Misconceptions in Car Audio
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Silver Member Username: GeekbikePost Number: 306 Registered: Dec-04 | DEBUNKING CAR AUDIO MYTHS ------------------------- This is going to be the start of what could easily become a long list of common car audio misconceptions. Here goes: "Underpowering a subwoofer can hurt it." Think about this, what does volume controls do? It reduces the power to the speaker. How often do you blow a speaker by turning down your volume? A speaker can be run with 1 watt for a million years and it will not be damaged one bit. Damage will only occur when you crank up the gains on an amplifier to compensate for a lack of power, which brings me to my second point. "A 2000watt amplifier can be bought for $100." To achieve even 1/2 the stated amount of power, the signal being sent to the subwoofer will be so distorted and square, it will no longer be music coming out. Consequently, the amplifier will then burn out within 30 seconds. These ratings commonly come from companies including Boss, Lightning Audio, Legacy, Pyramid, etc. "If you're having electrical problems, a capacitor will solve all your problems." A capacitor might help stop your lights from dimming on the short term. But in the long term, your entire electrical system may fail. More stress will be placed on your alternator; causing it to break down faster and subsequently, the rest of the electrical system will suffer. A high output alternator is the only way to solve your problems. Also, the rule for capacitors is 1 farad for every 1000w peak power. A 100-farad capacitor corresponds with 100000w peak power. A greater load is placed on the alternator, causing it to burn out faster. Bigger is not better in this case. "There is such thing as the ultimate box." If there were such a thing, wouldn't everyone use it? Why would there even be more than one design? Every enclosure has advantages over others, but also has some drawbacks. Sealed will provide great quality, but suffers on how loud it can become. Ported offers loud, low-end extension but will take up a great deal more space. A Quasi-Eighth Order Series Tuned Dual Reflex Bandpass enclosure will insane SPL for the size, but are insanely difficult to design. "Speaker A is better than Speaker B." The speaker itself is only one part of the equation. If properly implemented, a $15 subwoofer can sound louder and better than a $100 subwoofer. Also, the design of every type of speaker will offer distinct advantages and disadvantages with regards to sound quality and sound pressure level depending on how it is enclosed. Because of the differences in response between different speakers in different situations, it is impossible to compare the two. "Cheap equipment is crap." This partially ties into the previous point, but how a speaker is implemented determines how it is going to sound. Additionally, if someone were working with a small budget, the money he has spent would have gone to the best system they could afford. There are always going to be worse products to buy, and in comparison to that, their system can be called good. |
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Gold Member Username: InsearchofbassPost Number: 3246 Registered: Jun-04 | good post knacko |
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hiphophipopanaymous Unregistered guest | "Underpowering a subwoofer can hurt it." This is true except because this is a list for beginners you didnt fully explain the consequences of sending to small of power with gains high can have, a.k.a. a clipped signal, which is basically a square signal that the sub is trying to draw from the amplifier that will damage the sub and knacko, i know you pretty much said this, but im trying to make it easier for a beginner to understand |
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Gold Member Username: Jonathan_fGA USA Post Number: 4227 Registered: May-04 | I feel the biggest problem in car audio is the installation and utilization of the equipment they have. I've seen tons of well installed systems that other people would say "that is crap" and I've seen top dollar component speakers installed in factory locations with no attention to sound deadening or even isolating the rear wave from the front. The point is that you can install a pair of Sony 6x9s in kick panels and make them sound better than poorly installed Focal, Dynaudio, DLS, and other high end component systems. Most people don't realize that and refuse to accept that. The install accounts for at least 75% of the final result. And it isn't just installing the equipment correctly, it boils down to choosing equipment that will work well with your setup. Most people aren't educated about this, and that's why this forum is here. |
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Bronze Member Username: Big_osoPost Number: 57 Registered: Jun-05 | this is going to be the most posted topic in this forum i garuuuuunty |
