Advanced Discussion

please people, i am working on an assignment that require that i compare two amplifiers( Velleman K4004 amplifier vs Amplimo A120amplifier) the task is to determine between the two amplifiers the one with better SOUND OUTPUT.i hav the following equipments to work with, true RMS multimeter,oscilloscope,function generator,variable resistor,the two model of amplifiers mentioned above i have chosen the following specs from a range of online research i have conducted as a means of determining which is better btw the two 1. gain 2. frequency 3. linearity 4. noise 5. bandwidth 6. output dynamic range 7. input and out impedance 8. damping factor please my problem now is how to us…

I need to replace four of these, but cannot figure out the vales to find the part. Help?

I was reading a port area article on here. Port Area - SSA Car Audio Forum Utilizing the recommendations from other in that article and going back and looking at white papers from various manufacturers from the likes of JL, JBL, and Boston Acoustics etc,,, I notice that their port size recommendations are in the 3-4" area. Even on woofs that are known to be seeing 500+ watts. Why? After looking at those enclosure recommendations it is very apparent that the port noise is going to be horrendous let alone compression. Also utilizing the port area calculators in the above listed topic, I noticed that port resonance frequencies drop in frequency the larger the port diamete…

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 talked to a rep. at DC and he said i need 17inches of port area per cubic foot of airspace. how can i tell the port area of a round port? im going to be building 4, 4" in diameter ports, that will be tuned to 33HZ. the box is going to be 5cubes when its all done. i just dont know if i i will have enough port area to keep the port noise to a minimum. any help?

Ok I've been trying to do a lot of reading about the more technical side of audio. I was thinking about different styles of port and how they effect the output of the box. So on to my main question. What if you had a circular port that started off small and grew into a larger diameter. Say it begins as a 3" port and ends up say a 10" port (pulling numbers out of my butt) What advantages or disadvantages would this have?? If you think about it wouldn't it make it louder?? When you helling into a cone your louder, or when you cup your hands around you mouth your voice is louder then without. Wouldn't the same apply for car audio applications??? Any informative incite would …

I have been building boxes for sometime and I notice that a lot of boxes have the same concept but are built a little different. When I build a ported box for two subs I normally direct the air out of the front (depending on the application) of the enclosure with a divider between both chambers. I have seen some enclosures with no divider coming out of the front, just a big hole. Does adding or taking away a divider give off a different sound? I also add one in the middle just to make the box more rigid. I am building two ported boxes for a van. Would it be better to port it in the front like I have been doing or to go another way. I would think that by porting it out the…

Hey everyone, I'm having issues designing an all purpose (SQ while being loud) ported enclosure for my RE '06 XXX15 sub. I had a ported enclosure built. Its approx. 3.5ft^3. It has a rectangular L port with a port area of 60in^2. At the time when I designed the enclosure, I hadn't discovered WinISD or any other similar programs and just used the RE L Port calculator. This enclosure was supposed to be tuned to 35Hz. In short, its a mess. There is alot of port noise and it barely reporoduces anything under 35Hz. So I went back to the drawing board and learnt how to use WinISD. From what the program is telling me, it can't be tuned to 33Hz (which I want to achieve) unless th…

i've been trying to figure this out for a while now.. in a ported enclosure, how would you determine the phase of the sound emanating from the port at any given time? e.g. you have a 4cu.ft box tuned 40Hz.. and you play 3 tones, 35Hz, 40Hz and 45Hz.. will the phase of the port ever be in-phase with the sub? or will the tuning of the box and tone being played determine the phase of sound coming from the port? or would the distance between the back of the woofer and the port determine it?? i know the phase of the sound coming directly off the woofer's cone is 0 deg.. what i want to get is the phase of the sound coming from the port to match that coming from the sub at the d…

Alright all you smart folk, here's what I am wanting: http://www.partsexpress.com/pe/showdetl.cf...tnumber=180-960 I want to be able to run that directly off of my car's electrical system. You can see from the description that it runs off of 6VDC from the included power supply. So, what would be needed is a power supply to convert the 12VDC from my electrical system to 6VDC. I've also had something about Zener Diodes mentioned to me....but I'm not really sure what those are all about. Anybody want to give me a quick run down of the best way to go, and how each is accomplished (i.e. what a simple yet effective PS design would consist of, what Zener diodes do and if they …

Hey guys, just wondering what your input was about passive radiator boxes used in car set-ups??? I used to have a set-up of 2 12" VMax(the red older surround version) with 2 AE speaker 1050g PR's and its lows were pretty amazing. However, I had to have a pretty large box to utilize them like I did. Are there any advantages to me trying to use these PR's in say a SQ set-up or are there better alternatives out there? Let me know what your thoughts are! thanks

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…

My HU it a JVC AVX830. I have the option to change the q on my lows and mids in the eq. Now I've noticed when I change the q to a lower setting the speakers seem to play "louder". What does this do? Is this based off the qts of the driver? How should it be adjusted. Right now I can't seem to get the tuning right. It either sounds hollow and muffled or the highs drown out the words. Could someone enlighten me?

