t100

i need help with retuning my amp.. its a volfenhag 2000w amp.. can anyone help me?? i appreciate any help

tc

Been around car audio a long time, and have no idea what you mean by retuning an amp? You mean setting gain(s), crossovers, etc?

t100

im trying to get my amp to work right with my l7 15

tc

What's not working right about it?

What are the rest of the stuff in the system (head unit, crossovers, equalizers, speakers, etc)?

What kind of box (sealed or ported) is the sub in?

What kind of music do you listen to, and how do you want the sub to sound? (Let me guess - hip/hop and AS LOUD AS POSSIBLE!) LOL

t100

it seems ti hit like crap... it doesnt sound right with the beat... i just run one L& 15 at the moment.. but my box is custom ported.. i listen to rap most of the time, and when im working on the weekends its country.. my speaker is bridged.. its 4 ohm

NC-B17A

you bridge an amp not a speaker. is your sub a dual voice coil if so you may have one coil out of phase with the other.
Also the amp you have may not have enough power for the sub.
"volfenhag" does not make an amp that can produce 2000w RMS.
What size fuses are in the amp?

marko3xl3

Yes it does, the ZX8400 2ch sub...

NC-B17A

Marko no they don't.
There is not a car amp on the planet that can make even half that power for 179.99 retail. I have installed a cpl of these & its prob more along the lines of 200 RMS or so

marko3xl3

I am not commenting on what they can and cannot do, all I am saying is that they sell one with the claim of 2000W. What do you expect the guy to do, ask about info on a 200W sub (or should I say 199W) to confuse the heck out of people who try to help, and then later explain how utterly perfect his first post was? That's stupid...

You should've at least warned us what you are about. No sub performs exactly to the specifications.

Plus, to be honest, I believe the sub might just pull of 2000W. For how long? Probably a very short time if maxed out, probably seconds. But the company never states the duration, only 2000W. I don't think they state RMS either, so that means 2000W peak.

tc

Sorry for leaving you hanging... How about posting brands & model numbers of all the equipment in your system.

Is the sub single voice coil or dual? How many ohms for each voice coil? Do you know if it's wired series or parallel? It's real easy to think you're doing series and it be parallel out of phase, with the voice coils fighting each other...

As for the guys above bickering about power ratings - get over it. It's just a number printed on the case. At the end of the day, the expense in making an amp is in the power supply and the FET's. The number/size of FET's pretty well determine the size of the power supply. You will find that ALL amps come out to about $1 per REAL watt and the mfg will put whatever rating corresponds to their marketing directive. NOBODY needs 2000W and I know - I had 4 built USAmps USA400's that did 1800W each (tested and verified). Most music will only take a couple watts to reproduce at very high levels in a car. Classical music is more demanding on an amp that rap/hiphop because more of the frequency range is at a high level for longer periods.

Speaker ratings are similarly ridiculous. If the signal is CLEAN (not clipped), speakers can handle A LOT of musical power, because it has a relatively short duration. I was putting >900 watts to each 12W0 (rated for what - 200W maybe) in a ported box, and never blew a speaker because I went to great pains to make sure the signal wasn't clipped.

NC-B17A

No bickering here just stating fact. If the coils on the sub are in phase then the problem may be that Kicker L7 15 has an rms power rating of 1000w & is being under powered thus the amp is clipping at a low volume due to the load that is being placed on it.

runethechamp

The Power Rating of a speaker has nothing to do with how much load it puts on the amp. The impedance is what determines this. Low impedance = high load on the amp.

tc

Actually, it's better reflected by the efficiency (measured in dB) of the speaker

NC-B17A

1st off where is t100 with some more info about his gear.

you are not entirely correct sir.
most high power subs are less efficient then say a speaker of the same size but lower power handling.
are you talking about 1 watt 1 metter? If so you are incorrect that has nothing to do with how efficient the speaker is.


Efficiency
Although a speaker's efficiency rating is almost always correlated to its sensitivity rating, it is actually a different measurement. The efficiency rating for a speaker is a measure of how well a speaker converts watts of electrical power into watts of acoustical power. Most speakers have a very low efficiency rating — between 1% and 10% — so manufacturers rarely provide this information, choosing instead to list sensitivity ratings.

tc & others I am not tring to start a keyboard war with anyone i am just tring to pass along info that may be helpful to others that I have gained in the lst 16+ yrs of installing thats all.

Bumpin' Yota

I agree with everything you have stated.

People read what this man says and take it to heart, he is correct.

While I agree the above CAN happen, I dont think that this is the case for our new posters problem. I suspect that either he has a few setting mixed up on his amp or perhaps his box is suspect.

someone suggested that he change the output phase of his subs - this will have a minimal effect at best as the frequncies his one sub plays do not overlap with very many of the frequencies played by the mids and highs. Scratch that theory.

someone else suggested that the coils of the L7 were out of phase with each other. If this were the case he'd be getting either NO output at all or very very very negligable output. So scratch that off the list.

to the poeple bickering about power. Stop it its not helping the origional poster. If you want to get technical ill happily oblige in another thread and im sure many others will.


To the origional poster if the box is good and the wiring to your amp is of sufficient gauge as well as good voltage going to the amp, your issue may just reside in the settings on your amp.

As a rule I set the LPF (low pass filter) to ~80hz if the box is ported I set the SSF (sub sonic filter) to the tuning of the box. If it's sealed, I turn the SSF off. I turn the bass boost OFF. Gain I set according to whats driving the amp. If its an OEM deck with some line out converters Ill usually set the gain to about 1/2 initially. then Ill check everything out with a DMM, and if everything checks out, Ill replace the fuse and power up the system. From this point I listen to the system and peform my fine tuning on the amp.

Now if you have a crappy box, no matter what you do at the amp you'll get crappy sound. If you have 8ga wire feeding your "2000watt" amp you'll get crappy sound. If you have a bad ground on your "2000watt" amp you'll get crappy sound...

To origional poster

midiwall

I dunno if I would scratch so quick... He said An out-of-phase 50-80hz kick drum thwack is gonna sound "off" the beat. The beat will still be implied by other things in the spectrum, hi-hat, scratching, etc. so you'd definitely be able to feel it.

runethechamp

I would check the following:

- The phase of the sub. It's only one, but I do remember some reading I did on this a while back where things could sound just a little bit off with the wrong phase on the sub.
- Are you applying any low pass filter on the output of the amp? The Kicker website doesn't supply an impedance curve for the sub, and while I'm no expert on this, the sub might put a high load on the amp at a certain frequency higher up than what it's supposed to handle and then causing the amp to clip like NC-B17A said.
- All wiring to the amp like Bumpin' Yota sid.
- Make sure the box is within specs supplied on the Kicker website.
- Check that the sub is hooked up properly with the dual voice coil.

Edit: Just thought about something. If you "bridged" the dual voice coils on the sub, meaning you did a parallel coupling of the connectors on the sub (positive to positive, negative to negative), you are effectively looking at a 2 ohm impedance from the sub, which will require your amp to be able to supply a lot of current. The amp is rated as being stable down to 2 ohms in stereo and 4 ohms in mono, so this could potentially be a problem.

NC-B17A

LOL where is t100 he is the guy with the problem

runethechamp

He says he has no problem in the amp grounding thread.

tc

Oops - NCB17A is correct - I meant sensitivity (dB @ 1W 1M) not efficiency.

Sorry if I sounded argumentative, I am just trying to educate peole NOT to place too much stock in the "power ratings" of speakers OR amps. They are just entirely too subjective to be used for anything valuable.

t100 - where are you, we need more info! Or at least post what you did if it's fixed now...