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#1
Posted to rec.audio.car
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help with three subs
So I got a custom box(for free) that fits 3 10" subs. The subs are
going to be the sony xplod 10's, and I was wondering if there is a way to wire them so that I have stereo from two subs, and mono from the middle? Is it possible to do it all with only one amp? Thanks. |
#2
Posted to rec.audio.car
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help with three subs
So I got a custom box(for free) that fits 3 10" subs. The subs are
going to be the sony xplod 10's, and I was wondering if there is a way to wire them so that I have stereo from two subs, and mono from the middle? Is it possible to do it all with only one amp? Thanks. Your question is a little confusing. I'm not sure what you're asking here. Typically your subs are ALL wired in mono. You gain basically nothing by trying to hook up subs in stereo. I would DEFINITELY suggest all three of your subs be wired in mono (combine your left and right channels into one channel and have that go to your sub). Then use your single amp to drive all three subs. Make sure that the load all three subs present to the amp does not exceed the amp's bridged mono capability. In other words, if you have three 4 ohm subs and you wire them all in parallel, this will present a 1.3 ohm load. Make sure your amp is capable of driving such a load. I don't know exactly WHAT subs you have or the amp you have to drive them so I can't specifically speak to this. If you give us that information, we can better help recommend a configuration that maximizes the amp and subs. MOSFET |
#3
Posted to rec.audio.car
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help with three subs
MOSFET wrote:
So I got a custom box(for free) that fits 3 10" subs. The subs are going to be the sony xplod 10's, and I was wondering if there is a way to wire them so that I have stereo from two subs, and mono from the middle? Is it possible to do it all with only one amp? Thanks. Your question is a little confusing. I'm not sure what you're asking here. Typically your subs are ALL wired in mono. You gain basically nothing by trying to hook up subs in stereo. I would DEFINITELY suggest all three of your subs be wired in mono (combine your left and right channels into one channel and have that go to your sub). Then use your single amp to drive all three subs. Make sure that the load all three subs present to the amp does not exceed the amp's bridged mono capability. In other words, if you have three 4 ohm subs and you wire them all in parallel, this will present a 1.3 ohm load. Make sure your amp is capable of driving such a load. I don't know exactly WHAT subs you have or the amp you have to drive them so I can't specifically speak to this. If you give us that information, we can better help recommend a configuration that maximizes the amp and subs. MOSFET "The subs are going to be the sony xplod 10's..." |
#4
Posted to rec.audio.car
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help with three subs
Ok, thanks, I didn't know if wiring subs in stereo would sound better
than mono, because I've had two different systems in my car before, and I wired one in stereo, and it sounded awesome. The amp I'm getting will definitely be 1 ohm stable, too. Probably the kenwood excelon x812d. |
#5
Posted to rec.audio.car
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help with three subs
I'm sure that you'll get awesome stereo sound out of your subs with the
kenwood excelon x812d mono block amplifier. Really, I think that you will. LOL In article om, "xman" wrote: Ok, thanks, I didn't know if wiring subs in stereo would sound better than mono, because I've had two different systems in my car before, and I wired one in stereo, and it sounded awesome. The amp I'm getting will definitely be 1 ohm stable, too. Probably the kenwood excelon x812d. |
#6
Posted to rec.audio.car
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help with three subs
wire mono( parallel). that amp can take it no problem -- KOA |
#7
Posted to rec.audio.car
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help with three subs
"KOA" wrote in message ... wire mono( parallel). that amp can take it no problem -- KOA Captain's point was that amp is mono so you can not even hook it up stereo if if you wanted to.... |
#8
Posted to rec.audio.car
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help with three subs
"e-nigma" wrote in message ... "KOA" wrote in message ... wire mono( parallel). that amp can take it no problem -- KOA Captain's point was that amp is mono so you can not even hook it up stereo if if you wanted to.... Yes, but if that Kenowood mono amp is one ohm stable, you should be able to connect all three Sony subs in parallel no problem. It should work GREAT for you! MOSFET |
#9
Posted to rec.audio.car
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help with three subs
