 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Driving, Maintenance, Tuning / Car Audio / May 2004Is this Overkill?
Forgive my noobiness. You all have been so helpfull so far. I'm currently considering a sub/amp package. Right now I am running two Infinty 6x4 component plate speakers up front and two Infinty 6x9 3-way speakers for rear fill. These are running only off of the HU. A Pioneer DEH-P660. My question is if I get two Infinity Kappa 10" DVC subs and feed them 250w RMS apiece from a RF Punch amp will this be overkill for this set-up? Or will the sound still be able to match up well enough? I've been reading through a lot of threads on Amperage today and read a lot of recommendations saying that 75-100 watts to a single 10 or 12 inch sub can be quite loud and satisfying. I've never had subs before so don't know what these set-ups sound like and if I'm really just overdoing it on the bass end of things. The thing is, I have the money to spend to go with the high power/2 subwoofer deal. I'm not going to run an amp to the 4x6's though. What you guys think? And whats the benefit from DVC over a single voice coil sub? Thanks again! There is a reason you have gain controls on your amp.. i don't think that would be over kill, just set it to a decent level. Adair "Dan Erick" <daniele@heartland-paper.com> wrote in message > Forgive my noobiness. You all have been so helpfull so far. > [quoted text clipped - 17 lines] > > Thanks again! The gain control is not a volume knob... n8 > There is a reason you have gain controls on your amp.. i don't think that > would be over kill, just set it to a decent level. [quoted text clipped - 23 lines] > > > > Thanks again! Why do you say that..?? When I turn the gain control the volume goes up and down..... http://www.installer.com/tech/gains.html Why do folks insist it is NOT a volume control..?? > The gain control is not a volume knob... > > n8 I guess if you had the amp gain set nearly to one extreme or the other, you might have problems, but I use it as a "volume knob" too, to adjust relative volume between different speakers. Once you've found the optimum gain setting to maximize output power without distortion, any gain setting below that should be fair game. Scott Gardner >Why do you say that..?? When I turn the gain control the volume >goes up and down..... http://www.installer.com/tech/gains.html [quoted text clipped - 3 lines] >> >> n8 > I guess if you had the amp gain set nearly to one extreme or the > other, you might have problems, but I use it as a "volume knob" too, I dont use the gains AS a volume control per se... But IT IS just as much of a volume control as the headunit volume control is .... > to adjust relative volume between different speakers. Once you've > found the optimum gain setting to maximize output power without > distortion, any gain setting below that should be fair game. Without distortion..??? Would you set the amp gain so that the radio CANT distort the speakers..?? if so, most folks would NOT be happy with those gain settings... I explain it here... http://www.installer.com/tech/gains.html Eddie > Scott Gardner > [quoted text clipped - 5 lines] > >> > >> n8 No, I don't set the amp gain so low that the deck is incapable of sending distortion to the speakers - I don't think that's possible. If you turn the radio all the way up, the output from the radio WILL be distorted, and there's no gain setting on the amp that will "remove" this distortion. I initally set the amp gain to a very low level, so that even with the head unit all the way up, the amp isn't being driven to full volume. Then, I gradually increase the head unit volume until I hear that the head unit is beginning to distort. I back it off a little and record the volume level. That's where the head unit is producing maximum output without audible distortion. Then, with the head unit at that point, I turn the amp gain up until I hear distortion from the amplifier (or the speakers start audible breaking up). At this point, I now have the amp gain set such that the amp is beginning to distort just as the head unit is beginning to distort. The last step is to adjust the gain on the amp so that the speaker volume is in balance with the rest of the system. In this last step, I only turn the gain DOWN, never up. (kind of like when you're using an equalizer, it's better to cut down the peaks than it is to boost the dips). The only thing the owner of the stereo has to remember is not to turn the head unit up beyond the point where the head unit begins to distort. That's always a risk you have to take since, as you said, if you set the amp gains so low that the user can NEVER clip the amp, you'll never be able to drive the amp to full volume. Scott Gardner >Without distortion..??? >Would you set the amp gain so that the radio CANT distort the [quoted text clipped - 4 lines] > >Eddie > No, I don't set the amp gain so low that the deck is incapable of > sending distortion to the speakers - I don't think that's possible. Sure it is. Suppose you have a 2v head unit. Set your amp's gain to "8 volts". > If you turn the radio all the way up, the output