sidneyfox

Hi there,

I finally decided to replace the torn sub on my 04 LS430. I got an ID8V.3 D4 wired serially on both cores, but polarity reversed.

Here are the picture of the wiring and FFT plots comparing to the stock ML sub. I don't have a calibrated mic so the graphics are only for comparing.

I looked at Kicker CompD and Polk MM840DVC, but both front frames are too thick for the bracket. I only had to cut little plastic on the bracket to get ID8 to fit. As shown on the FFT plots, ID8 is very close to the stock ML sub, except of the bump and dip from 39Hz to 63Hz.

Sidney

Gene01

Two questions if you don't mind - I am curious about the application of this speaker.
What is the impedance of each of the two voice coil segments?
Why was it necessary to wire them in reverse polarity?
Thanks for posting - very interesting.

Lavrishevo

iTrader: (1)

http://www.sonicelectronix.com/item_...D8-D4-V.3.html

Just don't forget your are running half the impedance the factory amp is designed for. If you loose your amp it's going to be a nightmare. They are over 2 grand to replace... Not worth it in my opinion.

sidneyfox

The factory sub is 12 ohms. ID8 each coil is 4 ohms so I'm running it at 8 ohms by connecting them serially. Do you think I will damage the amp? Has anyone run into problems loading the amp with a 8 ohms sub? I will turn down for now. I would install the stock if they wouldn't keep tearing the diaphragm. I had to reverse the polarity because that's how the ML was connected. You'd lose everything above 50Hz if you don't reverse the polarity.

Gene01

Thanks for the information.

Lavrishevo

iTrader: (1)

Ohm loads vary depending on what you are sending though the speaker. The ML sub is somewhere between 16 and 12. The rule of thumb is to try to keep the impedance correct for what the amp was designed for. Will it ruin an amp? It's hard to say. You might be better of doing two after market subs to match the ML impedance. Like a 8 and a 4. Personally, I wish the ML sub was normal in this aspect as the aftermarket subs probably will last longer and may even sound better.

HiloDB1

iTrader: (3)

As long as you're not playing it hard (ie excessively loud or playing test tones recorded at 0dB) it will be fine. Speakers are not static in their parameters. The speaker impedance varies due to a number of reasons such as enclosure, power, heat, and frequency. The speaker will never go below the Re value of the coil, it will only go up.