Subwoofers, Speakers & Amps

It will probably work fine, but the name MB Quart is not known for their amplifiers. Since the brand was sold to an amplifier company some time ago, they've added the name to an amplifier line. It's nothing special, and has nothing to do with the old MB Quart speaker line.

Be aware that the above amplifier is not a 1200 Watt amp. It's a 320 Watt amp that somehow manages to double that in bridged mode - 640 Watts with no distortion specs that I can see. It's also a class AB amp, so if you plan to use it for subwoofers, it will suck some serious power from your car's electrical system. A class D amp is more efficient for subs.

Good amp to use for your front speakers if you like it really loud.

Aaron,
Do you happen to have a link to an article or something that explains the different Classes of amplifiers.
Above you refer to class "D" and class"AB".
I would like to know more about this subject.
Thanks

Here is an explanation of the different classes of power amplifiers, sourced from www.rocketroberts.com:

• Class A: Class A amplifiers have very low distortion (lowest distortion occurs when the volume is low) however they are very inefficient and are rarely used for high power designs. The distortion is low because the transistors in the amp are biased such that they are half "on" when the amp is idling (this is the point at which the semiconductor devices are most linear in behavior). As a result of being half on at idle, a lot of power is dissipated in the devices even when the amp has no music playing! Class A amps are often used for "signal" level circuits (where power requirements are small) because they maintain low distortion. High end Class A audio amplifiers are sometimes used by the most discriminating audiophiles. Distortion for class A amps increases as the signal approaches clipping, as the signal is reaching the limits of voltage swing for the circuit. Some class A amps have speakers connected via capacitive coupling.

• Class B: Class B amplifiers are used in low cost designs or designs where sound quality is not that important. Class B amplifiers are significantly more efficient than class A amps, however they suffer from bad distortion when the signal level is low (the distortion in this region of operation is called "crossover distortion"). Class B is used most often where economy of design is needed. Before the advent of IC amplifiers, class B amplifiers were common in clock radio circuits, pocket transistor radios, or other applications where quality of sound is not that critical. For example, a siren driver is one application of a Class B amp. Siren drivers are amplifiers that are basically driven into clipping (to produce a square wave type signal). In such a drive situation there would be little need to care about crossover distortion (the design can be less expensive due to reduced parts count).

• Class AB: Class AB is probably the most common amplifier class currently used in home stereo and similar amplifiers. Class AB amps combine the good points of class A and B amps. They have the improved efficiency of class B amps and distortion performance that is a lot closer to that of a class A amp. With such amplifiers, distortion is worst when the signal is low, and generally lowest when the signal is just reaching the point of clipping. Class AB amps (like class B) use pairs of transistors, both of them being biased slightly ON so that the crossover distortion (associated with Class B amps) is largely eliminated.

• Class C: Class C amps are never used for audio circuits. They are commonly used in RF circuits. Class C amplifiers operate the output transistor in a state that results in tremendous distortion (it would be totally unsuitable for audio reproduction). However, the RF circuits where Class C amps are used employ filtering so that the final signal is completely acceptable. Class C amps are quite efficient.

