subwoofer near monitor???

[pradeep_chauhan]

If you have tinkered with electronics before I would suggest the LM 3886 audio amp. Ypu can download the data sheet from national semiconductors and make a 68W rms amplifire with JUST 4 additional components (excluding the speaker and the power supply) Its very easy and there are very few things that can go wrong as the IC has protection against all possible mistakes one can do.
Yes the older sound cards had small amps like LM386 (1-2W) built on but this trend has been discontinued possibly due to the scarce board space both on the mobo and the cards also the amps need some type of cooling and addl power supply these things are at a primeum on board. Also If a amp is provided then it ties down the user to use it thus limiting the sound card's employment and sound performance.

 

[neerajvohra]

An incorrectly set up or unsuitable design of subwoofer can seriously compromise the accuracy of your monitoring environment. We outline the performance characteristics of the different types and show you how to incorporate a sub for optimum effect within your system.

Many people who have never actually worked with subwoofers say that it doesn't really matter where you put the sub, because low frequencies are omnidirectional. However, this statement is very misleading, because the physical placement of the subwoofer has a huge effect on its frequency response. Also, the interaction between the sub, satellites and listening room will cause peaks and troughs in the frequency and time domains, the effects
The closed-box speaker construction, with its typical frequency response.
of which are clearly audible. Can you tell if a speaker is wired out of phase within a few seconds of listening without having your head facing the speakers? Anyone who is 'tuned in' to phase anomalies will 'feel' the same effect from a badly placed sub in a good room.

In a multi-channel system there must obviously be a compromise. I would suggest that placement with the front speakers is favoured, as they carry the most important audio information and, once again, a centre position is ideal. However, experimentation shows that any frontal position is workable

Placement with respect to walls and other large structural features should be considered next. The majority of smaller subs will be designed so that they can be used out of the way against a wall. If such a unit is used freestanding, the frequency response and output level will suffer. On the other hand, a number of companies produce subs which are designed to be used freestanding and give best results when moved away from walls or other hard surfaces. The rule here is to check with the manufacturer and experiment with placement and/or listening position when performing the system setup.
When choosing a frontal position, care has to be taken if the sub is placed in a corner, as two problems arise. Firstly, corner placement will increase the low bass output of the sub and will often make it boomy. Secondly, using only one subwoofer will encourage the formation of standing waves in the room. This effect is exaggerated with a sub placed in only one corner. The effect of this can be heard as uneven bass throughout the listening room with some areas being boomy and some being bass light. It is possible to minimise this problem by using two subs, along with a shelving filter that curtails the rise in low end -- an approach I use in my own listening room.

Cant Give You Information better than that!!

Enjoy!!!!

 

[klinux]

*www.crutchfieldadvisor.com/ISEO-rgbtcspd/learningcenter/home/speakers_placement.html

lots more online guides to speaker positioning . but in the end depends on persons interests in music and a bit of trial and error i guess .

 

[Nemesis]

@neerajvohra: pls post the source and dont just baltantly plagiarize....

 

[pimpom]

@klinux : The LM3886 mentioned by pradeep_chauhan is a nice IC. I have the data manual in CD and book form (sent to me by the manufacturers National Semiconductors) and I've used it a few times for purposes other than a computer sub-woofer. A practical design will yield something like 50W output instead of the theoretical 68W. Their LM12 is even more awesome. But there are practical factors you have to consider first.

For one thing, it needs a hefty power supply transformer able to supply more than 100W, at voltages that may not be available as standard (I make my own transformers). The IC also needs a huge heatsink.

And these are for a single-channel, single-IC amplifier. For a 5.1 system, you'll need four other amps. Even if you don't use an LM3886 for each amp, you'll need something that can keep the satellite speakers blaring at levels that can match the sub-woofer, let's say at least 30 real Watts each, not the inflated power ratings shamelessly quoted by manufacturers these days.

While I want to encourage everyone to get their hands dirty by practicing electronics, I suggest that those with limited experience try something less ambitious at first, such as the TDA 2000 series ICs.

 

[klinux]

@pradeep / pimpom and all the other electronics guys : Why not make ur own sites with basics of electronics (indian version) or group together to bring out the best u guys have ??? . i checked up SISI has a few electronics courses , but not sure how useful . BSC electronics (corres) after an MCA sounds odd , but i think its worth it . I have a couple of friends who do electronic engineering projects here in chennai . i ask , they build lol . these guys started their own centre just after getting outta college . they focus mainly on java programming , cell phones , bluetooth and robotic projects . this is done just in weekends mind u . Hope u guys can form some sorta coalition in ur spare time . Thanx for all the info

 

[pimpom]

klinux, this is not the first time you've asked me about my own website. I've never found time before, but you've really got me thinking now.

The thing is, IMO explaining the basics of electronics is more difficult than writing more advanced stuff for those who already know the basics well I mean really explaining things so that anyone who's interested enough can get a firm grasp. Standard textbook approach is not suitable for that. Textbook presentations may be technically correct, but not at all suited for those who want or have to learn by themselves (as I did).

Mentioning technically correct but useless explanations reminds me of the helicopter joke about Micro$oft. If you haven't heard it, here's one source - *www.ajokes.com/jokes/1725.html

This joke is one of my favourites because it agrees exactly with what I used to think about MS help-files long before I heard the joke.

 

[ctrl_alt_del]

Can anyone direct me to any website where I can find some help on making my own 5.1 speaker system? I have looked around and failed. If the site is an Indian one, its even better.

 

[klinux]

@pimpom : true , i think last time it was regarding amiga . we used to have these books in school like 101 electronics experiments and stuff . a cool indi site with animation explaining stuff would be gr8 . I will try to get some basic info or easy info on electronics online . maybe a wiki might help too , with everyone puting in their info whenever possible . Will think abt it next weekend .
Addition : well if above is too hard , all might be able to put in their computer / computer accessory mods on here itself . funkymonkey had his rig up here , and i added one abt front panel audio . maybe that might be easier