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Silver Member Username: IlluminatorPost Number: 777 Registered: Apr-05 | "Damage will only occur when you crank up the gains on an amplifier to compensate for a lack of power.." Nah, clipping may cause damage if the speaker is rated the same as the amp. If the speaker is 3 to 4 times underpowered there is virtually no way a clipped signal can damage the speaker. |
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Silver Member Username: Daddy_phat_sackPost Number: 289 Registered: May-05 | "nothing is better than jl audio" we all no that this isnt true. for example: dd, aa, adire, re, and eclipse- just to name a few |
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Silver Member Username: GeekbikePost Number: 307 Registered: Dec-04 | Jexxen, I know what you are saying, but I didn't want to add that in case someone didn't quite understand the concept and applied it to a lower powered speaker. |
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Silver Member Username: IlluminatorPost Number: 792 Registered: Apr-05 | Ah, all right. My bad. |
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Bronze Member Username: LettoMilwaukee, WI Post Number: 41 Registered: Jun-05 | Question. When an amplifier says that it has say: 500W RMS @ 4 Ohms Bridged. Does this mean with the gains all the way down, mid-way, all the way up? Where is the best place to have them if the RMS of your amp matches the RMS of your subs? |
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Silver Member Username: IlluminatorPost Number: 797 Registered: Apr-05 | It means with the gains matched to the voltage output of the headunit...and that's how it should be set up regardless of the setup of amps and subs. The gain is not a volume control. |
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Bronze Member Username: Bigred2069Post Number: 43 Registered: May-05 | how can u better "implement" your system, im always on a low budget, so what are some ways to make your system sound better, if you dont have the money to just buy the best stuff? |
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Bronze Member Username: LettoMilwaukee, WI Post Number: 43 Registered: Jun-05 | Can you explain to me how you do this? The gains on my amp (Rockford Fosgate 501S) are just knobs with nothing around them... What should I do about the gains? I know I have them wrong because the amp used to overheat a lot with my old subs (i haven't installed the new ones yet). Like turn them half way? or what? My deck is an Alpine CDA-9831 (60W x 4). |
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Silver Member Username: IlluminatorPost Number: 799 Registered: Apr-05 | Here's a way to do it without knowing voltage: 1. Turn the gain control on the amplifier all the way down. 2. Turn up the volume control on the source unit(Alpine) to approximately 3/4 of maximum. 3. Adjust the gain control on the amplifier until audible distortion occurs. 4. Adjust the gain control until audible distortion dissapears. 5. It should now be calibrated properly to the output of the source unit. I got these instructions from my user's manual to my MTX amp, it generally applies to all external amps, though some people prefer turning their headunit up to full volume then adjusting so they can get as loud as possible before distortion. |
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Silver Member Username: JeremycGermany Post Number: 748 Registered: Jun-04 | "Nah, clipping may cause damage if the speaker is rated the same as the amp. If the speaker is 3 to 4 times underpowered there is virtually no way a clipped signal can damage the speaker." Sorry but I have to disagree. As you know an undistorted (non clipped) audio signal is a sine wave, (AC signal) Since the current is always changing the speaker is always moving, and the voice coil has time to cool, as the siginal changes. A clipped signal on the other hand becomes a DC signal. Since the speaker freezes as this signal passes thru it causes the voice coil to heat up very very quickly. That heat is what is so hard on a speaker. So it doesn't matter what your amp and speaker are rated at. Both of those ratings are set for an AC signal. When you start sending a DC signal thru a voice coil those ratings no longer matter, and even the smallest amp can burn up a voice coil in a very short amount of time. |
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Silver Member Username: IlluminatorPost Number: 800 Registered: Apr-05 | "A clipped signal on the other hand becomes a DC signal. Since the speaker freezes as this signal passes thru it causes the voice coil to heat up very very quickly" A DC signal? That isn't possible. The clipped signal is still constantly changing polarity whereas direct current does not change polarity at all. If the amplifier was capable of producing DC then yes, the speaker would fail, but it simply doesn't. |
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Silver Member Username: IlluminatorPost Number: 801 Registered: Apr-05 | Here we can see the difference between AC(the white line) and DC(the yellow line).  Here is a clipped signal, obviously still changing polarity.  |