Now I know this has a lot to do with individual preference so this will be very subjective. I was thinking today about where cassette tapes rank as far as audio mediums. I have never seen a real list broken down anywhere, just someone saying "Vinyl is better than CD's" or something of that nature. Let me know if I forgot anything, but this is what I could remember off of the top of my head (not in order obviously). How would most "audiophiles" arrange these from best sounding to worst? DVD-A/SACD (possibly separate?) Cassette Tape Vinyl Digital Storage (Flash/Hard Drive) 8-Track Reel Tape CD

I am curious, alot of infinity subs and solobarics and such call for a pretty small ported enclosure volume (less than 1.5 cuft for a 10) If a sub has a recommended enclosure volume for a vented box of 1 cuft, what would happen if you put that sub in a 1.75 cuft enclosure?

I need to build a new test enclosure and in the process prefer to use a removable baffle. In the past I have used something like this: http://www.madisound.com/catalog/product_i...products_id=768 I am also curious if anyone has any specific implementation recommendations on bolt spacing, overlap of the gasket, better gasket materials, and so on.

I have a Soundstream Rubicon RUB1.2500D, and would like to either remove/disable the SSF circuit, or modify the SSF pot so that I can simply turn it off that way. I haven't looked at the resistance of the SSF pot yet, but could I change it out with a different value of pot to make it so that it is disabled at its lowest setting, instead of the standard 10-40 hertz? I have some experience in repairing and modifying amps, and power supplies and such, but I never have encountered something like this, yet.

hey guys i have a quick question. what is the benifit of tuning your box closer to the res. freq of the car instead of to the sub? in spl competitions?

i have a 1997 mercury mountaineer (ford explorer). does anyone know what the resonant frequency is of my truck. when i find the resonant frequency what will that acomplish? do i need to catch my 1/4 wave at the dash at the frequency? im not quite catching this theory.thanks for any and all help

Now we will start with : Sealed enclosures : A SEALED enclosure will be the smallest,and is the simplest of enclosures and will have good low frequency extension, but might not have the best low frequency extension. If space is limited. and its a good choice for SQ fans (Sound Quality). PORTED enclosures (Bass Reflex) : A PORTED enclosure will generally have a better low frequency extension for a given response shape,but would require a larger enclosure. If you made the enclosure as small as the sealed enclosure, but ported it to gain the low frequency response, the output would deviate from the desired flat response. Ported enclosures are slightly more difficult to desi…

So does anyone wish to share thier secrets? Only thing i've heard is use iron rod instead of wood for bracing.

okay so a couple weeks ago my first h/o alt that i had singer instal a self excite and extrenal reg. on started being all buggy and sometimes not charging at all when i would turn on my car, well it just finally started getting colder in mn so I kinda wondered if that was the problem, anyway i already had a better alt on the way, a mechman 320 self excite. and when i installed it i was in a friends heated garage, and it fired up right away. Now every morning on my way to work it takes like 5-10 minutes of straight battery power before the alt kicks on. however if I drive home from work, get same problem, but then maybe an hour after car sits when i get home I go out aga…

Hi Guyz, Not sure if I'm in the right section... Firstly, please don't flame me on this one... Just trying new things. Let's say I will use a Maxxbass 103 processor that adds upper harmonics to the sound, making a component sounds like it is playing deeper due to the psychoacoustical effect. I have also read that it actually decreases (on some frequencies) the Xmax by 4. The component I'd like to use in that example is the RL-i8 Here is my question: Due to having the Xmax decreased, will that mean the component can handle more power 1/ for not reaching maximum excursion with the power applied 2/ for having a dual voice coil instead of one - that might sound stupid…

I tried to read the threads on how to make a slot port and etc. etc. I tried to use the ones on the net, but people keep saying they are off. So if you happen to have microsoft excel, you can use this on and plug and chug some numbers in to get your required port length. This is based off the equation on JL Audio's site and it also takes into account End correction. If anyone has any input or if the JL Audio equation is wrong, then let me know, I just wanted to do my port right. http://www.uploading.com/files/CFXVZ5QA/Sl...ulator.xls.html

I read this a while back, not sure if i posted it or not. -------------------------------------------------------------------------- Optimum Speaker Placement An often asked question by consumers on our tech support line is: "What's The Best/Optimum Speaker Placement"to achieve perfect imaging? The attached images show good speaker placement and speaker angle for both door/kick panel and A-pillar installs. Try to get as close as possibly to these speaker placements and speaker angles on your installs and imaging will always be improved/close to perfect. Stock door panels are often more than 30% muffling up clean clear…