[MidLifeZ]

Redid my entire stereo last week and have some questions on setting up amps and head unit...

Head unit is a Sony, 2v pre-outs to front, rear and sub

Have two amps, one for dash and door speakers, other for 2 subs

Question is should I set the HEAD UNIT to send FULL RANGE and then make adjustments for crossovers on the amps or ??

 

[LiveToDrive]

If you have good quality amps with full crossover control then YES I prefer to use full range and adjust at the amps. Only if your amps don't have hi/low crossover controls would you rely on the head unit to control that.

There is one HUGE exception to that rule for me...if your head unit has a good parametric EQ then you can leave your mid-range/high amplifier to pass-thru and keep the crossover active on the subwoofer amp.

Most head units do NOT have good EQ's however, but if you can adjust at least 9 bands then I'd use it.

The best sounding system I ever had used full pass through on head unit, an amazing external EQ (I forget how many bands, but it was a lot) to 2 amps with crossover set to 80 Hz cutoff on sub and 40 Hz boost (based on a box that was tuned for 30 Hz). It was like candy to my ears. I was running Boston Acoustics separates (full-mid-high) in custom enclosures and two JL Audio W0 12" subs in custom box. Obviously there's no room for this in a Lotus, but you get the idea.

 

[MidLifeZ]

Thanks! Here is the head unit below. Speakers are Focal in dash and behind seats in OEM spots. Doors have Kicker 6.5" free air subwoofers. My car is an esprit so absolutely no place at all for a sealed box.

Is the EQ in the head unit one which would do the trick as you describe?

Sony CDX-GT710HD Car Stereo Receiver

and some of the specs..

DM+ (Codec enhancer) : Yes (Gen2.1)
EQ : EQ7: 7 band EQ with +/- 6 dB adjustment at 63 Hz, 160 Hz, 400 Hz, 1000 Hz, 2.5 kHz, 6.3 kHz and 16 kHz.
High Pass Filter : Selectable on/off at: 50, 60, 80, 100 or 120 Hz.
Loudness : Dynamic
Low Pass Filter : Selectable on/off at: 50, 60, 80, 100 or 120 Hz.
Output Power (4ohm, 1kHz,16V)(W) : 52 watts x 4
Pre Out : (3) Front, Rear and Sub
Rear Bass Enhancer : Yes
Sirius/XM Connector : Yes
Subwoofer Direct Connection : Yes
Time Alignment Custom : Adjustable
Time Alignment Preset : Yes

The amps are

SOUNDSTREAM PN4.520D
and
SOUNDSTREAM PN2.350D

 

[LiveToDrive]

Nice amps. So-so head unit, but it should be fine. I see it has the EQ, but I know from experience the cheaper head units have very limited adjustment on the EQ and not the best filtering. Best bet will be to tune it both ways. Try the pass through and adjust on amps first, then turn off crossovers and use the EQ. Go back and forth on your favorite song until you hear what you're looking for.

Another tip is to adjust your amplifier gain so that your head unit can be turned up nearly 100% for maximum volume. You'll never get 2V output from the head unit unless you're up high enough in volume. This way your amp is boosting a clearer signal and runs cooler/more efficiently (and no clipping).

I also suggest coming back and listening again a few hours later after your ears adjust for both settings. Your ears can get fatigued after listening for so long and you lose the ability to hear it correctly.

Ultimately the limiting factor will be the acoustics of the car. I have no experience with the Esprit, but I know with my Elise it's a lost cause. I could squeeze out a little more clarity I'm sure, but not much. Also, free air subs are OK when you absolutely have no place to put an enclosure, but when possible the subs should be mounted in a properly sized enclosure...even free-air subs sound better in a box. I once made custom kick panels in my doors for 6.5" mids and I sealed them based on the correct volume the speakers were rated for. It's sound you can feel.