Wondering if a subwoofer would make much difference given my room limitations

crazyfingers

crazyfingers

Full Audioholic
I have a subwoofer, an REL 12" self-powered, that I got along with some PSB powered speakers for the TV when I want to live stream concerts. But most of the time the speakers alone are just fine and the subwoofer is just there.

My current 2 channel stereo has a pair of Allison Three speakers. 10" woofers. They are designed to be in the room corners. I could plug the REL into the NAD C 658 sub-outs and see what happens. The NAD will cut off the Allison's at 80Hz and send 80hz and below to the subwoofer. But I don't think that I can just activate and deactivate them with a switch. I think that NAD switches the subs on if something is plugged into the sub-outs. So comparing with and without means unplugging them and replugging them into the RCAs

Also, because of the room arrangement (which is full of clutter and isn't going to change much soon) the sub would need to be significantly off to the right by the TV, not by the speakers.

Allison Three Speakers
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The two speakers are in the only two corners that work. I can't do much about the clutter at this time. It's mostly my wife's. It is the basement after all, formerly a 2 car garage before it was finished as a room.
2023 04 27 17 03 52a.jpg


The TV is on the other wall to the right of the right speaker. It's the only sensible place for the TV given that the pillars would obstruct view even if I could get the clutter out. The Sub is below the TV on the right side. I might be able to move it closer to the speaker. The Turntable is under the bandana so that spot is out. I'm not very keen on putting the sub on top of the vinyls where the old preamp and EQ are sitting for the moment. I think that at most I could swap locations of the table that the TV is on and the sub but then I wouldn't have easy access to the controls on the back of the sub. I can't rearrange the speakers and put one to the right of the TV. There is a door outside to the deck and a bathroom on that side and then the speakers would be even farther apart. (If anyone is curious, the Amp is a Carver M400 and is on top of the component cabinet with the Star Trek models)
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So I see two considerations. Would the REL really make much difference to the sound given that 1, the Allison Three's have good bass and 2, the sub would be well off to the side on the other wall, would it be just too strange? I know that bass is non-directional but still....

At some point I expect I'll just give it a try but I'm curious what people think. It's easy enough to run two RCAs to the sub from the NAD but comparing with and without is not so easy.
 
crazyfingers

crazyfingers

Full Audioholic
By the way, the NAD does have DIRAC LIVE but I haven't done that yet.
 
j_garcia

j_garcia

Audioholic Jedi
Low bass waves are longer than this room, so it would not matter that it would be off to the side. What does matter is that where you put it works for the room.

This particular sub will add output, but probably not extend too much beyond the Allisons. For a room this size, it is probably not sufficient to add usable impact. You could still get something newer that is about the same size that would likely have much more usable output if that is what you are interested in. That sub says -6dB at 24Hz, which means usable output is probably closer to 30Hz.

https://rslspeakers.com/speedwoofer-12s/ This one will extend much lower, still not require much more space and won't break the budget. Only issue is them being in stock. If the size matters, step down to their 10".
 
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crazyfingers

crazyfingers

Full Audioholic
That's useful. I did hook them up and I discovered that I can toggle the settings in the NAD for Subs on or off in the undocumented settings (not in the manual) However the volume on the sub is very low. People are complaining that this NAD's sub outs are lower gain than the lows coming out of the main speaker preouts. I get better bass with the subs off. So Now I wonder if something like a headphone amp between the sub-outs and the sub would be a cure? Use it to turn the volume up on the signal going to the subs.
 
isolar8001

isolar8001

Audioholic General
That's useful. I did hook them up and I discovered that I can toggle the settings in the NAD for Subs on or off in the undocumented settings (not in the manual) However the volume on the sub is very low. People are complaining that this NAD's sub outs are lower gain than the lows coming out of the main speaker preouts. I get better bass with the subs off. So Now I wonder if something like a headphone amp between the sub-outs and the sub would be a cure? Use it to turn the volume up on the signal going to the subs.
REL is really big on using the high level/speaker line inputs rather than using the standard RCA sub input...it seems some of them are designed with that in mind. Don't know much about this approach myself, maybe someone else can elaborate.

 
crazyfingers

crazyfingers

Full Audioholic
REL is really big on using the high level/speaker line inputs rather than using the standard RCA sub input...it seems some of them are designed with that in mind. Don't know much about this approach myself, maybe someone else can elaborate.

My particular RELs only have low level inputs. They work well with the sub-outs on the PSB speakers but are very low volume on the NAD. Since people have said that the sub-outs on the NAD are very low, I wonder if a headphone amp would boost the input into the RELs if put between the NAD and the RELs.

