[Brishti]

With the age of new LED lights and Xenon's being as popular as they are now, I was wondering why single barrel headlights are still not as popular. Examples such as Jeep Compass Bi-Xenon come to mind and its setup seems more elegant than the twin barrel "Projector + Reflector" setup on the Fortuner.

The next is the cost because Bi-LED/Xenon bulb "Low-High" would cost less than two separate bulbs. What do you all think?

[self_driven]

Cost is definitely one factor. Competition is another. All it's needed to start the trend is one manufacturer and others will follow suit to stay relevant in the market. This is how features trickle down to smaller segments over time. There was a time when the DRLs we see every other car flaunting now were a novelty.

About the single vs double barrel thing, I think that's more to do with the market positioning and general design language of the car. Double barrel head lamps look more premium and are, in most cases, more powerful and effective at night. Personally I prefer the projector + reflector arrangement to a bixenon projector or single barrel halogen setup. Projectors and reflectors have their own strong points which can be utilised well in such a setup. While the even spread and sharp low-beam cutoff of a projector is good in the city, nothing beats the high-beam throw/range of a reflector setup (with a nice powerful bulb of course) on highways and pitch dark areas.

[Na_sh]

Originally Posted by Brishti

With the age of new LED lights and Xenon's being as popular as they are now, I was wondering why single barrel headlights are still not as popular....

Both the hardware are completely different.

Bi-LED/Xenon uses a single source of light which is controlled by a shield. Low beam is a truncated version of high beam.

A projector gives you the best low beam output. A wide and uniform spread of light with a razor-sharp cut-off line. This also has the least light scatter outside the required area. The best high beams are usually from a halogen in a reflector setup. The reflector is made up of multiple surfaced angled to concentrate the light from the source bulb to create a bright hotspot, resulting in illumination that reaches the distance.

In short - Single projector unit gives you the best low beam. A Single reflector has a better high beam. Dual beams offer the best of both worlds.

Would love to know from experts too.

[a4anurag]

I've experienced both kinds from the cars I have at home. I mean:

1. Creta gets a single barrel setup with a halogen bulb (HB3 9005 with a motor-driven shield which switches between low & high beams) and
   
   
   
2. Ertiga which comes with a twin-barrel halogen setup with individual beams for low and high (H11LL for low beam in a projector and HB3 9005 for high beam in a reflector).
   

There are a couple of combinations that can be observed in each kind. For example:

1) Single Barrel with bi-beams:

• H4 halogen bulbs in a halogen reflector unit (most commonly seen - Alto)
• Bi-beam halogen bulbs in a halogen projector (Eg: Creta)
• Bi-beam HID projector (Eg: S-Cross)
• Bi-beam LED projector (Eg: new-gen Fortuner)

2) Dual Barrel with individual beams:

• Halogen reflectors with independent beams for low & high (Eg: Polo)
• Low beam halogen projector and high beam Halogen reflector (Eg: New Ertiga, XUV 5OO)
• Low beam HID projector and high beam halogen reflector (Eg: Tata Harrier)
• Low beam LED projectors and halogens for high beam (Eg: Innova Crysta)
• Dual LED projectors (MG Hector)

Of all these combinations, for the sake of simplicity, I prefer the single barrel headlight unit with bi-beams preferably equipped with a powerful projector to give me the best of both worlds. Due to this wiring is lesser and lesser bulbs in the system which in-turn lesser items that could fail. One would also need to keep two kinds of bulbs in stock.

This is the reason I upgraded from a halogen projector (HB3 9005) in my Creta to an HID projector (single barrel). There is one downside of this setup - pass function is lost.

But if looks and overall lighting are given priority, I will get a dual-barrel headlight from the Polo or XUV5OO and swap the low beam halogen projector to a HID one and leave the high beam bulb as halogen in the reflector as such - reason, as stated above the pass function works as desired and is immediate.

[GTO]

Mod Note: Thread moved to the Tech forum!

[07CR]

Correct me if m wrong, I always thought having a dual barrel headlamps was the better headlamp setup for the spread and throw of light as compared to a single barrel one.

