ARTICLE: The Team-BHP Guide to ADVANCED Car Audio
This article expands on the Team-BHP Guide to Basic car audio.
By now you should have mastered the art of matching a head unit (HU) to an amplifier and selecting speakers to suit your taste and needs. In this section we will discuss systems with multiple amplifiers, additional processors and special bass-enhancing loudspeakers.
One final note: the choices and scale of car audio equipment at this level is quite varied and the best solution depends entirely on your own personal preferences. You can add CD changers, DVD players, video screens, multi-channel processors for home theater sound and much, much more. Soon we will see the advent of satellite radio – some head units already include tuners for XM, HD radio and Sirius. The sky, as they say, is the limit.
For more information, take a look at the Car Stereo cookbook.
At the advanced level, the front speakers should be component speakers. The rear speakers can be co-axials in the case of owner-driven cars. If the owner usually sits in the back seat, the components are best put in the back.
Components can be:
- 2-way components -- A mid-bass & a tweeter, controlled by a 2-way crossover, or
- 3-way components -- A mid-bass, a mid-range and a tweeter controlled by a 3-way crossover.
In the case of some entry-level 2-way components speakers, the crossover is substituted with an in-line filter that gets most of the job done (frequency separation) at lesser cost.
Some 2-way crossovers allow bi-amping, which means that the mid-bass and the tweeter can be powered separately by an amplifier. Here, 2 4-channel amplfier (at least 4 channels are needed for this) is configured so that 2 channels feed the tweeter, and the other 2-channels feed the mid-bass. Biamping allows a lot of flexibility and creativity in tuning the sound.
Similarly, 3-way component speakers can be tri-amped, depending on the capabilities of the Head Unit and the crossovers.
Component speakers sound best when they are powered by an amplifier. The power output from a Head Unit will not bring out the best in components.
Once component speakers are amped, the area where the mid-basses are installed (usually the front doors) will need to be damped to eliminate vibrations.
Installation of component speakers
Installation of 2-way components is easy (except for the additional wiring hassle).
Positioning: The mid-bass is installed in the doors, and the tweeters are installed at the point where the A pillars meet the dash (or nearest to this point).
Aiming: The tweeters are aimed at the head-rest or seatbelt harness of the opposite side (so that the path of the two tweeters will cross a bit forward of the gear lever). Proper aiming of the tweeters help in good staging of the sound -- the sound will appear to be coming from the front of the front-seat passengers (at at least chest level).
Wiring: The output from the amp is wired into the crossovers. The crossovers then give separate output to the mid-basses and the tweeters. It is generally recommended that the length of wire from the crossovers to the tweeters & the midbasses be as short as possible, for best effect.
Power: For best results, feed the components the continuous power in RMS that they are rated at. A little more power than the minimum rating will be even better, as long as the gains are set so the speakers are not driven to distortion at 90-100% of the HU's volume. Though this is the best scenario, we may not always be able to feed the components their minimum rated RMS power (budgetary limitations for amps). But aiming to feed at least 80% of the speaker's minimum RMS power will be a good idea.
Installation of 3-ways is more complex, simply because of the possibilities that exist.
Positioning & Aiming: The midbass is usually installed in the front doors. Positioning/installation of the midrange & tweeters is an article unto itself.
The midrange and tweeter must be installed as close to each other as possible. And generally, they should not be installed more than 8-12 inches away from each other, with 12" being the maximum. The output from the midranges and tweeter have to blend well for best results. If they are installed far apart, the output may not sound very coherent.
Both the midrange and tweeter must be aimed at the head-rest of the opposite side (from the side of their installation) for best effect (for two-passengers). If the driver is a real audio nut, and he wants the best soundstage for himself, the passenger-side midrange and tweeter must be aimed at the driver's headrest.
For really good effect, path-length differences (a separate story for another day) should be accounted for as much as possible in installation. That is, the length between the LHS midrange and tweeter and driver's headrest, and the RHS midrange and tweeter and the driver's headrest must be as close as possible. For this, kick-panels are used. The midrange and tweeter are installed in custom enclosures/panels called kick-panels (as they are fitted next to where the driver's/passenger's feet will rest in the footwells). The kick-panels (LHS & RHS) are aimed toward the driver's headrest. Some HUs/Processors have settings to adjust path-length differences.
The midrange and tweeter can also be installed at the base of the A-Pillar and aimed like in the 2-way component installs.
If aimed properly, the Mid-bass, the midrange & the tweeter can be installed one above the other on each doors, for maximum coherence of sound (and a cool look when the door is opened).
[Of all cars in India, the Santro is the car that gives the best install possibilities (in stock locations) for 3-ways. The mid-basses can be in the doors, the midranges in the dash pods, and the tweeters can be in the dash near the A-pillars, or mounted in the dash above the midranges. The midranges and the tweeters actually fire directly into the cabin, and with some install magic in the pods, they can be decently aimed too.]
Wiring & Power: Same as two-ways. Except here, more power (10-20% over and above the minimum continuous RMS rating of the speakers) would be a real blessing.
Nice job Hydrashok but many cars like the Indica also offer dash mounting and door space for 2-3 way component systems and I would not keep the midrange (different from midbass) and tweeter more than 6" apart.
In fact I would prefer their c-c distance to be 6-8" effectively meaning that they should be as close to each other (physically) as possible. As wavelegths get shorter (higher frequencies) these differences are more easily noticed.
Don't the Indicas and Altos have dash pods that fire upward into the windscreen? That's why I didn't mention them. I think firing anything towards
the windscreen messes up the imaging.
