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Man In The Box
126 Posts
Discussion Starter · #1 ·
Howdy all, its been a while.

I want to give my box a little auditory love, but realized I have a very limited scope of knowledge of audio systems. I've compiled here, what I know, and I was hoping someone with experience would help me fill in the gaps so I can know all I need to know about wiring up an audio system. so I was hoping an xB audiophile would be willing to help me out. A lot of my questions are more about "Why?" and "How?" than "Who?" "What?" "When?" and "Where?". This is so I, and hopefully others, can understand the concepts of audio electronics.

So here's what I'm wondering/assuming. Correct me if I'm wrong.

Subwoofers: are made to produce a low frequency sound that is harder to replicate with a smaller speaker size. The larger the speaker, the deeper the sound potential is.

The Material of the sub driver should be firm and lightweight. Most subwoofer cones are made of either a variety of polymers, Kevlar, carbon fiber, sandwiched layers of paper, ceramics, or light metals like magnesium or aluminum. Heavier cones produce better low frequency sound whereas lighter cones produce better mid-range sound.

Q1: What impact does the material of the sub cone have on it's performance and longevity?​

The Shape of subs are usually conical, octagonal, hexagonal, or square. At a given cone size, the square has a higher surface area.

Q2: Does this have any particular effect on the volume or clarity of the sub?​

Speaker Magnets are what move the speaker cone back and forth using polarity changes to the permanent magnet attached to the rear. These magnets usually are made of either ceramic or ferrite magnets, but could also be neodymium, strontium or AlNiCo. The movement of the magnets are what generates the pressure to the cone, producing sound.

Q3: Does the type of magnet affect the overall sound of the speaker?​

Voice Coils are either a Single Voice Coil(SVC) or a Dual Voice Coil(DVC). A SVC has only one set of terminals, meaning it can only be run at one ohm level, whereas a DVC can be run at two different ohm levels.

Q4: I assume this just helps with the flexibility of installation, and makes upgrading audio easier as the time comes. Would wiring dual coils on two separate channels compromise the sound or integrity of the coil?​

Impedance(Ω-Ohms) is the resistance in a system to alternating current. The higher the Ohms the more resistance there is in the system.

Q5: I know that this number must match the amplifier's, but why? And what does this rating represent as far as quality? Is it better to have low impedance speakers wired normally or higher impedance speakers wired in series to lower the impedance?​

Maximum Peak Power (W-Watts) is the amount of energy a sub can withstand in short bursts.

Q6: I assume this is to avoid blowing a sub. Does this have an effect on the sound quality?​

Maximum Root Mean Square (RMS) Power (W-Watts) is the highest amount of energy in which a sub can safely operate without overloading or distortion.

So this is the number that can ruin subs in the long run. I assume this is one of the more important factors in choosing a sub.​

Sensitivity (dB/W-Decibels per Watt) is the volume of sound produced with one W of energy.

Q7: Can this number be lowered or raised to better match the rest of the audio system, so the bass doesn't overpower the whole sound?​

Amplifiers: increases the power of the audio signal sent from the head unit by boosting the amplitude.

The Class of amplifier dictates how the sound gets to the sub from the audio source. Class A (Analog) amps constantly receive, boost, and send the source signal, which makes them very hot. Class A/B (analog) amps only boost about 50% of the total input sound but are much more efficient at exporting that sound. Class D (Digital) amps are relatively new, and achieve highest efficiency because they turn the subs off and on as necessary, but in doing so, produce a pulse that alters the harmonics of the audio signal.

Q8: In a car, does having a Class D amp attached to a subwoofer cause enough distortion to warrant choosing an alternate class?​

Power in an amplifier is what decides how big of a sub can be used. In a multi-channel amp, the power and resistance is divided between the channels, but if necessary, can be combined together to create a higher Wattage and Ohm rating. ex. A two-channel amp with 250 W and 2 Ω can be bridged to make a single 500 W, 4 Ω channel.

Q9: As the power (Wattage) of an amp increases, can it handle resistance more easily? What effects come from having too much or too little resistance at the amp?​

The Channel rating of an amplifier gauges how many outputs an amp can provide power to. For every channel in an amp, a certain amount of power and impedance exists. Mono amps have only one channel output, which is ideal for a single sub setup, but can be wired in series or parallel to power two subs if necessary. Two-channel amps provide two outputs for two separate subs, but can be "bridged" to provide power to a single sub at 4Ω. Four-channel amps have four outputs that can power four subs or speakers, or two, if bridged. Four-channel amps cannot be bridged to a single output.

Capacitor: stores a temporary electrical charge that can be released during periods of extreme power strain.

Crossovers: divide music into high, low and midrange frequency ranges, and then directs signals to specific amplifiers or speakers.

Bass Expanders: improve low frequency reproduction in a car audio system

Reconstruction Processors: reshape the output of factory stereo's preset equalization curves to ensure optimal performance out of aftermarket amplifiers and speakers.

Q10: My question on all of these, is how necessary are they in getting started with audio equipment. These seem to me to be tools of refinement for subs and amps, rather than crucial pieces of equipment.​

Theoretical Questions:
Q11: In this photo, a mono 2 ohm amp is wired to a DVC sub at 4 ohms. It looks to me like both sets of the DVC are wired in series. Does this work because the DVC splits the impedance between both coils by being in series?​
Q11-2: I guess this picture in contrast explains what I'm wondering. Because a DVC sub has two separate pairs of connections, does it function in a circuit in the same way as these two SVC subs?​

Guys and Gals, I realize I asked a lot of questions, like... A LOT. But I'm just trying to get all the specifics down so that when I get my moolah scraped together, I know exactly what I need, and how it all fits together. I hope having all this data helps some of y'all out. I know that putting it together has helped me a ton more than I thought it would.

:p That was a lot of typing. Whew!

These are the websites where I found the most relevant and informative data.

Speaker construction:

Subwoofer and Amp Facts:

2005 XB
27 Posts
Your higher end subwoofers will handle more than their suggested RMS. I ran two Image Dynamics 12" woofers at 50W above their RMS and they are still playing (~7 years later). Fifty watts is just an example, others run their subs at +100W over RMS.

Capacitors are just band-aids used to cover up electrical problems. If your electrical system is fine, then your sound system will be fine.
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