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Silver Member Username: ScubasteveAnnapolis, MD Post Number: 128 Registered: May-05 | Even if the signal is fully clipped, its still going from peak to peak dozens of times a second and the speaker doesn't lose much ability to dissipate heat. |
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Silver Member Username: GeekbikePost Number: 312 Registered: Dec-04 | A fully clipped signal cannot exceed twice the power of the unclipped signal. For example, a 100w unclipped signal cannot exceed 200w when fully clipped. If a subwoofer rated at 500w is coupled with that amplifier, there is not enough power to even heat up the voice coils. A fully clipped signal will move peak to peak dozens of times per second as scuba steve stated, but the air cannot move fast enough to flow back into the motor structure before it is pushed out again. The movement of air is what cools the voice coils and with the quick movements of the cone, the air cannot fufill its job. This leads to heating of the voice coils and eventually, failure. |
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Silver Member Username: IlluminatorPost Number: 802 Registered: Apr-05 | Ok, if you were to use equal power from a square wave signal and a 'clean' signal they would both produce the same amount of power dissapation and therefore the same amount of heat output. The only difference is that the clean signal causes the speaker to have a higher excursion so it gets better cooling. This is why I said it may cause damage to the speaker. But keep in mind this is with the same amount of power the speaker is able to handle. Underpowering a speaker causes even less heat buildup and consequently nearly no chance of failure. EDIT: I didn't see Knacko's post when I originally posted. I fully agree with him but i'll keep my post anyway... |
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Bronze Member Username: LettoMilwaukee, WI Post Number: 44 Registered: Jun-05 | Jexxen, I have a gain on each channel, since my speakers are bridged on my amp, I'm using both of them. Do I have to adjust them both at the same time or do I do one at a time? |
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somethingredicolousihavetomakeup Unregistered guest | A Quasi-Eighth Order Series Tuned Dual Reflex Bandpass enclosure ---whats this, sounds crazy...are they hard to design? |
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Gold Member Username: InvainMichigan United States Post Number: 2983 Registered: Aug-04 | "Ok, if you were to use equal power from a square wave signal and a 'clean' signal they would both produce the same amount of power dissapation and therefore the same amount of heat output. The only difference is that the clean signal causes the speaker to have a higher excursion so it gets better cooling." The clipped signal also has very high distortion, and will sound terrible when played through a sub.  |
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Silver Member Username: IlluminatorPost Number: 812 Registered: Apr-05 | Letto: I'm going to guess you would want to adjust both at the same time. Joe:Truly! But that's not what I was trying to indicate! |
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Gold Member Username: InvainMichigan United States Post Number: 2985 Registered: Aug-04 | I know, haha. Just thought I'd point that out. I have a thing against distortion... |
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Gold Member Username: InvainMichigan United States Post Number: 2986 Registered: Aug-04 | Letto: Like jexxan said, both will need to be adjusted at the same time. You can get one gain set, and then set the other one the exact same as the first, instead of going through the trouble of listening and toying around with both. |
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Silver Member Username: 54danny54Post Number: 532 Registered: Nov-04 | hey Knacko...form ya post that started this was it from mythbusters by any chance lol....they say debunking myths alot lol |
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Silver Member Username: JeremycGermany Post Number: 753 Registered: Jun-04 | Yes an AC signal can become a DC siginal. You ilistrated that very well with your own pictures. What do you think the flat part of your second AC wave is? |