Our Amaze has a single headlamp with a reflector for high beam. The low beam is sufficient for cities, however the high beam is found lacking on the highways.
I recently drove the first gen elantra (which had a simple dual barrel, non projector setup), but the dual beams helped a lot on the highway, since I had both the low and high beam on at the same time.

[RMN]

The advantage of using a low beam projector + high beam halogen setup could be cost. Using a single projector would require it to be a dual beam which means the projector needs to have a solenoid that opens/closes a shield. If the solenoid fails, that means the entire headlamp would need to be replaced since it's a sealed set up and cannot be repaired. This wouldn't go down well with owners of vehicles under a certain price range. Using a single beam projector with a high beam reflector means there is basically no points of failure or maintenance required.

The other advantage is that, halogens reflectors always give a better spread when it comes to high beam cause unlike projectors, there aren't any sharp cut offs and this is great for highways that aren't lit up.

Whenever I retro fit projectors, I personally prefer to get a dual halogen setup and plonk a bi-xen projector to the low beam. That's a lot of light!

[Samir Taheer]

Originally Posted by self_driven

While the even spread and sharp low-beam cutoff of a projector is good in the city, nothing beats the high-beam throw/range of a reflector setup (with a nice powerful bulb of course) on highways and pitch dark areas.

I don't believe this to be true - The issue we have currently is the quality of Bi-Xenon setup's. I have a Morimoto Bi-Xenon H1 set-up in my LC and I have yet to see light output from a Halogen set-up even come close. To be honest generic Aux lights have a tough time adding additional illumination.

Originally Posted by Na_sh

Both the hardware are completely different.

A projector gives you the best low beam output. A wide and uniform spread of light with a razor-sharp cut-off line. This also has the least light scatter outside the required area. The best high beams are usually from a halogen in a reflector setup. The reflector is made up of multiple surfaced angled to concentrate the light from the source bulb to create a bright hotspot, resulting in illumination that reaches the distance.

I think it basically boils down to the fact that -- Quality is off the essence!!

Generally technology has moved on from the Halogen in Reflector Set-up. Possibly about 8 years ago the fact that it is the best set-up may have been true?

I am open to correction!

Most likely it has something to do with Cost - Bi-Xenon's have moving parts, more expensive bulbs and would have to be replaced as a unit.

[Kosfactor]

Originally Posted by Samir Taheer

I don't believe this to be true - The issue we have currently is the quality of Bi-Xenon setup's. I have a Morimoto Bi-Xenon H1 set-up in my LC and I have yet to see light output from a Halogen set-up even come close. To be honest generic Aux lights have a tough time adding additional illumination.

There are few vehicles in the market that now come with proper headlamps that are not compromised due to design limitations. While HID \ LED is a lot more advanced , it isn't yet time to write-off the halogen yet.

HID takes a few seconds to warm up and will need a halogen to provide high \ pass beam, cornering beam. fog lamp etc.

A large (7 inch or above) round reflector and halogen bulb is a cheap, effective combination. The beam pattern is very good for our highways, even with just a 55\60W lamp. When it starts to rain, it works better than a lot more expensive set up.

I do not know a lot of science behind this, but an H4 running properly feels as close to daylight as possible.

AUX lights from Hella are cheap (for driving beams - 500 \ 700 series), but very effective if setup properly and wired up as per their instructions on the box.

[GeeTee TSI]

Interesting videos on headlights here especially on the concept of source and reflector options determining the headlamp 'type'

Getting the focus/cut-off right is one reason I am dithering in aftermarket upgrade of my Polo's headlamps

[Archie_27]

I have a 2017 Vento Highline with a dual barrel halogen setup which is majorly used for highway runs and an Elite i20 Asta (O) with a bi beam Halogen projector setup which I use for city.

The headlamps on both seem quite adept for the respective usage as the infamous unlit and unpredictable highways of our country require a powerful throw and pass function of light provided by the dual barrel setup of our VW. And the Elite i20, with its projector beam and a neat cut off line used mostly on low beam in the city seems better for the said use.

I don't really feel the need to upgrade any of them for purposeful reasons. But I might plonk an HID in the i20 for pure aesthetic reasons. I don't wanna put an HID in the VW because I reckon the reflector setup might cause glare onto the oncoming traffic.