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New member Username: Mia420Miami, Fl Usa Post Number: 1 Registered: Mar-10 | hello im about to get 1 or 2 12" cvr kickers but not sure what box,radio or even amp to get along with it i drive a 03 hundia tiburon i listen to rap so might be more intrested into the bass but also want to be able to hear words any suggetions i would greatly appreciate it |
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Silver Member Username: Simple_smithLapeer, Michigan United States Post Number: 359 Registered: Dec-08 | Pioneer makes solid head units that are fairly cheap. ($80- 170ish) for 2 CVR 12s i would get the DVC 4 ohm so you could buy an amp that does 800 watts @ 1 ohm. for an amp, an Audioque 1200, that way you can have good clean power for a decent price ($249) then i would put then in a ported box 4.4cu.ft. @ 35hz how much are you paying for those subs? and what is your total budget? |
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Platinum Member Username: Rovin1 15 = 152.5 DBs ...Trinidad & T... Post Number: 16074 Registered: Jul-05 | kicker's recommended box specs actually work pretty good - just build the largest box they rec & it will sound good for the $ that AQ is hard to beat ... |
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Silver Member Username: Simple_smithLapeer, Michigan United States Post Number: 360 Registered: Dec-08 | just off the top of my head, i think kicker recommends 1.75-2.25 per sub, so 4.4 is just about perfect for 2 |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12470 Registered: Dec-03 | Alpine, Pioneer, Clarion, JVC. all have good head units. get one with F/R/S pre-outs and a built in crossover. a signal processor would be even better if you can afford a better model. After that I'd buy a good set of front separates or coaxials from a company like Focal, Alpine, CDT, Infinity (Kappa or better) or similar, then add a decent little 2-channel amplifier rated for about 45 watts RMS @ 4 ohms per channel. Use it for the front speakers. forget head units for driving speakers of any size. No matter what a head unit tells you, it only puts out about 8-15 watts RMS with a lot of distortion, and the difference using a dedicated amplifier is night and day. after that, get a wiring kit, and a decent sub amp that puts out about 400-600 watts RMS @ 2 ohms. If you get one 12" sub, I'd go with a 3rd order bandpass box. For 2 12" subs, go straight ported enclosure tuned to about 35Hz. Have the box built. Don't go pre-fab. as for amplifier companies, anything made by DEI is decent (orion, a/d/s, directed, viper, etc) but really just avoid the super-cheap crap companies (like "SoundStorm") and I'd skip Sony or Kenwood. otherwise, that should do it. just make sure the gains on the amps are turned up too far, cross the subs over at about 60Hz with an 18dB slope, and XO the front speakers at about 100-120Hz, 12dB slope. forget rear fill speakers. they only mess things up. |
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Bronze Member Username: Slo2sixtyPost Number: 29 Registered: Mar-10 | my loaded kicker package in their box (2 12s) sounded really good. But their kinda pricey. Mine were pre wired at 2 ohms from the factory |
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Bronze Member Username: CwruckPost Number: 75 Registered: Feb-10 | hey glasswolf why would you suggest to cross over the subs at 60 hz? dont you think thats pretty low? i would think more like around 80. and you said set the high pass for the speakers at 100-120. that would leave a huge gap from 60-100 hz |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12480 Registered: Dec-03 | 80Hz is high. That's starting to get into midbass range, but try it. see what you think. 60Hz keeps the subs tight, and punchy and deep, like subs should be. You need to understand how a crossover works. 80Hz LPF does not mean the subs stop at 80Hz like a brick wall. with a Q factor of 18dB, this means at one octave above 80Hz (160Hz) the subs will play 18dB quieter than at 60Hz, and at 320Hz they will be 36dB quieter, and so forth. 18dB slope is steep but you want subs to roll off pretty quickly. The midrange/midbass driver will roll off more shallowly at 12dB Q, so if your HPF is set to 12dB slope @ 100Hz, then at 50Hz, you'll be 12dB down, and at 25Hz you'll be 24dB down. The point is if you look at this on graph paper, you'll see that the two overlap. the HPF and LPF. If you set both HP and LP to the same point, neither would roll off at all until they meet, which makes a big warm spot and causes a lot of muddy, warm midbass that makes the system sound boomy and less sharp. you want the gap there to allow the two ranges to meet in the middle. |
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Gold Member Username: The_image_dynamicSan Diego, California Post Number: 5646 Registered: Dec-06 | ^^^^ I have been trying to convince people here of that for years. Another factor involved is the hump at around 100hz that most car interiors promote. I have had great luck in many installs crossing the subs over at 60-70hz and using a 120hz high pass for the comps. This smoothes out the bass peak very well, increases the transient attack of the comps, as well as greatly increases their power handling. |
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Bronze Member Username: CwruckPost Number: 76 Registered: Feb-10 | thanks glasswolf that is very good knowledge! i never thought about that before. I thought the slope was much much more than that, but that makes perfect sense. because i have been crossing over at 80 hz and i thought it sounded good, but ill try what you said! But my speakers have very good bass down to about 70 hz, mostly because of their enclosure. so what about home recievers? sorry to get off topic, but i have always crossed them over at 60 hz.. and i dont think recievers give specs to the db slope. also what is the average db slope of a trunk? mine seems to be around 30 hz.. is that too low? i think that seems about right though because higher bass like 60 hz and up never seem loud, even in higher tuned boxes, but i have tried a box tuned to 25 hz and it really brings out the lows and moves a lot of air, and even boxes tuned to 40 hz still sound good at 30 hz and lower. sorry to be off topic, ill start a new thread if you dont mind explaining all of it |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12491 Registered: Dec-03 | Brad, I believe you're referring to the "transfer point" and yeah it's there in pretty much every car. Home audio is a completely different beast because you're talking about a much bigger "cabin" (room) and VERY different acoustics. For example, a sealed box in a car has a "flat response" but in a home, a ported box is "flat." Most home AVRs set the LFE XO point at 120Hz or 80Hz. A lot of that will depend on the mains you're using, and if they are satellite speakers, or floor standing mains, what their response curve looks like, and what the room acoustics are like. The crossover applies the "Q" or "slope" which is by definition, how quickly the volume dops off after that point in the frequency range. What you're asking about is around what frequency audio because harder to hear through obstructions. I lot of that again depends on the acoustics of the given situation. 