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Silver Member Username: MixneffectOrangevale, Ca. USA Post Number: 225 Registered: Apr-05 | Knacko, Underpowering a subwoofer can hurt it." Think about this, what does volume controls do? It reduces the power to the speaker. How often do you blow a speaker by turning down your volume? A speaker can be run with 1 watt for a million years and it will not be damaged one bit. Damage will only occur when you crank up the gains on an amplifier to compensate for a lack of power, which brings me to my second point. I beg to differ. Heres why: Underpowering a subwoofer can hurt it because it is said wrong. It is "using a crappy lower power rated amplifier at high volumes will damage subwoofers". What is the difference? Well, use a high quality class A amplifier that has control on its power curve which maintains it evenly from off to max. Even if this amp is rated at 100 watts and you use a subwoofer that can handle up to 500 watts of continous power (continous, not RMS), it will not damage the subwoofer because the woofer gets clean managed power even at full blast. Now, take an average 100 watt amp and run it full blast through a subwoofer that can handle up to 500 watts (or even 100 watts for that matter) will damage the sub. Why? Because most amplifiers will put out clean power only up to 70% of its capacity. After that point it will redline (just like a car motor) and the power will decrease and it will emit garbage results. Thats why people say lower powered amps may damage speakers, because they take in consideration that most people cannot afford a $5000+ amplifier that is built right. |
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Silver Member Username: MixneffectOrangevale, Ca. USA Post Number: 226 Registered: Apr-05 | Some high end amps (typically in home audio) will have a governer that doesnt allow you to turn the volume up past its manageable range. Manufactures will then under-rate the amp to be able to market their amp as a quality product. There is alot of other engineering involved in maintaining quality, even, and clean power. I am not an electronics engineer, but this is how I can explain myself. |
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Silver Member Username: MixneffectOrangevale, Ca. USA Post Number: 229 Registered: Apr-05 | Johnathan, I want to comment on your statement: Posted on Tuesday, July 05, 2005 - 10:46 pm: -------------------------------------------------------------------------------- I feel the biggest problem in car audio is the installation and utilization of the equipment they have. I would like to make a comment with an analogy. For instance the difference between a teen girl learning to put on makeup and an experienced woman/artist. Most people throw in designer brands together and claim they have SQ. You re right! It takes experience and design, but most of all a seasoned EAR. I hope there arent any teenage girls reading this and therefore got offended. (lol) I am sure you re all beautiful. |
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Silver Member Username: GeekbikePost Number: 317 Registered: Dec-04 | With my second point, I stated that someone with a low powered amplifier will crank up the gains to compensate for that lack of power. The same thing would closely apply with the volume control. Both will be sending a clipped signal to the subwoofer. Class A amplifiers are very rarely used in car audio, if ever, so I didn't even think of taking them into account. The only thing I really know about them is the super low efficiency (20 or 30%). |
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Gold Member Username: InvainMichigan United States Post Number: 2993 Registered: Aug-04 | You could use a class A/B for mixin's example. At low volumes, the sub may be actually underpowered, but since the volume is low, no harm done. When you crank it though, the amp switches over to class B, and becomes more effecient with the higher the volume. With the volume cranked, the amp can be powering the sub just fine. Your gonna get the highest amount of power from an amp right before it goes into clipping, and with a high quality amp, you can underpower a sub and still turn the volume up a decent amount. Most high quality hand made amps are pretty hard to drive into clipping. |
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Silver Member Username: IlluminatorPost Number: 822 Registered: Apr-05 | "Yes an AC signal can become a DC siginal. You ilistrated that very well with your own pictures. What do you think the flat part of your second AC wave is?" My bad, I thought we were talking constant DC the whole time. I phail. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7870 Registered: Dec-03 | on a side note; "Cheap equipment is crap." in regards to this statement, price can reflect the cost of better materials and R&D of a product. You won't get world class performance from a $70 amplifier, but price is not, as noted, a direct reflection of quality. I could charge $900 for a really crappy amplifier just as easily as I could for a good one. The point is, while expensive doesn't equal good by definition, you'll never find "too good to be true" prices for really good equipment. the cost of development and production will always be reflected in the price in some way. you get what you pay for, so don't be afraid to pay a little more for products with proven reliability, durability, and performance. that's not to say you can't build a good system on a budget you just need to shop wisely. as for too little power, as noted on BCAE1 and repeatedly here, clipping is what will damage a speaker, which is usuallyc aused by trying to compensate for a lack of sufficient power by setting the input