from the radio WILL > be distorted, and there's no gain setting on the amp that will > "remove" this distortion. You're assuming all head units clip at max output. >> No, I don't set the amp gain so low that the deck is incapable of >> sending distortion to the speakers - I don't think that's possible. > >Sure it is. Suppose you have a 2v head unit. Set your amp's gain to "8 >volts". See below. >> If you turn the radio all the way up, the output from the radio WILL >> be distorted, and there's no gain setting on the amp that will >> "remove" this distortion. > >You're assuming all head units clip at max output. Well, I haven't come across one yet that doesn't. After all, the preamp in the head unit is just another amplifier in the signal chain, and it's subject to clipping just like any other amplifier. It would make setting gains easier if you could always turn the head unit up all the way to its maximum volume without any distortion, but that's not usually the case. Regardless, it doesn't matter to me whether the deck distorts at max output or not. If it does, I back it off until the distortion stops and proceed with setting the amp gain. If the deck doesn't ever distort, then I would leave the head unit volume at maximum and proceed from there with setting the amp gain. As far as recording levels in the music go, I use a variety of recordings to set amp gains. In most of the recordings, I've normalized the RMS levels to -3dB, which is typical of modern CD recordings. I also have a few recordings from my vinyl records that are closer to -5 dB RMS to simulate "softer" recordings. I have no control over what the user plays - it may be something so poorly recorded that the RMS level is -9 or -12 dB, or it may be so badly mixed that the RMS level is 0 or -1 DB. All I can do is set the gains using typical recordings and go from there. Scott Gardner Scott, you may be mistaken! > >You're assuming all head units clip at max output. > Well, I haven't come across one yet that doesn't. Most amplifiers can be driven to full output and clipping with a little over 1 volt of input signal... Most headunits can do at least 2 volts easily... many nowdays MUCH MORE.. So the headunit clipping isnt really an issue UNLESS you tuen the amp gain down so much that the headunit signal is drasticly reduced by the amp... Eddie Runner >Scott, >you may be mistaken! [quoted text clipped - 11 lines] > >Eddie Runner We're talking about two different things. I agree that any modern head unit will be able to drive just about any amp into clipping. What I'm talking about is the quality of the signal from the head unit. If you crank the volume all the way up on the head unit, you're likely to get a distorted signal from the head unit, since you will probably be clipping the preamp in the deck. To maximize the S/N ratio out of the deck, I like to use the maximum head unit volume setting I can use before distortion sets in from the preamp in the line-out stage of the head unit. This has nothing to do with whether or not the deck is capable of driving the downstream amplifier into distortion. If your head unit volume goes from 0 to 100, do you want the downstream amp to be driven to full volume when the head unit volume is at 20? Of course not - you want the widest range of usuable volume settings at the head unit, while still being able to drive the downstream amplifier to full volume. The only reason I wouldn't match the gains so that the downstream amp is at full volume when the head unit is at 100 is that by the time you turn the head unit's volume control up to 100, the signal from the RCA preouts will probably be pretty noisy. So, I find the maximum volume setting on the head unit that doesn't produce audible distortion **from the preamp stage in the head unit**. Let's say that number is 85. Then I set the gain on the amp so that when the head unit is at 85, the amp is being driven at the full volume possible without clipping. If this results in the subs (or whatever the amp is driving) being too loud for the rest of the system, I then turn the amp gain down until everything is in balance. Then I remember not to turn the head unit up above 85. Scott Gardner > We're talking about two different things. I thought we were talking about adjusting amplifier gain contrls > I agree that any modern > head unit will be able to drive just about any amp into clipping. before the head unit clips > What I'm talking about is the quality of the signal from the head > unit. if its not clipping its probably OK. headunit distortions is not something most folks worry about at all... (while using external amps) > If you crank the volume all the way up on the head unit, you're > likely to get a distorted signal from the head unit, since you will > probably be clipping the preamp in the deck. And my point is YOU WILL NEVER DO THAT! Most amps can EASILY be driven by a head unit without the headunit being driven too hard or clipping or distorting at all... EASILY! > To maximize the S/N ratio out of the deck, I like to use the maximum > head unit volume setting I can use before distortion sets in from the > preamp in the line-out