Newbie sub question (1 Viewer)

[paul haslett]

Hi all

I am looking to buy a sub, at the moment i have a 5.1 system but i hear that subs also have an amp inside them. If this is true in the future will subs also have 7.1 capability on their amps and if so could i keep my 5.1 amp and get the extra channels from the sub?

I am sorry in advance if this is a stupid question but i am still new to all this.

Thanks for any answers


Paul

 

[Geoff S]

Hi Paul, first off welcome to HTF!
If I understand your question right your asking is the built-in amp on a sub there to drive 2, all 6, or 8 speakers... That answer would be No.
Most consumer subwoofers have an amp built inside of them. This amp is to drive the sub only. You'll find a few that have an external amp instead, around also. The power otput on a sub's amp can be anything from a simple 5 watts on like, computer subs... all the way up to 1000+ watts RMS on home theater subs.
Add a two channel amp to that 5 channel amp to get those surround rear channels, assuming you PreAmp/Processor is 7.1?
And from the pre/pro there should be an RCA jack that says something like "Sub Pre-Out". Connect that to the sub via an RCA subwoofer cable to your sub, non crossover input if it offers the option of crossover/non-crossover. If you don't have a preout you'll need to run your sub as passive by using the signal from the mains.
Hopefully I hit the nail on the head.. let us know if this helps, and if you have any other questions feel free to ask. Also since you're new to this please take a little time to read through the FAQ, it'll answer many question you probably already have. Here's the link: http://www.hometheaterforum.com/htfo...threadid=55635

 

[paul haslett]

I was more thinking of upgrading to 7.1 without having to buy a new amp. The sub i was looking at has speaker wire conectors on the back and my friend said it has got an amp inside. My system has not got a 7.1 proc. I was just woundering if in the future the subs will have speaker conectors for 7.1 and if so could i get the sound from the two extra channels from the sub amp or is all the processing done on the main amps processor, if so why has the amp got speaker wire conectors on the back ?

Thanks for the help

Paul

 

[paul haslett]

so why has the amp got speaker wire conectors on the back ?

sorry mistake should be this:

so why has the sub got speaker wire conectors on the back ?

 

[Mark Tranchant]

The sub has speaker connectors on the back as inputs. This is for use in systems that do not have a subwoofer output: you connect the main speaker cables through the subwoofer, and it uses those signals with its own amp to drive its own speaker. They are not intended to drive extra channels.

In a modern 5.1, 6.1 or "7.1" system, you connect the main receiver sub out to the input on the subwoofer, and you don't use the speaker connectors.

I'd suggest that you read through this Basics area, and understand a lot more before spending any money. You need to understand that 5.1 means six separate, discrete channels on the recording. You don't just add more amps and speakers to a stereo to get 5.1, you need to split up the 5.1 signal into separate channels and amplify each one.

The centre of the system is the processor (which is integrated into a receiver) which takes the multi-channel input and splits it up as required. The sub does not do any processing, it just makes low noises.

Don't take this as an insult, but as advice: you've demonstrated a very low level of understanding in your question, yet you're talking about an upgrade to 7.1. With more understanding, you can probably achieve a better result with your existing 5.1 that you could with an ignorantly-set up 7.1 system costing lots of money.

Of course, once you've done your learning, you may still decide you want to upgrade, in which case you'll have a much better idea of what you need and how to set it up.

Read the Basics area and the FAQ fully, and ask any more questions you need to!

 

[paul haslett]

now i understand.

dont worry i have only just bought my system and dont plan on upgrading any time soon i am very happy with 5.1 sound. This was more a question for the future when i decide to buy a sub. i will not change my amp now just for 6.1 or 7.1.

I knew the input signal was put through a proc to unlock the discrete channels. i just didnt know if the subs amp did any processing

I just couldnt work out why you would have speaker conectors on the back of a sub and why it had an amp inside but now i see.

Thanks for the help

 

[paul haslett]

oh here is my system. i choose it after alot of internet research:

Denon 1802
Polk Audio 600 fronts ( i think cant rem num)
Polk Audio 300fx rears
Polk Audio centre
Plastation 2
Samsung 32 WS TV

any thoughts on new DVD player would be helpful as PS2 is playing up

 

[Geoff S]

FYI: Those speaker terminals are indeed inputs to use the sub as a "Passive Sub". You'd run both main channels into them from the receiver, and then from the sub back out to the main speakers. The Low Pass on the sub would take the bass frequencies from that signal and play them, driving itself with its own amp. The rest of the signal, and power will go right in and out to your main speakers. On an 1802 you have an active preout, and that receiver has its own crossover control. So you don't have to worry about using any subs crossover, or passive inputs which are more for an older 2 channel stereo system that you'd may want to make 2.1. We're talking older than Pro-Logic 1, but new subs remain backwards compadable with older setups.
As for DVD players you have many choices. Sony, Panasonic, Toshiba, Denon, Pioneer etc etc.
A good place to look for Equipment reviews by those who own them is at http://www.audioreview.com
I would also recomend demoing different systems in your price range. Ensure that they have good picture and sound first and foremost, most all will, and then check their features to see what you can do without to save money.

 

[paul haslett]

Thanks for all the advice

Paul

 

[Merrill]

Paul: Yah, someone else on this form with Polks.

 

[paul haslett]

my first speakers to and they are great although i ran out of money when buying the centre and got the PA 175i which is a bit weak. how much was your centre and how does it sound?

 

[John Garcia]

I think there is a bit of confusion here on speaker level inputs vs a passive sub, two very different things. If a sub has ONLY speaker level inputs and no power cord, then it is definitely passive, and will be driven by the receiver's amps and is meant to be used in conjunction with the main speakers. If the sub does have an internal amp, but still has speaker level inputs, it may still be used the same way as a passive, however it will pass a high pass filtered signal from the receiver to the mains, and provide amplification to the low frequencies it reproduces. The power provided to the mains in this case does not come from the sub's amp, it is simply looped through, which is why you cannot use the sub to peform additional amplification.

Merrill, you are not allowed to list your gear in your signature. When people do searches on gear that might be in your sig, every post you have will show up, relevant or not.

 

[John Garcia]

double

 

[Merrill]

Paul: Actually I don't get the Center until Wednesday (today) so I'll let you know. I love the rest. Now if I can just understand all the little nuances of the receiver, I would be all set.
All: Sorry for the forum faux pas. I thought I saw someone list their gear in the signature.