High end PA speakers

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#45

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#48
Ok, I guess it is just higher end than most of the crap I hear. From now on I'll call it "higher end than most stuff", is that better? Since when are you required to spend alot of money to gete high end? I think a well designed array will smoke alot of the PA stuff out there?

I want a small array of tweeters, a large array of mids, and a couple of well made subs.... I'm not using ONLY 4 inch drivers here. This isn't a massive 901 I'm making.
 
#50
The Paulinator said:
Should I be too concerned that the Pioneer 4"ers only handle 10 watts max? Will that be relevant when I am using 20 of them per speaker? It would seem that their collective power handling goes way up sonsidering each one won't be working nearly as hard.
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Not to worry as the total power handling is the sum of them all & the efficiency goes up when used in an array so less power is needed to reach high SPL.

The Pioneer 4" in a vertical line would be my 1st choice as they will maintain array coupling to higher freq than the others (theoretically around 3.3 kHZ) allowing to crossover between 3.5 - 4 kHz & thus the viability of using smaller tweeters for the tweeter array. The 6" could work but should be crossed over lower (roughly 2.5 kHz) & the 8" would need to be crossed over no higher than about 2 kHz, so the 6 & 8 inch limit your tweeter options.

I have little doubt that 2 - 4 vertical line arrays with about 18 each of those pioneer 4" matched properly with cross over to a decent tweeter array & crossed over at about 200 - 250 Hz to a decent woofer would kick *** in terms of SQ & coverage over the majority of commercial PA systems for club & hall size venue. For concert & stadium size it's a different league & would take much more to cut the mustard.


pinkmouse said:
Sorry, but this really doesn't sound like high end PA to me, more like a bigger version of a Bose 802 cab...:scratch: 😉
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Funny thing is for small venue the Bose 801/901 (even with all it's short comings) still sounds better than just about any of those standard commercial PA's available in it's size category that use a HF horn coupled with a direct radiating mid. That just does not work well for attaining even coverage, which is of paramount importance for a PA.
 
#51
The Paulinator said:
Should I be too concerned that the Pioneer 4"ers only handle 10 watts max? Will that be relevant when I am using 20 of them per speaker? It would seem that their collective power handling goes way up sonsidering each one won't be working nearly as hard.
Click to expand...

20 of those per side for dj app? You will end up frying them very quickly.

The efficiency of those is not enough to do what you want..

I have 132 of the 4 inchers, and 200 of the tweets, and I wouldn't consider the two panels for dj use..I would certainly toast them. I'm going to use them for side fill only, from about 100 hz up.

Think about it...when you wire them in series parallel, it will take only one loss to remove a string...there will be a cascade failure as the panel impedance goes up and the amp sees a lighter load..


Cheers, John
 
#52
jneutron said:

I have 132 of the 4 inchers, and 200 of the tweets, and I wouldn't consider the two panels for dj use..I would certainly toast them.
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Depends how large a venue your talking there. That combination
in an array should easily exceed max SPL of 125 dB/1 meter above 200 Hz & with an efficiency above 110 dB/watt/meter!!
 
#53
Stephen D said:


Depends how large a venue your talking there. That combination
in an array should easily exceed max SPL of 125 dB/1 meter above 200 Hz & with an efficiency above 110 dB/watt/meter!!
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Why do you consider the efficiency as being that high, from a starting point of about 89, if I remember correctly..

John
 
#54
It's *NOT* going to add up that fast. In order to see a 3dB gain, the drivers have to be physically in the same space. If they're immediately next to each other, your gain is maybe 2dB, and you have to take into account all the combing artifacts.

The advantages of line arrays are vertical dispersion, reduction of combing by using 3+ drivers, and increased power handling (thus, increased max SPL) by putting drivers in series and in parallel.

My speakers have 91dB drivers in them, and although there are 4 of them, I still count them as 91dB efficient in order to do my math. (Actually, I should count them *less* because I've raised their impedance to 16 ohms from 4...) and I calculate that, at 25 watts per side, they're 105 dB loud. And they don't sound that loud. Fortunately, people like loud bass better than loud midrange and treble, so the loudness I get really is enough.

You can get what you're looking for with horns easily, but it's quite expensive. Doing things my way is *MUCH* more cost-effective, but does take a lot more thinking.

Good luck.
 
#55
Stephen D said:
That combination in an array should easily exceed max SPL of 125 dB/1 meter above 200 Hz & with an efficiency above 110 dB/watt/meter!!
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Wow, if only that were the case.

