"Poor Man's" 5.1 Channel Surround From A Two Channel Amp

I have actually done this, but not all of it at the same time. This part on ce, that part another time, but there is no reason it can't all work togeth er.

Many people do not like new audio equipment, the tone controls suck, there is not much clipping headroom so that extra power is not there, to me most of it sounds like shit. And people might like how their old faithful amp so unds on their speakers. I have three amps and three pairs of speakers and t hey all sound different in different combinations, and I am half deaf !

This is true high fidelity surround there is no delay or effect. In fact wh en there is I do not consider it high fidelity because it is not putting ou t what is put in. With this, everything coming out of the speakers is exact ly what went into the amp. At the Asylum one said "You get one of those rec eivers and try all the modes, and then put it in direct mode and wonder why you bought it". I agree.

The circuit :

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The amp must be of conventional design, not BTL or with one channel inverte d like some Carvers and who knows what else. If it is not conventional ther e may be a caveat in the manual about the use of speaker level fed amplifie d subwoofers, as they only work right with a conventional amp. However in o lder equipment before subwoofers were in widespread use there may be nothin g and you'll have to figure it out on your own.

The rears are in series out of phase, with the + to the same + as the front s. This mixes the sound in the room properly. There is no return. The resis tors combine the L & R into the center. The return from all but the rears t ie together and feed the sub.

Just off the top of my head, C 1 should be from 47 uF to maybe 100 uF, depe nding on the speakers, the sub and the desired crossover frequency.

I think 6 ohms should do for R 1 and R 2. That gives differential signal lo ad to the amp only 12 ohms in parallel, with the summed impedances of the r ears in series. It should not fry the amp though I would recommend one that can handle 4 ohms without burning the place down. This setup imposes a dif ferent type of load on the power amp which depends on how it is mixed down.

Two resistors from anywhere, a cap from anyone who sells speaker crossover components, the wire and speakers and you are in business.It should work fi ne with tube amps if you're into that. Myself, I prefer good solid state de sign. High damping factor. DC coupling. And the fact that unless it is a cl ass A I can just leave it on forever. You would never leave a tube amp runn ing 24/7/365. Also, this setup may decrease the stereo separation of a tube amp due to the low damping factor some have.

So, what y'all think of this contraption ? I can tell you it sounds pretty good, at least on most of what I listen to.

Reply to
jurb6006
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Pretty stupid to use a trademarked name "Surround Sound" to describe your kludged up mess. Speaker count does not a Surround System make. Surround is DISCREET chanels with individual programming.

Reply to
Long Hair

Why are they being discreet are they hiding from someone

Reply to
bitrex

Surround is DISCREET chanels with individual programming. "

First of all, some surround amps have only one output for rear and wire the speakers together out of phase, except in parallel. Same difference. So th ere goes that definition.

In regular surround with no delay effects or hall or any of that shit, this arrangement does provide the same signals as a standard 5.1 surround syste m, but without the extra output amp stages. Granted that means you cannot c ontrol the level of each channel independently but whaddya want for nuthin' ?

The resistors successfully combine L and R to a center output, do they not ? The lack of a return to common on the rears effectively eliminates the L+ R component, does it not ? The capacitor shunts the higher frequencies acro ss the the subwoofer to common and thus also maintains a common at the hig her frequencies for the front L and R speaker, thus providing proper L to R separation does it not ?

Some kludges work just fine.

Reply to
jurb6006

I actually didn't notice that. When someone does that Iwonder if it is actu ally a typo, I make many, or they actually don't know the difference. It is not that important but just interesting with all the semi-literate people in the US. I mean with to and too. there, their and they're. I actually mak e that mistake sometimes and where you can't edit like here it is AARRGH, a nd I bitch about people being illiterate, worst when it really is NOT a typ o !

I also occasionally interpolate not and now.

"You are not f***ed" "You are now f***ed"

Kinda makes a difference, and no spelling or even grammar check could catch it.

Reply to
jurb6006

"Sound Field"? It does not... nuff said. When I watch a movie, I want to be able to keep from getting the impression that the character on screen in front of me, is talking behind me.

That is the whole reason it was developed.

Reply to
Long Hair

It does exactly the same thing, but without the delay. The dialogue is usua lly mixed pretty equal in L+R so that keeps it out of the rears. When it is slightly off to the side it is reproduced by the dominant side and the cen ter, and is considerably attenuated in the rears.

Too much business in the background is why they came out with the center ch annel. Some movies you practically have to watch in mono to understand the words.

Sometimes the intend for certain sound, once in a while part o f the dialog ue, to come from the rear. In this case it is mixed more in L-R which feeds it to the rear speakers more.

Actually, if you hear really really good audiophile speakers with superior imaging, the effect works anyway. The out of phase sound seems to come from the rear even without speakers there. But that is neither here or there.

Actually it was to make money. but it is cool, and Ilike it on movies that are full of cool effects. Days Of Thunder was great on my varimatrix quad s ystem, when the cars went behind you on the track (screen) they came fro th e rears and did indeed sound like they were going around you. On like Star Trek movies, when the ship is shot coming at you and goes off screen the s ound shifts to the rear. It's all in the mix, so to speak, meaning the audi o mixing board which is pretty sophisticated these days. It is NOT what one would buy at the local guitar/music store to say the least.

But on movies of substance, with a good story and little reason for special effects, I think they overdo it. Sometimes the delay is already there and to me it sounds like it is coming through a long hollow tube. They were doi ng it to most everything and even switching to mono didn't get completely r id of it.

Wanna bitch about something ? Movies and TV have much dynamic range. So muc h so that it can be hard to watch late at night with others sleeping. You t urn it loud enough to hear the dialogue and then something happens like a c ar blows up and it rattles the windows. There should be audio compression a s an available option. They got every other god damn feature, next year the y probably will brush your teeth.

But now FM radio is usually compressed to the point of barely listenable. A nd in some tuners that are older it might as well be because of all the ext ra signals embedded in there that are not filtered out by the IF strip like the newer ones. So they have this little funny noise.

Anyway, back to the topic. Yes it would be better with a separate amp per s peakers and the ability to adjust the levels of each channel. It would be n ice to just have a variable crossover for the sub. But the fact it, this k ludge works well enough for people who want to keep their old amp. And some of those old amps really do sound better. And if say, a poor Man has alot of speakers around and can afford a cap and two resistors it will work well enough.

And that's the point.

Reply to
jurb6006

Many years ago (well, like 10) I worked for a small retail shop that sold high-end audio production/DJ/wannabe rap star music gear, there wasn't a lot of staff so I was pressed into the role of HR department for a while, and spent a decent amount of time looking over resumes.

Even resumes contained a lot of silly errors; I remember one where the applicant had probably used a spell checker but didn't double-check that the results made sense. So instead of "Objective" on the cover letter it said "OBJECTION."

I'm sure the entry-level position they were applying for was rather objectionable but sadly they didn't make the cut for an interview.

Reply to
bitrex

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