5.1 + 2.1 = 7.2???

[inveterate]

I've got 8 channel onboard,,, I've got a 5.1 set up as is,, i was wondering if i can hook up a 2.1 speaker to the last 2 channels to make it a 7.1 ...cuz i've seen budget 2.1s that sound Decent enough for my small room.. Anyone know if this works???

 

[HDTVMan]

Would be interesting but yes it should work. Your just amplifying an audio signal.

 

[YOyoYOhowsDAjello]

Yeah, 7.2

Shouldn't be a problem.

 

[Ken90630]

i was wondering if i can hook up a 2.1 speaker to the last 2 channels to make it a 7.1

Don't you mean two 2.1 speakers (presumably as two more satellites)?

If so, yes, it should work. You're just adding two more satellites to your existing 5, thus giving you 7 satellites. With the existing subwoofer, you'll have a 7.1 set-up.

May or may not sound okay depending on how closely the 'new' two satellites sound compared to your existing satellites. Note that the chances are slim that the crossover frequency of different satellites from different systems will be the same. If the 'newer' two satellites are designed to cross over at a higher frequency than your existing ones, they'll be fed higher bass frequencies (by your 5.1 system's subwoofer) than they're designed to handle. In such a case, they will certainly distort and, in a worse case scenario, fry (the voice coils). If I were in your shoes, I'd check the crossover frequencies of the two systems and see how closely they match before I hooked everything up.

I'd also check the impedances of the different satellites and make sure they're the same. They may very well not be. Mixing speaker impedances, particularly in a 7.1-channel setup, isn't highly recommended. 😀

The best solution would be to acquire two more of the same satellites that your 5.1 setup uses. Since your onboard sound will handle a 7.1 setup, you'd be good to go.

EDIT: This will only work, however, if your current system allows for expansion by adding extra satellites. Some systems do, but most don't. 🙂 Thanks to DAjello for pointing this out to me, as I hadn't thought to mention it before.

 

[YOyoYOhowsDAjello]

Originally posted by: Ken90630

i was wondering if i can hook up a 2.1 speaker to the last 2 channels to make it a 7.1

Don't you mean two 2.1 speakers (presumably as two more satellites)?

If so, yes, it should work. You're just adding two more satellites to your existing 5, thus giving you 7 satellites. With the existing subwoofer, you'll have a 7.1 set-up.

May or may not sound okay depending on how closely the 'new' two satellites sound compared to your existing satellites. Note that the chances are slim that the crossover frequency of different satellites from different systems will be the same. If the 'newer' two satellites are designed to cross over at a higher frequency than your existing ones, they'll be fed higher bass frequencies (by your 5.1 system's subwoofer) than they're designed to handle. In such a case, they will certainly distort and, in a worse case scenario, fry (the voice coils). If I were in your shoes, I'd check the crossover frequencies of the two systems and see how closely they match before I hooked everything up.

I'd also check the impedances of the different satellites and make sure they're the same. They may very well not be. Mixing speaker impedances, particularly in a 7.1-channel setup, isn't highly recommended. 😀

The best solution would be to acquire two more of the same satellites that your 5.1 setup uses. Since your onboard sound will handle a 7.1 setup, you'd be good to go. 🙂

How would he hook up two more satellites to a subwoofer designed to use 5 speakers?

I'm pretty sure he wants to add a single "2.1 system" not 2.1 speaker to the mix.

 

[HDTVMan]

You mean he will have a 7.2 setup. 5.1 + 2.1 = 7.2.

BOOM BOOM BOOM. The neighbors will love you.

But some PRO sound systems have 2 sub woofers with a delay between them.

 

[Ken90630]

How would he hook up two more satellites to a subwoofer designed to use 5 speakers?

Good question. Obviously, the sub would have to allow for a 7.1 setup in addition to the 'stock' 5.1. I've read about systems that allow for additional satellites to be added later, although I don't use more than 2.1 myself so I don't have personal experience doing it. There was some Logitech or Creative set awhile back that had "the ability to upgrade by adding more speakers" as one of its selling points, but I don't remember the model number. Had something to do with gaming and "future proofing" it or something .... (And I don't game, so it didn't particularly interest me.)

I'm pretty sure he wants to add a single "2.1 system" not 2.1 speaker to the mix.

Well, he said "i was wondering if i can hook up a 2.1 speaker to the last 2 channels to make it a 7.1." The way it's worded, he says he wants to add one speaker. If he adds a full 2.1 system, then he'll have two subwoofers and 7 satellites. A 7.1-channel system is designed for 1 sub and 7 satellites, not 2 subs and 7 satellites. No? Howz his onboard sound gonna route bass frequencies properly to two subs, since there will presumably not be any option for a "7.2" system in the software or BIOS?