• Class D: The concept of a Class D amp has been around for a long time (~ 50 years or so), however only fairly recently have they become more commonly used in consumer applications. Due to improvements in the speed, power capacity and efficiency of modern semiconductor devices, applications using Class D amps have become affordable for the common person. Class D amplifiers use a completely different method of amplification as compared to Class A, B and AB. Whereas the aforementioned classes of amplifier operate the semiconductor devices in the linear mode, Class D amplifiers operate the output semiconductor devices as switches (ON or OFF). In a Class D amplifier, the input signal is compared with a high frequency triangle wave, resulting in the generation of a Pulse Width Modulation (PWM) type signal. This signal (which some people incorrectly identify as a “digital” signal) is then applied to a special filter that removes all the unwanted high frequency by-products of the PWM stage. The output of the filter drives the speaker. Please note that this is a VERY high level idea of how Class D amplifiers work! Class D amps are (today) most often found in car audio subwoofer amplifiers. The major advantage of Class D amplifiers is that they have the potential for very good efficiency (due to the fact that the semiconductor devices are ON or OFF in the power stage, resulting in low power dissipation in the device as compared to linear amplifier classes). One notable disadvantage of Class D amplifiers: they are fairly complicated and special care is required in their design (to make them reliable). Due to the high frequencies that are present in the audio signal (as a result of the PWM stage), Class D amps used for car stereo applications are often limited to subwoofer frequencies, however designs are improving all the time. It will not be too long before a full band class D amp becomes commonplace and less costly. Class D amps find use in many other applications besides audio. Class D amplifiers will probably eventually revolutionize audio power amplifiers: when they are perfected, their efficiency will allow outputs of 1000+ watts without the need for a cooling fan! They will also be small and lightweight compared to the class AB designs that are most common today.

• Other classes: There are a number of other classes of amplifiers, such as G, H, S, etc. Although some experts would certainly argue with me, most of these designs are actually clever variations of the class AB design, however they result in higher efficiency for designs that require very high output levels (500W and up for example). At this time I will not go into the details of all of these other classes. Suffice to note that Class D (among A, B, AB, D, S, G, H classes) is the class that represents a major delta in the way it operates as compared to the other audio amplifier classes. Sometimes the consumer marketplace promotes Class D amplifiers as being "digital". The marketplace tends to toss around the word "digital" a lot, there is no really standardized definition (that I am aware of) that deems an amp "digital". To find out what a vendor means when they use the word digital with regard to an amp requires research into the design of the amp. Most likely the vendor is just using a buzz word that the consumer may associate with a superior technology.

Link: http://www.rocketroberts.com/techart/amp.htm

Thank you very much. I have bookmarked this for future reference as well.

can someone help me find me a 4 channel amp that i can run my front and rear speakers off of that will make it louder than what it is now? i have those 5.25 mb quarts all the way around... cheaper the better.. i appeciate your help

I think I'll get a seperate class D amp, and a single 12 inch dual voice coil sub so I can run them at two ohms. Any suggestions on a decent amp/sub combo like this for about 300, not including installation and enclosure?

98riviera98 wrote:

can someone help me find me a 4 channel amp that i can run my front and rear speakers off of that will make it louder than what it is now? i have those 5.25 mb quarts all the way around... cheaper the better.. i appeciate your help

Look into Cadence. Very nice amps for the money.

http://www.woofersetc.com/index.cfm?fuseaction=product.brands&category_ID=3&brand_id=121&sort=priceLow

Great prices. I would suggest just amping the front channel and powering the rears with the deck as rear speakers ruin the sound stage unless properly delayed.

I'm not sure on the wattage of your speakers, but this one is 40watts rms per channel for $121 http://www.woofersetc.com/p6045/FXA4050--Cadence-4-Ch-200-Watt-Amplifier.htm

This one is 80 watts rms at 4 ohms and might be more down your alley http://www.woofersetc.com/p6045/FXA4050--Cadence-4-Ch-200-Watt-Amplifier.htm $180

Never look at max output on amps or speakers they mean nothing.

This is a really nice cadence amp (competition quality) 50 watts rms per channel for $200 free shipping http://www.woofersetc.com/p6032/ZRS5004--Cadence-400-Watt-4-Ch-Competition-Amplifier.htm

I used the 2-channel version of this amp in my friends vibe and he love sit. Plenty of power. If you're looking for 150 watts rms per channel you might want it. http://www.woofersetc.com/p6099/TXA6004--Cadence-4-Channel-High-Power-1200-Watt-Amplifier.htm

Seriously though, I would just power the front channels and use an amp like this http://www.woofersetc.com/p6096/TXA1502--Cadence-2-Channel-High-Power-300-Watt-Amplifier.htm $100 free shipping and 75 watts rms per channel to 2-channels.

