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dcofer

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Posts posted by dcofer

  3. Grounding

    in Electrical-battery- Alternators- Wiring

    Posted

    Sure, that works fine. I reference the frame in such vehicles for all return path connections for high powered accessories.

    Fair enough. This is why I come here haha, everyone does things slightly different and I like to talk things through and hear explinations and counters. my experience is high voltage and normally A/C (though I do work with some large UPS systems, 48v-500v battery banks that source high KW haha).

    Thanks again, now I have more to mill over while I wait for all the parts of this system to be available.

  4. Grounding

    in Electrical-battery- Alternators- Wiring

    Posted

    OK, let me explain why in my near 30 years of building car audio systems, I've never run a ground from the amplifiers to the front of the vehicle to connect it to the battery negative.

    1. That cable will have greater resistance over it's length than correctly utilizing the frame of a vehicle, like say a truck.

    2. Should the stock battery negative to the block come loose, lose integrity, or become otherwise a botteneck, the starter will source current from other ground paths. If you had no audio system, that could be from the bell housing to the firewall (via the braided ground strap most vehicles have) and then back to the battery negative via the accessory ground lead between it and the inner fender or core support. Over time, one or both of these grounds can become damaged from this excessive current. Let's say that the ground strap from the bell housing snapped - new return path could be via the transmission kick down cable or throttle cable. In my time, I've seen it all happen and people will often continue to drive a vehicle like this until it simply won't start. Ever seen a throttle cable burned in half? Now, let's just say that one installs a killer audio system and does run a nice big ground cable to the battery negative. Forget about whether it's better or worse than the frame for the audio system. Think about how this could function as a return path for the starter - for example, let's say that the accessory ground wire between the battery negative and inner fender was snapped because the connection between the battery negative and block came loose and what I describe above just happened. Here's the new return path for the starter:

    Bell housing to firewall, firewall to fender mounted antenna, antenna to radio, radio to amplifiers via RCA cables, amplifiers to battery negative.

    Not much survives.

    Guys, I will challenge you to make decisions that are safe choices - and not just because you heard someone tell you a friend told them on the 'net.

    I appreciate the clerification which does make sense. What about this situation, keep in mind I am not challenging but just getting all the information, Factory battery runs to the block as its ground (correct me if I am wrong about this factory location I do not have my truck with me), secondary battery is also located unter the hood and independantly grounded to the block as well and not connected to the factory battery and then to the grounding location. So Each battery will be seperatly grounded and no daisy chaining for either the pos or neg connections.

    I know its hard to describe without a drawing haha so if my description confuses I will hop on paint and draw it out if needed.

  5. Grounding

    in Electrical-battery- Alternators- Wiring

    Posted

    The ideal ground for your second battery is a run from the negative post on the first. Have you looked into CCA wire for your runs? It's a cheaper alternative to OFC cable. Knukonceptz has it for $2/foot in 0 AWG

    Depending on how serious his system is and power he is running CCA might not support the current load he has in mind....

    Another alternative to buying OFC audio cable from a big name is Welding cable.

    https://weldingsuppl...EF:OR:terms::PA

    I am not a fan of CCA, while it might be cheaper and ampacity is not an issue, I am only running a Sundown SAZ-1500 and a SAX-125.4 with 1x1/0 for the SAX and 2x1/0 for the SAZ, however you go from a resistivity of 0.102 ohms/1000 ft copper to 0.168 ohms/1000 ft cca which equates to a larger voltage drop which is counter productive to the purpose of the wire runs.

    I have looked into welding cable and still might go that route since OFC is only questionably better (experience from working in the electrical field).

    So, what happens to your audio equipment when the cable between your battery and engine block proves to be higher in resistance than the return path via your audio system? IE - corrosion and oxidation break down the termination over time, a piece of road debris hits the cable and cuts or damages it, or someone cuts it in a theft attempt of your vehicle?

    Consider the return path for the starter then . . .

    I am not quite sure what you are getting at here. My amplifiers are only wired to the auxilary battery and if any are cut then that component just will not work, however if the positive is cut it could short but that isnt relevent to the grounding style... might make more sense if clerified though.

    And my auxilary battery is in parallel with the factory battery and wired directly off the alternator and grounded to the block and not wiring directly to the factory battery itself.

    From most of the responses it appears It will be worth while to take my runs and complete the loop back to the battery instead of to the frame.

    I do appreciate all the responses though even if my responses sound otherwise =p

  6. Grounding

    in Electrical-battery- Alternators- Wiring

    Posted

    Sorry if this is long winded.

    Working in the electrical field and having a solid understanding of electrical flow in general, I wanted to get peoples recommendations.

