Gurus,

My only interest in the ICBM is its Stereo Subs option in the HT 5.1

The ICBM manual shows a 5 channel amp for the 5.1 HT set up with a 5 pre out receiver such as mine, my receiver doesn’t have “amp in’. I need separate amps.

Let’s take stock of my gear to get acquainted: Soon to arrive, 2 Mackie’s HR 824 powered monitors, AudioSource stereo amp EITHER for rears OR in mono for center, seems I’m missing an amp with this configuration.

Since the purpose of the ICBM is to better accommodate the “Stereo Subs” crossovers and to eliminate the now used fixed high pass.Will I only need the “Stereo Subs” portion of the ICBM in my 5.1 set up?

The other confusion I’m having is with the Mackie’s various crossover settings, how will the ICBM handle these OR will it bypass the Mackie’s controls?

Do I need another amp to configure the ICBM for its true intent, even though the real goal is to accomplish Stereo Subs in a 5.1 set up?

If so, I need another AudioSource amp for center or rears!!

What is the correct configuration for my purposes?

If all you want to do is have stereo subs supporting your left and right channels (no LFE, no crossover of data from other channels to the subs), you could simply connect the left and right pre-amp outputs to the ICBM, then connect the Mackies and subs to the ICBM. The only settings that would be relevant on the ICBM would then be the front crossover and the sub controls. In this case (and in any case with the ICBM upsteam of the Mackies), I would recommend bypassing crossover controls at the Mackies.

If you want to have stereo subs that also get LFE data from the .1 subwoofer output of your receiver and low frequency data from the center and surrounds, you will need to connect all six pre-amp channels (left, right, center, both surrounds, and sub) from the receiver to the ICBM, set all speakers to "large" at the receiver, and provide amps downstream of the ICBM for the center and both surrounds.

Thanks for the reply,

Yes, Stereo Subs with the LFE from the .1 sub output is correct, a full blown 5.1 with the ADDED feature of Stereo Subs is what I'm after.

Looking at the manual pg.6 shows your description of the 5.1 set up WITHOUT the second sub, otherwise that is the configuration...yes?

In recapping: The 2 L/F powered Mackie’s, the AudioSource stereo amp for rears, so it appears I’m missing either another AudioSource amp (mono) OR a single Mackie for center.

Do I have this correct?

Please add what I may be over looking.

Thanks,

I think you've got it squared away.

Thank you for setting me straight on that configuration.

Here’s is another idea suggested to me, I wanted your opinion on and if it’s doable without any major drawbacks, keep in mind HT 5.1 only.

“You only need stereo subs for 2-channel music. Multi channel signals direct most of the bass content to the LFE channel, and that is mono. There are a few exceptions, but they are rare.

Here's my advice, use the ICBM as a crossover just for your Left & Right speakers at this time. Set the L & R speakers to "large" in your receiver and turn the LFE output off so that ALL bass is sent to the L & R outputs. That will redirect the bass from the center and surround channels through the ICBM and the main speakers."

What say you?

Thanks again.

That should work fine in most cases, actually, and depending on your source components could be very well suited to your system since it would avoid the need for an extra amp. The one case where you could run into a problem is when dealing with DVD-Audio or SACD and a player whose internal bass management is not applied to those high-res formats, in which case the LFE data stays in the sub channel all the way through the receiver.

Thanks again,

I’m not a technical person…. Connections / Configurations are problematic for yours truly, sheer lack of Peptide / Neuropeptide, The brain works on a different plane.

With that now out of the way, I’ll proceed….

It seems at this time the suggested configuration the one you also endorse will be the final configuration.

If it helps, the receiver is an Elite VSX 36 TX, subs are Velodyne’s.

I’m now reviewing Pg.9 in the manual seems befitting to the scheme and present equipment on hand.

First question: Where is the connection to the 2nd sub made?

Appears with the Mackie’s the crossover might be 60 Hz, Continuing from there, can you please explain the employment of the various features in the ICBM that this scheme mandates for successful operation within the boundaries.

In a nutshell, what controls need to be engaged?

Finally…I’m a visual learner, clear defined diagrams work best…if the need arises.

Thank You,

Diagram illustrates present configuration.

The left side of the ICBM's rear panel has two toggle switches and two outputs (labeled "R" and "L" under a heading labeled "Sub/LFE Output" - those "R" and "L" outputs are where you would connect the right and left subwoofers. The preamp connections from the receiver will of course go to the LEFT and RIGHT IN jacks, and then the LEFT and RIGHT OUT jacks will be connected to the inputs on the Mackies.

