Under powered?

[lovedoc1]

I am getting sooo much more midbass from my rear coaxials then from my front components. The front comps. are RF T162S and rear are RF P1653. The comps are rated at twice the power as the coax. My amp is a Cadence Z4000 4X75 at 4 Ohms, 4X150 at 2 Ohms. Both sets of speakers are rated at 4 Ohms. The coax speakers are currently being pushed by their full RMS wattage, and the comps. only by half of theirs. Is this why so little midbass is being produced from the comps? If so, can they be wired to 2 Ohm, or can you only wire subwoofers to lower Ohm ratings? Yes I have already checked the crossovers all are on Full.

[Rare177]

ALOT of people have problems with midbass output in the doors, problem is the service holes, the purpose of your door is to act like a box, you need to seal it the sound waves from the front and back of the driver, having service holes does not help one bit with this, now take your rears, they are sealed off much better in comparison.

[lovedoc1]

Originally Posted by Rare177 ALOT of people have problems with midbass output in the doors, problem is the service holes, the purpose of your door is to act like a box, you need to seal it the sound waves from the front and back of the driver, having service holes does not help one bit with this, now take your rears, they are sealed off much better in comparison.

So it has nothing to do with the fact that the front speakers are under powered? Can I wire 4 Ohm component speakers to create a 2 Ohm load like you can with a subwoofer? How do I seal the door? Is it just by adding dampening material like secondskin? Do you not cut holes in it when you apply it to the door? Or, do you add an enclosure structure within the door?

[Rare177]

your door has service holes, you can seal these off with a few different things, aslong as it's air tight its fine, your goal is to make sure no air from the back of the sub can mix with the front, so sealed off front to back.

and no you cannot wire your component set to a 2ohm load if you want to keep the channels from left to right, which im sure you do.

[lovedoc1]

I have read that underpowering is bad for a speaker. If my comps are rated at 100 RMS and due to them being 4 Ohm my amp is only giving them 75 RMS is this harmful to the speaker? Also, since 100 watts must be increased to 1000 watts to be double the loudness can you even tell the difference between a 75 RMS set of comps and a 150 RMS set of comps in terms of how loud they produce clear sound.

I am also trying to select a subwoofer to accompany my system. My biggest worry is that the subwoofer will overpower the rest of the speakers, expecially at lower levels. Yes, I want it to be able to play loud and hit hard I just want it to be level with my front stage. I was looking at an Fi Q 12 1000 RMS. Will this be too loud? What about turning it down and up? Does that mean adjusting the gain to a lower setting? If so, that is confusing to me b/c I thought a gain's purpose was to match voltage output of you HU. Or, should I just select a subwoofer that has a lower power rating? It is just difficult for me to get power rating=SQ out of my mind.

[killa101]

Originally Posted by lovedoc1 I have read that underpowering is bad for a speaker. If my comps are rated at 100 RMS and due to them being 4 Ohm my amp is only giving them 75 RMS is this harmful to the speaker? Also, since 100 watts must be increased to 1000 watts to be double the loudness can you even tell the difference between a 75 RMS set of comps and a 150 RMS set of comps in terms of how loud they produce clear sound. I am also trying to select a subwoofer to accompany my system. My biggest worry is that the subwoofer will overpower the rest of the speakers, expecially at lower levels. Yes, I want it to be able to play loud and hit hard I just want it to be level with my front stage. I was looking at an Fi Q 12 1000 RMS. Will this be too loud? What about turning it down and up? Does that mean adjusting the gain to a lower setting? If so, that is confusing to me b/c I thought a gain's purpose was to match voltage output of you HU. Or, should I just select a subwoofer that has a lower power rating? It is just difficult for me to get power rating=SQ out of my mind.

You CANNOT damage a speaker from underpowering. The ONLY thing that is going to damage a speaker is overpowering it. Every time you turn down the volume you are underpowering your speakers so you can see it is not in any way bad.

Every time you double the power you gain 3 decibels. A 10 decibel increase is considered double the loudness.

You can easily adjust the sub so it will not overpower your speakers. You are right about how you adjust the gain but it is not bad to turn down the gain. If you were to turn the gain down your sub would not be as loud. It is only bad to put the gain higher than the voltage from the head unit.

[lovedoc1]

Ok, I have read too many varying opionions on this underpowering topic. Can someone please lay it to rest for me. If I set my amps gain by using the method of turning my HU to 90% and turning my gain until distortion is in the sub and I then back it down, and the sub is too loud and overpowers my front stage, can I turn the gain down in order to make the sub quieter or will it damage the woofer? Also, is the wattage output of the amp controled by turning the HU volume and not the gain?