EatDirtFartDust wrote:

I think I'll get a seperate class D amp, and a single 12 inch dual voice coil sub so I can run them at two ohms. Any suggestions on a decent amp/sub combo like this for about 300, not including installation and enclosure?

You looking for SPL or SQ. I would hope SQ, because $300 won't get you much for SPL.

Not a class D amp, but this sub http://www.woofersetc.com/p3170/RWE304---MB-Quart--12"-1000-Watt-Reference-Series-Subwoofer.htm wired to 2 ohms (dual 4 ohm voice coil), with this amp http://www.woofersetc.com/p6042/FXA1500--Cadence-500-Watt-Mono-Amplifier.htm which puts out 500 watts rms at 2 ohms. At that wattage you shouldn't need to worry about replacing your alternator. i put 900 watts rms worth of A/B amps in my friends vibe with no problems.

Or you could go with this sub http://www.woofersetc.com/p4994/ID12D2-V3--Image-Dynamics-12"-Dual-2-Ohm-Subwoofer.htm or this one http://www.woofersetc.com/p4995/ID12D4-V3--Image-Dynamics-12"-Dual-4-Ohm-V3-Subwoofer.htm depending on the amp you choose and go with a little cheaper amp to keep it under $300. This amp would work wired to 4 ohms and bridged, but you would need to cut the gain back a bit http://www.woofersetc.com/p6097/TXA3002--Cadence-2-Channel-High-Power-600-Watt-Amplifier.htm

I don't think I ever posted this here:


This is my RE Audio SE10 10" subwoofer in a ported box hooked up to a Hifonics Zeus 600 watt amp. Looks like this:


As far as my desire to be earth shatteringly loud it doesn't quite seem to do it. Heh, outside it doesn't anyway. I can turn it up and inside it is ridiculously loud. I bought these together from a guy for I think $225 or $230 and it came with the amp and box and sub all together. Now if I pop the trunk it gets way louder. Ha ha, I was driving around town last week with an end table in my trunk and a bungee holding the trunk down and I turned the sub on and DAMN it was even louder than normal. Otherwise, with the volume at a ridiculous level inside the car it's just making a bit of bumpity bump from the outside.

To be honest I haven't tried listening to it at a reasonable level like I would a home subwoofer, but given the sensitivity of the remote I have on it I'm sure it would provide quality bass to any music without overpowering. I'm not sure if I'm more limited by the subwoofer or the amp in this case for external volume. For those subs that are so ungodly loud that I can hear them down at the end of my street way before I see the car - are they like 10 times louder on the inside? If so forget that, that shit definitely sounds like it'll make you go deaf.

To make the bass loud on the outside, it helps to have a vehicle where the subs play inside the cabin. A hatchback or SUV are ideal, because the bass isn't isolated inside the trunk - the pressure more easily escapes out the windows.

You also need more cone area and/or motor excursion to move more air. And of course, this requires more power to drive. Yes, it can get a little rough in the cabin. Even if it's not actually deafening, it can give you a headache after a while.

Hmm, I always thought having it where they played inside the cabin would make them even more deafening inside the car. I haven't played it long enough or loud enough to give me a headache but I know some people are like...bass addicts or something. I like bass but I have reasonable limits and I turn it off after awhile. I like being able to hear the car and the road and with the sub booming I can't.

So basically then the weakest link in my setup is the amplifier? I'm not exactly sure what I would even upgrade to. It's not like there's a lack of car amps on my craigslist - if I wanted something it'd be easy to find a used one for a more reasonable price than new. Anything in particular you'd recommend or brands?

Having the subs in the cabin will be louder inside of the car as well as outside. The weakest link is your 10" sub. To move more air, you need more subs or bigger ones. It's all about cone area. Of course to push all of that air, you need to upgrade power as well.