Never mind should. It will work great until that poor kenwood melts. In article , "MOSFET" wrote: "e-nigma" wrote in message m... "KOA" wrote in message ... wire mono( parallel). that amp can take it no problem -- KOA Captain's point was that amp is mono so you can not even hook it up stereo if if you wanted to.... Yes, but if that Kenowood mono amp is one ohm stable, you should be able to connect all three Sony subs in parallel no problem. It should work GREAT for you! MOSFET |
#10
Posted to rec.audio.car
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help with three subs
what about running them with the kenwood 7252(that's what I meant for
stereo), my choice for mono parallel was the excelon. Also, does anyone know if the kenwood 9152 would work for mono-parallel wiring in my schematic; is it 1 ohm stable? |
#11
Posted to rec.audio.car
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help with three subs
xman wrote:
what about running them with the kenwood 7252(that's what I meant for stereo), my choice for mono parallel was the excelon. Also, does anyone know if the kenwood 9152 would work for mono-parallel wiring in my schematic; is it 1 ohm stable? Wiring subwoofers in stereo is not going to provide you with any sonic benefits because the human ear cannot localize sub-bass frequencies--especially not in a highly reflective environment such as an automobile interior. How the human brain localizes sound is rather complex, but basically the brain has a very tough time localizing frequencies whose wavelength is greater than the width of your head (see http://www.ausim3d.com/about/AuWeb_perception.html). This is why you can put a subwoofer in your center console, in the trunk of your car, or even underneath your dashboard and get roughly the same results in either case, something you most definitely cannot do with a tweeter or a midrange speaker--which are *very* finicky w.r.t. placement. There's another good reason not to do this "stereo-mono" thing. If your box is one big chamber, you're going to open yourself up to modulation distortion--where differences in the signal in one speaker has an adverse affect on the others. The result may be "inaudible" but yet still noticeable; meaning that you may not be able to put your finger on it but you'll notice that something isn't quite right--the bass response may very well be muddy. Even if your box is constructed of three individually-sealed chambers (which it really should be), you're still going to have an uneven amount of power going to all your speakers....one sub may have 2x the power of the other two. All this is going to do is wear-out one of your subs twice as fast as the others and again probably muddy-up your sub-bass response. So any way you slice it, this really doesn't make any practical sense. Wire 'em all up in mono is such a way as to make your amplifier happy, and in such a way as to deliver the *same* amount of power to each speaker (i.e. don't wire two in parallel and one in series with the parallel pair or something goofy like that). The idea here is to get all your subs doing the same thing at the same time and all at the same intensity. Anything other than that is going to result in a system that's destined to fail to live up to its potential. Lastly, you mention you bought a custom box but I didn't catch whether or not you had it custom-built for the speakers you have. If you didn't, then it's not really a custom box...at least not for your subs. All boxes are not the same, and not all subwoofers require the same volume (or even type) of enclosure to achieve optimum performance. If you have not done so already, please check with the manufacturer or a dealer of your subwoofers and have them look things over--taking this extra step may very well save you frustration over a less-than-satisfying-sounding system and even may save you money; improperly-sized enclosures can drastically reduce the life expectancy of any speaker. Check out the tutorials entitled "Designing Subwoofer Enclosures" and "The Myth of the Magic Box" on the JL Audio website (http://mobile.jlaudio.com/support_pages.php?page_id=141) for more detail on the points I've brought up here. -dan |
#12
Posted to rec.audio.car
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help with three subs
Thanks a lot for all the help guys. The verdict is I'm going with the
Kenwood excelon x812d wired in parallel-mono, and probably some added fans or a custom box for the amp with dual fans to keep an air path, since I'm sure that 919 watts will generate A LOT of heat. I'm also getting a 3 farad power acoustik capacitor; and I work on cars a lot, so should I just charge that with my battery charger before I stick it in my car? |
#13
Posted to rec.audio.car
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help with three subs
I hate to say this, but you'll never see 919 watts out of that amp, not even
