Speakers, Subs and Amps...i need help.

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S

Scene

New DJ
Jun 9, 2009
3
0
I have 2 main speakers which are 1650 watts each peak power at 4 ohms. does anyone have sugestions on what amp would be suitable for this pair. I have two 18" subs which are 2000 watts each peak power at 8 ohms. Does anyone know what a suitable amp would be for those. i think i need a crossover as well, not to sure.

Thank you.
 
Scene said:
I have 2 main speakers which are 1650 watts each peak power at 4 ohms. does anyone have sugestions on what amp would be suitable for this pair. I have two 18" subs which are 2000 watts each peak power at 8 ohms. Does anyone know what a suitable amp would be for those. i think i need a crossover as well, not to sure.

Thank you.
Click to expand...

Call these guys who are Sponsors of this Forum. If you give them the opportunity they will answer your questions with affordable options. http://www.northernlightfx.com
 
Start out by telling us the make and model of the speakers, some manus inflate the power handling of a speaker to the point of insanity!

Personally I like to run amps that are capable of running as close to the peak rating of the speaker as possible just for headroom! The trick is knowing how to use it!
 
Thunder said:
Start out by telling us the make and model of the speakers, some manus inflate the power handling of a speaker to the point of insanity!
Click to expand...

Agreed.... there are different approaches for each make.
Some do inflate them outrageously, while others do the opposite:

OK, edumacation time folks!:sqwink:

For example, EV does things a little different than some other manufacturers.

Most would tell you that you want to match the RMS for a speaker exactly. Others might tell you to add a little extra for headroom.

EV, on the other hand recommends you use no less than the RMS of the speaker, but would prefer you use DOUBLE the RMS of the speaker.
AND if you have a brickwall limiter set up, or can avoid things like a dropped live mic, or a huge clipped peak... They recommend using up to 4X the RMS (which works out to the PEAK rating) for continuous playback.

On the opposite side, I know a few cheaper makes that would likely fry something if you even dared to try to put in 1.5X the RMS! Although in most cases it is better to have more power than less.
 
ahoustondj said:
Call these guys who are Sponsors of this Forum. If you give them the opportunity they will answer your questions with affordable options. http://www.northernlightfx.com
Click to expand...

Thanks for the plug! We appreciate it!

Just a reminder to everyone: We are now NLfx Professional.
While the old url still works, we have changed everything over to www.nlfxpro.com and are phasing it out. Thanks!
 
ahoustondj said:
Call these guys who are Sponsors of this Forum. If you give them the opportunity they will answer your questions with affordable options. http://www.northernlightfx.com
Click to expand...

DJ Cam said:
I suggest fingding the RMS or program power. Peak power ratings can be misleading. With the proper speaker ratings it will be easier to assist you in your amplifer search.

Or you can provide the make and model of each speaker.
Click to expand...

Thunder said:
Start out by telling us the make and model of the speakers, some manus inflate the power handling of a speaker to the point of insanity!

Personally I like to run amps that are capable of running as close to the peak rating of the speaker as possible just for headroom! The trick is knowing how to use it!
Click to expand...

NLfx Specials said:
Agreed.... there are different approaches for each make.
Some do inflate them outrageously, while others do the opposite:

OK, edumacation time folks!:sqwink:

For example, EV does things a little different than some other manufacturers.

Most would tell you that you want to match the RMS for a speaker exactly. Others might tell you to add a little extra for headroom.

EV, on the other hand recommends you use no less than the RMS of the speaker, but would prefer you use DOUBLE the RMS of the speaker.
AND if you have a brickwall limiter set up, or can avoid things like a dropped live mic, or a huge clipped peak... They recommend using up to 4X the RMS (which works out to the PEAK rating) for continuous playback.

On the opposite side, I know a few cheaper makes that would likely fry something if you even dared to try to put in 1.5X the RMS! Although in most cases it is better to have more power than less.
Click to expand...

NLfx Specials said:
Thanks for the plug! We appreciate it!