Weird topic ... I may be off base here, but I'm not seeing how this is gonna work correctly. Then again, I've had a long day and am very tired .... :laugh:

Edited to fix a couple typos.

 

[YOyoYOhowsDAjello]

Originally posted by: HDTVMan
You mean he will have a 7.2 setup. 5.1 + 2.1 = 7.2.

BOOM BOOM BOOM. The neighbors will love you.

But some PRO sound systems have 2 sub woofers with a delay between them.

Most dual HT systems I think just have 2 or more subs without delay... and possibly just phase shift so they don't cancel each other out (after careful placement of course 😉)

 

[YOyoYOhowsDAjello]

Originally posted by: Ken90630

How would he hook up two more satellites to a subwoofer designed to use 5 speakers?

Good question. Obviously, the sub would have to allow for a 7.1 setup in addition to the 'stock' 5.1. I've read about systems that allow for additional satellites to be added later, although I don't use more than 2.1 myself so I don't have personal experience doing it. There was some Logitech or Creative set awhile back that had "the ability to upgrade by adding more speakers" as one of its selling points, but I don't remember the model number. Had something to do with gaming and "future proofing" it or something .... (And I don't game, so it didn't particularly interest me.)

I'm pretty sure he wants to add a single "2.1 system" not 2.1 speaker to the mix.

Well, he said "i was wondering if i can hook up a 2.1 speaker to the last 2 channels to make it a 7.1." The way it's worded, he says he wants to add one speaker. If he adds a full 2.1 system, then he'll have two subwoofers and 7 satellites. A 7.1-channel system is designed for 1 sub and 6 satellites, not 2 subs and 6 satellites (that would make it an 8.2). No? Howz his onboard sound gonna route bass frequencies properly to two subs, since there will presumably not be any option for an "8.1" system in the software or BIOS?

Weird topic ... I may be off base here, but I'm not seeing how this is gonna work correctly. Then again, I've had a long day and am very tired .... :laugh:

A 7.1 system is designed for 7 satellites and 1 sub, not 6 satellites and 1 sub.

So, he's at least talking about adding two speakers, so "a 2.1 speaker" makes me think the whole system (otherwise how would he have gotten "5.1 + 2.1 = 7.2" for the title?)

Bass frequencies for 2.1 systems (like your own probably) are done with an internal crossover in the sub, not a separate signal given to the sub.

You just have your own 2.1 system hooked up with a stereo jack, right?

 

[Ken90630]

Originally posted by: YOyoYOhowsDAjello

Originally posted by: HDTVMan
You mean he will have a 7.2 setup. 5.1 + 2.1 = 7.2.

BOOM BOOM BOOM. The neighbors will love you.

But some PRO sound systems have 2 sub woofers with a delay between them.

Most dual HT systems I think just have 2 or more subs without delay... and possibly just phase shift so they don't cancel each other out (after careful placement of course 😉)

You're prolly right. 🙂 But don't such systems have provisions in the software, during setup, to specify that two subs will be running? And howz the OP gonna get his onboard sound circuitry to run two separate multi-channel systems at the same time? I doubt if there will be more than one line-out on his mobo, so howz he gonna output sound to the 2.1 set? Presumably, the "8.0 channel onboard capability" he talks about is for a sub and 7 satellites? (Which is actually 7.1, but whatever.) Maybe if he had a sound card with 2 line-outs, that would work, but even then I can't see a provision in the software to run two separate systems. But again, I don't game (or use a computer for HT), so I admit this may be possible and I'm just not seeing how.

A 7.1 system is designed for 7 satellites and 1 sub, not 6 satellites and 1 sub.

Ooops. Typo by me. My bad. (Told you I was tired.) I've fixed my previous post to reflect proper speaker math. 😛

Bass frequencies for 2.1 systems (like your own probably) are done with an internal crossover in the sub, not a separate signal given to the sub.

I know that. I think you're reinforcing my point, no? 😀 Where are the bass frequencies for the second set (the 2.1 set) gonna come from if he has his 5.1 set plugged into the only output jack on the mobo? There won't be a "bass output" on the 7.1 system's subwoofer, so where is the 2.1 system's sub gonna get its signal from?

I'm too tired for this odd of a topic.

 

[alcoholbob]

".2" is just a liberal convention since there aren't actually two different LFE signals.

For music, stereo subwoofers are usually mated with the mains (usually placed directly under them, or very close to them, since LFE isn't really as nondirectional as you might think). For music playback, with only one sub, it's better to have it between your mains.