on a good day. In article .com, "xman" wrote: Thanks a lot for all the help guys. The verdict is I'm going with the Kenwood excelon x812d wired in parallel-mono, and probably some added fans or a custom box for the amp with dual fans to keep an air path, since I'm sure that 919 watts will generate A LOT of heat. I'm also getting a 3 farad power acoustik capacitor; and I work on cars a lot, so should I just charge that with my battery charger before I stick it in my car? |
#14
Posted to rec.audio.car
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help with three subs
I hate to say this, but you'll never see 919 watts out of that amp, not
even on a good day. Unless you've ALSO installed a 200 ampere HO alternator, I'm afraid Howdy is EXACTLY right. You will NEVER see 919 watts, no matter how many farads of capacitance you add. MOSFET |
#15
Posted to rec.audio.car
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help with three subs
well about how many can I expect with my current alternator? It's a 96
trans am with a 140 amp alt. |
#16
Posted to rec.audio.car
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help with three subs
You'll get about 500-550 watts, How clean it's going to be in that area is
hard to say. This amplifier has 2x30amp fuses. The power ratings on this amp are shady at best (see online manual), all of Kenwoods power ratings on this amplifier are at 100hz when you set the cross-over at 60 - 80hz as most people do, you'll see the power ratings drop big time. 140amp alternator is more then enough for it. In article .com, "xman" wrote: well about how many can I expect with my current alternator? It's a 96 trans am with a 140 amp alt. |
#17
Posted to rec.audio.car
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help with three subs
xman wrote:
I'm also getting a 3 farad power acoustik capacitor; and I work on cars a lot, so should I just charge that with my battery charger before I stick it in my car? Your capacitor should come with a small resistor on the order of something like 1kOhm. Whatever 12V source you use, make sure you charge that thing with the resistor in series with your power supply (be sure to hold it with a pair of pliers--it'll likely get kinda hot). A discharged capacitor looks like a dead short to DC until it starts charging up, and if you just slap 12V on it immediately, you're likely going to pop a fuse/breaker and/or create a nasty scar wherever the circuit is closed (from the arcing). Remember, three Farads is a LOT of capacitance--treat that thing like it's filled with lightning and don't try to charge it until *after* you've securely mounted it in your vehicle (and have a means to protect the terminals). And remember...NEVER EVER EVER lick a capacitor's terminals like you would a 9V battery...ever. Seriously. Don't. -dan |
#18
Posted to rec.audio.car
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help with three subs
In article . com, "D.Kreft" wrote:
xman wrote: I'm also getting a 3 farad power acoustik capacitor; and I work on cars a lot, so should I just charge that with my battery charger before I stick it in my car? Your capacitor should come with a small resistor on the order of something like 1kOhm. Whatever 12V source you use, make sure you charge that thing with the resistor in series with your power supply (be sure to hold it with a pair of pliers--it'll likely get kinda hot). A discharged capacitor looks like a dead short to DC until it starts charging up, and if you just slap 12V on it immediately, you're likely going to pop a fuse/breaker and/or create a nasty scar wherever the circuit is closed (from the arcing). Remember, three Farads is a LOT of capacitance--treat that thing like it's filled with lightning and don't try to charge it until *after* you've securely mounted it in your vehicle (and have a means to protect the terminals). And remember...NEVER EVER EVER lick a capacitor's terminals like you would a 9V battery...ever. Seriously. Don't. I'm running the calculator and the first formula I come across is time in secs. times farads = 1K times 3 Farad = 3000 secs. I think I would use no more than 100 ohms and about a 2 watt resistor. A 12 volt lamp is also good to use. greg |
#19
Posted to rec.audio.car
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help with three subs
you'll just be wasting your money on that cap. You have plenty of alternator power to keep up with that amp. -- KU40 |
#20
Posted to rec.audio.car
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help with three subs
KU40 wrote:
