Now a double-build thread, the leaf and the charger (conservation and excess )
So my leaf will be here in about 1-2 months, and I'm working on the audio system planning.
So first off, to set the stage, the car is all electric. That, among other factors, means this build has to take into consideratiom completely different priorities that a "normal" system.
(Kinda funny side-fact - the leaf will sit in the garage next to my 5-6mpg 1972 dodge charger with over 650hp and planned 2500w ... but you can imagine how much that thing gets driven )
Anyway - The primary design consideration is power consumption/efficiency/impact to range.
DESIGN GOAL 1: <10% reduction in range in most conditions, even if system cranked continuously
The leaf generally gets 100 miles per change, using a 24kw/h battery pack. In freeway driving that goes down, situations change, whatever. Point is, if we drive 25mph average (city driving), that's 4 hours. Any other conditions will be less time, so very rarely will we pass 4 hours of usage.
Ok, so we have 4 hours, and the total pack is 24kw/h. Therefore, it's using 6kw/h per hour, or 6kw continuous while driving.
With that in mind, if the stereo consumes 660w, that's 6.66 kw consumed when driving with stereo blasting. 24kw/h consumed at 6.66kw gives us 3.6h - 10% down.
Therefore, absolute limit of additional consumed pwer is 660w. Converted to amperage at 12v, that's 55A
Of course, the system will rarely constitute that much of a continuous drain, so range impact should be much less than 10%.
Quick note, the car operates at 480v or something like that, but has a 12v dc/dc converter and a standard 12v battery to operate accessories. The DC/DC is assumed to be over 100A capacity in order to allow for charging the battery in case of a run-dry, so 55A consumption should be OK.
DESIGN GOAL 2: minimal increase in weight
This one is pretty self explanatory, and also contributes to the idea above about not reducing range.
DESIGN GOAL 3: Minimum long-term impact on interior
Given the rapid changes to electric cars expected over the next 3-5 years, it's probably advisable to lease the car rather than purchase. Or be ready to sell at minimal notice. Either way, absolutely minimum impact to the interior is required.
DESIGN GOAL 4: retain stock head unit
The factory stereo is a large touch-screen unit that integrates with MANY car functions including climate control, navigation (with integrated charging station mapping), carwings, etc. I'm not sure it could be extracted, but even if it could, there would be enough degradation in functionality to justify keeping it. Plus, it plays into the above.
So those all relate to the car's specific design goals, now my personal design goals (taste, preference, etc.)
DESIGN GOAL 5: stealthy install
DESIGN GOAL 6: ~$3000 budget
DESIGN GOAL 7: Focus on front stage sound quality
DESIGN GOAL 8: retain functional rear speakers (but have them faded off when no rear passengers)
DESIGN GOAL 9: Still want nice sub system
So with all that in mind, I sat down with a pen and paper and put this together as a starting point:
-Stock head unit.
-Rear speakers on stock rear output
-Replace rear speakers with Infinity CS6030 (stock system operates on 2 ohm) for a bit of quality boost for rear passengers. No, I dont' expect much improvement
-Audiovox EQL operating as LOC and EQ. Connected to front output from head unit.
-JL Audio XD700/5. This is one of the critical selections. At 2 ohms it puts the setup at 300w (2 ohm) subwoofer channel, and either 2-channel or 4-channel output (more on channel selection later). This amp was chosen pretty much exclusively on efficiency. I can find nothing that puts out this level of power at this efficiency level. They're apparently using a full-range implementation of class D to achieve this. There are a couple other companies doing similar things - Cerwin Vega and Pioneer that I found - but in both cases the amps were a bit larger, and would have broken my power "budget". Also get sub level control knob since it won't be on seperate channels from the amp.
-3-way setup up front. Considerations: Precision Power PC3.65c component set possibly? Here's a critical choice I'm trying to make as well. I'm sure I want to go with a 3-way setup for the front, but I'm not completely locked in on configuration. The amp gives me the opportunity to put the midbass on a dedicated set of channels (2x100w if I use 2-ohm, 2x75w if 4-ohm - somewhere in between with 3-ohm, such as the precision power setup) and the mid-tweet on another set - which is what I think I'm going to do. Other options would be to bridge the amp and run 3-way passive ([email protected] ohm), but I might need to find another component set for that since these are 3 ohm... or maybe the amp would be OK with 3 ohm since it's >80hz.
Anyway, regardless of active/passive choices, I really like the set as it's gotten good subjective reviews, the magnets are neodymium (so very light), it's relatively affordable, I've been a lontime fan of PPI and I'm glad to see them coming back, and I like the small midrange flexible mounting options (might fit in a-pillar?, but even if not, very small kickpods)
-3x Eminence Lab 12 Gen II subs. Reasoning: There are a few general ways to increase subwoofer efficiency - Increase power (no can do here), high efficiency boxes (some need lots of space, others negatively impact quality), or increase cone area. The space ( see: http://www.nissanusa.com/ev/media/im...cessory-10.jpg ) is reasonably generous, but given the stealth design goal, I'd like it to all fit below the hatch. Space limitations won't allow anything as big as a 15, and width won't allow more than 3 subs. The eminence subs have great subjective reviews, are 6 ohm (allowing for optimal power with 3 subs), seem to work well with the power output (100w per sub), and they work well with the right size box. All the other 6ohm subs I found were structured for more power and would've suffered somewhat as a result. I did see 4/8 ohm subs that looked good as well, but none really looked "better", specs-wise for this power and space and need for efficiency - and with them I'd have either been leaving a little power on the table (3x8ohm)or stuck with 2 (2x4ohm). Also, I looked at doing a ported design, but the port lengths and sizes would need to be far too large for this application.
So what are your thoughts? Especially on front stage speaker selection and channel configuration, that's the one thing I'm least definitive about.
I was a little in doubt about how nice a config I could set up with these limitations, but now that I'm looking at the layout, I really thing it's going to end up being a great system!