Just a reminder to everyone: We are now NLfx Professional.
While the old url still works, we have changed everything over to www.nlfxpro.com and are phasing it out. Thanks!
Click to expand...

Jon Tuck said:
and thusly fair.
Click to expand...

Thank you. Alright so the whole setup is from technical pro. the 2 main speakers are the Fuse-215. And the subs are the SUB-1801X.
 
Here's the specs for your guys, such as they are

Here's the Fuse 215:

  • Two 50 oz. magnets
  • Frequency Response: 45Hz-20kHz
  • 1600 watts peak power
  • Inputs: 1/4" (6.35mm), bare wire terminal
  • Trapezoidal cabinet, perforated steel grill
  • Woofer: Two 15" woofers, 2.5" voice coil, 50 oz. magnet
  • Mid: 5" x 15" horn, compression driver 1.5" voice coil, 25 oz. magnet
  • Tweeter: 5 piezo
  • Sensitivity: 99 ±2dB (1W@1M)
  • Impedance: 8 ohms
  • Dimensions: 20.5"w x 47.5"h x 16.5"d (521 x 1207 x 420mm)
  • Weight: 85 lbs (39 kg)
  • MSRP: $339.00
http://www.technicalhifi.com/prods.php?prod=Fuse-215

Here's the Sub:
Listed as Bass 1801:

  • 90 oz. magnet
  • 2000 watts peak power
  • Sub amp: 2000 watts, Satellite Amp: 500w x 2 ch
  • Inputs: RCA
  • Sub Outputs: RCA, Satellite Outputs: 2 Speakon, 2 Banana
  • 18" woofer, 3" voice coil, 90 oz. magnet
  • Separate volume and low pass filter controls for sub
  • Separate volume and balance controls for satellite speakers
  • Switchable Satellite high pass filter
  • Single pole mount, stackable, 2 Integral carry handles
  • Frequency Response: 30Hz-300Hz
  • Sensitivity: 102 ±2dB
  • Impedance: 8 ohms
  • Dimensions: 22"w x 27"h x 24"d
  • Weight: 95 lbs
  • 110-220V Switchable

Scene, is that the correct sub-woofer? This is the only (Technical Pro) one I found with the number 1801.
http://www.technicalhifi.com/prods.php?prod=Bass-1801

or is this your sub?

Model: SUB-18X

  • 90 oz. magnet
  • Frequency Response: 30Hz-300Hz
  • 2000 watts peak power
  • Inputs: 1/4" (6.35mm), Speakon
  • Output: 1/4" (6.35mm), Speakon
  • 18" Aluminum frame, 3" voice coil, 90 oz. magnet
  • Built in 150Hz crossover with switchable low-pass output
  • Single pole mount, stackable, 2 Integral carry handles
  • Sensitivity: 102 ±2dB
  • Impedance: 8 ohms
  • Dimensions: 22"w x 27"h x 24"d (559 x 686 x 610mm)
  • Weight: 76 lbs (34.5 kg)
  • MSRP: $349.00
http://www.technicalhifi.com/prods.php?prod=SUB-18X

Scene, it is real handy to put up the specifications. Since this is just a short specification I cut and paste the whole thing. If it were a very long spec, I'd just post the pertinent facts. Scene, the comment "such as they are" refers to the lack of an RMS rating. Peak ratings are far more variable in their measurement. RMS ratings too may be played with. For example, how long was the speaker driven with x watts? In any case the RMS figure is a more dependable measure of raw power handling but the devil is in how the measurements were made.
 
Hey, Thunder, Ben...we waited fer ya

Ben and Thunder started to answer your question and I posted the specs just to grease the skids a bit. We've been waiting for them to get to your answer but it seems it's just you and me now Scene.


Basically there are two questions:
What amp?
Do you need a crossover?


The first consideration in selecting an amp is how much power. Usually this rating is selected using an RMS rating. Unfortunately Technical Pro doesn't publish an RMS specification. Peak power specifications can vary widely, anywhere from 5 to 20 times the RMS specification. Generally, dividing by ten is a safe bet. So, the 2 kilowatt subs need about 200 watts and the 1.6 kW tops need about 160 watts.