you'll just be wasting your money on that cap. You have plenty of alternator power to keep up with that amp. Well, that kinda depends upon how you define "keep up with", I think. If you're talking about consistent, relatively steady current draws of up to 140A, then yeah, that alternator will "keep up". But music is not typically sinusoidal--it's dynamic. What the alternator is not likely to keep up with are large transient spikes (especially those occurring in rapid succession) in current demand that cause supply voltage fluctuations. After all--automobile alternators were not designed for highly dynamic loads--they were designed to provide power to relatively static loads like lights and your A/C...the dynamic loads they *do* serve (intermittent wipers, turn signals, horns, etc.) are peanuts compared to the demands of a high-powered audio amplifier. It's a whole 'nother world. These fluctuations will mean degraded transient response ("attack") to one degree or another. Whether these fluctuations will produce *audible* differences in the system being discussed is, well, quite dependent upon just how keen the listener's ears are. But I'm pretty sure the amp will notice a difference and may thank you for it by running a bit cooler, particularly if the amp has a regulated power supply (which draws more current to compensate for voltage sags). Every amplifier has some degree of input volatage capacitance, but nothing like a big ol' quart-sized can of "dielectric sandwich". To the original poster: if you haven't purchased the capacitor already, my suggestion would be to install your system without it and see if your dealer would be amenable to giving you a "test drive" in your vehicle in the parking lot to see if the thing is going to be worth your while. If you've already purchased it, well, then go ahead and install it...unless you do the "test drive" on your own and determine that it doesn't make any difference in your system. If you're nice (and haven't boffed the capacitor), maybe they'll let you return it. -dan |
#21
Posted to rec.audio.car
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help with three subs
D.Kreft wrote: Remember, three Farads is a LOT of capacitance--treat that thing like it's filled with lightning and don't try to charge it until *after* you've securely mounted it in your vehicle (and have a means to protect the terminals). And remember...NEVER EVER EVER lick a capacitor's terminals like you would a 9V battery...ever. Seriously. Don't. -dan LOL!! Seriously, welcome back dKil. Nice posts. KeithS |
#22
Posted to rec.audio.car
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help with three subs
a couple weeks ago when my big amp went down i only had my two smaller ones going, and they pull probably about 50 amps at full tilt. I only have a 105 amp alternator and my voltage never dipped below normal. his amp will only pull 10 more, and he has 35 more amps from the alt. I'm fully confident he'll have no problems unless either the alt or battery are already weak. -- KU40 |
#23
Posted to rec.audio.car
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help with three subs
KU40 wrote:
a couple weeks ago when my big amp went down i only had my two smaller ones going, and they pull probably about 50 amps at full tilt. I only have a 105 amp alternator and my voltage never dipped below normal. Did you have your headlights and A/C on? Auto manufacturers typically only outfit their vehicles with enough alternator to run the car itself, nothing else, so when you're driving around on a hot, humid night with your high-beams and A/C on, listening to Depeche Mode at full volume (as I was prone to do in my younger days), things can get kinda rough, electrically speaking. his amp will only pull 10 more, and he has 35 more amps from the alt. I'm fully confident he'll have no problems unless either the alt or battery are already weak. This very well may be true, which is why I was careful to note that it would be a good idea to test the system with and without the cap. before making a "from-the-hip" decision either way. -dan |
#24
Posted to rec.audio.car
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help with three subs
Well, my battery is brand spankin new, one of those gold-level
batteries. My alt, doesn't really matter, because I have an extended warranty on my car, so if it dies, I just get a new one for free! The only reason I was thinking about getting a cap is because I always heard that if you have a high end system, you should run 1 farad of capacitance per 1k watts, and I also forgot to mention that I was also looking at some boss audio amp that put out 1200 watts RMS(3000 max), and that's why I was looking at a 3 farad cap. |
#25
Posted to rec.audio.car
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help with three subs
D.Kreft Wrote: This very well may be true, which is why I was careful to note that it would be a good idea to test the system with and without the cap. before making a "from-the-hip" decision either way. -dan I agree. I say to always try before making adjustments. and xman, if you're looking for a true 1200 watts, don't get that Boss. It'll give you 600. If you want over a kilowatt, provide us with a budget and we'll point you to some good equipment. -- KU40 |
#26
Posted to rec.audio.car
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help with three subs
