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Discussion Starter · #1 · (Edited)
I bought an AC-LGD to use as a resistor to replicate a load on my sony amp.
AC-LGD - AudioControl

Wondering if any can answer my question.

Attached is probably the same wire diagram everyone uses. It suggests using a resistor parallel with lc7i. This set up has one resistor in the circuit. 10ohm, 10 watt recommended?

My problem is the instructions included with the AC-LGD indicate that I should run both the + & - each through a resistor in a series to the lc7i (directly between amp and LC7i on each side). This results in the circuit seeing a resistor twice?

My concern is that I do not want to create too much resistance. But I also think I should follow the instructions. Audio Control does not specify how much load is actually created through the AC-LGD. Neither do the people saying we need to use resistors clarify why 10 ohms 10 watts is the recommended.

Can anyone help me? I am hoping I am simply overthinking this. I just do not want to cause damage to my OEM sony amp.

Edit: FYI I just emailed the manufacturer. So I will share if they give me an answer.
 

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Discussion Starter · #2 · (Edited)
Reading this.
Zobel networks

I am guessing the use of a zobel network (which AC-LGD does)requires I have to run the + & - of each signal through the AC-LGD for it to work right.

Since this product is designed for the use I am seeking I kind of have to trust the manufacturer knows what they are doing.
 

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that diagram is correct.

as far as how to hook them up to the LC7i is as easy as it gets. instead of running the the speaker wires coming from the OEM amp directly to the LC7i, you connect them to the AC-LGD and then plug the LDG right into the LC7i.

since the LC7i doesn't present a load to the amp, there is no double resistance. when connecting the speaker wires to the LGC, there is a terminal for both the positive wire (the wire with color) and the negative wire (the black wire) each LGD modules have resistors for two channels. the white(L) and grey(R) wires are intended for the front channels and the one with green(L) and purple(R) wires are intended for the rear channels, standard aftermarket colors

as far as why people recommend using 10 ohm 10 watt resistors is because the lower the resistance, the more heat that is going to get created. also higher wattage resistors tend to cost more money. since 10 ohm resistors is a higher resistance that the OEM speakers, the amp will not be pushing out as many watts (as it would if the speakers were hooked up) so you don't need more than 10 watts, and 10 ohms is low enough to keep the amp happy. as far as what values of resistors AudioControl used, you can bet they choose what resistors to use based on what would provide the right amount of signal and still present a low enough resistance to keep certain radios/amps from shutting off when they don't see a load present
 

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Discussion Starter · #4 · (Edited)
that diagram is correct.

as far as how to hook them up to the LC7i is as easy as it gets. instead of running the the speaker wires coming from the OEM amp directly to the LC7i, you connect them to the AC-LGD and then plug the LDG right into the LC7i.

since the LC7i doesn't present a load to the amp, there is no double resistance. when connecting the speaker wires to the LGC, there is a terminal for both the positive wire (the wire with color) and the negative wire (the black wire) each LGD modules have resistors for two channels. the white(L) and grey(R) wires are intended for the front channels and the one with green(L) and purple(R) wires are intended for the rear channels, standard aftermarket colors

as far as why people recommend using 10 ohm 10 watt resistors is because the lower the resistance, the more heat that is going to get created. also higher wattage resistors tend to cost more money. since 10 ohm resistors is a higher resistance that the OEM speakers, the amp will not be pushing out as many watts (as it would if the speakers were hooked up) so you don't need more than 10 watts, and 10 ohms is low enough to keep the amp happy. as far as what values of resistors AudioControl used, you can bet they choose what resistors to use based on what would provide the right amount of signal and still present a low enough resistance to keep certain radios/amps from shutting off when they don't see a load present
Thanks I really appreciate the informative response. You really help to make this forum great.

Audio Control also responded promptly:
On Wed, Sep 6, 2017 at 10:24 AM, Steve Hass <[email protected]> wrote:
XXXXXX,
Thank you for contacting us about this issue.

There are 2 resistors in the AC-LGD, one for each channel. The AC-LGD will not put too much resistance on your factory amp.
These AC-LGD’s have been installed in countless Ford factory systems, with no issue.

So, you would connect 1 AC-LGD to each stereo pair of your LC7i. For example, if you are using all 3 inputs(6 channels) of your LC7i, you will want 3 AC-LGDs.

Let me know if you have any other questions.
Regards,
Steve

From: XXXXX [mailto:[email protected]]
Sent: Tuesday, September 5, 2017 9:22 PM
To: [email protected]
Subject: AC-LGD Question

I bought your AC-LGD to use as a resistor to replicate a load on my 2015 ford focus sony amp as it is recommended when removing any speaker.

Attached is the wire diagram recommended for my car. It suggests using a resistor parallel with my lc7i. In this case there is one resistor in each circuit.

My problem is your instructions included with the AC-LGD indicate that I should run both the + & - each through the AC-LGD, essentially putting each signal through a resistor wired in a series to the lc7i. Not only does this result in the circuit seeing a resistor twice (once on - side, again on + side), but if I am not mistaken being wired in a series is also an importance difference in the way impedance is calculated. If I am not mistaken.

My concern is that I do not want to create too much resistance on my amp. How would you recommend I wire my system using your product?

Thank you for your time.

Edit: I think I figured out where my confusion came from in the first place. Each AC-LGD has 4 wires in & 4 out. This convinced me it was a pack of 4 resistors per unit. That is not the case, AC confirmed via email that each LGD has 2 resistors, built for 2 channels Left/Rear. For some reason I was thinking each unit had 4 resistors, 1 per in/output that is NOT the case.

Long story short for future readers, follow LGD's included instructions as they are correct.
 

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Hi...I had not seen mention of any kind of proper impedance matching between the HU and amp high level inputs being installed in any of the posted upgrades, I thought I would mention it. TacoTunes don't mention it either but their amps by design may take care of this. Maybe tacorob can comment on this. The HU is looking for 4 ohm loads (approx.) which the speakers provide but the average high level amp inputs are in the 15k to 20k ohm range.

smt assembly
 
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