15" subwoofers

[misscc803]

I need some replacements that will work with my American Audio Amp(one below). I was using some Gemsound Speakers(ones belows) and i have blew them at least 3 times. Im not sure what the reason was. I did what i was told to do but shit it still went out on me. But anyways i talked to a guy at a music store since i dont know much about speakers and shit and he said Gemsound sucks and would never sell or recommend it. So i still have the Gemsound boxes they are just missing the 15'' subwoofer. So can u guys help me out cause i cant do any local parties cause i dont have any speakers to use. I know i can put another brand 15" sub in there but i need some that will work hand in hand with that amp so they dont get blowed or whatever.

Thanks in advance.

AMP: http://www.musiciansfriend.com/produ...ier?sku=803184
Speakers: http://gemsound.com/products_speakers-tr_tr150.html

Nicole

[TragikRemix]

from expierence with other gem sounds,

they suck ass.

not that i've ever used them, but if they are like everything else Gem makes... stay away..

probably better off with Behringers..

[misscc803]

That really didnt help me. Im talking about DJ speakers now. This is for djing not for work in the studio. Can u recommend a particular brand?!

Nicole

[TragikRemix]

that didnt make sense?

Gem sound sucks.

if you want cheap, get behringer i guess..

[misscc803]

Maybe u dont understand what im asking. I need some REPLACEMENT SUBWOOFERS. Im not all about cheap. Im here looking for various brands that will work with the Amp i have now. Do you understand now? I need the subwoofers to go into the emty boxes i have now(gemsound tr-150 casing) that way i can start backing djing. Is there anyone else who knows about DJ SPEAKERS?

Thanks
Nicole

[TragikRemix]

Originally Posted by misscc803

Is there anyone else who knows about DJ SPEAKERS?

wow.. just becuase i don't use shitty gear doesn't mean you have to get hostile here.

replacement 15" speakers, got it.

if i knew anything about DJ SPEAKERS, because they ARE soo much different than every other speaker in the world, i would suggest a brand for you.

but i'm sorry, i'm retarted and can't help you.

.

[travelin travis]

Direct replacement woofers would probably be tough to choose. A speaker cab is designed around the drivers and crossover. You could slap any o' thing in there but the results probably won't be stellar. On the other hand, the cheapo drivers that were in the cabs to begin with probably didn't sound stellar. If I knew an easy answer I'd tell you but I don't. One option would be to have the original woofers reconed but they probably aren't worth the cost of doing so.

[NRS]

You probably need a decent pro audio PA type replacement speaker with good bass hanlding and it will probably cost you nearly what you paid for the entire cab. It will certianly be better than getting another GEM cab or similiar inferior model though.

I'd reccomend an Eminence an Delta 15LFA. It's got over twice the RMS power rating as your amp which will give you plenty of headroom and a higher excursion range (xmax) which is better suited for low end bass thumping DJ material.

They run about $99 each. Cant vouch for this ebay vendor but he's got em for $99 shipped:

Eminence Delta-15LFA

Also, know the limits of your equipment and make sure your not trying to make a meager pair of 15" cabs sound like your in a dance club that has massive dedicated subwoofers. Maxing out your EQ bass frequencies all the time to achieve that chest thump creates huge power spikes that are hard on speakers (and amps). Compressors can help or often lowering your frequeny bands below 100hz and bumping up your low mids instead (125hz-250hz) can achieve the same desired effect at a safer output level.

[misscc803]

Originally Posted by TragikRemix

wow.. just becuase i don't use shitty gear doesn't mean you have to get hostile here.

replacement 15" speakers, got it.

if i knew anything about DJ SPEAKERS, because they ARE soo much different than every other speaker in the world, i would suggest a brand for you.

but i'm sorry, i'm retarted and can't help you.

.

No i wasnt coming at u like dat. I wasnt sure if u were understanding me or i was misunderstanding you. Calm down partna. I asked if anybody else knew so i could get more help. But thanks for trying.

Nicole

[misscc803]

Ok well i take it the best thing to do is just go ahead and buy some new PA speakers. So with the amp im running what 15'' dj speakers would have enough power from that amp im using?

Thanks in Advance!!
Nicole

[travelin travis]

It depends on the music and performance that you're trying to get out of the amp/speakers. 200 watts per channel into pa speakers with bass heavy material might not seem that loud in a big room.

[Treeline]

Originally Posted by TravisinFlorida

It depends on the music and performance that you're trying to get out of the amp/speakers. 200 watts per channel into pa speakers with bass heavy material might not seem that loud in a big room.

There's apotential that the amp might be part of the problem. a 200 watt channel driving a 15" subwoofer and turned up loud is very likely to start clipping - distortion that causes the speaker cone to snap instead of vibrate. And with a consumer grade amp, the clipping is likely to start even sooner.

