I did a search on this subject but nothing came up.I have a pair of sealed 12s I want to run in stereo with the front speakers set at small.the subs do not have an out for the upper frequencies so I cant go that rout.I was wondering if I could use the tape or aux outs or the zone 2 outs to run R/L subs in stereo and just use the subs crossover.I know I will loose the ability to use the delay and may come across phase problems.I am just wondering if it is possible.I do have a ported sub I am going to use for the lower frequencies that the sealed subs are uncapeable of producing(15hz).I am aware of the crossover problems I am currently working with that but it would be sweet to run the 12s stereo for music and use another sub to help out in the HT department.

The question that I'd have with using the tape out is what happens with multichannel digital sources - do you have just the left and right passed to the tape out, or do you have nothing, or do you have downmixed stereo containing all five channels? If it's just the left and right, it could work, although you'll lose the LFE channel which will need to be redirected to the mains since you'll have no sub as far as the 990 knows (unless the left and right channels are routed to the tape out after the LFE is redirected). If there's nothing at the tape outs, obviously you're out of luck. If it's downmixed stereo, then you'll get a double-bass situation with low frequency from center, surrounds, and even LFE tucked into the output.

I basically run this way with an SVS sub and Rocket 1Ks with the powered woofers. I have played with a bunch of different hook up schemes. I keep coming back to the following setup. Fronts set to Large. Send the stereo outputs to both my regular amp and the two woofer plate amps. The downside is you will get double bass in the overlap between the stereo subs and the mains. I have managed to blend them together fairly well using the crossover and phase adjustment on the plate amps. The SVS only gets discrete LFE and the redirected center and rear bass. If you are really worried about the double bass you can get a set of hi-pass filters inline with the mains but you may have to deal with phase issues.

i am trying to get away from running the 850s full range.i have a anthem statement p2 driving them and i am woried about over driving them with hard hitting bass.i know i could go the FMOD rout to do what i want to do but they dont make a 40HZ version.i wish RDES had a choice of low pass and high pass crossover but unless the new version has it i am out of luck with that.

You might consider a new or used Outlaw ICBM to help out, placed between the 990 and your amplification. The ICBM is only 6.1, however, one can set all speakers to large except for the rear surrounds. The 990 outputs for the rear surrounds are run directly to amplification. The remaining 5.1 of the 990 are sent through the ICBM set up for stereo subs. The sub frequencies for the rear surrounds have been directed by the 990 to the subwoofer output of the 990 and are carried to the ICBM in the .1 channel. One ends up with stereo sub reproduction except for dual mono sub for the rear surround only. Any LFE's have been included all along.

If one then feeds a 5.1 direct source, such as SACD or DVD-A, then it is able to pass through the 990 largely unaffected and have 'stereo sub' analog bass management applied after the 990.

I would like to see Outlaw to begin selling a 7.1 version of the ICBM.

Edit: ICBM does not have balanced audio connections. Maybe something to add to a "7.1 ICBM?"