I can try putting my retired ADCOM preamp between the NAD and the REL but that feels overkill. But it might be an interesting experiment.
 
isolar8001

isolar8001

Audioholic General
My particular RELs only have low level inputs. They work well with the sub-outs on the PSB speakers but are very low volume on the NAD. Since people have said that the sub-outs on the NAD are very low, I wonder if a headphone amp would boost the input into the RELs if put between the NAD and the RELs.

I can try putting my retired ADCOM preamp between the NAD and the REL but that feels overkill. But it might be an interesting experiment.
Using a remote sub transmitter can/sometimes ups the level.....I know when I've used the wireless modules on any of my RSL subs, they are a lot louder that way.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
If it has LR inputs, try a Y splitter. It doesn’t raise the output voltage, but it does raise the input sensitivity. Might help.
 
crazyfingers

crazyfingers

Full Audioholic
If it has LR inputs, try a Y splitter. It doesn’t raise the output voltage, but it does raise the input sensitivity. Might help.
Interesting! The NAD preamp and the REL Sub both have L and R RCAs so I use two RCA cables at this time. What should I change?
 
lovinthehd

lovinthehd

Audioholic Jedi
My particular RELs only have low level inputs. They work well with the sub-outs on the PSB speakers but are very low volume on the NAD. Since people have said that the sub-outs on the NAD are very low, I wonder if a headphone amp would boost the input into the RELs if put between the NAD and the RELs.

I can try putting my retired ADCOM preamp between the NAD and the REL but that feels overkill. But it might be an interesting experiment.
Where is the gain set on the sub? If the pre-out levels are low you generally just need to up the gain on the sub.
 
crazyfingers

crazyfingers

Full Audioholic
Where is the gain set on the sub? If the pre-out levels are low you generally just need to up the gain on the sub.
That's the first thing I did after it was all connected to the NAD. I had put the sub's volume control to zero and turned it up as I listened to music. At 100% it's still too soft.

ETA: When connected to the PSB speakers I keep them at around 50% and it's the right volume.
 
lovinthehd

lovinthehd

Audioholic Jedi
That's the first thing I did after it was all connected to the NAD. I had put the sub's volume control to zero and turned it up as I listened to music. At 100% it's still too soft.

ETA: When connected to the PSB speakers I keep them at around 50% and it's the right volume.
Not sure I understand that....your PSB speakers are powered or ? Is your experience based on music without much sub content?
 
lovinthehd

lovinthehd

Audioholic Jedi
That's the first thing I did after it was all connected to the NAD. I had put the sub's volume control to zero and turned it up as I listened to music. At 100% it's still too soft.

ETA: When connected to the PSB speakers I keep them at around 50% and it's the right volume.
Hard to know your methods from that....or your tastes. What is "right volume" particularly?
 
crazyfingers

crazyfingers

Full Audioholic
Not sure I understand that....your PSB speakers are powered or ? Is your experience based on music without much sub content?
Ya. Do you remember this topic?


I ended up getting PSB powered speakers and an REL powered sub to replace the soundbar on the LG TV.

But most of the time the REL sub is overkill for TV watching so I'm experimenting also using the REL with the stereo that's headed by the NAD preamp>Carver M400 amp and Allison Three speakers.
 
crazyfingers

crazyfingers

Full Audioholic
It appears that the PSB speakers put out a much stronger analog sub-out signal than does the NAD. I can only bearly hear the Sub when connected to the NAD Sub outs. It appears that a low sub-out signal strength is a known design flaw on the NAD. I posted a link above to a support thread on the NAD.
 
lovinthehd

lovinthehd

Audioholic Jedi
Ya. Do you remember this topic?


I ended up getting PSB powered speakers and an REL powered sub to replace the soundbar on the LG TV.

But most of the time the REL sub is overkill for TV watching so I'm experimenting also using the REL with the stereo that's headed by the NAD preamp>Carver M400 amp and Allison Three speakers.
I'd consider any Rel sub to be less than optimal. If the Rel is not working well it's more likely your integration and/or expectations. Just not very good subs in the greater picture. If it's "overkill" that's surprising.
 
crazyfingers

crazyfingers

Full Audioholic
Ok.... As I said, the REL is working fine with the PSB speakers. It's not working well with the NAD and I believe that's because the NAD is outputting too weak an analog signal at the sub-outs based on the many complaints about the sub-outs on the preamp from others.

When 99.99% of the time the TV is used to watch 20 year old DVDs of Star Trek Next Generation, stream M*A*S*H off HULU or watch old John Wayne WWII movies and similar, the REL sub combined with the PSB speakers is overkill. The PSB speakers do just fine without the sub.
 
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