sensitivity of the amplifier too high and overdriving the input stage of the amp as a result. This causes DC voltage across the coils which can cause thermal damage. This distortion also causes a loss of linearity in cone travel, which can cause physical damage to the coil winding and fray the wire wrap, causing teh coil to short or freeze up. Either way you can kill a sub with an amplifier rated for less than the sub's power handling ability as rated if you set it up improperly. That being said, simply using a 50 watt amp on a 100 watt sub (example) isn't going to cause any damage at all. As the original post stated, that's like using a lower volume setting on a larger amp. same result. less power. every time you double the actual power from the amp, you gain +3dB from the speaker within operating limits. you have to increase the power from the amp by between four to ten times to reach twice the audible volume, and while an amp may be rated for 1200wRMS, that's usually with a non inductive dummy load on a tone generator. Music is dynamic and the average power consumption of an amp playing music is going to be lower than that of the same amp playing a generated tone on a dummy load instead of a speaker.. all of this comes down to mean that your ttypical listinging levels in a car, even when ya 'turn it up' is using only a small portion of the power the amplifier can really provide, and a mere fraction of the amp's rated power. you're most likely using about 100-200 watts on average when you have a loud car stereo and you're listening to music.. even if your system is rated for say 3000 watts RMS. just some things to consider. |
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Silver Member Username: FfxdevilarmsDubuque, Iowa United States Post Number: 503 Registered: Jul-04 | I have a question for you Glasswolf. If that is ture about it only using that many watts on average, why do you and most other people still recommend a HO Alt to pretty much everyone that is using 1000 watt rms amps???????? |
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Silver Member Username: IlluminatorPost Number: 824 Registered: Apr-05 | Chris, an amp that pulls 1000w RMS is pulling about 145 amps. Most stock alts put out below 80 amps. That equals a problem if you don't upgrade your alt. |
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Gold Member Username: InvainMichigan United States Post Number: 2995 Registered: Aug-04 | 145 amps? Depends on the amp. James Longo measured his Orion HCCA 250 G4 at over 900 wrms, and the G4's have 2 40 amp fuses. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7871 Registered: Dec-03 | the amount of current an amplifier draws depends on it's class, design, and basically it's efficiency. on average, digital amps (class D or T) are about 80% efficient class AB are around 50-60% efficient. What I recommend with any audio system for an alternator is to use proper cable sizes and keep the stock alternator at first. If you find you have voltrage issues after trying the system, then upgrade the alternator to something rated to supply enough current for the system at full output. Then you never have to worry about having enough current regardless of how the system is used. Extra batteries on an isolated circuit are also neccessary if you burp the system at SPL events or run the system for long periods with the car turned off at higher volumes. |
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Gold Member Username: James1115Wilton, Ct Post Number: 3542 Registered: Dec-04 | it all depends on the efficiency of the amp to get current draw. |
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Silver Member Username: IlluminatorPost Number: 825 Registered: Apr-05 | Yeah, I calculated that by using the RMS, doubling it, then dividing by 13.8v. Just an estimate, heh. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7874 Registered: Dec-03 | "Chris, an amp that pulls 1000w RMS is pulling about 145 amps. Most stock alts put out below 80 amps. That equals a problem if you don't upgrade your alt." a "1000 watt amplifier" (at a given load) will draw about 100A if it's class D. It'll draw about 135A or so if it's a class AB amplifier, at full output. Again though, full output equates to a dummy load and a signal generator at 100% full volume (peak output sine wave) Most stock alternators are between 60-100A, yes but that doesn't matter. What matters is the amount of reserve current those alternators have, which is anywhere from half to almost none. When you have nearly no reserve current already, and you go adding amps that draw arpound an average of 50A or more continuously, you have issues, which come out as a fried alternator, battery, and malfunctioning car or audio system, speaker damage, etc. this is why so many people need larger alternators. they overtax the one they have now because cars rely so heavily now on computers and electrical accessories. HVAC, power locks, windows, computers, wipers, lights, etc.. it all uses current. even engine management, fuel injection, fuel pumps, ignition systems, etc. on a side note, the 250HCCA is a class AB amp. less efficient, but better for full range than class D. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7875 Registered: Dec-03 | if you want to guesstimate current draw, take the amplifier's RMS wattage, divide by 12, then * by 1.2 for class D, or by 1.4 for class AB that'll be your RMS current draw factoring efficiency based on amplifier class which is fairly accurate if you compare to the mfgr spec sheets |