80Hz will travel pretty well, but the reason I like 60Hz as the XO point for a sub, is this: remember that 80Hz means the speaker is traveling back and forth 80 times in one second. The faster that speaker has to move it's mass in one direction, stop, reverse direction, and start over again, the harder it is to control that mass. Subs are large, fairly massive speakers. The lower you can cross the sub over, the tighter it's going to tend to be. That's also why subs can't really produce high frequencies. They can't move fast enough. By the way, when a box is tuned to 40Hz, you want to use a subsonic filter set to 40Hz, and that filter is a brick wall filter (very steep slope) to prevent the sub from playing anything lower than the tuned frequency. The reason for that, is below the tuned freq of a box, the sub unloads. The box no longer acts as a spring or suspension (resistance or cushion) for the speaker, and suddenly the speaker is, in effect, being played without any box. With a large amount of power going to a sub without any suspension or air cushion, the sub will over-excurt and brick itself. It;'s not a pretty sight to open your trunk and see bits of your sub scattered about like shrapnel. Also, below the tuned port frequency of a ported box, the sub's response drops off really fast anyway, so ou're not losing or missing anything by jsut cutting it off there. |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12492 Registered: Dec-03 | take a look at www.bcae1.com that site has fantastic information about slope, crossovers, speakers, and everything to do with car audio, and some on home audio as well. the guy who runs it is a good guy. |
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Bronze Member Username: CwruckPost Number: 79 Registered: Feb-10 | ya i was wondering what is the db slope of a home reciever? or does it cut off at the crossover point? Im using bookshelves and they drop to 60 hz and sound good, so i have my crossover set at that. and i noticed for my sub, its tuned to 37 hz and seems to be a very flat response, with a bit of a boost between 50 and 60 hz but of course that is because of my room ya i understand you want to set a sub sonic filter at your boxes tuning or else your sub will be destroyed pretty quickly. i just noticed even if you dont have the sub sonic filter set at the tuning but maybe 20 hz and your box in your car is tuned to 40 hz, you still have pretty good bass at 30 hz, so thats why i was thinking an average cars cabin has a tuning of 30 hz give or take a few and i figure when you open your trunk and sit inside the car you hear the higher basses that you wouldnt hear when the trunk is closed, because the trunk isnt sealed to create that tuning it does. sorry its probably hard to understand what im saying, but im sure you know exactly what i mean |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12496 Registered: Dec-03 | yeah the trunk in a car actually acts as a sub enclosure itself when the sub box is in that trunk. the car's cabin does the same thing which is why bass response changes when you crack a window. It's like going from a sealed to a ported enclosure in the cabin, or more specifically a 3rd order bandpass. Anyway, I think a home AVR uses a 18dB Q for it's LFE. I'd have to look at the specific receiver. It's usually in the manual somewhere. |
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Gold Member Username: The_image_dynamicSan Diego, California Post Number: 5649 Registered: Dec-06 | Glass... yes, it is basically a given car interior's "transfer function" or "cabin gain". And I am in no way trying to explain this to you -- I have read your stuff many times and am well aware that you know what you are talking about -- just trying to further clarify my point for the benefit of others who may read this. I am very busy, and alot of times I am only able to give an abbreviated version of what I am trying to say. Anyways... a low frequency driver placed in a car (as Glass touched upon above) basically becomes a bandpass scenario, where certain frequencys are accentuated more than others. This occurs because you are placing a cabinet inside of another cabinet. Let's say, for example, if you placed a high quality full-range (maybe 60hz - 14khz) driver in a car and you measured the frequency response with a calibrated, flat (+ - 1dB) and charted the curve -- in most cases you will see a severe rise (or hump, or peak) right around 100hz. This is roughly equivalent to the effect of a "loudness button" on a home receiver, which usually boosts the frequencies at or around 100hz by about 6dB, and some people like that added warmth or "kick". My ears are so used to listening to reasonably flat reference studio monitors that this rise is very annoying to me. The reason I said "most cars" in my previous post is because this phenomenon is mostly evident in smaller cars, and certain convoluted interior shapes. A massive vehicle, like an old Cadillac or a cargo van, will have different response peaks. |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12508 Registered: Dec-03 | yeah it was a bit different for my 66 charger. huge interior, separated trunk with a drop-down divider, and I used the spare tire well fiberglassed in as the sealed sub enclosure for the Fi Q 18. It was nothing like the two ported twelves I ran in my old festiva haha The fastback in that old dodge is like an amphitheater.. |
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Gold Member Username: Van_manBoston South, MA Post Number: 5209 Registered: Mar-06 | Great info post GlassWolf and Brad. Its nice to see informative posts again. So this definatly puts to rest my theory of "more is bettet". Here is the link GW spoke of. I am still refering to there for info. I like the new Amp repair section. http://www.bcae1.com/ |
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Platinum Member Username: GlasswolfColumbia, SC USA Post Number: 12511 Registered: Dec-03 | yeah I'm more of the KISS school of thought. I like things simple. My current car is running the head unit and signal processor, 2 amps (identical amps), 1 sub, and 1 3-way front stage speaker set. that's all I need for loud, and accurate. |