Clipping from a low power amp can blow a speaker pretty much instantly. That's one of the reasons pro live gear - be it for DJ use or live music - sounds good when it involves matched and higher grade components. Of course, they cost a bunch more, too.

A friend of mine has a DJ business and the power is in four Mackie SRM450 cabs. I have a pair for my live sound work - half the amount. It sounds great, but part of that is because the amps are designed to work with those individual cabs. Even then he (and I) have problems with extreme bass heavy or metal sounds. Both of us have had our cabs shut down on us as a thermal protection. It's a pain in the ass but it saves the speaker from blowing.

Because the music you're running through those speakers is probably driving the amp way past its comfort zone and torquing the hell out of the speakers. Turn it down or beef up the amp.

Go online and look at Peavey or Carvin speakers and you will probably find something that will work. Guaranteed they will be far better than what you started with. But add everything up before you order; new cabs might be cheaper.

[travelin travis]

good point. i assumed she knew about the clipping thing.

[misscc803]

Thanks to all for the advice. Yeah the man at the music store said Peavy was a good brand but i always have to ask around to be sure cause sometimes they will tell u anything to get an sale.

Thanks all!!

Nicole

[travelin travis]

Peavey does make some extremely reliable gear. I've seen some older Peavey solid state guitar amps take more abuse that absolutely no strong willed step child could endure.

Within reason, you shouldn't be too concerned with brand name. I mean consider each piece of gear on an individual basis rather than being within a brand name umbrella. A pile of crap is still a pile of crap even though it has a brand name logo on it.

I guess the only way to be sure of what you're getting is to do some research on what goes into manufacturing products to find out where the corners may be cut and talk to people that have used those products to help get an overall impression of performance and reliability.

[COOLCAT]

Originally Posted by Treeline

Both of us have had our cabs shut down on us as a thermal protection. It's a pain in the ass but it saves the speaker from blowing.

Because the music you're running through those speakers is probably driving the amp way past its comfort zone and torquing the hell out of the speakers. Turn it down or beef up the amp.
.

thats two good inputs.

this is probably a perfect reminder & example of cheap stuff and more expensive equipment materials used.

when your pushing it, thats when all the science and crap shines in the design and materials hold up.....or ...er...blows....depending on the perspective.

[boingoman]

Originally Posted by Treeline

There's apotential that the amp might be part of the problem. a 200 watt channel driving a 15" subwoofer and turned up loud is very likely to start clipping - distortion that causes the speaker cone to snap instead of vibrate. .

Hey, whoa. It's not distortion that kills speakers when an amp clips. It's the increased average power. Clipping is like compression with make-up gain, in that it cuts the peaks off and raises the average level the speaker has to handle. That means more heat in the voice coil. If the voice coil gets too hot, it fries.

Speakers blow for two reasons, mostly. They move too far from too much power, or get too hot from too much power.

[Mindset]

Hey one of you guys want to try this???

Get a laser pointer, and then some chalk, and a speaker, and one of those disco balls, break the crap out of the disco ball, and get all the glass, and crush it up, and paste it onto the speaker. Take the laser pointer, and point it at the speaker while it's banging out music, and take some chalk and put it in the air, and it should draw out sound waves.

I heard several respectable people doing this for scientific purposes and worked. I have yet to try it...

[Mindset]

Having not enough cab space will cause a speaker to blow or not the right box will cause the speaker to blow. Using a vented box, will raise the impedance around the resonance frequency causing the voice coils to overheat & blow. So watch what sub you put into what box.

too much power will cause speakers to blow obviously

not enough power will cause the voice coils to overwork & tear trying to keep that volume level.

also too much power will cause the magnet to over heat, and bend the voice coil because of the heat. The sub might still 'work' but it causes non-linear distortion because of the voice coil not being exactly where it needs to be in the magnetic field.

[boingoman]

Originally Posted by Mindset

not enough power will cause the voice coils to overwork & tear trying to keep that volume level.

There is no such thing as "not enough power" for a speaker. They react to how much voltage the amp puts out. Less power simply means less volume.

Put a 5 watt amp on a 1000 watt subwoofer. You will never ever blow that sub.

Originally Posted by mindset

also too much power will cause the magnet to over heat, and bend the voice coil because of the heat. The sub might still 'work' but it causes non-linear distortion because of the voice coil not being exactly where it needs to be in the magnetic field.

I think "saturated" may be a better word for the magnet, not "overheated". No power is passed through the magnet, it only acts as a heat sink to help cool the voice coil, which is what generates all the heat. Voice coils get hot because they have all the voltage and current from the amp passing through them, if they can't cool down, they will fail.