Mixing satellites is probably not the greatest idea, and not really practical off of a 5.1 amplifier. His original idea of a 2.1 set is plausible, since computer games don't have a seperate LFE channel, its really 7.0, meaning the second sub wouldn't be completely useless.

The concept does seem amusing (combining two multimedia sets for budget purposes) but I hope it works out for you.

 

[Ken90630]

His original idea of a 2.1 set is plausible, since computer games don't have a seperate LFE channel, its really 7.0, meaning the second sub wouldn't be completely useless.

Again, though, where is the signal for the 2.1 set gonna come from? He's running onboard sound, so no sound card, and I don't know of many mobos that have two line outs for two sets of speaker systems.

He can't run a full 2.1 system off the 5.1-channel system's sub, so where is the signal gonna come from for the 2.1 system? In short -- what is he gonna plug that system into?

What am I missing here? 😕 :laugh:

EDIT: Is that a typo in your post about the second sub not being completely useless? Didn't you mean to say that it would be useless?

 

[YOyoYOhowsDAjello]

Originally posted by: Ken90630

Originally posted by: YOyoYOhowsDAjello

Originally posted by: HDTVMan
You mean he will have a 7.2 setup. 5.1 + 2.1 = 7.2.

BOOM BOOM BOOM. The neighbors will love you.

But some PRO sound systems have 2 sub woofers with a delay between them.

Most dual HT systems I think just have 2 or more subs without delay... and possibly just phase shift so they don't cancel each other out (after careful placement of course 😉)

You're prolly right. 🙂 But don't such systems have provisions in the software, during setup, to specify that two subs will be running? And howz the OP gonna get his onboard sound circuitry to run two separate multi-channel systems at the same time? I doubt if there will be more than one line-out on his mobo, so howz he gonna output sound to the 2.1 set? Presumably, the "8.0 channel onboard capability" he talks about is for a sub and 7 satellites? (Which is actually 7.1, but whatever.) Maybe if he had a sound card with 2 line-outs, that would work, but even then I can't see a provision in the software to run two separate systems. But again, I don't game (or use a computer for HT), so I admit this may be possible and I'm just not seeing how.

A 7.1 system is designed for 7 satellites and 1 sub, not 6 satellites and 1 sub.

Ooops. Typo by me. My bad. (Told you I was tired.) I've fixed my previous post to reflect proper speaker math. 😛

Bass frequencies for 2.1 systems (like your own probably) are done with an internal crossover in the sub, not a separate signal given to the sub.

I know that. I think you're reinforcing my point, no? 😀 Where are the bass frequencies for the second set (the 2.1 set) gonna come from if he has his 5.1 set plugged into the only output jack on the mobo? There won't be a "bass output" on the 7.1 system's subwoofer, so where is the 2.1 system's sub gonna get its signal from?

I'm too tired for this odd of a topic.

He says he has 8 channel onboard sound... 5.1 set goes into the 5.1 outputs, 2.1 set goes into the rear output (7/8)

 

[YOyoYOhowsDAjello]

Originally posted by: Ken90630

His original idea of a 2.1 set is plausible, since computer games don't have a seperate LFE channel, its really 7.0, meaning the second sub wouldn't be completely useless.

Again, though, where is the signal for the 2.1 set gonna come from? He's running onboard sound, so no sound card, and I don't know of many mobos that have two line outs for two sets of speaker systems.

He can't run a full 2.1 system off the 5.1-channel system's sub, so where is the signal gonna come from for the 2.1 system? In short -- what is he gonna plug that system into?

What am I missing here? 😕 :laugh:

EDIT: Is that a typo in your post about the second sub not being completely useless? Didn't you mean to say that it would be useless?

no, not a typo.

the sub will be able to take bass info off the rear jack

 

[YOyoYOhowsDAjello]

Originally posted by: Astrallite
".2" is just a liberal convention since there aren't actually two different LFE signals.

