This Question Just may sound dumb.

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t.bake
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This Question Just may sound dumb.

Post by t.bake » Tue Aug 23, 2011 2:15 pm

If you are useing a full range top with a program rateing of 1k watts and then run the same enclosure in a two way system (sending 200 and below to the subs) will the pwr handling , or program rateing of said tops drop? because you are no longer useing wattage to produce the lower freqs. Sorry the question may be poorly stated. Thanks for any help

Marty McCann
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Re: This Question Just may sound dumb.

Post by Marty McCann » Tue Aug 23, 2011 2:26 pm

t.bake wrote:If you are useing a full range top with a program rateing of 1k watts and then run the same enclosure in a two way system (sending 200 and below to the subs) will the pwr handling , or program rateing of said tops drop? because you are no longer useing wattage to produce the lower freqs. Sorry the question may be poorly stated. Thanks for any help

No! Power is power. It does not matter, 1,000 Watts a full bandwidth, or within 1 Octave is still 1,000 Watts

rc.alex
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Re: This Question Just may sound dumb.

Post by rc.alex » Tue Aug 23, 2011 3:43 pm

I think what t.bake meant was, assume the crossover point on the tops is 1200 Hz. If you only sent 1200 Hz and above to the tops, wouldn't the program rating then be merely the program rating of the horns?

Of course in real life this wouldn't actually happen, but it's an interesting theoratical / helps-us-understand-better thought. Wouldn't the full range program rating decrease if you actually got alot closer to the crossover point on the tops?
2 x SP-2, 2 x SP-218, 4 x SP-1545M, 32FX, RQ2318, PV8, RQ200, CS-4000, CPX 3800, CS-1200, VSX-26

t.bake
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Re: This Question Just may sound dumb.

Post by t.bake » Tue Aug 23, 2011 7:45 pm

Thanks for the replys Got ya marty, I think rc is kinda getting to what Im asking. Ok I was useing 2 new sp2 with a gps 3500 in stereo 8ohm per side. On a average settings were amp wide open output at the board 0 to -3 db good vol clean no cliping nothing breaking up. Now gone two way . still stereo gps 3500 on tops 3500 on the subs 8ohm per side. x over at 200 0 to +3 on gain setting on x over. Eq mostly flat at 0 no gain increse. Now I can not run the amp for the tops over 1/2 -3/4 with out seeing a clip light on the amp and slight break up. All outher gain settings are as stated above. Trying to understand why I cannot run the amp wide open as before??? I can not stand distortion or poor sound or abused equip. In my simple mind Im thinking same applied wattage less consumption= some thing being over driven. Thanks a bunch!!!! enjoying learning curve

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SemperFiSound
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Re: This Question Just may sound dumb.

Post by SemperFiSound » Tue Aug 23, 2011 11:00 pm

t.bake,
Once you use the bi-amp jacks, you are bypassing all electronics in the cabinet.

For bi-amping an SP-2 you will need:
- A good quality crossover WITH a CD Horn EQ
- One amp to drive the lows at 650-850 watts per woofer (GPS-3500 is perfect!)
- One amp to drive the horns at 180-210 Watts per horn. (PV-900/GPS-900)

So, if you have a GPS-3500 (775/8; 1200/4; 1750/2) hooked up to the Horns of an SP-2, you are going to let the smoke out of the compression drivers VERY quickly.

Hope this helps,
Steve
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Josjor
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Re: This Question Just may sound dumb.

Post by Josjor » Wed Aug 24, 2011 5:55 am

A couple of questions:

1. What crossover are you using?
That could be the cause of your clippped signal.

2. You aren't, as Steve suggested, plugging into the SP2's bi-amp jack are you?
That jack is only if you are bi-amping the SP2's themselves or tri-amping the SP2's and a sub.
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Marty McCann
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Re: This Question Just may sound dumb.

Post by Marty McCann » Wed Aug 24, 2011 10:19 am

T.Bake, we are missing some information and you are missing some as well.

What it the sensitivity of the Subs versus the SP-2's? You did not report the name brand of the sub. We do not care if it is not Peavey. However you could easily have a Mid/High enclosure that has a 1 Watt @ 1 Meter sensitivity of 98 dB and the Sub may only be 94 dB 1W @ 1M

Even if , the sensitivities were matched, it is common in contemporary music to easily have the frequencies going to the sub boosted by 3 - 4 dB (or more in some genre's).

In regards to power versus frequency: a sinewave of 63.25 Volts at 100 Hz and a sinewave of 63.25 both equals 1000 Watts into 4 Ohms. Now you may have an octave of information going to a 4 Ohm sub that measures 63.25 Volts on an RMS reading voltmeter, while perhaps 3 octaves of information measuring the same 63.25 Volts is going to a 4 Ohm Mid/High system. Both systems would be getting 1000 Watts of power. No matter what the waveform or combination of waveform consists of, when the Root Mean Square (RMS) value is measured, that is what determines the power in Watts.

