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ncc74656

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Everything posted by ncc74656

  1. ncc74656

    cheap basic o scope

    i get it, just trying to follow. ok so i measure on the oscope and when it goes flat it is "clipping" right? so the intent is to measure this so you know that the signal is clean and no distortion from clipping is affecting music quality. if i am scoping a factory radio that shows a square wave at half volume i would know to setup the amps (gains) to match the mid way point of the radio. i measure output voltage to know the power I'm pushing, size of wire needed, know if a speaker might get damaged, etc. some times we set gains via target voltage?
  2. ncc74656

    rockford midbass drivers?

    yea it may, moving from midrange driver to sub is a big change as far as construction. i threw the Rockford into winisd and ill be damned if it wants to play anything over 190hz with any volume at all. the infinity refrence line holds a pretty nice curve all the way through 400hz. once i get some drivers that look ok on paper ill throw em in a box and see what i get sealed vs ported. after looking around i think the 3" and 1" mid/tweet from hertz is what I'm going to go with for my other 2 speakers. they can get killer loud on paper, good brand, good quality, and my co worker has some (not installed) that i can hook up on the board and test the sound of. makes things easier
  3. ncc74656

    rockford midbass drivers?

    i kinda like the idea of trying that... its rare to see, challenge to build, and unique... lol. I'm looking at the P3 and T1 slims at the moment online, i think the T would be a waste tho as its built with more Xmax and power handling that isn't needed for the frequencies i intend to use it in. the subs are stupid cheap (less than a crachendo 10"...) so maybe ill just grab one and see how it sounds in a box at work, guess i could put it in my truck to see how the cabin gain is at those freqs. there really isn't much to rattle in this truck, you may be right that the doors would make noise but the sp4 i had in there didn't do much in the way of rattles (compared to trunk lids that is). if i did that i wonder if i could make the hertz mili legend 3" match that volume... guess i wont know that until i know how loud the P3 might be
  4. ncc74656

    cheap basic o scope

    measuring output? you mean voltage? i feel that my brain may be turned off to some of this... so say i measure off an rca preout and see a clean signal, that signal is .8V max lets say. i then go to the amp and turn its gains up until its signal is not clipped or clipped to 10 ish % or until the voltage out matches what the "rated" power of the amp ought to be.
  5. ncc74656

    rockford midbass drivers?

    i just had an idea, i am planning to do all Rockford amps so maybe i consider the P3 slim line 12's for midbass o.O
  6. ncc74656

    cheap basic o scope

    here is my understanding. you measure the output of the radio to know how loud it can get before the signal gets clipped, then you have a basis for clean input to the amps. or dsp. you measure the output of the amps to ensure the speakers are not being over driven, you are setting a base level of maximum output, then during the rest of the setup you pull things back from there in your tuning. so you scope to ensure speakers are not damaged and clean signals are going to components
  7. ncc74656

    engine/exaust noise

    lol! go big or go home right? no i stripped the truck and put a new body on it due to rust so when i put it back together i wanted to try out this cascade audio stuff, never used it and just want to know how good it is. i ordered up all the stuff and ive got a gallon of spray left so I'm still going to use it, at the very least its hypophobic so it will help seal the inside of the cab from water and such (not rated for external so I'm using linex there) but yea, I'm filling every opening and area with expanding foam (the stuff used for doors and windows, not the great stuff) and then I'm adding thick rubber deflectors inside the fenders to deflect wind down and up instead of directly into the door jam so i hope to eliminate all the wind noise. i plan to use some turbo and valve cover blankets but then i also want to wrap the exaust manifold and pipes going back to keep heat away from the cab and other parts and also to eliminate rattles and such. given its a diesel ill never get it quiet and that's not my goal, i just want the engine sound to be smoother and in the cab a bit quieter. trouble is my EGT's easily peg 1500F when I'm hammering it, 1200F sustained while heavy towing and 650F cruise so finding sound absorption materials for under hood is a challenge
  8. ncc74656

    rockford midbass drivers?

