Sub woofer

Hi everyone

I have several doubts regarding subwoofer and its amplifier

-1- What is the basic difference(in construction,working and performance) between a subwoofer and an ordinary woofer ?

-2- When was sub woofer first introduced ?(And who introduced it ?)

-3- How can I detect a distorted output from a subwoofer ?

-4- What are the specifications of the box on which the sub is to be mounted ?

-5- Is the shape of the box significant ? Or is that the volume of the box that matter ?

-6- I have bought a subwoofer named 'DAINTY'.On the sub the following are written...8 Ohm,130W RMS,260W MAX .Have you ever heard a company like that ? Or is it a local make ?

-7- Will an amplifier constructed with a TDA 7294 work ?

-8-What should be the power rating (I expect VA,RMS output voltage,RMS output current) of the transformer to be used for maximum power output ?

-8- What are the rating of the rectifier diodes and the filter capacitor to be used for the dual DC power supply ?

Thanks in advance

Jean

Reply to
Jean
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On 17 Jan 2004 21:34:25 -0800, snipped-for-privacy@rediffmail.com (Jean) wrote: Sub woofer is something of a misonomer these days. Sub amps are generally no different that regular amps. some of the better high end sub amps are designed to to do a little better job of delivering low freq signals, other than that no difference and any good class A amp will do the job if it's bottom end will carry the desired lower cycles. Most so called "sub woofer" systems don't actually get into the sub range and generally have a clip point around 30-35 Hz. They just tend to boost the low end of the standard hifi to near equal volume levels of the mid and highs. This does result in better bass response, but we used to get the same out of good audiophile systems in the old days.(I used a Macintosh class A tube amp into Klipshorns and got better bass response than todays run of the mill sub systems. That said you can get real sub performance today, say that in the

18-24 Hz range if you take care in building the system yourself.(Or pay for it from an audiophile shop.) You have to make sure that your source material actually carries the low freqs you want to boost. Better CD's and most DVD audio/video material usually carries some decent low Freqs. Your preamp/sound card have to have the range to pass it and the power amp has to have the ability to carry it.(Some amps have cut-off or notch filters to stop low freq signals to avoid distorting audible signals. i.e. these amps can't handle the low freq due to design limitations, usually put in them to avoid blowing out todays marginal performance speakers.) Make sure the amp you choose has a low freq cutt-off near 0Hz. (I have an old class H amp that I sometime use for that, it's working range is 0-35,000 Hz) As for the driver/s it's best to keep to a sealed enclosure, especially if you plan to build yourself. Ported or folded enclosures tend to be very tricky to build for anyone without a audio test lab at their disposal. Sealed boxes tend to have a "tighter, punchier" sound as well, something desirable when listening to AV sources.(Tend to be best for video and 5.1 sound.) There are alot of good woofers on the market, my recommendation is to get a 12-15 inch woofer/s in a sealed box of the right size. Makes for an easier build/setup and you can always pack or remove stuffing in the box to get the right sound for your ear. Stay away from square boxes, they spell doom for low end response. Go rectangular and make sure you use some really thick mdf(at least 1 inch) or good quality 8-10 ply oak plywood(Birch is good also but very costly.) of at least an inch thickness.(I use 1-1/4 inch 10 ply acoustic plywood, but that has to be special ordered and most consider it overkill.)

As for your question about the "Dainty" ,never heard of it, but I'm mostly old school. Perhaps someone else here can help you on that as well as your questions on the rectifiers diodes on the dual power supply.(Not sure what type of system your trying to build. If you give me more details on the basic design I could help. i.e. will it be active crossover system or passive equal. etc??) Is the sub box you refer to internally powered etc???

Reply to
gothika

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