Advanced Discussion

Maybe this should be stickied... Impedance cannot be measured with a DMM. Only DCR can be measured with a single DMM, and this isn't impedance. There is no such thing as "Impedance Rise". There is an impedance curve, but this both rises and falls..... The system impedance will always be higher than the DCR of the driver under any condition. Many factors affect impedance, the biggest being the enclosure. Until you measure your complete alignment at all frequencies in it's operating range, you have no idea what the impedance is. Impedance changes do not change driver power handling, they change how much current you amplifier puts out at a given voltage.. Nobody owns a .7 …

It's kicking my ass. Who will help me understand it better?

I see all these vids of people playing 10 or even 5 hz test tones, and i dont really understand how. If you have it tuned to 35, you set the SS at 30 give or take. Then how is it that the sub can play a 10hz tone. Doesn't the box constrict it, and wouldnt it be unable to control the sub below 30 hz or so if tuned to 35? This may sound noob as hell, i dont care lol. Thanks for reading, Mitch

I might mess around with this sometime this week. +.6 v would do me good The second link is for float voltage, no need for it, but hooking it up to a switch wouldn't be bad. for a shtf moment while driving. http://www.smartgaug...uk/alt_mod.html http://www.smartgaug.../alt_float.html ---------------------------------------

hello everyone fist post .i really need your guys help with eq and crossover setting stopped doiing spl and entered the aq seen bud never knew how difficult it will be .got an alpine 9887 dlsr6a s inthe front doors with baffles and jbl coaxil in the back running of an jl xd600/6 2 jl 10w3v3 running of an jl600/1 all active can enyone please recoment good eq and crossover settings any help will be aprecuated thanks

Alright, so im working on a design for a new box for my NS 18. i am running a saz1500d on stock alternator and soon to be (hopefully) a new xs power battery(probably d5100) im gonna do it right at 5 cubes tuned to 35hz, so it will still be good for daily, and get me a little more spl for when i compete. so since i plan on competing as much as possible i was wondering how much port area to have. ik everybody says 12-16 but i was wondering if i should go more or less or just stick within that range. ik there are some people on here that are really smart when it comes to this subject so thanx in advance. also, is 35hz a good tuning for daily and a little bit of competing or …

I've never really tried my hand at making a great sounding front stage, I usually buy a set of components and throw an amp at them. This time around I would really like to understand what makes up a great front stage and why. what about cone size, do you start with choosing a tweeter and then work your way down to the mid woofer? Help me better understand the things I don't know.

i made a comment on a post on facebook, and tony d'amore said he would be happy to come to SSA and talk about the amp dyno , he actually told me there would be no debate because its science , so here is the topic. where he and we may discuss .. i mean .. talk about science

If you don't want to read my rant: Can someone explain how setting an amp with a DD-1 on track 5 with a 40Hz -10db can still cause me to overdrive my sub with STANDARD music. If I play my sub at 40 out of 47 volume for 1 hour, should the dustcap be warm? Hot? No change at all? 40/47 is less than the rated 1500 watts of the BL (at least at my best guess, especially at 13.8V instead of 14.4V). I want to protect my $1,000 investment in my trunk. I have had a blast with my new Fi BL 15. My head unit's "unclipped" volume is 47 out of 50, and I have never had it past 40. It is very loud, and with a 1500W RMS rating, it is probably getting 1200W at Vol. 40 hooked up to a R…

a subs ability to play lower frequencies loud and well? I'm talking about around 30-40 hz. Ive been told that the big factor is in fact not the box's tuning like I thought it was, so what exactly affects the subs performance at those frequencies?

I have saved a little money for some wood, and still have glue, clamps and screws from my other box. I wanted to give building a T-line a try since i have heard fairly good things about them. It's just a for fun box, for my 12" visonik i got a while back. Amp and power and all that is covered, it's going in the house for now (no car til who knows when >.<). it's for music, primarily low notes in rap music. i was gonna try for a tuning of ~27-29hz. Now on to the hard part. I havent had alot of computer time recently, but in the time i have had, i couldnt find a calculator for a 1/4th wave transmission line. The specs i can give you for my sub: 250rms rated (takes dou…

Well as it sits my subs were wired in series at the sub, then parallel at the amps which were strapped together. Putting each amp at .5ohm Apparently, if I wire the subs to be parallel at the sub then wire each sub to it's own amp with each amp still at .5ohm. It will increase coil efficiency. When wired in series you get double the amperage but half the voltage. Causing heat to build up and efficiency to be lost. In parallel it does the opposite, you get half the amperage but double the voltage. So you still get the same amount of power, it' s just with a higher voltage causing less heat build up and higher efficiency. Which is where the gain comes from Which makes sense…

Active 2-way with Full Range driver for the top end? This is not meant to be a pick my driver for me topic. My new dilemma is because of Adrian, he put the full range bug in my ear and I am starting to question my plans. I am not as versed in full range drivers as many others are on this board, so why not use the knowledge base. Setting: car - Mazda Protege5 wagon original front stage plans - Bravox CF603CF's power - many to choose from, so not an issue mounting location - FR's or mid/tweet would have to be at the base of the A-pillars (small manual car with no real room in the foot wells) Now where I am questioning my plans is that I have not had a passive set up in y…

I drive a reg cab truck. After hearing a friends Xterra and the relativly good imagining and sound stage I have decided to re work my set up. I will be keeping the CDT HD set, I am still very happy with them. Now, I need some Ideas for staging. Kicks are out of the question unfortunatly, atleast for now. I have been reading many, man sites about the topics of phase, Imaging, and sound stage. Most have stated the obvious of rear fill cancellation(doenst apply to me), phasing expecally in the upper freq. ranges, and the best locations for your sound stage. This has led me to think that If I could angle my comp set more that the sound would be better. I see the glassed …

Just been wondering why there is no love for them here??? Lol havent had any of their products they seem to be good and at a very good price but the curiosity is killing me at this point and decided to make this question here, wondering is there a dark history of why it seems like they arent very welcomed here in this forum???