[basicxj]

Originally Posted by lovedoc1 Ok, I have read too many varying opionions on this underpowering topic. Can someone please lay it to rest for me. If I set my amps gain by using the method of turning my HU to 90% and turning my gain until distortion is in the sub and I then back it down, and the sub is too loud and overpowers my front stage, can I turn the gain down in order to make the sub quieter or will it damage the woofer? Also, is the wattage output of the amp controled by turning the HU volume and not the gain?

Think of it this way- the gain knob is intended to allow you to match the output voltage of your head unit's pre-outs to your amplifier's inputs...output voltage on the head unit's pre-outs rises as the volume level increases until your head unit reaches maximum volume, so you want your gain levels to limit the amplifier from reaching full power before the full volume point on the head unit.

Properly set gain levels allow your amp to put out full unclipped power as you reach maximum volume on the head unit- too much gain allows your amp to hit full rated power before volume reaches max, and adding additional volume on the head unit after the amp reaches full power overdrives the amp, resulting in a clipped and dirty signal being sent to your speaker...an amp can get unpredictable and put out up to twice it's rated power when driven to the ragged edge and clipped hard, and proper gain structure is a means of eliminating that. People get into trouble by clipping the sh*t out of their amp (underpowering or not), and if gain settings allow it and the speaker can't thermally handle up to twice the amp's rated power (in the case of a 500 watt sub powered by an amp rated for 400 watts RMS that can potentially be overdriven to put out 800 watts of nasty peak power- actually more than rated) then that's when you hear of underpowering being a bad thing- I'll take 800 watts of clean RMS power and keep the gains down over pushing a weak amp to the ragged edge any day...eliminate the clipping and send a speaker rated power or less and it can take that rated power all day long.

[killa101]

Originally Posted by basicxj Think of it this way- the gain knob is intended to allow you to match the output voltage of your head unit's pre-outs to your amplifier's inputs...output voltage on the head unit's pre-outs rises as the volume level increases until your head unit reaches maximum volume, so you want your gain levels to limit the amplifier from reaching full power before the full volume point on the head unit. Properly set gain levels allow your amp to put out full unclipped power as you reach maximum volume on the head unit- too much gain allows your amp to hit full rated power before volume reaches max, and adding additional volume on the head unit after the amp reaches full power overdrives the amp, resulting in a clipped and dirty signal being sent to your speaker...an amp can get unpredictable and put out up to twice it's rated power when driven to the ragged edge and clipped hard, and proper gain structure is a means of eliminating that. People get into trouble by clipping the sh*t out of their amp (underpowering or not), and if gain settings allow it and the speaker can't thermally handle up to twice the amp's rated power (in the case of a 500 watt sub powered by an amp rated for 400 watts RMS that can potentially be overdriven to put out 800 watts of nasty peak power- actually more than rated) then that's when you hear of underpowering being a bad thing- I'll take 800 watts of clean RMS power and keep the gains down over pushing a weak amp to the ragged edge any day...eliminate the clipping and send a speaker rated power or less and it can take that rated power all day long.

Originally Posted by lovedoc1 Ok, I have read too many varying opionions on this underpowering topic. Can someone please lay it to rest for me. If I set my amps gain by using the method of turning my HU to 90% and turning my gain until distortion is in the sub and I then back it down, and the sub is too loud and overpowers my front stage, can I turn the gain down in order to make the sub quieter or will it damage the woofer? Also, is the wattage output of the amp controled by turning the HU volume and not the gain?

You should not be listening to any body that says underpowering is bad. The ONLY way to damage a speaker is by overpowering it. This can either be thermally or mechanically. Again, if you turn down the volume on your radio you are just basically giving the speakers less power. So you are underpowering them in that you are not giving them their RMS rated power.

If your sub is too loud after you set the gain properly than you can turn it down some more. It is only bad to turn it up past the proper setting. As basicxj said, turning the gain up too high will overwork the amp which is what leads to problems. Turning the gain down will just mean your amp is not amplifying the signal as much.

Once your gain is set you will not change it (at least not to control the volume on a regular basis). That means you are only changing the head unit output voltage. So the output of the amp will be determined by changing the volume on the head unit in this case. You can change the output of the amp by adjusting the gain but there is a point where your amp will stop being able to amplify the signal cleanly.

[Rare177]

the reason people say underpowering can blow a speaker is because people get small amps and max the gain out to try and get more output, this clips the signal badly and can damage a speaker

if your gain is set correctly, its not possible to blow a speaker from underpowering it, speakers blow from thermal limits or mechanical limits, thermal is when you feed too much power to the coil and it burns out, mechanical is when you push the sub too hard that the soft parts get damaged, underpowering can not cause either of the 2 problems.