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Silver Member Username: IlluminatorPost Number: 833 Registered: Apr-05 | I see, but shouldn't the setup be configured to handle maximum draw to prevent damage? |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7877 Registered: Dec-03 | not if you never intend to drive the system that hard not everybody wants to go deaf in their car.. some people just want a moderately loud, good SQ system.. that emans good reserve power for brief transients, but generally a low to moderate power consumption for daily use with good choices in the gear used. that doesn't usually mean the need for 5000 watts of amplifiers and three 200A alternators with a bank of deep cycle batteries in the trunk. horses for courses. choose the gear you use based on what you want out of the system.. you'll get the most from your investment without overspending or skimping out that way. |
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Bronze Member Username: Big_osoPost Number: 86 Registered: Jun-05 | you wouldnt need tree 200 amp alts for 5000 watts anyways just a good 250 amp and maybe two red tops if your using it everyday |
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Silver Member Username: IlluminatorPost Number: 836 Registered: Apr-05 | Ah, all right. Thanks Glass. |
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Gold Member Username: InvainMichigan United States Post Number: 2997 Registered: Aug-04 | "145 amps? Depends on the amp" I meant to put "class" after amp. My only point was that 145 amps seemed high for an amp pulling 1000 wrms. Glass, I got a question. Yes, I know how amps work and all the different classes, and yes I own the Orion 250. I was just wondering, when the Orion is played closer to full output, it's operating as a class B amp. The average for class b is about 50 - 60 % effeciency though, right? What I don't understand, is how with a total of 80 amps worth of fuses, the Orion can push 800 wrms, and even more at higher voltages. At 800 watts rms with 12 volts, the Orion would be operating at almost 80% effeciency. Is the G4 just built that good, and very effecient, or am I missing something? |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7879 Registered: Dec-03 | "you wouldnt need tree 200 amp alts for 5000 watts anyways just a good 250 amp and maybe two red tops if your using it everyday" wrong. 5000 watts of class AB amplifiers will draw about 625+A at full output. You need to factor in amplifier efficiency if you're going to figure for peak output of a system. with the Orion, the fuses are rated for RMS output with music. the current draw will be lower than if you were using a signal generator and a dummy load instead of a reactive load like a speaker connected to the amp. manufacturers use the output ratings using the signal generator etc to maintain a relatively comparable system as well as to attract people with larger numbers. The reality is you're not going to be getting 800 watts out of that amp in most situations, and just about never for more than a brief moment, which brings up another thing to consider.. read the bcae1 section on fuses and fuse ratings. you'll see that a 50A fuse doesn't blow the instant it sees 50A of current, or even 60A of current. a fuse is rated to handle a rated % of overcurrent for a specified amount of time. as that % increases, the time decreases, so a dead short will pop the fuse instantly, whereas a 20% overdraw may keep the fuse for as long as 5 minutes. What this means is that the Orion can actually draw more than 80A of current for a period of time without damaging the fuses, but you wouldn't be able to sustain that amount of draw indefinately, which plays right into the dynamic nature of the music signals being produced with a car stereo amp. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7880 Registered: Dec-03 | "every day use" is too vague of a term. If the person competes in SPL events or even street bass-off silliness, he's going to need an electrical system that can handle the draw of the stereo. If he's using an isolated battery, the yellow would be a better choice than the red top as well. Again, as I noted, the alternator size is going to depend on a number of factors. listener habits, current draw of the system, alternator reserve, and draw of the car itself.. there's no single answer for all cars and systems, Oso. |