You might want to run a test on the completed system to check that.

I think if that were the case, I'd line my end wall with woofers and reduce my amp to a 30 watt tube.😉

Cal
 
#56
A clustered array theoretically increases power efficiency by 3 dB for every doubling of drivers. Granted a line array is probably somewhat less than this but I'm not sure how much less. Even if it were only 2 dB that would still be over 103 dB/watt for 134 drivers which ain't shabby. This applies only to frequencies of & longer than 1 wave length distance of the driver spacing. Comb filtering isn't a problem until frequencies shorter than one wave length of driver spacing where the speakers no longer couple as one wave front. Napyladdy, this is why the speakers in your PA are to large to be ideally used as a full range array. They would be better crossed over to something in the high end. Smaller drivers will couple as an array up higher in the freq band & also not exhibit comb filtering & HF loss till higher up in the band.

Cal Weldon said:


I think if that were the case, I'd line my end wall with woofers and reduce my amp to a 30 watt tube.😉
Cal
Click to expand...

This guy CLAIMS to be quite comfortable with 1 triode watt into his 15 element array!? 😕 😀
http://www.geocities.com/dmitrynizh/labaffles.htm
 
#57
Nappylady said:
I calculate that, at 25 watts per side, they're 105 dB loud. And they don't sound that loud.
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I think the open baffle design is sucking some efficiency out of your speakers from low mid band on down because of your relatively small baffle cross section. Speakers are rated for efficiency in infinite baffle. For open baffle the baffle needs to be larger the lower in freq you want to achieve efficient SPL. Actually the same applies to sealed but I think to a greater degree for open baffle.

Cheers.
 
#58
jneutron said:


Why do you consider the efficiency as being that high, from a starting point of about 89, if I remember correctly..

John
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I was also thinking the efficiency rating of that speaker was 89 dB/watt which would arrive at my original off the top of my head calculation of just over 110 dB/watt for 132 speakers with 3 dB of increase in efficiency for every doubling of drivers under theoretical ideal. Just checked & the rated efficiency is only 86 dB/watt so that brings the ideal for 132 drivers down to 107 dB & if we want to shave that ideal 3 dB gain down to 2 dB per driver doubling as Nappylady suggests then we'd have 100 dB/watt which is still quite good. It also just occurred to me the 132 drivers you refer to as having is likely a stereo pair of 66 drivers per panel which would mean efficiency would be calculated for 66 rather than 132 drivers if that's the case. Regardless of the particulars I think the gist of the story remains the same --- efficiency increases considerably when many drivers are closely coupled in an array.
 
#60
The Paulinator said:
So you would still go with the 4's over, say, four 8" drivers in each speaker in a vertical MMTMM (or MMTTMM) arrangement? You think the fours would sound better at high volumes?
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Well I know nothing about those 8" you mentioned. Some 8" would be great for PA mids if they're made to go that high but you said they were Cerwin Vega woofers which may be not much good for anything above 500 Hz as is often the case for WOOFER's of that size. It's still a little unclear to me what type & size venues you want to be able to cover with this. That's important to know because you can just as easily sacrifice sound quality by overbuilding for SPL as underbuilding for SPL. I think a large enough array of the 4" would be great up to a certain venue size... say mid size wedding reception hall (roughly 300-400 people) but at some point a stack of 8" or 12" horn loaded mids & HF horns would do better & at some point beyond be necessary. I'm suggesting a vertical line array because of it's potential for extremely wide horizontal dispersion & limited vertical dispersion over a wide bandwidth (read good HF dispersion) which makes for good uniform coverage of the audience. Because of this type dispersion pattern SPL also varies less over distance up to a point, also making for more pleasant uniform coverage. How well a driver disperses HF is relative to it's size. As a rule of thumb, a speaker is unidirectional up to the freq at which the effective cone diameter is equal to the wavelength. As freq rises above this it becomes more & more directional.

An array of 8" could be great but as I said before would need to be crossed over lower... say around 2 KHz. Then what would you cross over to at 2 KHz that isn't a horn or to large to array well at high freq? Maybe an array of those expensive planar's?

If you want a proper understanding of line arrays & how to implement them correctly & to decide if they're suitable you absolutely need to read these documents.

http://www.prism.gatech.edu/~gte929u/LinusWP.pdf

http://www.audiodiycentral.com/resource/pdf/nflawp.pdf
 
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