Since you will be mixing the LFE signal into the front channels at the receiver and only connecting the front channel pre-amp outputs to the ICBM's inputs, the only front panel controls that you need to worry about are the left/right crossover point and the subwoofer level. The "LFE Mix" control does not apply because you are not using the ICBM's LFE input. Since the goal here is stereo subs, you'll want to have the MODE switch set to "STEREO". The LOWPASS switch can probably be left in "NORMAL". LEFT/RIGHT RECOMBINE should be set to "OFF".

Thank You Sir,

I am truly impressed with you, not only in your promptness, but also in your style.

Yeah, that Gonk, he's a keeper alright!

Greetings once again…The never ending infection continues to broaden with the usual unforeseen consequences. :rolleyes:

The Mackie’s arrived and are no longer considered for HT duty, they have replaced the Vandersteen’s C1’s in the audio only section. The Vandersteen’s are now the mains in the HT section, and all remains as per last communication.

The ICBM is connected as you advised, with the Vandersteen’s.

I’m planning on purchasing another identical amp for two possible purposes: Option one, would be to run them in mono block mode, Option two, might be to power the center and connect it to the ICBM.

The concern on this day, after reading the manual seems to be “Large and Sub Off/On”, where I don’t believe applies in my scheme, where the present configuration is: Sub/LFE off, the mains are large, and the rest are small.

If Option two is employed and keeping in mind the Stereo Subs is the applicable format in the 5.1 scheme, would I continue with the Sub/LFE off with this configuration and still maintain the present settings on the ICBM?

Elaborate, and suggest please...also, might you explain any speaker not connected to the ICBM in a “small” setting, is it still controlled by the receiver’s crossover? Hence, the receiver’s crossover is defeated only by the “Large settings?

Thanks,

So you currently have a two-channel Audiosource driving the Vandersteen C1's and want to add a second amp? With option one (running the Audiosource amps as bridged mono amps), you would need to make no changes to the bass management. With option two, I would do one of two things: leave the ICBM exactly as it is, or change the center to "large" at the receiver and pass the pre-amp signal through the ICBM.

You are currently running the receiver with the sub off, the mains large, and the center and surrounds small (if I recall the setup correctly), which means that the LFE track and the low frequency data from the center and surrounds is all being redirected to the mains, at which point the ICBM splits the signals between subs and speakers. The system would continue to function exactly as it does now if you were to put an amp in to drive the center. This is an acceptable approach, but I'd probably recommend something slightly different...

Since you have an ICBM already on hand, you can use it to gain greater control over the center channel crossover point. Set the center channel to "large" in the receiver, connect the center channel pre-amp output from the receiver to the ICBM's center input, connect the ICBM's center output to the amp's input, and hook the center to the amp. At this point, you can use the center channel control on the ICBM to select the most appropriate crossover point for the center channel speaker.

This is correct. If a speaker is set to "small" at the receiver, then the receiver applies bass management to the signal using the receiver's crossover point (with low frequency data steered to the subwoofer - or the "large" mains in the event that there is no subwoofer). If a speaker is set to "large" at the receiver, then the receiver does not apply any bass management and the signal bypasses the receiver's crossovers.

That is correct.

To summarize and conclude, it’s either fish OR fowl.

The extra amp for the mono block mode OR the extra amp to power center while utilizing the ICBM’s center channel control.

Is this the bottom line?

If so, your reply will influence the purchase of not one but two amps, one for center/ICBM, and the other for the mono block mode.

Thanks Again,

That is correct. The only way to use the ICBM to control the center's crossover point is to add an amp to drive the center channel. You can buy one additional amp (for a total of two) and have two monoblocks driving the mains (with the center and surrounds still on the receiver's power and the ICBM only providing crossover control for the mains), or have one amp driving both mains and another in mono mode driving the center (with the ICBM providing crossover control for the mains and center).

You could get two additional amps (for a total of three) and do a couple of things: three mono amps driving the mains and center (with the ICBM in line with all of them) while the receiver drives the surrounds, or one mono amp on the center channel and two stereo amps each driving a main and a surround (with the ICBM handling all bass management).

Thanks again,

You are truly helpful, as well as being knowledgeable of the product.

Until next time.

No problem, glad I could help.