i got a problem...

[stanga]

i just bought a pair of 350 watt THUMP! 15 inch subs and a 400 watt Linear 2-channel amp. i got them all hooked up and i cant get good sound at aaalll. u almost cant even see the subs move. could it be a wire-quality issue or something fixable? or does the equipment just plain suck?

[PaulD]

try turning the little knob on the amp that says sensitivity clockwise to about the halfway point or so and see what happens

[stanga]

no luck im new with these things. k this is what it says on the cardboard box the subs came in...
-2" voice coil
-4 ohm
-efficency 92dB
-24-4KHZ Frequency

and on the amp...
-Class A/B Circuitry
-2Ohm Stereo Stable
-Chrome plated terminals
-Low/High level inputs
-Frequency response 20-20KHz
-Built in LPF/HPF Crossovers
-THD Level > 0.5% at 4 OHM

help me haha

[DJ Brady]

Paul, could he have his amp switched to hpf?
Stanga, HPF is high pass filter, only allowing the upper frequencies to pass though the speakers hooked up to the amp (your subs). High frequencies (cymbals, uppper range of vocals, basically, the tsss tsss sounds in music) will be VERY POORLY reproduced by your subwoofers and they will only move the tiniest bit.

What Paul was suggesting you turn up will be a knob (maybe well displayed, maybe kind of hidden) marked "Gain", "Input Level", or simply "Level". It's possible your gain on the amp is turned all the way down. Gain isn't to be mistaken for a volume level but for all intents and purposes, it affects the volume your amp produces, if it's turned all the way down, it's 'amplification' will be minimal. You rarely, if never want to turn it all the way up, but if it's not seeing much signal, it's safe to turn it up a little at a time.. there's a technical process to safely set these levels, but a general rule of thumb is 1/3 - 2/3 is a safe zone for most amps.
Can you give us the brand name/model of your amp? we can help you locate the important setting controls if we know what type it is.

[stanga]

they are THUMP! subs and a Linear UL2200D amp

[stanga]

yea i found the dial it was way up. and its on LPF. i can get the sound loud, but its still not pounding. its acting like they are just regular speakers, not puttin out good bass at all

[stanga]

could it possibly be a wiring problem? do the wires make that much of a difference?

[DJ Brady]

No intention to insult you here, but did you see a dial that said "Freq" or "Frequency" and it was turned all the way up? Generally, amps with built in crossovers have a dial for the high or low pass adjustment placed next to the gain adjustment.
I looked for the ultra linear website but couldn't find it.. I wanted to look at the schematics/manual of the amp to offer better advice..
sorry I can't help more right now.

[stanga]

yea i fould the LPF Level dial. it was at 3/4s. whats the Ohm property. could that have somethin to do with it? cause my subs each have 4 Ohm while my amp says 2 Ohm Stereo Stable...

[DJ Brady]

Ohms is the resistance load your amp sees.. w/out getting too technical, one 4 ohm speaker on each channel of your amp (in stereo mode) will show your amp a 4 ohm load.
Ohms are on a 'per channel' basis. so I'm going to explain it as one channel.
If you bridge your amp into one channel (if yours allows it, most do now, and wire one 4 ohm sub to it, your amp sees a 4 ohm load.
If you wire 2 subs, it gets more technical, depending on how you wire them. There's two ways, series and parallel.
Series is 'daisy chaining' your speakers, positive out of the amp, positive in to one speaker, negative out of that speaker into positive of the next speaker in the chain, negative of THAT speaker back to the negative of the amp. One long circuit.
Series circuits COMBINE the ohms of the speakers in the eyes of the amp. so 2 Four ohm speakers will create an 8 Ohm load on the channel

Parallel is just as it suggests, each speaker basically gets it's own dedicated wire off the amp channel. This type of Ohm load on the amp is different, 2 Four Ohm speakers wired parallel would show the amp channel a 2 ohm load.

Here's a webpage showing picture demonstrations and the mathematical equations needed for calculating impedance.
http://www.termpro.com/articles/spkrz.html

[stanga]

so for the specs i listed for my amp how would i wire it to get max performance and possibly fix the problem im having?