stage of the head unit. Thats retarded! The head unit should be set so the headunit has a useable swing to the volume range.... > This has nothing to do > with whether or not the deck is capable of driving the downstream > amplifier into distortion. Sure it does, because if the headunit can drive the amp to clipping before the headunit clips, then you probably wont ever have to worry about the headunit clipping.... I certainly dont worry about it. > The only reason I wouldn't match > the gains so that the downstream amp is at full volume when the head > unit is at 100 is that by the time you turn the head unit's volume > control up to 100, the signal from the RCA preouts will probably be > pretty noisy. I would set it so the amp gets loudest at about 75% of the radios volume setting... it has nothing to do with the RCA peouts being noisy.... Why would they be noisy? Almost sounds like you havent really worked with many headunits and amps.. ;-) Eddie Runner >> We're talking about two different things. > [quoted text clipped - 47 lines] >volume setting... it has nothing to do with the RCA peouts being >noisy.... Why would they be noisy? Why would they distort? Is it so hard to believe that the internal preamp might start to distort before the volume knob reaches maximum? >Almost sounds like you havent really worked with many headunits and >amps.. ;-) > >Eddie Runner Look at Mark's post about the tests done on head unit outputs. Several of the units tested *did* distort before the maximum volume on the knob was reached. What's so wrong with setting the gains so that the amp is driven to maximum volume before that point on the head unit's pre-outs (if the deck in question has such a point) is reached? You say that the gains should be set so that the head unit has a "usable swing" to the voltage range. Well, my method maximizes that swing. You set the gains so that the amp is fully driven when the head unit is at 75% volume. Where do you get 75%? Is it just a number you pulled out of your hat? I've worked with plenty of head units and amps (although we don't seem to disagree on the amp part of the procedure - just where to set the volume on the deck), and I have heard head units that put out a distorted signal before maximum volume was reached. All I'm doing when I set my gains is making sure that the head unit will drive the amp to full volume, while maximizing the usable range on the volume knob. Honestly, it sounds like the only difference in our methods is that you choose 75% as an arbitrary volume setting on the head unit, while I choose to find where the head unit starts to distort. If you're never worried about the head unit distorting, why not use 90% or 100% instead of 75% and give the user a wider volume range on the knob to work with? Scott Gardner > Look at Mark's post about the tests done on head unit outputs. > Several of the units tested *did* distort before the maximum volume on > the knob was reached. Ok, if a head unit CLIPS near the point where the volume control is ALL THE WAY.... It would be likely the amp could STILL CLIP FIRST! So my point is, the headunit clipping is IRRELAVENT!! Only a fool would turn the amp gain down so far as to have to turn the headunit to MAX...!! I guess you still havent read my paper on gains, or you would have already seen this... http://www.installer.com/tech/gains.html > What's so wrong with setting the gains so that > the amp is driven to maximum volume before that point on the head > unit's pre-outs (if the deck in question has such a point) is reached? Only a real dumbass would EVER set them that way! Not something I spend time worrying about... ;-) > You say that the gains should be set so that the head unit has a > "usable swing" to the voltage range. Yes, a swing that is comfortable to the user.... > Well, my method maximizes that > swing. MAXIMUM..?? So the user has to turn and turn and turn the volume knob before he gets it loud..?? If you had read my paper you would see that I think most folks like to be comfortable with the volume knob, thay dont want the system BLARRING when they barely move the volume control, and they dont want to have to crank it and crank it and crank it to change from a low setting to a high setting or from a high setting to a low setting...... It should be a comfortable swing. > You set the gains so that the amp is fully driven when the > head unit is at 75% volume. Where do you get 75%? Is it just a > number you pulled out of your hat? For most folks around 75% is a pretty comfortable swing.... > I've worked with plenty of head units and amps Not as many as me! Its been 30 years for me now...I still install nearly every day.... > (although we don't seem > to disagree on the amp part of the procedure - just where to set the > volume on the deck), SET..?? I let the customer SET it wherever he likes it... there is no SET place that is right or wrong, in fact it is best if he can turn it UP and DOWN!! ha ha ha > and I have heard head units that put out a > distorted signal before maximum volume was reached. Why would you have ever had to turn a headunit up that far..?? Set it up my way