) So at the risk of sounding like I am differing slightly with Tony, do not ever trust amp or speaker ratings to keep you "safe." If you hear distortion - turn it down - something is going to fail. And failure = $$$$
Although scholars will debate the why, a smaller solid state, driven into distortion, will sound much worse and may be more likely to damage your speakers than an "overpowered" amp that is loafing along. This is a strong argument for buying the biggest, best amps you can afford. So, if given a choice, I would rather run my "700w" speaker with a 1,000w amp than with a 500w amp. But what is the point, if it will fill the venue at 150w?
As always, Tony's advice on speakers, is spot on - he has the real world scars to back up his comments.
I am VERY partial to powered speakers, if only because:
-- They tend to have BIG amps.
-- They tend to be bi-amped.
-- Then tend to have failsafe protection.
I have always thought that a pair of the new generation of powered 12"/horn (Mackie, etc.) speakers coupled with ONE powered sub was a great combo. (Two subs are generally too much and can actually cancel if not placed properly.) Advantages include possibly better articulation/clarity on your voices with easily controlled bottom. Then run your monitors off a separate power amp or powered mixer.
Final thought: What is your venue? Most bands are way too loud and too loud costs gigs. Good, clean, undistorted sound, on the other hand, gets 'em dancing and drinking and gets you hired.
Very few bands need half the trash they are carrying. (See the Beatles at Shea stadium.) Buy less and buy better. And learn how to set it up and equalize it correctly. A good book or some time with a pro may be worth more than half of the monitors you want to buy.
Free advice being worth, etc.
DiploStrat ;-)
3putt
Contributing Member
***
Mid-Mo.
One note short of a chordJul 28th, 2010 09:32 AM Edit Profile Print Topic Search
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Tony and Diplostrat.....THANK YOU!
Why 6 cabs?.....we picked up all 6 cabs from CL for $1000. They are in great shape. I liked the configuration because we do some (not often) outdoor shows and I thought we could set the 1x15's on top of the subs angled a bit out to reach wider than the stage and put the 2x15's beside pointing straight out. It would give us some versatility. Some gigs we'll just take the 1x15's on poles and leave the rest of the gear in the van. On the larger outdoor shows we will be micing the amps and will want as much coverage as possible if that makes sense.
Again, thank you guys for your help. We will take your advice and do the research. Thanks for getting us started in the right direction.
Tony Wright
Contributing Member
****
Stillwater, OK
Built for comfort, not for speed.Jul 28th, 2010 10:19 AM Edit Profile Print Topic Search
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"...do not ever trust amp or speaker ratings to keep you "safe." If you hear distortion - turn it down - something is going to fail. And failure = $$$$..."
AMEN!
DiploStrat...
Funny you mentioned the Mackie speakers. About 3 weeks ago, I picked up a pair of used Mackie C300i on Craigslist/Tulsa. They are the UNpowered version but sound OUTSTANDING. I plan to mate these speakers with my MAckie 808M for rental gigs...but I am thinking these may find a place in my "private reserve" when I thin down the inventory in a year or so.
===============
3Putt...
DiploStrat mentioned speaker efficiency. Basically, how efficiently a speaker converts the electrical energy from the power amp to sound waves is measured by the "Sensitivity" ratings on a speaker. If you want a tool to determine if Brand A model 101 will be louder than Brand X model 202...and both have the same size woofer and the same Watt ratings...then go look at the "Sensitivity" rating.
Sensitivity is measured at 1 Watt at 1 Meter.
More "efficient" speakers will be louder than less "efficient" speakers. You can check "efficiency" ratings of your speakers by looking at the "Sensitivity" ratings on the specifications from the manufacturer.
Typically, your rating should be shown as: "xx" dB SPL at 1 Watt/1 Meter.
Do not misread and look at the "Maximum SPL" rating which is a "projection" of what the speaker can theoretically achieve.
A speaker with a Sensitivity rating of 98 dB will be much louder than a speaker with a rating of 93 dB. A difference of 3 dB will be noticable. It would be similar to doubling the Watts from your power amp. A 6 dB increase is generally accepted as "50% louder" and a 10 dB increase is generally accepted as "100% louder" according to many sources.
But the point is that you will notice a difference with 3 dB increase...
Now before you rush out to buy or sell anything...doubling the "power" does not equate to "double the volume". As I indicated above, doubling the power usually results in only 3 dB increase in output which equates to about like turning an amp from 5 to 6 or maybe 7. You will "notice" the volume increase, but it will not be "twice as loud".
So, how do you get more volume when needed? By doing a combination of things. Many of those "things" involve making wise choices before you even connect the cables. Some of those choices are "freebies" like using good "Gain Structure" (making sure you get the strongest and best signal from the instrument or other source to the speaker by utilizing the proper input gain on each device in your system) and another "freebie" would be using good speaker placement.
By and far, my experience is that buying good sounding "efficient" speakers is the best way to get more volume...because it takes the power from your amp and converts it to sound waves.
I generally look for speaker cabinets that have 95 dB or better Sensitivity ratings. I believe all my current inventory are 97 dB at 1W/1M or better. (Peavey PR-15 is 97 dB; JBL MRX515 is 98 dB as an example)
Your PV115 Sensitivity is listed on Peavey dot com as 95 dB 1w/1m. The PV215 is rated at 98 dB and the PV118 is shown as 95 dB. Thus, your 215 should sound louder than the 115, right...maybe more than you realize. The 3 dB with the extra speaker and the extra power should make the 215 a far stronger speaker when on stage with the 115 at the same time. Which brings us back to my comments about "why so many cabinets"?
Do you already own this gear? If so, rock on.
(Edited to delete useless information after I discovered you already own the various PV model cabinets.)
(Second edit to add:)
When you place the mains on the subs adjacent to the 2-15 mains. Try to get the two "horns" on the PV115 and PV215 as close together, angled so there is little area that the angle of the two horns overlaps. It is called "splaying" the speakers using the angle of the trapezoid speaker cabinets and the angles of the horns to better cover a wider area.
When you play especially large areas, you will get more from your two subs if you place them side by side, center stage, front, ground level. Trust me, you are using the physics of sound to get more for free. Ground coupling will ALWAYS improve bass frequencies more than if they are setting on a stage. Placing the two subs side by side also allows an additional coupling.
Whazzat? Can't put them side by side, center stage, ground level....then off to one side, side by side, ground level, within 2 feet of the wall. Corner loading is even better (stack the subs if corner loading.) Check the article below. Tim Padrick is a really good guy and makes me look like a novice. He is one of the people I ask question when I can't find it on his page.
By the way, visit his "Why your band should not buy a PA and what to get if you do" article. Really good stuff. (Linked thru Tim's "Live Sound Page" on the article below.)
Lesterstrat
Moderator
Florida
Wear a cape & let 'er rip!Jul 28th, 2010 10:30 AM Edit Profile Print Topic Search
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"I have always thought that a pair of the new generation of powered 12"/horn (Mackie, etc.) speakers coupled with ONE powered sub was a great combo. (Two subs are generally too much and can actually cancel if not placed properly.) Advantages include possibly better articulation/clarity on your voices with easily controlled bottom. Then run your monitors off a separate power amp or powered mixer."
I've been sold on that thought process (and is what I do) for years now. It's the only way I'll fly now days. In addition, load-in/load-out and setup time is next to nothing.
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