8 replies to this topic

[Spudley]

Hi Guys,

I'm kind of new to the big db league, but I have a good knowledge of installing amps/subs/speakers of a reasonable standard.

I'm currently installing a pair of JL Audio W7 13.5" subs, a pair of JL Audio Slash V2/1000 mono amps (1 for each sub), 2 pairs of Morel Elate splits and an Alpine PDX-F6 all into a mates VX Berlina.

The boxes are built to JL Audio specification and are slot ported, and built of 21mm (I think) MDF.

I have set the LPF and settings as per JL instructions (recommended settings for this amp/sub combo) and wired each voice coil to each output of each amp. IE: each amp has 2 outputs, one for each voice coil.

I set the gains by having them all the way down, setting the HU volume to 30 (out of 35) and started turning the gain up until I could hear some audible clipping, and then backing the gain off.

I did happen to notice that when it did clip, the "Low Ohm" light flickered on top of the amp, not sure if that's normal :S

After getting one sub set, I proceeded to the next sub and amp.

My questions are:
A) Have I done everything correct?
B) Have I missed something?
C) Should I be concerned of the "Low Ohm" light?

The reason I ask is because I believe these subs should be able to push more air before clipping than what they are. Currently the gain is only set at about the 9-10 o'clock position, with 12 o'clock being half way.

Any help would be much appreciated.

Cheers,
Spudley.

Edited by Spudley, 22 January 2012 - 01:45 PM.

[D34M0N.inc]

Looks all good, what sort of battery power are you running? Could be having volt drop causing it to clip, so maybe check your voltages at the amp?

Or maybe the Headunit sub volume needs to be raised a bit?

[barcode]

what power wire are you running?

[Spudley]

It had a standard RACV wet cell battery, put in an Optima D34 and still did it.
Raising the sub vol just made it clip earlier.
Power was from Stinger 0ga cable to 2x 0>4ga Stinger distro blocks (1 for 12v+, 1 for neg)

I put it down to voltage drop as well, although it didn't drop below 12v (measured at the distro blocks) so I just de-tuned the gains on the sub amps and recommended he gets a 1 or 2 farad capacitor.

Is this true, or should it help?
Otherwise, it's a pretty disappointing performance on JL's part in my opinion.

Currently each voice coil is wired to each output of the amps. Should I be wiring the subs differently?

Cheers,
Spudley.

[D34M0N.inc]

A farad cap is just a band aid to the problem, more battery power before a farad cap for sure, i'd of left the standard batt in the front and ran the optima directly in the back. Less volt drop that way.

Thought to try another HU as that could be sending a clipped signal.

[Hez]

^^

1F cap won't really do much. I picked one up extremely cheap and it did nothing to my old system (maybe because it was an Aerpro?), so it's just sitting around somewhere gathering dust.

I had 2 JL W6v2 12's and those things banged even in a sealed box, and they are more of an SQ sub. So to hear that the W7 isn't really moving much air is a little odd to me.

What headunit are you running? (I'm going to guess Alpine ) Trying another is very a good idea if you have one handy.

My suggestion, only use one imput on the amps, and wire each sub&amp like this.
This will mean there less wire being used (shorter wires are always the best way to do it if you can)




I'm only in Box Hill, so if you're still having problems (I know this thread is like a month old LOL) Let me know.
I'm no expert myself but like you have done my basic rounds, and a fresh pair of eyes/ears can't hurt

EDIT: Just came to me that if you've connected each coil of the sub to the imputs of the amp, that would result in a .75ohm load. (As they are Dual 1.5ohm subs if I am not mistaken)
This could explain the "Low Ohm" light coming on!

Edited by Hez, 05 March 2012 - 01:51 AM.

[Sorin-Andrei]

Before you change anything else, what is the impedance of the coils?

[TEGBOY]

A few things to check:

You will want to wire them to a 3 ohm load. Remember these amps will do a 1000rms at any load between 4-1.5ohm.



"Low Ω" (Amber): lights to indicate that the impedance of the speaker load connected to the amplifier is lower than the optimum impedance load range for the amplifier. When this light is on, a protection circuit engages and reduces the power output of the amplifier. The amber indicator will also light when a short-circuit is detected in the speaker wiring (this can be a short between the positive and negative speaker wires or between either speaker wire and the vehicle chassis).

Input Sensitivity Level Setting
JL Audio amplifiers utilizing the Regulated Intelligent Power Supply (R.I.P.S.) allow delivery of their rated power when connected to any load impedance from 1.5 - 4Ω per channel and when connected to a charging system with any voltage from 11 - 14.5V. This design is beneficial for many reasons. One of these reasons is ease of setup. Because each JL Audio amplifier will always deliver the same amount of power within its operational range of impedances and supply voltages, the maximum, unclipped output is very predictable.
This makes setting the gain structure via the input sensitivity controls very simple. Following the directions below will allow the user to adjust the input sensitivity of the amplifier(s) simply and easily in just a few minutes using equipment which is commonly available in installation bays.
Necessary Equipment
• Digital AC Voltmeter
• CD with a sine-wave test tone recorded at 0 dB reference level in the frequency range to be amplified for that set of channels (50 Hz for subwoofer channels, 1 kHz for a midrange application). The CleanSweep® Calibration Disc contains the appropriate test tones and is available for sale at http://store.jlaudio.com Do not use attenuated test tones (-10 dB, -20 dB, etc.).
The Nine-Step Procedure1) Disconnect the speaker(s) from the amplifier’s speaker output connectors.
2) Turn off all processing (bass/treble, loudness, EQ, etc.) on the source unit, processors (if used) and amplifier. Set fader control to center position and subwoofer level control to 3/4 of maximum (if used to feed the 1000/1v2).
3) Switch the “Input Voltage” switch to “Low” and turn the “Input Sens.” control all the way down.
4) Set the source unit volume to 3/4 of full volume. This will allow for reasonable gain overlap with moderate clipping at full volume.
5) Using the chart on this page, determine the target voltage for input sensitivity adjustment according to the nominal impedance of the speaker system connected to the amplifier outputs.
6) Verify that you have disconnected the speakers before proceeding. Play a track with an appropriate sine wave (within the frequency range to be amplified by the 1000/1v2) at 3/4 source unit volume.
7) Connect the AC voltmeter to the speaker output connectors of the amplifier. If the channel pair is operating in stereo, it is only necessary to measure one channel. If bridged, make sure you test the voltage at the correct connectors (L+ and R–).
Increase the “Input Sens.” control until the target voltage is observed with the voltmeter.
9) Once you have adjusted the 1000/1v2 to its maximum low-distortion output level, reconnect the speaker(s). The “Input Sens.” control can now be adjusted downward if the amplifier requires attenuation to achieve the desired system balance.
IMPORTANT!
Do not increase any “Input Sens.” setting for any amplifier channel or channel pair in the system beyond the maximum level established during this procedure. Doing so will result in audible distortion and possible speaker damage.
It will be necessary to re-adjust the “Input Sens.” for the affected channels if any equalizer boost is activated after setting the “Input Sens.” with this procedure. This applies to any EQ boost circuit, including source unit tone controls or EQ circuits. EQ cuts will not require re-adjustment.

Nom Impedence

4 ohm or higher - Target AC Voltage 63.2V
3 ohm - Target AC Voltage 54.7V
2 ohm - Target AC Voltage 44.7V
1.5ohm - Target AC Voltage 38.7V

Edited by TEGBOY, 01 March 2012 - 03:07 PM.

[SAM77H]

on a side note have you checked your wheel alignment with that lot in the boot? Those subs weigh a ton (excluding box) and I know with 1 I had uneven tyre wear.