http://www.installer.com/tech/gains.html and you wont ever have those problems again..... > All I'm doing > when I set my gains is making sure that the head unit will drive the > amp to full volume, while maximizing the usable range on the volume > knob. MAXIMIZING....????? Why????? And that sounds like your setting the headunits volume as high as it will go... NOT A GOOD procedure as some recordings or sources may be HOTTER or may be LOWER in volume, which could mean the headunit wont play as loud since the volume control is already MAXXED OUT. The 75% I recomend would give you plenty EXTRA swing if you ever needed it because of a low recording.... > Honestly, it sounds like the only difference in our methods is that > you choose 75% as an arbitrary volume setting on the head unit, while > I choose to find where the head unit starts to distort. And thats why YOUR meathod is a bad one... MY WAY the headunit is not near its limits YOUR WAY, its about to stressss out!!! ha ha ha > If you're never worried about the head unit distorting, why not use > 90% or 100% instead of 75% and give the user a wider volume range on > the knob to work with? Because it is manytimes uncomfortable for a user to have to go UP and UP ad UP to change from soft to loud (or vise versa).... AND REASON 2, becuase a softer source or recording may need to go up higher than usuall, and if your already MAXXED OUT then that cant happen... Eddie Runner http://www.installer.com/tech/gains.html > >You're assuming all head units clip at max output. > > Well, I haven't come across one yet that doesn't. Most of them nowadays don't - at least not until the very highest of the high. Some of the Pioneer decks don't at all. > After all, the > preamp in the head unit is just another amplifier in the signal chain, > and it's subject to clipping just like any other amplifier. Different point altogether. The reason amplifiers are subject to clipping is because we SET them that way. If you set your amplifier to the "8 volt" mark, it won't clip. > It would > make setting gains easier if you could always turn the head unit up [quoted text clipped - 6 lines] > distort, then I would leave the head unit volume at maximum and > proceed from there with setting the amp gain. I wouldn't do it that way. It doesn't give you any cushion. Oftentimes, you need that cushion to get quiet recordings to reach their maximum level. I have several cds that are just too quiet. To illustrate, if you check out some of the decks on the carsound.com review site, you'll find that the Pioneer DEH9300 and Rockford RFX 9000 did not clip. They didn't perform this test for all the HUs they tested though. But all the Kenwood ones appear to clip right away, and so does the Alpine they tested.  SignatureMark remove "remove" and "spam" to reply > > >You're assuming all head units clip at max output. > > [quoted text clipped - 25 lines] > you need that cushion to get quiet recordings to reach their maximum level. > I have several cds that are just too quiet. So some of them do, and some of them don't. It really doesn't change my procedure, though. I'm still trying to find the maximum deck output voltage before the onset of distortion. For decks like the DEH9300 and the RFX9000, that point just happens to coincide with the maximum volume position on the knob. Scott Gardner >To illustrate, if you check out some of the decks on the carsound.com review >site, you'll find that the Pioneer DEH9300 and Rockford RFX 9000 did not >clip. They didn't perform this test for all the HUs they tested though. >But all the Kenwood ones appear to clip right away, and so does the Alpine >they tested. >> >You're assuming all head units clip at max output. >> [quoted text clipped - 25 lines] >you need that cushion to get quiet recordings to reach their maximum level. >I have several cds that are just too quiet. Well, it depends on what you consider "too quiet". Earlier, I said that I use quite a few music tracks to set gains. Some of them are recorded as low as -5 or -6 dB, which is MUCH quieter than a normal recording. So, there is some "cushion" built in when I set my gains. Now if, while setting the gains, I used a recording that had been normalized to 0 or -1 dB, that would be a different story altogether. Scott Gardner > Well, it depends on what you consider "too quiet". Earlier, I said > that I use quite a few music tracks to set gains. Some of them are > recorded as low as -5 or -6 dB, which is MUCH quieter than a normal > recording. So, there is some "cushion" built in when I set my gains. > Now if, while setting the gains, I used a recording that had been > normalized to 0 or -1 dB, that would be a different story altogether. Yeah. This is a very important aspect of the gain setting procedure that shouldn't be glossed over. Most people, myself included, don't generally use a -6 dB disc to set their gains. So they need to provide a cushion. >> Well, it depends on what you consider "too quiet". Earlier, I said >> that I use quite a few music tracks to set gains. Some of them are [quoted text clipped - 6 lines] >shouldn't be glossed over. Most people, myself included, don't