[Mindset]

I think "saturated" may be a better word for the magnet, not "overheated". No power is passed through the magnet, it only acts as a heat sink to help cool the voice coil, which is what generates all the heat. Voice coils get hot because they have all the voltage and current from the amp passing through them, if they can't cool down, they will fail.

Actually the magnet is part of sound reproduction. When the voice coil is powered up, and it enters the magnetic field, the neutrons move to x place etc & it's part of how sound itself is created. Just like microphones.

The current reaches the voice coil inside the speaker, creating an electro-magnet that will either be repelled, or attracted by the fixed magnet at the bottom of the speaker. That causes heat, generated by both the voice coil's and the fixed magnet.

The current goes to the voice coil and changes + to - to + rapidly, which it's polarity from + to -, and of course magnets attract opposites, which then either pushes or pulls the voice coil which causes the cone to move which then causes air pressure to change, and that is sound.

[boingoman]

Originally Posted by Mindset

The current reaches the voice coil inside the speaker, creating an electro-magnet that will either be repelled, or attracted by the fixed magnet at the bottom of the speaker. That causes heat, generated by both the voice coil's and the fixed magnet.

The heat is generated by the current moving through the wire, not by the magnetic fields interacting. I have never, for instance, noticed my guitar pickups getting hot when I play.

I will need some kind of proof that a magnet gets hot when something passes through it's field. Even if it does heat, I would bet the temperature rise will be in millionths of a degree, or at least not enough to affect the voice coil at all.

So when I said the magnet acts only as a heat sink, I meant it does not generate any significant heat by itself.

[Mindset]

Well, application has something to do with it. Your playing a guitar. I sometimes do car audio competitions (many back in the day) The moments of the subs & frequencies it's responding to will differ from yours being not hot, and mine that's banging out bass.

I agree that the magnets itself do not create heat altogether , but my point was that they do heat up because

Anyways, for the thing about blowing subs because of less power thing...

"It should also be mentioned that it can sometimes be easier to blow a speaker with an amp that puts out less power than the speaker is designed to handle! The reason for this is that an amp that is being overdriven can generate a lot of distortion and the RMS level of the amplifier output will be a lot higher than what the operator thinks it might be, and the speaker can blow." Taken off this site...
http://www.rocketroberts.com/techart/spkr.htm


Ok, here you go http://www.patentstorm.us/patents/58...scription.html

The rotor is constructed so that it may be submersed in oil to provide greater heat dissipation. A motor will generate heat as a result of the excess energy that is not converted to mechanical energy as the power is applied to the motor. The motor will eventually burn out because as the power increases, the motor cannot dissipate the heat fast enough, therefore the available power handling is lowered to compensate for the excess heat. The present design can be completely submersed in oil because the shaft can be sealed. Conventional systems with longer excursion and high power using voice coils are not capable of being submersed in oil because there is no way to seal them. The Ferro fluid normally used with voice coils is insufficient because the oil will be blown out of the magnetic gap at high power with long excursions. The presence of oil also increases the damping of the unit, reducing distortion.

Motor = basically the magnet & parts

http://www.criticalmassaudio.com/cat...d&productId=20
http://www.tcsounds.com/tcmotor.htm Buy yourself a good mag and high power handling coils, and Kevlar coated cones, etc and build a sub, they are great.... if you do it right

Also, my subs in competition were very hot to the touch.

[boingoman]

Originally Posted by Mindset

Anyways, for the thing about blowing subs because of less power thing...

"It should also be mentioned that it can sometimes be easier to blow a speaker with an amp that puts out less power than the speaker is designed to handle! The reason for this is that an amp that is being overdriven can generate a lot of distortion and the RMS level of the amplifier output will be a lot higher than what the operator thinks it might be, and the speaker can blow." Taken off this site...
http://www.rocketroberts.com/techart/spkr.htm
.

Yup, that's right. The main thing to take away is that an amp that is rated below the power rating for your speakers may be able to produce enough RMS power when clipped to fry your speakers. Too much power, in other words. All you have to do is have a little restraint, and not clip your amp.

The part about distortion isn't right, though. If distortion killed speakers, a lot of guitar amp companies would be out of business, and rock music would be a lot less awesome.

Sorry to be so picky about the voice coil thing, I just wanted to make sure it's understood that the voice coil is the source of heat in a speaker, not the magnet.

Interesting link to the speaker patent. Seems like a take on Tom Danley's Servodrive stuff, but capable of much greater excursion.

[firby]

If you are a DJ looking for PA speakers try JBL and then EV. Really if you have mid level JBLs you are ahead of the game for DJing. Just buy them, cry, then have a drink and spin records. It gets better.