    I will be starting my build within the next month or so but I have already recieved my spare XS 3400 which is under the hood behind driverside healdmight (2011 silverado) and will be fabing up my battery lugs and amplifier adapters/reducers in the near future. But I wanted to get peoples opinion on how to do the amplifier grounding.

    From my knowledge I would think it would be best to run a direct run back to the battery which would produce a solid clean ground. This would also allow voltage drop to be calculated easily since "wire" size and material resistivity is constant. However, being a vehicle and not a building, I am not sure how much this will benefit the system.

    I mainly ask this just because if it is indeed the ideal way to complete the loop then I will run my return lines back to the battery. Otherwise if the benefit is not significant then it will save me from doubling the cost for the wire which is fairly significant (currently ~60ft of 1/0). The cost difference, while significant, is not a deal breaker if the benefit can be justified.

    Either way it will be run back to the battery or cleanly bolted to the frame then sealed.

    Amps are sundown pre-orders so I have some time and am not rushing. Just trying to do this system right the first time, no longer a budget build and the wallet is slowly bleeding as the components are being ordered haha.

  7. SAZ-1500D v.3 / SAX-125.4 Pre-Orders

    in Sundown Audio - GREAT Amps/Subs! GREAT Customer Service!

    Posted · Edited by dcofer

    Ive been planning it pick up a 100.4 and a 1200 but this seems liek the way to go with this pre-order. How would one go about pre-ordering? I guess going direct would be the easiest way but do you just state in a note that you are pre-ordering these items? (never used paypal)

    Also my plan is for two(2) SA-8 V.2 's under the seat of my silverado since i only have 9 inches of height and just over 1 cuft ported down there with a fiberglass box (could do a 10 if fired into the seat), would the 1500 be too much for them or would they eat it with proper tuning? (going to use the 3sixty.3 for processing when it ships)

    If the subs can take this or you convince me that the 10 would work better then you will def be hearing from me shortly.

    Yes you would state in the note what you are ordering.

    Two SA-8 v.2 will work better than an SA-10 -- especially with a 1500D for power.

    You will have a hard time accidentally damaging two SA-8 v.2 on that power.

    Gooood Gooood, the response I was looking for.

    Pre-order is goin in shortly has been submitted. Now its gonna be hard to be patient, but well worth it. Gotta wait for that 3sixty.3 anyways >.> and need to get a quote for a pair of those beastly SA-8V.2s :diablo:

  8. SAZ-1500D v.3 / SAX-125.4 Pre-Orders

    in Sundown Audio - GREAT Amps/Subs! GREAT Customer Service!

    Posted

    Ive been planning it pick up a 100.4 and a 1200 but this seems liek the way to go with this pre-order. How would one go about pre-ordering? I guess going direct would be the easiest way but do you just state in a note that you are pre-ordering these items? (never used paypal)

    Also my plan is for two(2) SA-8 V.2 's under the seat of my silverado since i only have 9 inches of height and just over 1 cuft ported down there with a fiberglass box (could do a 10 if fired into the seat), would the 1500 be too much for them or would they eat it with proper tuning? (going to use the 3sixty.3 for processing when it ships)

    If the subs can take this or you convince me that the 10 would work better then you will def be hearing from me shortly.

  9. $400-500 New setup

    in General Audio - Can't find a category for your question? Ask here.

    Posted

    HereSSA has this nice little Stetsom 500w amp for ~$300, appears to have a small footprint also, and you can pick up a 12" from any of the brands above for reasonable price. Would prolly put you near the $400 range then an amp kit and your set. Cant imagine it being over $500 total. Check out soundsolutionsaudio.com, their store has some good brands as well that should be able to meet your goal.

  11. Fourth Order Bandpass Question

    in Subwoofers / Enclosures

    Posted

    You always go with more ported than sealed. Some people go 1:1.5ish sealed:ported. Some people go as much as 1:3 sealed:ported. Tuning is normally between 40-60. Bigger sealed is more efficient, smaller sealed is more power handling. More ported is peakier output, smaller ported is more bandwidth. That's all I can think of right now

    Mmkay yeah thats what my calcs and response curves were coming out like, I knew most people went ported > sealed for car applications, Im still tweaking my volume ratio and tuning frequency but doign the calcs can only show so much, Just gonna need to slap it together and throw it to the wolves and hope the design holds up.

    Again thanks for the replys, Ill prolly throw up a test build soon, I think the cmp8 has endured the tapered t-line long enough and needs a new home haha

  12. Fourth Order Bandpass Question

    in Subwoofers / Enclosures

    Posted · Edited by dcofer

    Its one of those situations where you just gotta talk it through, and everyone I have to verbalize my thoughts to around me would look at me with an empty expression and no understanding <_< haha

    Guss I should just grab a beer and break out the spare MDF I have laying around and just build it and let the trial and error begin :drinks:

    EDIT: also winisd lets you change units now, you just click on the unit image next to the box and it cycles

  13. Fourth Order Bandpass Question

    in Subwoofers / Enclosures

    Posted

    Actually just graduated in May haha, did electrical engineering. matlab is a great tool, cant edit quite as easily as say excel but I know how to grid out equations and graphs in it better. I could get a super flat response with 2:1 sealed:ported with the t/s parameters I had availible, anything else seemed to have a distorted curve.

