Aphrodite + Sub ?

[Donos]

Hi

I'm planning to get a sub (probably BK) to work with both AV receiver (via low level input) and my existing Aphrodite (via high level speaker input). Not planning to have AV and audio inputs live at same time, but to have them cabled permanently.

Sub manual warns against use of Class D amp for high level connection. I'm pretty sure the Aphrodite's amp is not class D . . . but it gives rise to a question :- has anyone else successfully connected Aphrodite to a sub using speaker connections (rather than low level preamp output) ?

 

[liam_b]

If you want to have two 'systems' connected then you'll need to make sure that whatever sub you buy has seperate crossover settings for the low and high level inputs.

You might need to be careful about the exact layout of your wiring, especially the mains power sources for the two systems as you might create a huge ground loop. You may be able to avoid it by feeding mains power to everything from the same outlet and using a large multi way mains block, if all the equipment is close together.

Aphrodite has a normal class AB power amplifier section.

 

[Donos]

Liam_b :- Thanks for confirming that the Aphrodite has a class AB amp . . . for all the user documentation I received with the unit (and downloaded from the old TMA website), I wasn't sure what class of amplifier it used !!

Question is thus :- is it safe to assume I can use a class AB amp (since Liam_b has now clarified that is what the Aphrodite uses), with parallel connections to :-
- my main speakers,
- high level input of BK subwoofer (high impedence = 100k ohm)
without fear of damaging the Aphrodite ?

Has anyone else done this with :-
- with Aphrodite ? or
- with equivalent TMA amp (such as 60iRV, I think) ? or
- with other similar 2-channel class AB amp ?

(and yes, as you suggested, I'm planning to get a sub with separate crossover settings).

 

[Donos]

Hi - still looking for an answer to this one, if anyone can help.

I contacted IAG helpdesk, and they advised me NOT to connect Aphrodite to sub via high level connectors . . . no reason given, and I'm not sure I understand why :- I'd have thought that connecting a high impedence sub (say 100kOhm, in the case of BK) in parallel with nominal 8Ohm speakers would leave the impedence virtually unchanged, so that there would be a negligible additional load on the amp.

However, in the absence of anyone saying they have done this safely (and successfully), I will have to go with their advice. My only option will be to use the preamp outputs from the Aphrodite to the sub. However this limits the possible choice of subs (to ones which support independent LFE and low level inputs).

 

[mlinhares]

I was considering a sub for my Aphrodite also, maybe a BK (like you) or a Rel, and was going to connect it with high level... never thought that it could cause or be a problem.

If anyone could shed some light it would be very helpful.

 

[Dr Udo Zucker]

Hi, Aphrodite includes a preamplifier output which is much better suited to connect to an active subwoofer. Make sure the sub inlcudes its own crossover so that you can blend it nicely in with your main speakers' low bass capability.

 

[Donos]

Thanks Dr Zucker,

Yes - I think I'll go with the safe choice of using the preamp connection to a sub's low level input ... I don't want to risk damaging the Aphrodite by connecting it via speaker / high level connection if nobody else has done it safely (particularly since the IAG help desk would not endorse such connectivity).

It's disappointing that so many subs "share" the same two RCA connectors to act as either LFE (mono) or Low-Level 2-channel (rather than having three separate connectors to allow both inputs at the same time), but I've a short list of a few subs that have totally separate inputs which will allow it to connect to both :-

- Aphrodite Preamp . . . into sub's crossover (as you suggest)
- 5.1 processor LFE output . . . bypassing the sub's internal crossover