Audio Systems: speaker box

Question
QUESTION: How big and size in inches should the amp be test

ANSWER: Amplifier testing is conducted using test standards that have been developed by the accepted testing organizations for the country the amplifiers are sold into. In the USA the amplifier testing standard used is published by the Consumer Electronics Association located in the Washington DC area.

For example the car audio testing standard - which is very old is found at:;

http://global.ihs.com/search_res.cfm?MID=W097&input_doc_number=EIA-517

and there are others.

I didn't understand the full nature of your question about testing so if the above does not relate to your interest please send me more explicit request and I will try to answer it objectively.

Thank you.



---------- FOLLOW-UP ----------

QUESTION: Hello thanks for the quick response. Now I have more of a serious question.  I have 2 critical mass 10ss2 subs . I M looking for sq sound but also nice tight kick . The amp I have to run these is steg k2.03 1000 watts rms bridged at 4ohm s . The car is 2000 buick century with mid to large size trunk. Now I was hooping I could get info on what type of box u recommend and internal size in inches and what size of mdf. The driver is 5 7/8 in height and each sub is 500 watts rms and 1000 watts max . These subs are 2ohm nominal. Thats why I am running the amp bridgedvat 4ohms

Answer
Got it.  I fully understand what you want to do but without more specific details of the drivers it is difficult to design the box.  Most manufacturers of drivers will give the Q numbers and even suggest box size or designs for various applications. If the driver manufacturer does not then you must measure them by yourself. There are many online places you can find with google to perform the measures and others that will help you decide the best box for what you want to get out of it.  Often you can find in forums of others who have same or similar designs that have worked for them.  There are lots of arts and guesses with speaker design.

Power ratings are less important than are sensitivity measurements. If a particular driver is more than 2db more or less sensitive then you must build in attenuation to the higher rated unit so they will match for even sound quality.  And, crossover capacitors are a function of impedance and crossover point recommended by the woofer and/or midrange drivers.

In car systems designs the box/driver often behaves as an air pump rather than a true open-air driver box.  So, depending on how you intend to load it into the trunk space you may end up just getting a closed box system and hope you get enough excursion from the woofer drivers to pump enough are to get some good bass going -  more with the windows rolled up to keep the box of the car pressurized when low frequencies start bouncing around.

There are many software and design web places to find online.  Here is one that may be of help to you; it will produce tones and ideas for your testing and checking out when ready.

http://freetestaudio.blogspot.com/2009/11/freeware-subwoofer-enclosure-design.ht

You can find lots of other information that will guide you with a few google searches.  Not knowing your level of technology and engineering skill it is hard.  But, let me tell you the best sounding automobile installations are those who have taken the time to experiment with a few changes until they get optimum performance in the cavity of the particular car they are loaded into.  The size of the trunk, the size of the box and the drivers are all important elements of the final equation and results.

For connection to the amplifier just make sure you are not giving the amp an impedance load that is lower than it is rated for otherwise it will give you problems (like the amp can melt down if driving a load too low in impedance).

Good going.  Wishing you luck and great performance.