| Budget SQ & SPL Systems | |
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| I've had a heap of messages and questions lately regarding budget systems or basic upgrades so I've prepared the following as a guide to assist. With Tax Return tme coming I'm sure a number of people are looking to invest a little of that hard earned cash in upgrading some stuff they may have been putting off for a while.
There are a number of ways to ensure good resuls in your system even if your on a budget. The most important thing I consider when planning a budget SQ system is trying to minimise what would need to be upgraded later on if you decide to expend the system Every time you buy and then sell something you lose money so ideally try to get components that you can keep in an upgraded system. Two exmaples of this are: - Selecting a good quality 4 channel amplifier that you can use to run front stage and sub now and then front and rears speakers or active front stage later on - Selecting a single good quality sub now and then adding a second one later on for additional low frequency emphasis It is also very important to remember that good sound is as much about planning and installation as it is about the actual equipment used. I have tried to make this tutorial simple and easy to understand so for further specific information please refer to the other more detailed tutorials. Many people get caught up spending all their time on deciding which particular brand of equipment to use and then neglect to properly plan the install or skimp on poor wiring , connections and sound deadening. I have tried to outline some ways to maximise your dollar to get a good Sound Quality (SQ) or Sound Pressure Level (SPL) system without spending $000's. For the most basic of systems use the following as a QUICK reference - The biggest restriction in a factory system is headunit power. Most factory headunits are only around 4 x 10rms. A good aftermarket headunit will offer 4 x 16-18rms and you'd be supprised the difference this makes. - If you have more $$ to play with get a good quality pair of front splits. A number of good ones are available for around $300 (a little less if you shop around or get them on sale) - Next upgrade is to add a good 4 channel amp to replace your headunit's 4x16-18rms with 4 x 50rms. - Finally adding a single sub running off 2 channels of your amp, while running the fronts off the other 2 will provide the base for a really nice sounding system without blowing the budget. While there is no fixed price all that can usually be done including cables etc, for $1,000 - $1,500 The advantage of the system outlined above is there is no need to get rid of anything and you can smply keep adding to make the system better and better. Typical factory looking speakers are made from modestly priced materials and are limited in their power handling SQ Systems Front Stage The single most important thing in any SQ system is the front stage – type and installation. Typically in a $1,000 system I would allow $300 - $400 for the front stage. - Get the largest front stage you can fit in, ideally 6" or 6.5"splits - You are much better to get a better quality 2 way front stage than a cheaper 3 way front stage. This will also be cheaper and eaiser to instal - Ideally buy a pair of speakers that you will not need to upgrade at a later stage Amps Power is not just power and all amps are not the same. I suggest a good quality 4 channel amp. Something approx 4 x 50rms allows you to to run the front stage with 50rms per side (tripple what the best headunit provides) + 1 x 180rms for a sub. When you upgrade later on you can keep this amp to run front and rear speakers (or an active front stage) and add a dedicated subwoffer amplifier. Once again you are better off puchasing 1 x good quality 4 channel amplifier than 2 cheaper ones. Generally low budget systems will not allow you to purchase 2 good amplifiers. Look at the amplifiers explained section as to what to look for in an amp. You may be able to get something cheaper by compromising on some of the features (such as elaborate crossovers flashy displays and getting a plainer amp with better SQ specs (STN, Dampening factor, T.H.D @ rated power etc..) Cables – Power, Earth and RCA's It is important to select suitable sized cabling for your system. Obviously more powerfull amps may require larger cable but as a rough minimum guide 1 x amp = 8 gauge 2 x amp = 4 gauge 3 or more amps = 2 gauge or 0 gauge As a rule I always run 4 gauge. It's not much more expensive than 8 gauge and you don't need to update later on if you add a second amp. The thicker cable also helps reduce voltage drop will help prevent headlight dimming and also protect your amp. Definitely worth the money Expect to pay approx $6 - $8 per metre for 4 gauge You must have the same size (or larger) earth cable as you do power cable. It is also important that the earth cable is connected properly. Sand or rub back the paint to expose bare metal and ensure a solid connector is used on the end of the cable. Keep it as short as possible It is best to have the shortest earth connection possible so do not connect the earth back to the battery's earth, unless it is a boot mounted battery. RCA's A common misconception is that you need to have the latest gold plated $100 + RCA's to get the best sound... That's not the case. Look for - Twisted pair RCA's offer the best shielding - Look for good quality connectors on the end of the RCA lead, Very cheap RCAs use poor quality plastic and the connectors have little flex and you often have problems with them breaking internally. I have had a lot of problems with those $15 blue ones from Autobarn. - I typically allow approx $40 for a good quality RCA. Sub/s Generally in a budget system a single good quality sub is best - Consider a dual voice coil sub as it maintains