See attachment for some SP-2 series packages and their performance capabilities.



TKANUTD
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t.bake
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Re: This Question Just may sound dumb.

Post by t.bake » Thu Aug 25, 2011 12:59 pm

Thanks everyone! Ok moore info tops, useing full range connection allways. the subs are older sp 4oo watt , X over peavey ( sorry cant rember mod # have to unload trailer) 2way stereo 3way mono. Sorry may have miss stated Im not bi amping tops running full range with 200hz pass to the subs. No prob with the lows I know my amp could kill the drivers Im carefull(8 ohm in stereo) run the amp aprox 1/2 sounds good no distortion or clipping. Adjusting Gain at X over down to aprox -6db still unable run above aprox 0 to +3 at the board with amp for the tops all the way up(clip light and the hf driver getting un happy) tops are @ 8 ohm per side. Im I just being anal ? outher bands we compete with tell us our mix is better than most been asked to come help them mix LOL. Been told by many leave it alone kicking butt for what we got . I just gotta understand it all LOL and you ALL are a great help thanks!!

Marty McCann
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Re: This Question Just may sound dumb.

Post by Marty McCann » Thu Aug 25, 2011 2:09 pm

Well that indeed is a lot more information. Now it would take an understanding of the genre of music and the make up of the ensemble as well at the desired sound pressure level at a stated distance.

As I now see it, you have a very high X-Over point between your Sub and SP-2 of 200Hz.

Most folks on this forum would tell you to set the X-Over point at 100 - 125 Hz.

Yet at 400 Hz you say that the Amp driving the SP-2 goes into DDT before the Amp driving the Sub. This is strange in that with that high of a X-Over point it should be the other way around.

However is your band a large Jazz Ensemble with 5 Tpts, 5 Bones, and 5 Saxes? If so, now I would understand.

But somehow I don't think so. Now you could have a faulty passive X-Over component or even a shorted voice coil turn somewhere, but I doubt that for now.

You have apparently been successful with your system even though you do not know why.

The X-Over that you have is probably one of 3rd Order (-18 dB/Octave) Butterworth filters. Very useful in its day, but basically an obsolete standard.

However here is the best way to get the most our of the system that you have.

Set the X-Over point at 125 Hz.

Have the output on the X-Over fully counter clockwise.

Have the inputs on your GPS Amps wide open.

Play a real CD (No MP-3's) of music that represents your style.

Set your channel slider to OdB and your masters, and increase the CD channel inputs until you read +6 on the output of you mixer.

Now turn up the Low Pass output of the X-Over until you think the Sub is loud enough in that venue. If you hear distortion, turn it down until it stops.

Now turn up the High pass output of the X-Over until you think it matches the level of the Sub. Does it sound good? Then don't worry where the knobs point.

t.bake
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Re: This Question Just may sound dumb.

Post by t.bake » Thu Aug 25, 2011 2:37 pm

Marty you are of GREAT help you just cleared up a ton of stuff in my mind and gave a million moore qusestions lol. Everyone on this fourm has been great. cant wait to mess with x over point. thinking that may be what is been a issue . The subs have not been a issue I get good levels and i am carefull with them. Checked all the driver all good and often ck restance at the cabs dont think I have a prob with them. Got spairs whin in dout I change then out. Thanks again to everyone. Itching to turn knobs NOW!! thanks for the direction and paticance for us that dont know but love learning. THANKS!!

t.bake
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Re: This Question Just may sound dumb.

Post by t.bake » Sat Aug 27, 2011 1:15 pm

Thanks Marty! things went well last. Gain structure at the X over was a Issue and lowering X over point helped. Big thanks to everyone. Clean and punchy with clear crisp vocals. Now to learn how to control the innerminent peaks in vocals and drums compressor/ limiter ?? thinking that is my next step in getting the most out of what we have. We have a verry wide rande of dynamics in our song set (Etta James to Led Zepplin) That seem to make keeping a good mix all night a real job. Time to hit the books THEN the bank account, Thanks for all the help everyone.

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Re: This Question Just may sound dumb.

Post by mo_bluesman » Fri Sep 02, 2011 2:54 am

Marty McCann wrote: Now turn up the Low Pass output of the X-Over until you think the Sub is loud enough in that venue. If you hear distortion, turn it down until it stops.

Now turn up the High pass output of the X-Over until you think it matches the level of the Sub. Does it sound good? Then don't worry where the knobs point.
That was my comment, there is no substitute for human ears. While books and meters are great tools, common sense and a good ear always get you there.

t.bake
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Re: This Question Just may sound dumb.

Post by t.bake » Fri Sep 02, 2011 12:06 pm

Verry true ears are gear ya just cant buy and need every night. And they will tel ya the truth if ya learn to listen THANKS AGAIN TO ALL !!!

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