    well i think I'm going to go sealed vs ported on the SP4 and i think I'm going to go with 2 of them. given this i "think (maybe)" it can play above 80 hz but id have to test this and see just how much of a fall off i get, being an 18 and all i just don't know how high i can go with out having issues. i am fine with running a sub instead of a midrange up front, i spent a bit of time tonight looking at subs that could possibly be used as midbass up there. my best guess is a useable frequency range of 80-450hz. i think id be wanting the midrange to play around the 400hz if for no other reason than to keep them moving (air flowing) for cooling reasons. given that i was looking at the inifini refrence line and there factory sub replacement 8" woffers. i may be off the mark here but i feel like i want a 10 or 12 up in the door (i easily have the space for it) (and id kinda like to be able to say aww man you got a 6.5" midbass, that's nice, i have a 12... lol) big d*cking aside however i do want it to sound good. i was thinking of a sealed enclose because i was worried a ported would create to much of a peak and make it hard to tune the sub and mid transition but maybe ill just have to sit down in winisd and play around with boxes to see if i can get a somewhat smooth response curve. from my measurements i have up to 2.7 cubic to use in each front door if i were to either build a box in there OR turn the door itself into the box. if i did go ported id want the port to be as close to the sub as possible right? that would make the phasing/group delay easier to correct for
  9. ncc74656

    cheap basic o scope

    i use the customers music and source to control variables. i get what your saying, when we do an install and set things up with scopes we can say the subs are with in spec under present conditions. if they change source, turn up gains, add bass boost, etc. and blow up their subs we can say it is not covered and would not have happened had they not done this. we operate under MECP which dam near mandates using scopes to setup systems like this coworkers and myself have setup gains on amps with test disks and every time i hear a system setup this way it sounds like crap, the subs sound WAY under worked which they are as the drivers can always handle more dynamically than static test tones... i have scoped many aftermarket radios and have never seen a clipped rca signal out of the HU even at max volume (on any name brand anyway) so i personally don't think the radios play a large role in sending bad signals into an amp but rather the source of the music is what does this. so you scope an amp with say a -3db tone and get what? a point at which the CD or USB input with a static load will clip on the output and then we stop... but even mecp states you want distortion, up to 10% they claim on a sub output as you cant hear it and you will get more output. wouldn't it make more sense to just tune until you can hear the music sounding crappy and pull it back a bit from there? maybe simply play the system for 15 min or so at this level and see if any of the components are getting hotter than they should, wouldn't this be a more real world way to test if things wont blow up down the line? its worth noting that 90% of our installs are not trying to balance one driver to the next, its just adding subs to be as loud as possible or replacing a couple speakers here or there... in an ideal world id like to replace everything and then the scope/amp power/power handling wouldn't be the limiting factor but rather the next driver in the line, balancing the transfer from midbass to mid range to tweet so as to not have a smooth transition between all this. in the last 3 years ive only had 2 customers spend the money for such a setup however. the rest just want it as loud as it can go if it were you... how would you setup systems (assuming the operator will NOT turn things down if it sounds shitty) for clients on basic builds. most of what we do is not 3 way active with DSP but rather coax or 2 way component on 2 channel amps off a factory HU.
  10. ncc74656

    rockford midbass drivers?

    determine my space? they are going in the bottom of the doors, that much i know. for midbass most of it will be Omni directional but i cant fit an on axis 10"... the midrange and tweet will be mostly on axis however. end of the day i want midbass that will keep up with my 18" SP4
  11. ncc74656

    engine/exaust noise

    yea idk if I'm up for a 10K measurement but i am trying to do what i can. i really like the spray on because i think its easier to install and ive been told its about equally effective compared to the stick on. i spray it on 1 thin layer at a time and go to about 1/8 - 3/16" thick. i then use 1/4" closed cell foam with lead in the center over the high noise areas. then i used this arcryllic/ceramic vinal that's 3/4". ive never used this company before but i heard good things and they seem to supply all the factory damping for mercies, bmw, the germans... i also put my factory barrier over this so i have 1.75" thick of damping material from the bottom of the windshield to the start of the seats. i enjoy the sound as well and i will still be able to hear it I'm sure, i have compound turbos on a diesel with next to no exaust on it. but I'm trying to get a lower sound floor to make my dynamic range and music sound better. i also don't want wind noise coming in either.
  12. ncc74656

    rockford midbass drivers?

    ya know ive seen that a lot... I'm looking for a midbass but they are listed as a 10" mid range... like wtf? who would want a mid range THAT large? the off axis response would be terrible.
  13. ncc74656

    cheap basic o scope

    yea i get that... i make a point to use the customers music so at least to start with its reasonably set but yea your right that once that changes the "tune" is irrelevant. idk, i guess it comes down to we charge to do things to amps for "tuning" and id like to actually DO something worth while there, ya know?
  14. ncc74656

    rockford midbass drivers?