The real question is: if it sounds good and loud inside the car, why do care what it sounds like outside?

duster_do_little wrote:

EatDirtFartDust wrote:

I think I'll get a seperate class D amp, and a single 12 inch dual voice coil sub so I can run them at two ohms. Any suggestions on a decent amp/sub combo like this for about 300, not including installation and enclosure?

Not a class D amp, but this sub http://www.woofersetc.com/p3170/RWE304---MB-Quart--12"-1000-Watt-Reference-Series-Subwoofer.htm wired to 2 ohms (dual 4 ohm voice coil), with this amp http://www.woofersetc.com/p6042/FXA1500--Cadence-500-Watt-Mono-Amplifier.htm which puts out 500 watts rms at 2 ohms. At that wattage you shouldn't need to worry about replacing your alternator. i put 900 watts rms worth of A/B amps in my friends vibe with no problems.

I will take these suggestions very seriously. thank you.

I suppose so AA, it would probably be too expensive for my tastes to make the sub loud outside the car. Hah, I still can't imagine the kind of bass you'd get from this:


Needless to say, you'd only need one of those...

EatDirtFartDust wrote:

duster_do_little wrote:

EatDirtFartDust wrote:

I think I'll get a seperate class D amp, and a single 12 inch dual voice coil sub so I can run them at two ohms. Any suggestions on a decent amp/sub combo like this for about 300, not including installation and enclosure?

Not a class D amp, but this sub http://www.woofersetc.com/p3170/RWE304---MB-Quart--12"-1000-Watt-Reference-Series-Subwoofer.htm wired to 2 ohms (dual 4 ohm voice coil), with this amp http://www.woofersetc.com/p6042/FXA1500--Cadence-500-Watt-Mono-Amplifier.htm which puts out 500 watts rms at 2 ohms. At that wattage you shouldn't need to worry about replacing your alternator. i put 900 watts rms worth of A/B amps in my friends vibe with no problems.

I will take these suggestions very seriously. thank you.

NP, I get a lot of my gear off woofersetc and they are great to work with. Cadence makes some really reliable amps and MB Quart makes some quality subs and speakers. The sub I posted is a somewhat older model from when they were still a german company. Since then, they were bought out by a mexican company and quality went downhill. That sub pounds in my friends 09 pontiac vibe. You can't see anything out of the mirrors because of the vibration. On the car audio forum that I belong to, the audiophiles all suggest cadence as a lower budget very reliable amp. They don't lie about output like many companies and they are made with quality components. The MB Quart sub is a great SQ sub as well. The ID that I posted is supposed to be a little better for SQ, but it costs more and lacks in the output.

Shintsu wrote:

I suppose so AA, it would probably be too expensive for my tastes to make the sub loud outside the car. Hah, I still can't imagine the kind of bass you'd get from this:


Needless to say, you'd only need one of those...

The problem with the 22" jackhammer is that it requires 3000 watts rms and to use it to its full potential you need 6000 watts rms. To get that kinda power you need multiple massive alternators, an amp to run it ($4000), multiple batteries, and a cap to send continuous power.

The car would basically become a show car and you wouldn't be able to drive it very much.

The jackhammer is completely unnecessary from a musical point of view. It's only sold to SPL competitors, or to people who want to make a lot of noise. A properly installed quality 10" sub - with enough clean power - is good enough for most concert level listening (115-125dB). Beyond that, you're making noise.

Yeah. I prefer a 12" because it will produce lower bass a little better. The 500 watt rms MB Quart that I posted is about the highest decibel you would ever want for SQ.

Right now I just have a 150 watt rms MB Quart 8". Not enough bass for me. At first I just wanted a sub to fill in my bottom end, and this works, but now I want more. It does sound great though. My next sub will probably be an ID, and I'll get a cadence to match it.

A 12" will sometimes play louder and deeper than an 8" or 10", but there are a few exceptions. Some high excursion subs out there will play just as low and loud as the larger diameter subs. Example: JL Audio 8W7, an 8" sub that really can hang with your average 12" sub: