Combining NAD 3020 and 1000W Class D amplifier? Got some random passive speakers and amplifiers and unsure what the limits are.

[1niltothe]

Posting here because I'm a n00b curious about principles, learning - especially the electronics (ohms, wattage etc). Not intending to set up the best audiophile system in the world.

Say you had a mish mash assortment of 2nd hand Ebay speakers and amplifiers and wanted to combine some of them. Like a mongrel.

A passive subwoofer and a passive bookshelf speaker, powered with two amplifiers, along the lines of bass / mids & tops:

1000W Class D amplifier -----> subwoofer (300W RMS / 600W Peak).

NAD 3020 ----> bookshelf speaker (100W max input).

Is it possible to combine them? If so, are there various ways to do it, or only one?

I.e. would it be a case of sending signal from the NAD 3020 pre-amp to the INPUT of the 1000W power amp?

Am I right in assuming the NAD 3020 would struggle with the passive subwoofer, and the power amp would blow up the bookshelf speaker?

---

Again not super concerned with the finer details of sound quality per se. It's all stuff that already is lying around, and I'm mostly curious.

Also don't mind fiddling with different connectors - e.g. speakon / bare wire / jack.

Connection ports of subwoofer - image here. It shows the specs and Speakon pass thru.

Connection ports of 1000W power amp - image here.

 

[nerdstrike]

The bookshelf would only fire its tweeter across the room if enough input voltage was applied to the kW amp. That is dictated by the amp gain and the signal amplitude (from your pre-amp). I would expect the NAD to clip hard trying to run the sub loud - potential for bad sound as well as stressing any weaknesses inherent to the system.

With gain in mind, the 3020 might conceivably run its own amp and the external one if the gains are proportionate. What's missing is any high/low pass for the respective frequency ranges. That poor 12" cone will be trying ineffectively to emit kHz noises, and the bookshelf will double the bass that it can.

My guesses, assuming you can make a wiring solution for mono.
1. NAD runs both: low volume only. Some distortion from lack of hi/lo pass. Clipping amp can lead to damage.
2. NAD runs bookshelf, pre-amp to second amp to sub: Sub may be disappointingly quiet with (guess!) lower gain from the second amp.
3. NAD pre-amp to second amp, to both sub and bookshelf: Balanced volume with risk of blowing the bookshelf if too loud, distortion from lack of crossover as 1.

I don't know if there are any consequences to running dramatically different loads on L/R channels of a single amp.

 

[Apesbrain]

Use two RCA "1 male-to-2 male splitters" from the NAD preamp output to:
1. The NAD power amp input
2. The subwoofer amp input 1 via "RCA female-to-TS" cable. May be hard to find so another option is an RCA extender and an "RCA-to-TS" adapter. Combine the left/right sub leads using another adapter.

Connect bookshelf speakers to NAD speaker outputs using bare speaker wire.
Connect subwoofer amp output 1 to subwoofer via Speakon connector.

Keep levels down until you verify how all this works. The NAD volume should then control both the bookshelf speakers and the sub. Adjust the relative level of the sub via volume control on front of sub amp. You won't have any control over subwoofer turnover and phase, so that's a wild card.

EDIT: "Combine the left/right sub leads using another adapter."
It's possible that this might cause issues. You can skip this adapter and just run one of the sides over to the sub; it won't make much difference. If you do this, you only need one splitter from the NAD preamp output and leave the bridging loop in place on the other channel.

 

[nerdstrike]

Oh, I didn't realise the amp had per channel volume knobs! I assumed it was a pro-style amplifer only. I guess that's just level matching then.

 

[MaxwellsEq]

Posting here because I'm a n00b curious about principles, learning - especially the electronics (ohms, wattage etc). Not intending to set up the best audiophile system in the world.

Say you had a mish mash assortment of 2nd hand Ebay speakers and amplifiers and wanted to combine some of them. Like a mongrel.

A passive subwoofer and a passive bookshelf speaker, powered with two amplifiers, along the lines of bass / mids & tops:

1000W Class D amplifier -----> subwoofer (300W RMS / 600W Peak).

NAD 3020 ----> bookshelf speaker (100W max input).

Is it possible to combine them? If so, are there various ways to do it, or only one?

I.e. would it be a case of sending signal from the NAD 3020 pre-amp to the INPUT of the 1000W power amp?

Am I right in assuming the NAD 3020 would struggle with the passive subwoofer, and the power amp would blow up the bookshelf speaker?

---

Again not super concerned with the finer details of sound quality per se. It's all stuff that already is lying around, and I'm mostly curious.

Also don't mind fiddling with different connectors - e.g. speakon / bare wire / jack.

Connection ports of subwoofer - image here. It shows the specs and Speakon pass thru.

Connection ports of 1000W power amp - image here.

If you are interested in learning more, you will benefit from studying amplifier sensitivity and gain.

Sensitivity gives you an idea of how many incoming volts are needed to drive the amplifier to maximum voltage output (watts are not a particularly useful guide to anything).

Gain lets you know how much the amplifier will magnify the incoming voltage, and because this is a large/ scale-y number it's normally quoted in dB.

To give an example of a CD player feeding into an amplifier driving a normal loudspeaker, a 100W amplifier with normal sensitivity and a gain of 30dB will sound much louder than a 3000W amplifier with the same sensitivity and a gain of 3dB.