Surround sound / Subwoofer noob question

[Corpus_Chain]

Hi all,

I'm thinking about switching from stereo to surround sound in my living room, but upon looking at some second hand Onkyo receivers, I have a question!

Are there receivers that have a sub output that is speaker level, rather than pre-out level? I currently have an REL Q50 sub connected to my stereo amp via speaker connections (just connected to the normal speaker connections on the amp). The amp also has a line level input, but using the speaker connection means that the sub volume is linked to the amp volume and it is always at the right level. It was terrible when I had it connected via line input, as it was almost never at the right volume for whatever the amp volume was.

Obviously I could connect the Q50 to the front/center outs on the receiver, but my concern is that this would limit the sub's activity to when there is sound in those channels and it wouldn't always be active when needed (eg an explosion at the rear speakers).

Please help me understand this. I have zero experience of surround sound beyond reading What hi-fi over the years!

 

[thewestfield]

If you look on Rel's website - rel.net - there are a number of guides to connecting a subwoofer in different ways. The section is called "How to connect my subwoofer".

Hopefully this should help.

 

[hiacedrifter]

Hi all,

I'm thinking about switching from stereo to surround sound in my living room, but upon looking at some second hand Onkyo receivers, I have a question!

Are there receivers that have a sub output that is speaker level, rather than pre-out level? I currently have an REL Q50 sub connected to my stereo amp via speaker connections (just connected to the normal speaker connections on the amp). The amp also has a line level input, but using the speaker connection means that the sub volume is linked to the amp volume and it is always at the right level. It was terrible when I had it connected via line input, as it was almost never at the right volume for whatever the amp volume was.

Obviously I could connect the Q50 to the front/center outs on the receiver, but my concern is that this would limit the sub's activity to when there is sound in those channels and it wouldn't always be active when needed (eg an explosion at the rear speakers).

Please help me understand this. I have zero experience of surround sound beyond reading What hi-fi over the years!

Hi, I've been looking into REL connections to a Marantz AV receceiver via line level and high level input. I think I now know what I'm doing, and would be happy to talk you through it via direct message? Please PM me if you'd like to chat.

 

[DT79]

Hi all,

I'm thinking about switching from stereo to surround sound in my living room, but upon looking at some second hand Onkyo receivers, I have a question!

Are there receivers that have a sub output that is speaker level, rather than pre-out level? I currently have an REL Q50 sub connected to my stereo amp via speaker connections (just connected to the normal speaker connections on the amp). The amp also has a line level input, but using the speaker connection means that the sub volume is linked to the amp volume and it is always at the right level. It was terrible when I had it connected via line input, as it was almost never at the right volume for whatever the amp volume was.

Obviously I could connect the Q50 to the front/center outs on the receiver, but my concern is that this would limit the sub's activity to when there is sound in those channels and it wouldn't always be active when needed (eg an explosion at the rear speakers).

Please help me understand this. I have zero experience of surround sound beyond reading What hi-fi over the years!

If you’re going to use a surround sound receiver, assuming it’s something from the last 25 years and it’s at least capable of doing Dolby Digital 5.1 sound, then it’s going to have bass management functionality and an RCA sub output socket which you would use to connect to the LFE input socket on the Q50 (whichever of the RCA input sockets is marked ‘LFE’).

In the receiver you will set a ‘crossover frequency’ for your connected speakers; the frequency around which the sound going to your speakers will roll-off*. Then the LFE (low frequency effects) channel (the .1 in 5.1) plus any bass content beneath the designated crossover frequency for ALL your speakers will be directed to the sub. This is how it’s intended to work and how it will be easiest for you to set up and work the best.

*The crossover frequency should be well within the speakers‘ capability for producing bass, and in most AVRs can be set independently for each speaker position. Basically, see what their specs state the lower roll-off frequency to be and set the crossover frequency a fair bit higher. I.e. if the speakers are stated to go down to 40hz, go for 60hz as the crossover. You can leave the crossover as ‘none’ or ‘full range‘ (everything for that channel goes to that speaker and none of it is redirected to the sub), but there’s no sense in doing that unless you have speakers that are genuinely flat down to 20hz). The default approach is to use 80hz, so if in doubt just do that.

Hope that helps.

 

[rabski]

I've never tried it (our AV setup and hi-fi are totally separate), but some subs AFAIK have both high-level inputs and an LFE input. I assume it is possible to set them differently and somehow switch between the two.

The other solution is slightly more space consuming, but you could keep the REL for music duties, using the high level connections, and pick up a used sub for cinema stuff. The quality doesn't need to be as high, and there are some serious bargains around for AV subs.

Last point. Be careful and check in terms of high level outputs and some processor/amps. Most high-level inputs require the negative terminals to be joined. Many AV amps are totally floating output, and will not take kindly to terminals being connected together. You need to check this carefully to avoid damaging something.

 

[Corpus_Chain]

Thanks for the replies. It seems like the answer to my question is probably that the REL sub is a hi-fi sub rather than an AV sub and that is why I can't imagine it functioning with an AV receiver. I've mentally moved away from the surround sound idea anyway, and the replies just confirm that switching over would be difficult.
Thanks again for your help, folks.