    I havent used winisd in a long time, Ill have to look into it again and see how the numbers compare. Yeah I knew they tend to be more spl oriented enlosures but since ive never made one I thought it would be a fun project, plus I enjoy figuring out the math behind the build haha, its nice to plug it in and visualize the ideal response of the system.

    thanks

  14. Fourth Order Bandpass Question

    in Subwoofers / Enclosures

    Posted · Edited by dcofer

    I have a Crystal CMP8 and a cheap 200w continuous amp laying around and have decided that I want to mess around with a few box designs for it for the sake of learning.

    I can build standard ported enclosures just fine but I have always been interested in the bandpass enclosures.

    Now I have frequency response equations for the fourth order bandpass and can plot them via Matlab, but beyond that I am not sure completely what I am looking for in a design.

    I have gotten the flattest response with a 2:1 sealed:ported tuned to 55hz with minimal gain and a f3l~32hz, f3h~80hz and when I do 2:1 ported:sealed the f3 stays about the same but the gain is stupid high around the tuning frequency with no real plateau. And many of the fourth orders I have seen buiild have larger ported chambers then sealed.

    My question is what should I really focus on for a fourth order bandpass enclosurewhen it comes to gain and how much I should worry about the flatness of the response curve?

    The plan is loud and clear on music, as much as I like to see numbers I do not compete currently.

    Please dun just respond telling me to buy a plan, and I'm not looking for professionals to divulge secrets, just rules of thumb. This is for learning and a project when I have time off work. If this were for a serious build I would just purchase a plan so its done right, but its not.

    Thanks

    EDIT: I can post my MATLAB graphs if requested to see what I am gettign via my equations.

  15. Tank's AMD Gaming rig

    in Computer Talk - News, technology, advice

    Posted

    Nice rig, Looks similar to the one im going to be building in the next couple days once my mobo comes in. Im testing out one of Thermaltakes water cooling systems so Ill let you know how it works out, kind of a step between the corsair one and a true full water cooling system.

    Thermaltake BigWater 760 but i picked it up for $130 off tiger direct but don't see it anymore.

    Yeah price gets up there, just memory, cpu, cooling, mobo ran me a little over $600 (then microsoft said "bend over" and took another $300 >.>)

  16. Benchmarking Programs

    in Computer Talk - News, technology, advice

    Posted

    I always find bench marking a little over rated, sure it can give you the physical limits of your hardware ins extreme situations but from my experience the best way to benchmark is to play a game and monitor the important part, frame rate (I use Fraps but I'm sure there are others out there) because it gives you real time feedback about how the game is performing the way you play it and if its online bench marking is kinda useless since the addition of network play can tax even the best of systems due to having to draw randomly based on other players unpredictable decisions. Not to mention games are generally capped at 30fps and even though you might read higher then that you normally wont see a difference.

    Just my 2 cents

  17. snail shell enclosure for level 5's

    in DC Sound Lab - Big Bass on ANOTHER LEVEL!

    Posted · Edited by dcofer

    That is def an interesting SS designs, must have been specifically for that sub (the way it should be) if I can find the infor I remember getting the design info of of powered4sound for free before it became nolteaudio.com and it was mor like a tapered horn for the crystal audio subs. I built a basic one for a kicker comp a while back and to me came out amazing. Should be interesting with real powered subs =p

  20. Will this box work?

    in Subwoofers / Enclosures

    Posted · Edited by dcofer

    It is low on the port area side however I am not completely sure how to do it on areo ports but one 4" areo 10" long should tune you around should tune you to ~35.11hz using Torres calculator. If you can get one wth flares on both ends

    edit: This port and before you seal it solid you can test different lengths and see if it is sounding right to you but I would start at 10" long

  22. Will this box work?

    in Subwoofers / Enclosures

    Posted · Edited by dcofer

    If I had time I could input it into Torres Calculator and use sketchup to model it but I currently dont that that time. I do recommend downloading that calculator as it is made by one of the member and is very user friendly. It might be good to read his main post to to figure out what all the calculations and fields mean.

    As for the port you could also look into using say an aero port or just a standard circular port running along the back wall instead of a slot port, just something to look into. Also probably tune it to 32-36Hz.

    Port area you want to try andhave 12-16 inches squared per cubic foot of net volume (volume after all displacements)that is also displayed in Torres calculator (not visual like the RE one though).

    Good luck

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