generally >use a -6 dB disc to set their gains. So they need to provide a cushion. I didn't used to pay that much attention either, until I started transferring my vinyl LPs to the computer. I noticed that even when I adjusted the recording levels so that the peaks in the music were just shy of clipping (like -0.1 or -0.2 dB), the overall volume of most of the songs from vinyl sounded much "quieter" than CD recordings. I did an experiment and recorded a dozen songs from vinyl that I also had on CD. For all of the recordings, both from vinyl and CD, I adjusted the recording levels so that the peaks were just short of 0.0 dB. For the vinyl recordings, this always gave an average (RMS) level of -5 to -6 dB. For the same songs recorded on CD, the RMS levels were closer to -3 dB. This meant the the CD versions of the songs were almost twice as loud on average than the vinyl recordings. It also meant that the CD recordings had a smaller dynamic range, by about 3 dB. I did more research and found out that even though CD as a recording medium has the potential for a MUCH greater dynamic range than vinyl, most recording engineers don't take advantage of it. As a matter of fact, the trend with modern recordings is to actually COMPRESS the dynamic range, so that the overall loudness of the song can be greater without clipping the signal. To make matters worse, most FM radio stations also have real-time "compressors" that compress the dynamic range even further, raising the RMS volume level without clipping the signal (clipping would cause them to go outside the frequency band allotted to them by the FCC, and possibly attract a penalty from the FCC). All of this is an effort to make the station louder to attract listeners. As a result, the volume difference between the quietest parts of a song and the loudest parts of the song has been reduced greatly. Scott Gardner > Most of them nowadays don't - at least not until the very highest of the > high. Some of the Pioneer decks don't at all. I dont notice any that clip, at least not enough for me to ever notice or worry about it. Certainly NOT a factor that I worry about when setting gains. > Different point altogether. The reason amplifiers are subject to clipping > is because we SET them that way. If you set your amplifier to the "8 volt" > mark, it won't clip. Wont get loud enough to make most folks happy either! Eddie Most folks WOULD NOT be happy with a system set up so the amp cannot clip like you recomend.... there is an example of it in my paper... http://www.installer.com/tech/gains.html > No, I don't set the amp gain so low that the deck is incapable of > sending distortion to the speakers - I don't think that's possible. [quoted text clipped - 35 lines] > > > >Eddie But you CAN clip the amp with my gain-setting procedure. All you have to do is turn the head unit up further than the threshold setting that I used when setting the gains. The procedure I use ensures that the head unit will be putting out its maximum possible clean signal at the same time that the amp begins to clip. If I used a higher volume setting on the deck when setting the amp gains, then the deck would begin to clip before the amp. If I use a lower setting on the deck, then the amp will clip before the head unit is producing its maximum clean output, and S/N ratio will be lowered. I can't figure out what you think is so wrong about having the head unit and the amplifier clip at the same volume setting. It's true that if you used my method, and later played a recording that was made at a very low level, like -9 dB RMS, you won't get full volume out of the amp without clipping the head unit, but that's a risk that's always going to be present. If you set your gains based on a recording that's at -9 dB, then anytime you play a recording that was made at a proper level, you'll clip the amp before you even get the volume knob on the deck past 1/4-turn. Scott Gardner >Most folks WOULD NOT be happy with a system set up >so the amp cannot clip like you recomend.... [quoted text clipped - 40 lines] >> > >> >Eddie > But you CAN clip the amp with my gain-setting procedure. All you have > to do is turn the head unit up further than the threshold setting that > I used when setting the gains. then you MUSt be doing it the way I suggest here http://www.installer.com/tech/gains.html >> But you CAN clip the amp with my gain-setting procedure. All you have >> to do is turn the head unit up further than the threshold setting that >> I used when setting the gains. > >then you MUSt be doing it the way I suggest here >http://www.installer.com/tech/gains.html Like I said in my other post - your method and mine are really the same, only you use 75% of max volume as an arbitrary setting on the head unit, while I just turn it up until I hear the head unit distort. For what it's worth, that usually ends up being somewhere around 75%-80% anyway, so the end results of you adjusting gains and me adjusting gains wind up about the same. Scott Gardner > Like I said in my other post - your method and mine are really the > same, only you use 75% of max volume as an arbitrary setting It is NOT an