Yeah, well a lot of 7.1 systems are running the same signal for both rear speakers, so I'm perfectly fine calling two subs a 7.2 system 😛
Plus a pretty good authority in computer speaker systems says that's how the math works 😉
http://www.klipsch.com/product/product.aspx?cid=516

 

[Ken90630]

He says he has 8 channel onboard sound... 5.1 set goes into the 5.1 outputs, 2.1 set goes into the rear output (7/8)

Okay, but I betcha his "8 channel onboard sound" has only one line out jack from his mobo, with the mobo mfgr figuring that the user will run 1 sub and 7 satellites. I'll betcha there aren't two line outs on his mobo, and if there aren't, this isn't going to work. 😉

Now, of course, just to spite me, the OP will post that he has a mobo with two line outs. :laugh: So as a pre-emptive strike, I'll ask right here for him to post the brand & model of this mobo for verification purposes. :laugh:

Sorry, guys, I'm gonna remain skeptical on this one until proven otherwise. Having said that, however, I've learned a ton about computer audio from DAjello by reading his posts
over the last 6 months or so, and I'll freely acknowledge his superior expertise in this area. I have a looooong way to go to reach his level when it comes to computer audio.
On this topic, however, I just don't see how the OP can run two separate systems off of onboard sound (unless there are two line-outs on his mobo). Now if he had a sound card with two line outs, that would be very different, wouldn't it? 😀

 

[Ken90630]

Originally posted by: YOyoYOhowsDAjello

Originally posted by: Ken90630

His original idea of a 2.1 set is plausible, since computer games don't have a seperate LFE channel, its really 7.0, meaning the second sub wouldn't be completely useless.

Again, though, where is the signal for the 2.1 set gonna come from? He's running onboard sound, so no sound card, and I don't know of many mobos that have two line outs for two sets of speaker systems.

He can't run a full 2.1 system off the 5.1-channel system's sub, so where is the signal gonna come from for the 2.1 system? In short -- what is he gonna plug that system into?

What am I missing here? 😕 :laugh:

EDIT: Is that a typo in your post about the second sub not being completely useless? Didn't you mean to say that it would be useless?

no, not a typo.

the sub will be able to take bass info off the rear jack

What rear jack? Presumably there will only be one on his mobo (since he's using onboard sound), and that jack is occupied by the sub from the 7.1 system. No? 😕

Well, I was tired when I first got into this thread and now I'm wiped out. Time for sleep, lads. I'll check in in the morning to see if and how I got things mixed up. If I'm all wet on this, by all means enlighten me. We've pretty much run this into the ground, so there can't be much further to go. :laugh:

 

[alcoholbob]

If its really an 8-channel analog card, there should be 4 outputs; L/R/Headphones, Center/Subwoofer, Surround L/R, and Surround Center L/R. In gaming, with no LFE channels, the entire shabang, 20-20khz, will be sent to all channels. If its an onboard soundcard, the line-in jacks will double as surround outs (since they are cheap bastards trying to save money and space).

In analog mode for gaming, the first three jacks will be utilized by the 5.1 speakers. The last jack can be utilized by a 2.1 system. Simple as that. Each powered MM speaker set will provide its own bass-management. If you are adding a crappy 2.1 set, you might not even hear the second sub with all the noise the big one is outputting 😛

 

[YOyoYOhowsDAjello]

Ken, as Astrallite said, the motherboard will have 4 "line outs".

He'd need at least three to get the 5.1 system he has now working properly. Each speaker needs its own signal as you know, so plugging a 5.1 speaker system into a single line out would not work either (well, he might be able to do matrix mode etc, but not properly).

On a lot of motherboards that support 5.1 audio, there will be a green, blue, and pink jack for front out, line-in, and microphone. These should be reassignable to front out, surround out, and center/sub in the sound utility program for the integrated audio.

In this case, the OP has 7.1 audio so there are at least four jacks that can be assigned to do analog out.

Check out his motherboard pictures and you'll see there are 6 jacks. So, I'm not sure which ones, but one of the ones on the right must be able to be reassigned to be an output so he can use the three on the left and one on the right for 7.1 use.

All he needs to do is plug his 5.1 set in normally and set the onboard audio to 7.1 and plug in the additional 2.1 set into the 7/8 rear output jack that he just reassigned.

 

[Ken90630]

Okay. I'm convinced. 🙂 You guys are right and I was off base. 😱

On a lot of motherboards that support 5.1 audio, there will be a green, blue, and pink jack for front out, line-in, and microphone. These should be reassignable to front out, surround out, and center/sub in the sound utility program for the integrated audio.

Wow. I had no idea you could "reassign" jacks like that (obviously). Needless to say, that changes everything! :laugh: This being the case, obviously the OP's idea will work.

I also neglected to notice that he posted his mobo model in his sig. Duuuhhh .... Maybe this experience will teach me to not get involved in threads when I'm extremely tired like I was last night. And I obviously still have a ways to go to have a better handle on computer audio (particularly HT and gaming considerations, since I do neither). Just wish I wasn't so busy and had more time to spend learning.