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Gold Member Username: Taylor17Kopperl, Texas Post Number: 2430 Registered: Jan-05 | I have alt problems evidently... I did you're little gestamate thing, and just with my amp that is powering my subs... not including my amp to the speakers, I'm pulling 93.33333 The stock alt on my truck is 105A I think... 1998 chevy 1500. How do I find the alts reserve? |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7890 Registered: Dec-03 | if your lights aren't dimming and voltage is steady I really wouldn't worry about it. 93A is a peak draw. you won't pull that all the time, if ever. if you do need to upgrade the alternator I'd go to a 200A range. |
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Gold Member Username: Taylor17Kopperl, Texas Post Number: 2434 Registered: Jan-05 | Lol... the lights dimn real bad... I've just been putting buying a HO alt off, but if it can hurt my equip I'll prob look in to getting one. Yeah, I prob wouldn't go less than 200A just for the sake of upgrading. |
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Gold Member Username: Taylor17Kopperl, Texas Post Number: 2435 Registered: Jan-05 | Oh, and the voltage has actually dropped to 9V one time, but usually stays around 11.5V when running. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7897 Registered: Dec-03 | yeah the low voltage causes amps to clip and as a result, you'll shred the speakers good idea to upgrade |
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Silver Member Username: FfxdevilarmsDubuque, Iowa United States Post Number: 512 Registered: Jul-04 | I understand that there is high current draw with 1000 watt amps, but why did you say that it would only produce 100-200 watts on average?? |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7913 Registered: Dec-03 | because "1000 watt amplifer" means 1000 watts at full power, full volume, with a sine wave and non inductive load. most people don't play their system at 100% volume all the time.. they play it at a fraction of full volume, which means the amplifier is only putting out a fraction of it's power. remember every time you double the audible volume, you're using four to ten times the power.. that means at even half of the full output of the amp, you're only using a quarter to a tenth of it's actual power rating. make sense? |
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Silver Member Username: AlpineuserWinchester, TN Post Number: 675 Registered: Mar-05 | this is all according to how you have your amp setup really. I mean if u have a 1200wRMS amp and u have it set to produce 34V (ie setting the gains) at 1/4 volume then u will be producing full power at 1/4 and anything above that will start to become a clipped signal. |
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Gold Member Username: Taylor17Kopperl, Texas Post Number: 2478 Registered: Jan-05 | Good point. |
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Bronze Member Username: LettoMilwaukee, WI Post Number: 65 Registered: Jun-05 | Question. Where do you measure or find the voltage from your HU in order to set the gains properly? Once you have this measurement and know how much voltage your HU puts out, how do you go about setting the gains? I was told earlier about setting your HU at 3/4 volume adjusting til audible distortion occurs, then turning it down til it disappears. This is how you can do it kinda like makeshift, not knowing the voltage, correct? So how would you do it knowing the voltage? |
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Silver Member Username: TboltCollipark, GA Post Number: 138 Registered: Dec-04 | you could connect a voltmeter to the hu preouts and measure the voltage that way. On your amp, the gain should have a voltage range like 500mV-16V you match the output from your hu to the gain on the amp. You will set the gain perfectly everytime. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7918 Registered: Dec-03 | use a DMM and a scope. if the gains are set PROPERLY, the amplifier should never clip. "gains" aren't a volume or power control. They're meant to be used to match the line voltage to the input stage of the amp so you don't overdrive the amplifier and damage both the amp and speakers. |
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Bronze Member Username: LettoMilwaukee, WI Post Number: 66 Registered: Jun-05 | Can I measure the voltage at the end of the RCA's from the HU? Or is that different? Also, I don't think my Amp has numbers or anything around the gain controls, is there a way to know the voltage that it is at? I don't have a users manual because it was the display model and the only one left at the store... maybe online or something? It's a Rockford Fosgate 501S. By the way, thanks guys... |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 7925 Registered: Dec-03 | www.bcae1.com has several guides to doing all of this in different ways. this thread is getting way too long though. need to start new topics for new questions |
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Silver Member Username: TboltCollipark, GA Post Number: 145 Registered: Dec-04 | glasswolf, how much does a scope cost |
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