D.Kreft Wrote: Did you have your headlights and A/C on? Auto manufacturers typically only outfit their vehicles with enough alternator to run the car itself, nothing else, so when you're driving around on a hot, humid night with your high-beams and A/C on, listening to Depeche Mode at full volume (as I was prone to do in my younger days), things can get kinda rough, electrically speaking. -dan I know my A/C pulls a ton of current. It drops my voltage down about a volt by itself, with nothing else running. That's about equal to a large, full volume bass hit with my 1000 watt sub amp (and other two amps running full tilt as well). So one could say that the A/C affects the electrical system as much as my stereo does. Add them together and it would be bad when running around town, stopping at lights and whatnot. If I keep the speed (and subsequently RPM's) up, I'll usually sustain about 1 volt down from normal with both running full tilt. but it's ok for me, because I'm more of a windows-rolled-down kind of guy except on long highway trips, and I'm not going to listen to my stereo at even 1/4 volume the whole way. so I can see your point. However I still think he'll be fine with his 140 amp alt. and 60 amp-pulling amplifier and A/C. With the topic of transients and dynamic range in music that you were talking about earlier, I think it helps my case as well. I read an article a few months ago (afraid I can't find the link) that did a test on these transients and the normal power being supplied by the amplifier, and IIRC it found that on average, even at full tilt, an amp is only supplying something like 10% of it's rated power. It only has small instances where the actual output goes up to RMS rating or beyond. However I would imagine this varies quite a bit with the music being played especially when comparing bass lines, which in many systems have the largest amplifiers. For example rock, with it's quicker kick drum hits, has just those small spikes in output followed by pretty much nothing until the next hit. Some rap, meanwhile, has extended bass drops that require an amp to put out more power for longer periods. Athough it still may be fairly low given impedence rises in sub systems, some go over 20 ohms at certain frequencies (my sub actually spikes over 40 ohms at 52 hz! that's a whopping 25 watts from my 1000 watt amp). so anyways, that was a long-winded pile of tangents. I think the moral is.......put it in your car and we'll see from there. ha -- KU40 |
#27
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help with three subs
And remember...NEVER EVER EVER lick a capacitor's
terminals like you would a 9V battery...ever. Seriously. Don't. -dan LOL That was great! |
#28
Posted to rec.audio.car
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help with three subs
And remember...NEVER EVER EVER lick a capacitor's
terminals like you would a 9V battery...ever. Seriously. Don't. -dan Actually, a long, long time ago when I was young and stupid (well, OK, just young), I was working on a friend's car and I needed to cut the positive wire that ran from a .5 farad cap (the rest of the system was disconnected from the battery) but the cap was fully charged. I used a thin bladed razor knife to cut the wire and SOMEHOW while I was cutting the wire it must have made contact with the car's chassis. It wasn't so much as a spark, but an explosion. It VAPORIZED a whole section of the razor knife I was using (a square inch chunk just disappeared). I'm trying to imagine what that would do to your tongue.... MOSFET |
#29
Posted to rec.audio.car
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help with three subs
In article , "MOSFET" wrote:
And remember...NEVER EVER EVER lick a capacitor's terminals like you would a 9V battery...ever. Seriously. Don't. -dan Actually, a long, long time ago when I was young and stupid (well, OK, just young), I was working on a friend's car and I needed to cut the positive wire that ran from a .5 farad cap (the rest of the system was disconnected from the battery) but the cap was fully charged. I used a thin bladed razor knife to cut the wire and SOMEHOW while I was cutting the wire it must have made contact with the car's chassis. It wasn't so much as a spark, but an explosion. It VAPORIZED a whole section of the razor knife I was using (a square inch chunk just disappeared). I'm trying to imagine what that would do to your tongue.... I was wondering if anybody had done that, like sticking a screwdriver across the cap. Of course I have stuck a screwdriver across a battery. The battery which was a large one inside an Army van which I opperated and charged batteries to run remote radio planes. Well, the battery caps were off. I heard a rushing sound and leaped out of the van. Looking back saw gushers of battery acid hitting the ceiling of the van. Man, I used to get all kinds of holes in my clothes from those batteries. greg |
#30
Posted to rec.audio.car
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help with three subs
I would just like to thank everyone for all the help; I ended up
getting the two sony P5 12's with a kenwood 9152D Amp, and I got the cap because at least, it couldn't hurt anything, and since I could get it for a good deal. This new system POUNDS. Thanks everyone for everything. xman |
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