View Full Version : Mazda3 question
11-24-2012, 02:52 AM
I would like to upgrade the system in a 2010 Mazda3 (6 speaker, not bose). At very least the front, and rear, and considering a sub (10?). My question is, what is the best way to power better speakers in this car (assuming the stock unit is weak). Would an amp in the back, to power a small sub and a few speakers be a better route? I'm not sure how to attack this upgrade so any guidance is appreciated!
I assume that two sets of speakers in this 6-speakers system are a woofer and tweeter in the front. I can think of the following possibilities:
Standard front+rear+sub setup:
This involves a set of front component speakers (separate tweeter and woofer) using their passive crossover boxes, and a set of rear coaxial speakers. There are several possibilities for the amplifiers:
1. (easiest to install, budget option) Single 5-channel amplifier powers all speakers and a 2ohm subwoofer (or 4ohm dual voice coil subwoofer wired in parallel for final 2ohm impedance).
2. One four channel amplifier to power the cabin speakers, and a mono amplifier to power subwoofer. This is more expensive, but better if you intend to run something like a 1000watts to your subwoofer, as 5-channel amps can't do that.
3. One relatively high performance 4-channel amplifier uses two channels to power front speakers, and the rear channels in bridged mode to power a 4ohm subwoofer (or dual 2ohm voice coil wired in series). Rear speakers continue to use the car's stereo amplifier.
Simple audiophile setup:
You use a head unit with an _active_ crossover capability, such as Pioneer DEH-80PRS or Clarion CZ702. A single five-channel amplifier is using full range channels to power the (relatively high end) front woofers and tweeters, and sub channel for the subwoofer. Rear speakers are not used. There are variations of this with regards how many amplifiers you use and how to arrange them. I use DEH-80PRS with its auto-tune and some additional manual tweaks. This sounds much better than conventional setups.
Of course, there exist more sophisticated setups, which also cost a lot more, but I will stop here. My preference is the last option, which has the best promise for good sound quality, specially imaging. I understand that this is not always a good advise for a beginner, as it can be costly and one needs to get the head around the concepts such as active front stage. In the light of this, I would recommend to look into the very first setup. 5-channel amplifier powering front and rear speakers and a subwoofer. This is simple and cheap(er than others). I'd recommend to look into an affordable but well built Class D 5 channel amplifier, such as Alpine MRX V70 or Polk D5000.5. Class D amplifiers are very small in size, so easier to install in a compact space, and run just warm (as opposed to often burning hot Class A/B amps that take twice the space). If you're not satisfied with this, you could convert this setup into active front stage setup later on. A typical 5-channel amplifier will give you 300-500 watts on subwoofer channel, which is plenty to fill the car with sound with the right subwoofer. If you can fit a 1cu ft sealed box, you could go with a 12 inch subwoofer as long as it is an appropriate subwoofer for this box size (a lot are not). For 0.5-0.8sealed, a 10 would be better. 12 inch subwoofer will give you a bit more SPL due to large cone area. Another option is Alpine's SBR subwoofer. It's Alpine's 8 inch Type-R subwoofer in a ported box fabricated by Alpine for this subwoofer. These have very good sound quality, and being a ported box subwoofer, it can match the sensitivity of a typical 10 inch sub in a sealed box, but give a lot more energy in 30-50Hz frequency region. About 0.6 cu ft total space used, which can fit in almost any car.
By the way, have you decided how to send signal to the amplifier? If you already have an aftermarket stereo, then that's easy as you just run cables from its pre-amp ports. If you want to keep the factory stereo then you need to convert a high level signal into low-level pre-amp signal. Some amplifiers already have input for high level signal. Others need a processor/converter.
11-24-2012, 05:35 AM
zako's post is pretty thorough, but incase tl;dr
5 channel amp is probably easiest route to power 2 sets of components up front, 2 coaxials in the rear, and a sub. a powerful 5 channel is also expensive.
mb quart has some decent budget equipment(if you are on a tight budget). a 4 channel(for speakers) 4x80w + 1000w monoblock(for sub) can be had for ~~$220
you will need to change out the HU and get one with RCA preouts for you to send signals to the amps. stock unit probably pumps out 15w rms to the stock speakers anyway.
Well, if you hurry you can buy an Alpine MRX-V60 (older version of V70) for $200 for sonicelectronix right now (this is a Black Friday deal, so it won't last). V60 and V70 are basically the same thing, with V70 being said to have 10% more power. Your ears will never tell a difference. Even the V70 is not that expensive, the regular price being about $300 online.
I am not a big fan of MB Quart's conventional Class A/B designs. They're very good value, as long as they work, but the amps can run too hot on a hot day. Here in Texas, the amplifier is already hot simply from sitting in 110F degree weather in a parked car, and then a typical A/B design will get stupid how once you turn on the stereo. My MB Quart REF4 does. And the quart mono blocks are not very good IMO, other than in the watts per dollar department. I can't obstruct air flow around it with cargo or it will shut down even on a cool day. I would take the Alpine MRX or Polk Class D 5-channel any day over MB Quart.
11-24-2012, 06:56 AM
You can also use a JL Audio cleansweep dsp to keep oem eastetic. It's becoming more common now because oem head units are getting more complex to replace and din adapters can be expansive or/and can look very odd.
11-27-2012, 01:46 AM
I like the MRX-60 Amp from Alpine because I don't have to replace the head unit...seems like a good start. Any speaker recommendations (speakers and sub, 2 ohm vs 4 ohm setup)? Something in the 100 range for speaks and maybe 200 for sub? somewhat flexible on both...
For subwoofer, you may consider Alpine's SBR subwoofer. It's Alpine's Type R 8-inch subwoofer in a small ported box customized for specially this sub. The box is very small, so you don't give up a lot of space. The R8 is considered overbuilt relative to its bigger cousins. It has good sound quality, and being in a ported box, it can compete with a 10 inch sealed box subwoofer from the same family in output while delivering a lot more energy in 30-50Hz region which is typical of a ported subwoofer tuned low. The price online is just under $200 which is a good value since the subwoofer without the box costs at least $100 while buying a custom box will cost you a lot more than $100. It's wired for 2ohm impedance, so it will make an effective you of the subwoofer channel on a 5-channel amplifier or mono amplifier. This box is very small, which is an important consideration for a small car.
If you would like something different, consider Infinity Kappa 120.9w in a 1cu ft sealed box with a bit of polyfill stuffing. It can have surprisingly good impact with just 250watt amplifier, but will handle up to 500watts with easy. To my ear it has clean, balanced sound, without exagerating any particular frequency. The subwoofer can be bought for $150 online, and the box you can get from parts-express.com. They have a 1cu ft approx sealed box enclosure for cars. Sonicelectronix.com also has well priced sealed box enclosures in a variety of volumes and cone diameters, priced very attractively.
I don't know what exists good among $100 speakers. Some guys like Pioneer-D series components, which cost maybe about $125 online. I'd recommend to look at JBL MS-62C as they have been having very good reviews on forums, but they cost a bit more.