Do you need a crossover? As I read the specification, it says the sub has a built-in cross over. Passive crossovers in commercial systems are rare. It's presence in this system is yet another indication these drivers will only handle one or two hundred watts RMS. Large inductors to handle high power at very low frequencies are expensive.


As Ben said, one school of thought was to match RMS ratings as closely as possible. Thunder mentioned matching the peak rating BUT in this case connecting a 2kW amplifier would be out of your price range and probably cook the passive crossover. Given a small mistake it will blow the cones out of the boxes and across the room. But then Thunder did say the trick is in knowing how use it. Generally, if there is no [electronic] limiting in the system, match the amplifier power to the speaker power ratings, just like Ben said in the beginning. Don't hesitate to check for a recommendation from the manufacturer. I'd read the user documentation but Technical Pro doesn't seem to publish it on their web site.


In your private message to me, you indicated an interest in the Crown XTI 2000. I own one and I'm very impressed with its built-in DSP. At 800 watts into 4 ohms per channel it is probably too much power for your set up. The XTI-1000 should be sufficient. I might suggest it or the 2000 if you were looking to provide an upgrade path to an improved system. If you intend to use the passive crossover built into the system the DSP in the XTI line will be of limited use. You might as well buy a less expensive amplifier in the XLS line or check out basic amps from QSC. Many people on ODJT swear by them. Jeeze Ben, Thunder, chime in 'cause I don't know what you'll recommend. Oops! Thunder votes PEAVY!


The best solution, the standard configuration for your kind of system (two top and two subs), is an active cross over and two stereo amplifiers. This would allow you to by-pass the inefficient passive crossover in the sub. It has the disadvantage of cost. You would have to buy an additional amplifier and an active crossover.


Hope that helps.
 
Balanced Line said:
Ben and Thunder started to answer your question and I posted the specs just to grease the skids a bit. We've been waiting for them to get to your answer but it seems it's just you and me now Scene.


Basically there are two questions:
What amp?
Do you need a crossover?


The first consideration in selecting an amp is how much power. Usually this rating is selected using an RMS rating. Unfortunately Technical Pro doesn't publish an RMS specification. Peak power specifications can vary widely, anywhere from 5 to 20 times the RMS specification. Generally, dividing by ten is a safe bet. So, the 2 kilowatt subs need about 200 watts and the 1.6 kW tops need about 160 watts.


Do you need a crossover? As I read the specification, it says the sub has a built-in cross over. Passive crossovers in commercial systems are rare. It's presence in this system is yet another indication these drivers will only handle one or two hundred watts RMS. Large inductors to handle high power at very low frequencies are expensive.


As Ben said, one school of thought was to match RMS ratings as closely as possible. Thunder mentioned matching the peak rating BUT in this case connecting a 2kW amplifier would be out of your price range and probably cook the passive crossover. Given a small mistake it will blow the cones out of the boxes and across the room. But then Thunder did say the trick is in knowing how use it. Generally, if there is no [electronic] limiting in the system, match the amplifier power to the speaker power ratings, just like Ben said in the beginning. Don't hesitate to check for a recommendation from the manufacturer. I'd read the user documentation but Technical Pro doesn't seem to publish it on their web site.


In your private message to me, you indicated an interest in the Crown XTI 2000. I own one and I'm very impressed with its built-in DSP. At 800 watts into 4 ohms per channel it is probably too much power for your set up. The XTI-1000 should be sufficient. I might suggest it or the 2000 if you were looking to provide an upgrade path to an improved system. If you intend to use the passive crossover built into the system the DSP in the XTI line will be of limited use. You might as well buy a less expensive amplifier in the XLS line or check out basic amps from QSC. Many people on ODJT swear by them. Jeeze Ben, Thunder, chime in 'cause I don't know what you'll recommend. Oops! Thunder votes PEAVY!


