Is there any danger to an amp if...

[Dean Landon]

I have an Adcom GFA-585 powering my Adam ANF-10 monitors. I purchased an Infinity PS-10 subwoofer.

Is there any danger to the amp or monitors if I connect the ANF's and subwoofer to the Adcom's left and right speaker output?

According to the Infonity manual, it's ok, but I wouldn't want to risk it.

Thanks...

[dbbubba]

I am not familiar with the exact specs of any of those speakers or amps, but I'll assume that the sub woofer has speaker level inputs for the left and right channels.
Most passive subs have two voice coils (one for each amp channel.)

As long as the amp can run at the impedence level produced by the combined ANF-10 and the PS-10 everything will be OK.

Personally I prefer a powered sub, but my meager home theater rig has a passive sub.
I have Radio Shack Minimus 7s powered by two Crown DC150s and the front channels have a Radio Shack pasive sub. I'm OK because Crowns can run at rediculously low impedence levels all day long. 2 ohms is fine.

It's all in the combined impedence of two voice coils per channel.

DB

[dbbubba]

I just looked at your posted diagram.

Just use "Y" cables and feed the ADCOM and the PS-10 with the same source.
Any modern source will feed two amps without any problems.

You don't need to use the SPKR inputs.
Use the LINE INPUTS.

DB

[Dean Landon]

Originally Posted by dbbubba

I just looked at your posted diagram.

Just use "Y" cables and feed the ADCOM and the PS-10 with the same source.
Any modern source will feed two amps without any problems.

You don't need to use the SPKR inputs.
Use the LINE INPUTS.

DB

Hey DB,

Thanks for your input. Shouldn't I be feeding the Adams and sub with the Adcom?

[Ziggy!!]

Originally Posted by Imagine

Hey DB,

Thanks for your input. Shouldn't I be feeding the Adams and sub with the Adcom?

The sub is active, it already has its own power amp. Just feed it the same line level signal that you are feeding the power amp for your Adam's.

DON'T wire it like you have shown in your diagram. Wiring it like that will cause the load on your amplifier to half, because you have your adams wired in parallel to your sub. This can destroy a power amp.

Go line level into your power amp, then some your power amp into your Adams.
Use that same line level via a splitter, or from a seperate monitor send on you desk and go straight into your sub. Don't connect the sub to the power amp in anyway if your adams are already using it.

Since you are feeding the sub a line level signal from your console or converters use the "line level in" jacks.

[Dean Landon]

Originally Posted by Ziggy!!

The sub is active, it already has its own power amp. Just feed it the same line level signal that you are feeding the power amp for your Adam's.

DON'T wire it like you have shown in your diagram. Wiring it like that will cause the load on your amplifier to half, because you have your adams wired in parallel to your sub. This can destroy a power amp.

Go line level into your power amp, then some your power amp into your Adams.
Use that same line level via a splitter, or from a seperate monitor send on you desk and go straight into your sub. Don't connect the sub to the power amp in anyway if your adams are already using it.

Since you are feeding the sub a line level signal from your console or converters use the "line level in" jacks.

Ziggy,

Currently, I'm using an SPL 2381 monitor controller. It has 3 stereo monitor outs. "A" for the Adams S2.5-A, "B" for the sub and "C" for the ANF-10. I'm trying to free up one of the monitor outs on the 2381 for the NS-10's, which is powered by a second Adcom.

Is there any other way to connect the sub?

Thx!

[Ziggy!!]

You can try using a line level splitter.

http://www.sweetwater.com/store/detail/SplitterBox/

Split the line level outputs of the SPL 2381 for one stereo pair. So instead of having just a left and a right signal you will have 2 left and right line level signals. Send one pair (1 left & 1 right) to the power amp for your ANF-10's and send the second pair to the line level inputs on your sub.

[Dean Landon]

Hey Ziggy,

Thanks, I appreciate the info. Do you know if using a line level splitter would alter the sound?

[max cooper]

Originally Posted by Imagine

Hey DB,

Thanks for your input. Shouldn't I be feeding the Adams and sub with the Adcom?

I've connected active subwoofers to amplifier speaker outputs for years. Many hifi gear manufacturers recommend connecting the sub this way (Naim Audio, for one).

It seems counter-intuitive, but I've never had a problem.

But yes, just like in the diagram.

Here's a bit from REL on the same topic:

http://rel.net/index2.htm

"For audiophile 2-channel applications in particular, REL recommends the use of the high level input from the host system amplifier’s loudspeaker terminals. In this way, a REL sub-bass system receives the same signal and will thus reproduce the same character of bass as the host system’s loudspeakers, albeit at still lower frequencies."

[Dean Landon]

Max,

Thanks for the info. Are you sure connecting it via the diagram can't damage the amp?

[max cooper]

Originally Posted by Ziggy!!

The sub is active, it already has its own power amp. Just feed it the same line level signal that you are feeding the power amp for your Adam's.

DON'T wire it like you have shown in your diagram. Wiring it like that will cause the load on your amplifier to half, because you have your adams wired in parallel to your sub. This can destroy a power amp.

There's a really good reason for taking the subwoofer signal from the speaker ouputs instead of splitting the output from the preamp (or monitor controller, or whatever).

Many subwoofer manufacturers recommend this, and the load presented to the amplifier from the subwoofer amplifier inputs won't significantly change anything, and it especially won't halve the load to your amp.

If the subwoofer were passive and you wired it in parallel with your speakers to your amp, you might worry, depending on the amp.

anyhow, the reason for taking the sub feed off of the amp output is to minimise any phase distortion between the main speakers and the subwoofer.

Amplifiers introduce some phase shift (yes, the one in the subwoofer too) but we do what we can to minimize that. If we take the subwoofer feed before the amplifier, the subwoofer signal is pre-amp phase shift.

does that make sense?

[dementedchord]

do what you wish...personally i doubt the phase shift idea as max suggested... but my decision would be based on the fact that i used to do warrantee work on those things and i can't remember ever seeing one that used the line levels... ALL of them were on the speaker levels..... YMMV?

[max cooper]

Originally Posted by dementedchord

...personally i doubt the phase shift idea as max suggested... but my decision would be based on the fact that i used to do warrantee work on those things and i can't remember ever seeing one that used the line levels... ALL of them were on the speaker levels..... YMMV?

Not my idea, really. This came from a tech at Naim Audio.