Connecting a subwoofer to my Nad C350?

B&W · 2 Apr 2008 at 20:39

Hi, I don't get much bass from my speakes and I have a yamaha amp lieing around. It has speaker terminals and I know you can connect it by wiring the speakers to the sub, then the sub to the amp.

But I guess sound quality wouldnt be too good that way and id loose the benefit of the amp?

Is there anyway I can leave my speakers wired up to my amp and connect the sub to my amp somehow?

badbob · 2 Apr 2008 at 21:18

Depends on the system, there are a few methods

1) AV amp + active subwoofer- use subwoofer pre-out.
2) Stereo integrated amplifier + active subwoofer- use L/R preouts (stereo pair) or stereo run of speaker cable
3) AV amp or stereo amp with passive subwoofer, subwoofer pre-out of L/R preouts to the subwoofer amplifier, then speaker cable to the driver.

You need to list exact bits of kit (sub and sub amp) Either way you need to send audio from your NAD to the sub, either low or high level, depending on the sub.

B&W · 2 Apr 2008 at 21:39

Hi, its a stereo amp. The sub is active I believe with two rca labelled L (mono) and R (input 2).

There are speaker terminals at the bottom and I know how to use these to get the sub working in tandem with the speakers, however I believe this will mean that the sound quality will be affected as the speakers will be gettin the signals from the amp. is that true?

If so what other way is there to wire it up.

badbob · 2 Apr 2008 at 22:26

Just use a stereo pair of RCA cables from the NAD pre-outs to the subwoofer.

B&W · 2 Apr 2008 at 23:24

thanks

I just have 1 question, I connected two of the ends of the cable to the preouts on the amp. Theres two inputs on the sub, if i stick the rca cables in either 1 or both at the same time it works.

Should I just use one plug to the sub or leave em both plugged in?

badbob · 3 Apr 2008 at 00:02

You should use left & right, although the subwoofer is mono you want to combine left & right audio, and send that to the sub. Of course you're sending full range so you need to adjust the crossover on the subwoofer.

B&W · 3 Apr 2008 at 00:11

thanks once again, the sub has no crossover just a volume knob. its nothing special but my speakers only go down to 70 hz so needed something to reproduce the lows.

badbob · 3 Apr 2008 at 00:36

Then you need to filter out HF, the NAD pre-out is full range..and if the sub doesn't have a crossover it'll attempt to do full-range, and sound horrid. Your NAD isn't a AV amp so you don't have a subwoofer filtered output.

B&W · 3 Apr 2008 at 02:11

well how can I filter out the hf on the preamps. dont think its possible

MikeHunt79 · 3 Apr 2008 at 02:24

Look for an active crossover. I use a DCX2496, but there are others around.

badbob · 3 Apr 2008 at 02:26

^Probably more expensive than the sub itself..I'd just buy a new sub, as that should have a crossover (some ones don't, as shifting towards AV) ie Paradigm Servo 15.

B&W · 3 Apr 2008 at 02:29

I guess id have to pay more then £50 for a new sub with crossover....

B&W · 3 Apr 2008 at 02:32

BTW my system:

SB X-Fi xtreme audio
Nad C350
B&W DM110
Yamaha SWP201 amp. (part of a 5.1 sorround package)

badbob · 3 Apr 2008 at 02:33

You can buy a active subwoofer with crossover for £50. But I wouldn't recommend you did. If your rig is pretty good budget, which from the NAD it is, then you need to get a good sub...no point getting a farty mid woofer which'll just ruin your stereo sound field. Checkout BK XLS 200, IMO don't touch anything lower than that. Although if you're really skint get the Gemini.

B&W · 3 Apr 2008 at 02:39

ok dude cheers, dont think ill be buying a new subwoofer just yet. However i may invest in a cyrus 1 or 2 amplifier. I used to have the cyrus 1 and to me it sounded more lively then the Nad, granted the Nad has more power and is technically better I prefered the cyrus sound.

mite pick 1 up from ebay

MikeHunt79 · 3 Apr 2008 at 03:48

badbob said:
^Probably more expensive than the sub itself..I'd just buy a new sub, as that should have a crossover (some ones don't, as shifting towards AV) ie Paradigm Servo 15.

Yea I guess a DCX is overkill for this really (Unless he's got a Danley DTS20

)...
You can build a simple LPF yourself for less than a tenner with a few op-amps, caps and resistors, and a +-15v supply if you don't mind a little soldering...

I'm not really aware of anything commercially available for less than £100 tho, but there is probably something if you dig a little.

86JR · 3 Apr 2008 at 03:53

You could make your own passive crossovers.

MikeHunt79 · 3 Apr 2008 at 11:15

twoblacklines said:
You could make your own passive crossovers.

Passive crossovers will work, but they aren't really a good idea if the filter frequency is anything less than 1KHz... I'd go for active.

EDIT: Passive won't work actually, as the sub has it's own built in amp.

lozza23_uk · 3 Apr 2008 at 13:19

MikeHunt79 said:
Passive crossovers will work, but they aren't really a good idea if the filter frequency is anything less than 1KHz... I'd go for active.

EDIT: Passive won't work actually, as the sub has it's own built in amp.

why couldnt the signal be filtered passively before it hits the sub?

MikeHunt79 · 3 Apr 2008 at 13:29

lozza23_uk said:
why couldnt the signal be filtered passively before it hits the sub?

Active filter = line level filer, which can be used in a pre-amp for example.

Passive filter = speaker level filter, which has to be used between the amp and speakers. Uses high powered components, and is not as good as active.

So unless he dismantles his sub he's going to have to use an Active filter.

This site is awesome, lots of great info, and I find it pretty easy to understand:

http://sound.westhost.com/biamp-vs-passive.htm

http://sound.westhost.com/bi-amp.htm