QuestionHi Brian;
Ive been reading your literatures and i find them such a great knowledge base for tech questions. Thank you.
I am currently setting up (on my own!) my car audio upgrade for my van (Toyota Hiace Grandia). Im using a Pioneer 3250UB head unit which only has 2 pairs of RCA preouts (F/R). Behind the last row seat lies my ported box for a 12" JBL GT512. on the box ive mounted two 4 channel amps (both at 3600 watts), 1 to drive the mid highs (2 4" under front dash, 2 6" on side panels at the middle, and 2 6.5" under the last row seat), the other for 1 sub.
Here's what ive done so far: i used the head unit's front preout for the 1st amp (mid high), used a RCA y-connectors to split the red plug to ch1 and ch2, the white one splitted to ch3 and ch4 of the amp. ive set the 1st amp to HP, then will adjust later once everything is wired properly. Now i did this because im planning to drive front dash speakers and the one in the middle.
On the second amp, ive used ch 3 and 4 bridged for the sub, set the amp channels 3 and 4 to LP. now im wondering since ch 1 and 2 on this amp still is free, can i use this to drive the pair of coax under the last row seat, say set the amp ch 1 and ch2 to HP?
Im doing all my hands on this, (DIY). il be playing more of mellow music, and occassional RnB. Here are my questions:
1. on these connections ive made, will the fader work accordingly? what do you recommend or what changes dya suggest?
2. will the second amp with its capacity 3600 watts(for the sub/rear coaxials) be able to handle this setup without a hitch?
3. Any other recommendations.
Il appreciate your wealth of answers. thank you very much. looking forward to hear your word on these.
Goldwyn
AnswerHi Goldwyn,
Sorry about the long delay in answering your question.
Traditionally, when wiring 4-channel amps, channels 1 and 3 are used for left-side speakers, and 2 and 4 for the right channel. If you follow this standard, you'd want to split the white RCA output to 1 and 3 instead of 3 and 4; and you'd split the red output to channels 2 and 4. This is to preserve the left/right channel separation.
You won't be able to adjust the fader between the two sets of speakers connected to the first 4-channel amp; all four speakers will be running from the head unit's front channel outputs.
Typically, head units with dual pre-amp outputs like yours will allow you to designate the rear pre-out set as a full-range "rear" output, or a mono "subwoofer" output. If you designate it as a subwoofer output, you'll gain the ability to control the subwoofer volume through the head unit controls, and the subwoofer level will remain constant no matter how you set the fader control. On the other hand, using the output in "rear" mode will deliver a full-range stereo signal to the amplifier; it will be affected by the fader control and subwoofer volume control won't be an option.
You can certainly use the subwoofer amp to drive your set of rear speakers as well; you'd just have to connect RCA splitters, similarly to the way you've set up the other amp. In this case, you'd need to set the pre-out for "rear" use, not "subwoofer". Your fader control would reduce the volume of the dash and side panel speakers as you adjusted it to the rear, and reduce the volume of the under-seat speakers and subwoofer as you adjusted to the front.
I can't really comment on the suitability of the amplifiers for the speakers and sub without knowing more about the amps; the "3600 watt" rating seems like a peak power rating, and isn't all that useful for matching components. Some amplifiers feature a set of RCA outputs in addition to the pairs of RCA inputs. If your amplifiers are equipped with this feature, this opens some other wiring options that might give you more effective control over the system.
Hope this helps!
Brian