arbitrary setting.... it is a setting that has had MUCH thought and MUCH experience in determining......... And for most folks much better than your MAXXED OUT SETTING! Eddie Runner http://www.installer.com/tech/gains.html >>Most folks WOULD NOT be happy with a system set up >>so the amp cannot clip like you recomend.... >>there is an example of it in my paper... >>http://www.installer.com/tech/gains.html The only part of your tech paper that I would change is the last section where you talk about adjusting levels in a multi-amp setup. Once you have all of the individual gains set correctly, and you're trying to balance the relative speaker volumes against each other, I would change the text to explicity state that you should always make the adjustments by LOWERING the gain on the speakers that are too loud, never by raising the gain for the speakers that are too soft. It might seem intuitively obvious to you and me, but your paper seems directed to a wide audience, so I'd try to make that clear, rather than just saying "make the adjustments to the amplifiers so the levels are the same". All in all, a great piece, though. Scott Gardner > The only part of your tech paper that I would change is the last > section where you talk about adjusting levels in a multi-amp setup. [quoted text clipped - 4 lines] > the adjustments by LOWERING the gain on the speakers that are too > loud, never by raising the gain for the speakers that are too soft. Why? Then you could be introducing head unit distortion! :) >> The only part of your tech paper that I would change is the last >> section where you talk about adjusting levels in a multi-amp setup. [quoted text clipped - 6 lines] > >Why? Then you could be introducing head unit distortion! :) Lol - I know you're pulling my chain now, but that's really not true. If all you're doing is bringing down the level of the speakers that are too loud, there's no reason to have to turn the head unit any further up to compensate - you're not trying to adjust the OVERALL volume of the system, just the relative volumes between the speakers. On the other hand, if you have all of the gains set properly, and then adjust the relative volumes by turning the quieter speakers UP, you'll cause that amplifier to clip sooner. If you properly attenuate the speakers that are too loud to bring the system into balance, and the resulting overall volume is too quiet, then you need more powerful amps. This is the same reason why you should begin equalizing by cutting the peaks rather than boosting the dips. Cutting the peaks ensures that if you weren't clipping before the equalization, you won't be clipping afterwards. Scott Gardner > Lol - I know you're pulling my chain now, but that's really not true. > If all you're doing is bringing down the level of the speakers that [quoted text clipped - 13 lines] > if you weren't clipping before the equalization, you won't be clipping > afterwards. I usually don't go out of my way to do either. The fine-tuning part introduces relatively little overall difference to the volume knob. It's the initial gain setting where you tend to have to deal with the issue. But then again, my preout doesn't clip so what do I care? :) >> Lol - I know you're pulling my chain now, but that's really not true. >> If all you're doing is bringing down the level of the speakers that [quoted text clipped - 19 lines] > >But then again, my preout doesn't clip so what do I care? :) Yep, I'm not saying it's always an issue, I've just seen too many people that go to a lot of trouble to set their gains properly, and then think nothing of throwing in 6-12 dB of boost in three or four different bands. Depending on how much boost they introduce, and what bands they're boosting, it could make several dB of difference between the input and output signals of the equalizer. After all, if the gain controls on amplifiers are really just volume controls, then so are the sliders on an equalizer - they just affect sections of the signal at a time rather than the whole signal. ;) Scott Gardner Could it be Scotts ears that clip? Or the fact that he likes to MAXXIMIZE the headunits volume control... ha ha ha > But then again, my preout doesn't clip so what do I care? :) I never said to maximize the volume contol, chuckles - I said to maximize the usable volume swing. Try reading the paragraph again. And it's not a big deal for me to have to turn the volume knob "up and up and up", as you put it. There's only about 1 1/2 complete turns from minimum to maximum on my volume knob anyway. You set the gains any way you like, and I'll do the same. I must still not be explaining myself correctly, because so many of the problems you seem to have with my methods stem from not understanding what the hell I'm saying. Scott Gardner >Could it be Scotts ears that clip? >Or the fact that he likes to MAXXIMIZE the headunits volume control... > >ha ha ha > >> But then again, my preout doesn't clip so what do I care? :) > I never said to maximize the volume contol, chuckles - I said to > maximize the usable volume swing. like ALL THE WAY UP..?? if thats not what you mean then EXPLAIN IT! >> I