And yes, tweeter + mid -- the closer the better :-) I guess 12" is a bit too much (checked it on a scale). But this would mean custom installs would be necessary in most cases. I have got mine installed (all in the door) so they are almost touching each other (about 3 and half in. center to center)
Although overlooked by most, this forms an extremely important component of your job.
Speaker Wires: When you a buy a decent pair of speakers with some cable inside, it is perfectly fine to use these in case you have no amplifier.
However, the minute an amplifier is in the equation, it is time to chuck those in-the-box cables and go for better speaker cables.
For components, Speakers etc, I recommend a good OFC (Oxygen free Copper) speaker wire that should be 16 or 18 gauge. It is not necessary or recommended to go for overly thick cables in this case, as it may actually prove detrimental to the higher frequencies.
For the Subwoofer I would definitely recommend 10 or 12 gauge speaker cable. I also find that taping up your speaker wires in PVC tape (I am referring to a WRAPPING tape, available at auto stores, this is not glued) provides stability, protection and ease of installation. Do not use twisted electrical cable etc.
In case you need to have a removable joint - especially in the case of a boxed/tube subwoofer, (In case you need to go to the airport, or to fold up the seats, lay out a clean mattress, fresh smelling sheets, 2 glasses and a bucket of ice for the Champagne so you can make out madly in the rear of the car which is parked somewhere in the hills…. So… where was I? haaan..), please use either an XLR male female connecter, ot a SPEAKON male female combo. If you leave bare wire hanging around, it may touch each other, blowing up your amplifier in the process.
While attaching the speaker wire to the speaker, either use crimped spade connectors or solder the wire directly to the speakers.
Extremely important and quite easy to do. 3 wires for the amplifier, a thick one running to the battery terminal, one more of equal thickness running to the chassis of the car and a thin one (any gauge will do) running from the remote on terminal of the HU to the amplifier.
A recommended alternative to using a cheap Chinese wiring kit is to buy automotive wire. Though automotive wire does not follow the AWG concept. This means that if you go upto your auto parts guy and ask for 4 gauge wire, in all likelihood, he will not understand.
You can however ask for certain numbers like 65/24 etc. The numbers are based on the number of strands and their individual gauges. Or in sqmm, I will be able to elaborate tomorrow with precision, on the finolex sizes available.. There are some excellent wires made in India, Finolex is one of them I can recommend.
You can buy 7 meters of the thickest variety and 5 metres of the thinnest. I find that this will suffice most common 2 and 4 channel amplifiers below 100W per channel.
If you have 2 amplifiers, I just recommend doing this twice over.
In cases of higher powered amplifier and multiple amplification, I recommend using imported original power cables, possibly distribution blocks, inline fuses etc.
Remember, do not run these power cables on the same side of the car as the Audio cables.
RCA Patch cabling:
Basically the wires that carry sound from your HU to your amplifier. Can change the tonality of your system, BUT remember, you need to have good quality amplifiers and speakers to appreciate this tonality.
Allow me to explain. I personally don’t use car audio RCA cables, I prefer to make my own, using high grade audiophile wire, from companies like Van Den Hul or transparent and solder them to Neutrik RCA pins using wonder solder. I experiment with carbom based, silver based and many various wires. I can do this because I have sensitive ears and I use good equipment. I am from the industry so I do not perceive these things with the same monetary value as most of you do. What’s my point?
Even a half decent system needs a good pair of RCA patch cabling. Avoid the Chinese kits. Instead I find that a good 5 metre RCA cable from MX (an Indian company, commonly available) has better performance than a Chinese unbranded RCA cable. Of course if you can afford a 5 metre cable from AR, Connection, Monster etc there’s quite nothing like it. Watch out for fake Monster though.
You can safely run your RCA cabling along with the speaker cabling. Remember to keep them away from the power cables. I wrap these too. Navin and a few audiophiles sometimes wrap these in tin foil (yes the cooking kind) and earth the foil. This will debatably protect your audio signal from external interferences.
I hope this was useful, more tomorrow.
It is possible to buy the finolex power cable in Sq mm.
You can buy 1 mm for the sq remote on (blue) cable and atleast 10-16sqmm for most medium amplfiers.
If you are using a high powered amplifier/monoblock that may need more current, go for 25sqmm and that will do the job nicely.
why do you say this ?? whats the problem if this is done ?
guys,you forgot about caps
Electromagnetic Interference or EMI. The supply and signal wires if placed close together may have EMI.
Radiative coupled noise due to close proximity of wires. The signal cables will pick up the noise on the supply wires due to the alternator.
This has been on my head for a while now. How about starting a thread on car audio installation. There's a lot of info in bits and pieces in the ICE section, but how about an article. Something which explains the importance of the installation process in lay man's language.
I stumbled upon this article on google:
Beginner's Guide to Car Audio Installation - DIY
Maybe something like that. Not many people know the importance of an install. They spend a lot of money on equipment but end up dissatisfied with their system simply because it hasn't been installed correctly. Most of them haven't even heard a well installed system!
It'll be great if some of the audio gurus could shed some light on this very important but overshadowed aspect in audio!
I think Gunbir and Autophile did post a series of install pics some moons back. I dont knwo if I can search them. However when it comes to an install common sense goes a long way. I am pretty short of time for the next few days maybe we can make this a collaborative effort.
Sure.. we can definitaly work on something..
Describing what a sub woofer is, that too in *the advanced* audio thread, sounded too funny! No offence, Navin.
But excellent idea to compile stuff from everywhere to one spot. Could we think of a TBHP-pedia wiki component here, GTO?
|All times are GMT +5.5. The time now is 22:08.|