your flexability down the track for wiring - Look out for sensitivity. If you only have limited power try to get a sub with higher sensitivity as it will play louder for the same power. It doesn't matter if you select a sub with a higher power handling than your amp can produce. It means you can upgrade the amp at a later stage if you wish. NOTE: Selecting a sub with higher power handling does not mean that it is bullet proof and cannot be destroyed by a less powerfull amp. SQ SUMMARY Shop around. I just bought a pair of competition splits retailing at $899 , for $399 brand new so it pays to shop around and haggle for a good deal. There is plenty of competition around so if your prepared to invest the time you can same some $$'s. SPL Systems Front Stage Often in pure SPL systems a front stage is not necessary at is just added expense, but most Bass fans still like something up front to rock along to. Power handling and output are the two main concerns here as you try to get a front stage to match up with the barrage of BASS coming from behind you. - Get the largest front stage you can fit - Get speakers with higher power handling and run them highpassed from 100htz - Don't expect too much from your front stage. It will probably not be able to keep up with your subs so enjoy the sound of the rattling windows and number plates because that's what you will be hearing on a daily basis - Amps In SPL Clean power is Clean power and a number of the specs that are of interst in SQ systems are not as important here. Total Harmonic Distortion (THD) at quoted power is an important statistic and it is also important to have an amp with good quality protection devices as you will be pushing it's limits you need to ensure it will protect itself and the speakers to which it is connected. Look for low voltage protection, soft clipping, clipping status LED's and best of all remote sub gain control with clippling LED. 850rms @ 1%THD @ 13.8v - Is a lot better than 850rms @ 10%THD @ 14.4v Monoblocks are almost exclusively used in SPL systems for a number of reasons, the two most important being - Ability to drive low impedence loads i.e. 1ohm - Efficiency – Monoblocks are up to 40% more efficient than class A/B amps meaning they are smaller, and operate with A LOT less heat. They also draw less current to provide the same output so they are better for your battery and electrical system. The Earthquake and JBL amps pictured above are rated at 3000rms and 8110rms respectively so you can imagine the current draw they have to produce that amount of power Cables – Power, Earth Battry's & RCA's The best option is to have a boot mounted battery mounted as close to the amp/s as possible If that's not possible use thick cables that are able to supply large amounts of current for short bursts. I would reccomenend 2 gauge or 0 guage (although this is pretty expensive and hard to work with) 0 Gauge is approx $16 - $18 per metre Voltage drop is one of the biggest killers of good SPL numbers as well as frying amps and/or speakers. Having a rear battery is a great way to help reduce the chance of this occuring. Capacitors are also usefull but a 2nd battery is better Use thick speaker cable as the subs will be taking large amounts of voltage in short bursts and you need to ensure the amp is able to transfer this to the subs. RCA's As SQ is not the aim good quality RCA's are less of an issue but I would still get a good quality twisted pair RCA's . You may also need to have a longer RCA you can operat the headunit outside the car. This may be required as you must be outside the car for any figures over 140db to count in officially sanctioned SPL competitions. Sub/s This is the heart of any SPL system. Most of it comes down to common sense. Large subs More cone area Greater power handling + correct box design = Higher SPL. 12" or 15" subs are usually used (often in pairs) in large ported enclosures. You need to consider how much space you are prepared to sacrifice BEFORE buying the subs as many SPL subs require very large boxes to obtain maximum results 6c/f sub enclosures are not uncommon There are a number of sub manufactirirs that have a reputation of building good quality SPL subs and it's worth noting that Crossfire and Digital Designs (DD) hold 8 of the 9 world SPL records between them. Others such as Earthquake (Magma and SubZero series) Apline Type X, JL Audio W7, JBL and Soundstream all have good reputations on the SPL scene. Jaycar have also had success with their higher model subs (doubble stacked magnet ones) and these are definitely worth considering if you on a budget. BOX Design This varies from vehicle to vehice and with each sub but on 90% of occasions the best results are obtained using ported enclosures. Although not normally as musical and transient, ported enclosures allow you to tune the box to peak at a particular frequency and coupled with the cabin gain of the vehicle, obtain a peak at a particukar freqnency. SUMMARY For a budget SPL system I would consider getting one good amp + one good 15" sub in a large ported enclosure + boot mounted battery. Later on if you decide to continue expending you can always add another sub the same and another amp if necessary. Invest in a boot mounted battery right next to the amp something like an Optima works well. As a rough guide. 1 x Sub $400 1 x Amp $600 1 x Battery $350 1 x Wiring Set $100 Hope that helps... I'll be looking out for you all on the SQ and SPL competition circuts.. |
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| Document Summary | |
| Document description: | Part 5 of Pyroay's Car Audio Tutorials |
| Document written by: | pyroay on 08 2005>, Copyright © 2013 pyroay, all rights reserved. |
| Document revised: | 04 2013 - Revision 1.1 |
| Document views: | 10524 since 08 2005 |
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