never said to maximize the volume contol, chuckles - I said to >> maximize the usable volume swing. > >like ALL THE WAY UP..?? >if thats not what you mean then EXPLAIN IT! Since a distorted output from a head unit has never been a problem for you, don't worry about it. What I meant by "maximizing the usable volume swing" is to choose a "set point" for the head unit while I set the amp gains such that I maximize the range that you can turn the volume knob without the deck output distorting OR the downstream amplifier clipping. Note that after all of the adjustments are done, it WILL still be possible to clip the downstream amp, simply by turning the head volume past the "set point" that I used while setting the amp gains. In theory, if I never heard the head unit distort, my "set point" would be 100% on the head unit's volume knob. Normally, this would mean that you might not be able to get full volume from the amplifiers while playing a soft recording. However, the songs I'm playing while adjusting the gains were recorded at -6 dB, which is very soft. This extra 3 dB of attenuation gives the "wiggle room" necessary to ensure that the user will always be able to drive the amps to full volume, unless they're playing a song that was recorded ridiculously low, like -12 dB. Like I said, since distortion from the head unit has never been a problem for you, you can ignore that whole part of my post and just use 75% for the head unit "set point" volume like you recommend in your paper. Scott Gardner > Once you have all of the individual gains set correctly, and you're > trying to balance the relative speaker volumes against each other, I > would change the text to explicity state that you should always make > the adjustments by LOWERING the gain on the speakers that are too > loud, never by raising the gain for the speakers that are too soft. Its pretty common that I do it the way you say NOT TO.... I sometimes get ALL the gains OFF so there is no sound and then set something (like the subs) as a reference point, and then bring the fronts and backs up till the listener hears them... So I guess I prefer to do it the way you say NOT to do it... I got a pretty good track record in the last 30 years... wonder how many 1000s and 1000s of cars I have done that way..?? >> Once you have all of the individual gains set correctly, and you're >> trying to balance the relative speaker volumes against each other, I [quoted text clipped - 12 lines] >I got a pretty good track record in the last 30 years... wonder how >many 1000s and 1000s of cars I have done that way..?? What happens if the sub amp (to use your example) is much more powerful than the other amps in the system? After you've set the subs to whatever level you like, now you have to raise the other amps' gains up to balance the other speakers' outputs with the subs' output. If the other amps are significantly less powerful, you could end up clipping them before they reached an appropriate volume relative to the subs. Now you have to lower the sub amp's gain and begin again. If you set all the amp gains so that the amps are all reaching maximum volume at the same time (when the head unit is at 75% or whatever number you choose), then you can proceed to adjust the gains downward for the speakers that are too loud. This way, you know that when the head unit is at 75%, the quietest speakers in your system are being driven at max volume, and the other speakers have been attenuated to an appropriate level. You way obviously works for you, and mine works for me. If you follow my procedure, you'll still extract the maximum clean overall volume from the system, and you don't have to worry about setting the gain on one amp too high while trying to raise it up to match the level of another amp. Scott Gardner > What happens if the sub amp (to use your example) is much more > powerful than the other amps in the system? After you've set the subs [quoted text clipped - 3 lines] > clipping them before they reached an appropriate volume relative to > the subs. Now you have to lower the sub amp's gain and begin again. I set the amps so they are the same sound level to the listener. or the sound level that sounds best to the listener... If 1 amp is 10000watts and 1 amp is 40 watts, that would probably be a really BAD BAD DESIGN, but I would set the amps up so they sounded good together...Balanced.. Equal to the listener.... Some folks might like a little more bass or a little more outta the back or front speakers, I would set it up so it sounded good to em... BUT, if you turn it up it would be obvious that the 40 watt amp would clip way before the 10,000 watt amp... So IF the user wanted to exceed the point where the weaker amp clips, I would certainly NOT CHANGE the gain structure, instead I would suggest a better system design for the user.... Do you in some way want to modify when the amps clip??? If so, by doing that would really make the system sound unbalanced and BAD..... Eddie Runner >> What happens if the sub amp (to use your example) is much more >> powerful than the other amps in the system? After you've set the subs [quoted text clipped - 25 lines] > >Eddie Runner I agree that having one amp that could overwhelm the other amps in the system isn't a good design, but some people don't buy all new equipment at once, so temporary mismatches often occur. I'm sure you've seen a lot of this in your shop. When I'm dealing with one amp that can easily overwhelm the others, I set up the gains so that when the weaker amp is being driven to max volume, the stronger amp is only putting out just enough power for the overall system to sound balanced. The way I get there is by initially setting the gains on both amps so that they're being driven to max volume when the head unit is at 75% (or whatever set point I use). At this point, I now have an unbalanced system, with the stronger amp overpowering the weaker amp. To bring the system into balance, I can either increase the gain on the weaker amp or reduce the gain on the stronger amp. Obviously, reducing the gain on the stronger amp is the way to go. When I'm done, the amps will be balanced. For a given input from the head unit, I'll be using a lot more of the smaller amp's potential power output, and less of the stronger amp's potentialpower output, but with mismatched amps, that's what's going to have to happen. Scott Gardner >> Once you have all of the individual gains set correctly, and you're >> trying to balance the relative speaker volumes against each other, I [quoted text clipped - 12 lines] >I got a pretty good track record in the last 30 years... wonder how >many 1000s and 1000s of cars I have done that way..?? I would still re-word the last paragraph about adjusting gains in a multi-amp system. If a reader were to follow the directions in your paper word-for-word, he'd set the head unit to 75%, and adjust all of the amps so that they're being driven to full clean volume. So far so good. At this point, let's say he notices that his front component speakers aren't loud enough relative to the subwoofers. Since all you say in your paper is to "make the adjustments to the amplifiers so the levels are the same", he might be tempted to just increase the gain on the amp that's powering the component speakers. If he increases it very much at all, he's going to be clipping his component amp, since it was already being driven to max volume from when he adjusted all the amp gains earlier in the procedure. The smarter thing to do would be for him to lower the gain on the subwoofer amp instead to bring the relative volumes into balance. This will give him the maximum overall volume out of the system while keeping all the levels correct relative to one another, and not causing any of the amps to clip with the head volume at 75%. It probably seems obvious to you since you've been doing this for so long, but I just though it was worth mentioning since someone with little or no experience might be using your paper as a guide to set up his system. Scott Gardner Not a volume control in that sense that turning the gain down is gonna prevent someone from blowing up their gear... n8 > Why do you say that..?? When I turn the gain control the volume > goes up and down..... http://www.installer.com/tech/gains.html [quoted text clipped - 3 lines] > > > > n8 I would get a kicker kx700.5 to amp every speaker in the system . Then get a SINGLE Kicker CompVR DVC 400w rms sub or Fosgate , have someon who knows how to build a lovely sealed box and run the sub at 2 ohms . It will be quite sufficient .. Here ya go cheap >> AM http://tinyurl.com/2ntuv and >> Subs http://tinyurl.com/29age and http://tinyurl.com/35gcf If you really WILL NOT amp the components still the CompVr 10" or 12 single with an appropriate box ( or SubZero or SubZone sealed * excellent boxes BTW ) and a 400 watt 2 ohm mono capable 1 channel clas D amp P.S. If you really would like to have 2 Infinity subs , get the SV versions , run them in series at 2 ohms ( with a capable amp of cours ) . -- Mister_ Yes it IS a volume control... If you turn up your headunit volume control to a point where the speakers are overpowered the voice coil could get hot and burn up (too much power to the speakers) ALSO, if you turn up the gain on an amp to the point where the speakers are overpowered the same thing can happen.... whats the difference..?? NOTTA!!! Eddie Runner > Not a volume control in that sense that turning the gain down is gonna > prevent someone from blowing up their gear... [quoted text clipped - 8 lines] > > > > > > n8 Install your gea rin your car... Turn the subs OFF... Turn up your volume on your deck to the loudest possible setting you would ever put it... slowly turn up the gain on your amp(s) untill it sounds good at that max-volume level. Be happy :D >Forgive my noobiness. You all have been so helpfull so far. > [quoted text clipped - 17 lines] > >Thanks again! > Install your gea rin your car... > [quoted text clipped - 5 lines] > slowly turn up the gain on your amp(s) untill it sounds good at that > max-volume level. ...and then turn your gain up a little higher than that to account for softer recordings. |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2009 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.