First, I'm going to go through and list the equipment I have then example and ask the questions. Ride- 01 Ford F-250 CrewCab Headunit-Kenwood X789 Sub Amp-ZX1500 Sub-12" Fi Q Box- 2.3cuft Net with two 4" Aeros tuned to ~30hz Ok, so I bought the amp off Craigslist for $50, and only thing it needed was sent off for warranty repair. And had the original receipt, so I got a basically refurb ZX1500 for $65($15 to ship). So when I got it back from Kicker, I wanted to test it, so I through my box in the back seat. The sub was wired in series, so 2.8ohms. Played it for a good little while, the sub showed no sign of stress, and was quiet loud. Not 150dB, but you get the picture. S…

OK SO IM TRYING TO FIND THE BEST WAY TO GET THE POWER AND QUALITY WITH OUT GETING A DIVORCE.! LOL IVE GOT ROOF MOUNT, DOOR MOUNT, DASH MOUNT, REAR DECK LID AND I HAVE A SPACE BEHIND THE REAR PASSANGER SIDE WINDOW WERE ID LIKE TO PUT THE ROCKFORD FOSGATE PUNCH PRO 6" 4 OR 8 OHM MIDRANGE. IM REALLY NEEDING A GOOD AMOUNT OF HELP IV DONE THE FIBERGLASS MYSELF AND IM VERY INTERESTED IN COMPLEATING MY PROJECT. THE HELP I REQUIRE IS SUCH: 1. I NEED TO KNOW THE BEST SPEAKER TO CHOOSE FROM EITHER THE PUNCH PRO 6" 4 OR 8 OHM MIDRANGE , BOTH HAVE THE SAME MOUNTS BUT IM OPEN TO SUGGESTIONS OF OTHER BRANDS BUT DEPTH MAY NOT EXCEED 2.26" 2. I NEED TO KNOW THE BEST AMP OR AMPS TO DO THI…

I thought this would be interesting since different materials have been a hot topic recently. As in: Non-pressed paper, pressed paper, pulp, plastic, wood fiber, IMPP, carbon fiber, Aluminum, Titanium, woven fiber, poly, etc... which material would be the best to use in what application etc....

someone should do this with a voice coil and make the sub-woofer super efficient!!!

would someone like to try to explain the effects that I am starting to notice with the serious increase in humidity and temperature? I have a faint Idea, but I was curious to hear from more experienced SPL'ers

What are the advantages of lowering the temperature in the cabin to gain higher dbs. example: refrigerating the cabin to say 50f before taking a spl reading VIA portable refrigeration unit powered by a generator.

Hello i have a question for you tech guys. my truck peaks at 48 hertz and my wall is tuned to 38 hertz. do i need to retune my wall to 48 hertz to match the trucks resonance for cabin gain to take effect? im currently doing 154.3 and i want to break the 155 mark. been reading for hous on multiple forums and read different things and just getting confused. can some one please help.

I'd like some knowledgeable input on this topic. I have been told to o-scope amps with no load but am wanting to know if any of the following i've been told is true or not. Do not have a load as the amp output from the amp could fry the oscope. Do not have a load as the reading may be off. Well, i've always o-scoped amps with no load. I've o-scoped class d and class ab amps like that with no problems. Today, i attempted to o-scope this class d amp and it got damaged immediately. I contacted the manufacturer and was told it MUST have a load on it or it will do what it did. I ask why and it is due to the amp seeing 0 ohms... Wouldnt the amp go into protect? I dont understa…

From time to time I like to divulge information that helps people understand subwoofer performance. For this particular post I'm going to copy an article from Adire Audio on subwoofer speed. "There's a common misconception out there that heavy woofers must be "slow", and light woofers must be "fast". If a woofer A's moving mass is higher than woofer B's, then woofer A is probably going to be sloppy, or slow and inaccurate. Can't keep up with the bass line. Woofer A simply can't respond as fast as woofer B. There's also this concept that the "acceleration factor" (BL/Mms) is an indicator of woofer speed/transient response. High BL, combined with a low Mms, should give…

Hi guys, my sub amp (Soundstream 2000 monobock) is acting weird. You will hear the subs pop out and then the amp goes into protect. Any time of day, any volume level, music/no music. It's totally random. Just wondering if any of you would have any ideas. I have 165A alternator (stock), 1/0Ga wire to amp. The batt meter on the car stays at 14 volts. The gain on the amp is all the way down. No bass boost. It also seems random when the amp resets itself so I can begin to use it again. Let me know if you need any more info. I'm also wondering if my subs could be the problem. They are dual 3 ohm wired in series to 6 ohm per speaker input (there are 2 on amp). The speakers wire…