    that narrow range is what i was concerned about with going that route. i figure if I'm doing midbass I'm only using a narrow range anyway so id get more output (80-600 or what not) and then mid range/tweets get high quality. between the store and coworkers ive got a selection of high end parts to listen to but I'm worried i wont be able to get as loud as i want it to be as the drivers are meant for more quality than volume...
  15. ncc74656

    cheap basic o scope

    my ears are too f*cked for that stuff, i mean i know when i hear distortion but I cant hear shit in the higher frequencies. i would prefer a way to visually see whats going on rather than trusting my ears.
  16. ncc74656

    engine/exaust noise

    the truck is still appart but yea i plan to do that, i have done a frame up rebuild on this guy. i used cascade audio spray on dampner on the wheel wells and firewall, used their VB4 lead damper on the trans tunnel and up the center of the firewall, and their 3/4" MLV products from bottom of windshield to under foot. i plan to do this type of deadening all the way through the cab, rear wall, and roof. ive seen exaust wraps but they don't seem to keep the heat in as well as i would like (compared to blankets) and idk how their acoustic properties are (if any consideration is given at all to them).
  17. ncc74656

    rockford midbass drivers?

    i havnt really decided on much of anything yet, and yea i bought those crachendo mids years back and they were crappy, they also had no specs. it just kinda threw me that Rockford of all people would have no specs listed for what appears to be a spl driver? in either case I'm leaning towards the c7 or hertz mids/tweets with a larger midbass to better keep up with my sub. the aerospace is the DSP i plan to use and i think I'm going all Rockford for the amps (two 2500.1's, a 1000.2 and a 4 channel of some type)
  18. ncc74656

    cheap basic o scope

    what do you use for checking the quality of input signals? MECP hoots and hollars about scoping every single line, the scope would be able to tell you where a factory amp's "cleanest" power output is, no? we had a harly in the shop a while back that showed up to about 1/2 volume a clean sine but anything past that looked more like a damn PWM signal... I'm using my scope on an old orion 2500.1 amp that I'm trying to fix, my first delve into doing that kind of circuitry work (I'm expecting it to end in fire...)
  19. ncc74656

    Audison Bit One

    the CD contains test tracks to de-equalize the factory audio system. its just pink/white noise and iirc it tells you what its looking for during the setup so you can just download your own pink/white noise and or use an app to generate it. usb is a normal usb cable, the DRC could be frustrating as you are intended to use this as your volume control. having said this it is more than possible to use your radio and just don't change any settings on it once you have it setup. long story short you should be able to use this just fine as it is.
  20. ncc74656

    cheap basic o scope

    i picked up one of those jtec build your own o scope kits, it was quite fun to build. I'm playing around with that little guy, cost me 25.00. coworker bought a 4500.00 o scope for this but that is just insane to me...
  21. I am looking to use my laptop in cars to do RTA measurements and perhaps FFT later on as i play around with things. From what i have been reading the phantom power is required for many of these XLR connections. I have seen some battery operated flat response mics but the price jumps quite a bit. i am intending to buy the trueRTA application and perhaps the LEAP software or some derivative there of. I am looking for some guidance on what microphone and accompaning hardware is needed to accomplish this. am i able to use my onboard sound card or should i buy a USB card with higher performance. anyone ever used a PC for this type of work and have a setup that works well?
  22. ncc74656

    Measurment microphone for RTA/FFT

    allright, sounds like a plan. ill order this cheap one and go with that for now: https://www.minidsp.com/products/acoustic-measurement/umik-1
  23. ncc74656

    Measurment microphone for RTA/FFT

    http://www.bhphotovideo.com/bnh/controller/home?sku=294376&Q=&c3api=1876%2C92051678162%2C&O=&gclid=CjwKEAjwxoG5BRCC7ezlzNmR8HUSJAAre36jBzjUGKWjfS6D8Tfb9om1RtfAooWL8d81fb9CVMgPsxoCniXw_wcB&is=REG&ap=y&A=details thats one of the mics i was going to look into
  24. ncc74656

    Measurment microphone for RTA/FFT

    for the basic day to day the relative differences would work fine for me i think. secondarily I want to be able to play around with off axis db/spl graphs to better understand speaker placement and lobbing. finally i intend to follow some of the design suggestions in the LDC and try my hand in building myself a home stereo with my own passive crossovers, so i would be using this mic and software for room analysis and general speaker response planning. im fine with spending extra money to be able to have a quality product i can rely on.
  25. ncc74656

    Measurment microphone for RTA/FFT

    yes i am looking to use a 1/24 octave rta for comb filter analysis, i would also like to use this laptop with some of the LEAP style software with FFT's. im fine with buying a 300.00 card if it allows me to accomplish my goal, that said i would like to buy this equipment once instead of doing trial and error with it. i have the USB-C port on this so i can adapt any PCI-E desktop card into this laptop IF required BUT id much rather have a more self contained measurement apparatus. over the last year i have studied much of vance dickason's work, he has many how-to's and setups that have worked for him but most of it is pre 08 and thus many of the products are not in production anymore. im basically trying to recreate some of the setups he recommends in books such as the LDC.
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