I apologize to the OP, and I thank you guys for the education. 🙂

 

[inveterate]

Okk,,I bought me some $18.99 2.1s AND 7.2 has been BORN.... The SUBS work by the way but only for the rear channel,, So i got a "Stereo Base" i guess.. so if i run in a circle the base moves front and back,,, it def adds to the 3D since base has to be shared usually and is A-directional. Now it has 2... THIS MAKES ME want to buy 4 seperate 2.1s and get directional base for each... THAt'd be Sweet.. I've got a big enough room,, so,,,, NEXT Allowance...

 

[YOyoYOhowsDAjello]

Originally posted by: inveterate
Okk,,I bought me some $18.99 2.1s AND 7.2 has been BORN.... The SUBS work by the way but only for the rear channel,, So i got a "Stereo Base" i guess.. so if i run in a circle the base moves front and back,,, it def adds to the 3D since base has to be shared usually and is A-directional. Now it has 2... THIS MAKES ME want to buy 4 seperate 2.1s and get directional base for each... THAt'd be Sweet.. I've got a big enough room,, so,,,, NEXT Allowance...

Save up for a HT set where the speakers cross over to the sub at around 80hz so the sub will be hard to locate 😉

 

[HDTVMan]

Hey tell us how it goes with your 7.2 setup.

Most subwoofers allow you to turn them off while the other speakers still work.

 

[Ken90630]

Originally posted by: YOyoYOhowsDAjello

Originally posted by: inveterate
Okk,,I bought me some $18.99 2.1s AND 7.2 has been BORN.... The SUBS work by the way but only for the rear channel,, So i got a "Stereo Base" i guess.. so if i run in a circle the base moves front and back,,, it def adds to the 3D since base has to be shared usually and is A-directional. Now it has 2... THIS MAKES ME want to buy 4 seperate 2.1s and get directional base for each... THAt'd be Sweet.. I've got a big enough room,, so,,,, NEXT Allowance...

Save up for a HT set where the speakers cross over to the sub at around 80hz so the sub will be hard to locate 😉

Good advice. If the low bass is directional -- i.e., you can locate where the sub's sound is coming from -- it's typically because the crossover frequency is too high. And in such cases, the sub is being asked to reproduce frequencies that would be better handled (more accurately) by the system's satellites. (This is assuming a decent system, set up properly and with no other significant detriments to the sound or the room's acoustics.)

But to each his own, of course. If you like directional bass, go for it. 😛 For music reproduction, I'm not sure how accurate your new system would be if it were measured. For gaming, however, that doesn't matter and you may like the effects of your unusual setup. In the end, whatever sounds best to you is the most important thing. 🙂

 

[alcoholbob]

In practical applications, bass isn't entirely non-directional, since there are several ways of figuring out where its coming from; for example you can feel the reverberations on the ground and have a general idea where its stronger and where its not. Most MM sets are crossed over at 120-160hz (and even most receivers cross over at 100, well into "obviously directional" territory). The .1 channel in movies (or the LFE channel) runs at 25-120hz, which is why all these MM sets are probably getting THX certification, first for the bass, and for the crossover frequency, which is certainly in "directional" territory...(since in movies, first the LFE channel is 10db above the rest of the frequencies, and second, the subwoofer will also play all frequencies off the mains under where the crossover is set; bass dominates the rest of the frequencies; I suppose in that context they assume bass is so loud you don't care where its coming from, so "directional" be screwed).

In music however, bass is said to be "directional"--I suppose for those picky golden ears who notice such things--under a certain frequency and usually a 80hz crossover is suggested. There are also music listeners who claim that bass is directional for them even under this point (I suppose "feeling" the bass like how I described it may be one of the many things they are experiencing). As a result, they suggest the sub to be in the center between the two mains for stereo music playback, so you get the best compromise between time delayed bass signals for each speaker. Idealy every speaker would be mated with a subwoofer so you aren't getting bass out of phase--in some of the fancier theaters, they actually spend the money doing that, although its far more expensive (especially in terms of power consumption) than fewer subwoofers placed strategically. In a 5.1 case, I suppose its best to keep it centered between the left/right/center (LCR) channels yet again, because most of the sounds are coming from there (and it doesn't seem like you are losing as much for the rears; directional bass from the rears seems like a small price to pay).

In this case, For inverterate, the front sub should be lined up with the center channel and the middle of the LCR soundstage like as described before, for matching the fronts LCR. The second sub should be behind him, for one of the surround pairs. Its better than getting no bass for the surrounds, and plus if bass is coming from all around him, it also won't seem as directional (although of course, this does sound like a bit of a disingenuous solution to his problem). However, it's probably as good as it's gonna get in his situation.