[tesla99]

I've seen a number of posts re: connecting to REL subwoofers. Is there a current best option to connect from an IDA-8 to a REL TZero - high level or low level without endangering the amp ?

[John Casler]

In some applications, the speaker outputs from the power amplifier are used as source signals for devices such as REL sub woofer. For such application, usually the receiving devices should have DC offset blocking capability because some amplifier by design has floating ground (DC offset) on the speaker outputs.

The following models have no DC offset on the amplifier speaker outputs and the negative terminal is also the ground:
NuPrime STA-9, MCH-K38, IDA-6, IDA-16, STA-9X, AMG STA

The following models’ speaker outputs can not be connected directly to sub woofer input:
NuPrime Reference 20, ST-10, IDA-8, ST-10M, Evolution One, Evolution Two, Evolution STA, AMG One, MCX-1,2,3,4

REL has provided instructions for connecting Class-D amp with floating speaker outputs to their sub woofers, please contact REL. All currently shipping REL sub woofers can be connected directly to any Nuprime amps.

https://nuprimeaudio.com/faq/

[tesla99]

Thanks John. My dilemma is that as per your advice from NuPrime - they recommend using the low level connection ( not high level ) from the IDA-8 to the sub , whereas REL recommend the high level output from the IDA-8 using the positive speaker terminal along with grounding via an unused RCA port.
I guess I'm looking for real world experience here.

[rustydoglim]

REL has put in DC blocking cap on the sub input for class D amps that have floating ground (amp speaker outputs + & - instead of + & 0, something to do with half-bridge versus full bridge design), therefore it is now safe to connect to IDA-8 speaker output.

Our engineer recommended that you use the line level output from IDA-8 because it has lower noise than speaker outputs.
Your real world listening test is to compare the two methods yourself.

[FILTHpig]

REL has put in DC blocking cap on the sub input for class D amps that have floating ground (amp speaker outputs + & - instead of + & 0, something to do with half-bridge versus full bridge design), therefore it is now safe to connect to IDA-8 speaker output.

Our engineer recommended that you use the line level output from IDA-8 because it has lower noise than speaker outputs.
Your real world listening test is to compare the two methods yourself.

Would this be the same for the new IDA-9 as well?