The best solution, the standard configuration for your kind of system (two top and tow subs), is an active cross over and two stereo amplifiers. This would allow you to by-pass the inefficient passive crossover in the sub. It has the disadvantage of cost. You would have to buy an additional amplifier and an active crossover.


Hope that helps.
Click to expand...

That wasn't Ben, it was me, the "Bloggerator!" :sqcool: LOL
Ben's alter ego perhaps? :sqwink:

I would suggest the Crown XLS amp as well (we have Cash Rebates going on on these till the end of the month) or the QSC GX series. I am still a bit reluctant to recommend specific wattage here. I would base it on the RMS ratings for these speakers, but there are none. You will definitely want to play it safe and not overpower these... On the under hand, under-powering could be just as bad IMO.

Now, I don't know what your price range is, but there are a few other options to consider. Have you thought about possibly upgrading any of these speakers to a powered set? Just trying to think outside the box here.
 
shoes off again?

NLFX Pro said:
Sorry guys... I was on 3 flights yesterday, 3 more tomorrow, and then 2 more on Friday... been just scrambling to keep up. Bob... you'll have to get my back on this one. ;)

Ben
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DON'T LET IT HAPPEN AGAIN - NO EXCUSES!

You show me a man on that many flights in that space of time and I'll show you a guy that wears loafers.
 
I am sorry for not getting back on this one I did a little checking and honestly can;t find much on these units.

But from what I have seen these things remind me a whole lot of the old Gemini and Sound Tech passives, Honestly if they are of the same ilk you don't want to run much more than 150 watts to any one of them.

But I could be wrong on this, it is just that looking at the "specs" something is more than a little hinky with these boxes!

I mean when you take a 1w1m reading on a unit in chamber you get a reading and that is it, there isn't any plus or minus 2 DB to it it is 96 or 99 or 102 or whatever the reading will be constant and consistant!
 
Thunder said:
I mean when you take a 1w1m reading on a unit in chamber you get a reading and that is it, there isn't any plus or minus 2 DB to it it is 96 or 99 or 102 or whatever the reading will be constant and consistant!
Click to expand...

Actually the sensitivity is measured using a frequency sweep over the full range of the cabinet. So, the +/- could be an indication of how flat that SPL curve is over the operating range of the cabinet.

Without seeing the actual SPL curve, it is not possible to know for sure. No plot, no sale.
 
Try to stick with reputable brands when possible. As Steve mentioned, many of the cheaper speaker system makers deliberately inflate their specs by using fuzzy testing "standards". These "standards" are for salespeople, not engineers or sound system designers.

With speaker systems, the true importance is on the drivers. A 3" voice coil on an 18" driver? Eminence's basic 18 sports a 4" coil. Of what material are they wound, copper or aluminum? That makes a big difference in how much power they can handle and for how long.

Piezo horn drivers, lack of Neutrik or Speakon connections, no balanced line inputs on actives... these things just don't occur in systems designed for pro sound apps.

Of late there have been many sub-par OEM drivers coming out of China. They're inexpensive for a reason. :)
 
soundinmotiondj said:
Actually the sensitivity is measured using a frequency sweep over the full range of the cabinet. So, the +/- could be an indication of how flat that SPL curve is over the operating range of the cabinet.

Without seeing the actual SPL curve, it is not possible to know for sure. No plot, no sale.
Click to expand...

Actually you are wrong, the sensitivity is measured at it highest level for one watt one meter on a full frequency spectrum and this is taking into account the higher DB from the HF driver.

So a HF driver may have an SPL of 107DB @ 1W1M while the LF driver may be 98DB @ 1W1M the resulting box SPL will reflect 102 DB@1W1M.

The "curve" (drop off) is reflected in the minus 3DB and minus 10DB in the frequency range as in.

45 Hertz - 3DB to 18K Hertz -3DB

And

40 Hertz -10DB to 18.5K Hertz -10DB

There is no (+) plus to it!
 
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