What went wrong? I just hooked up my outdoor audio system, with less than successful results. I had great expectations and started with 2 Boston Acoustic Voyager RK8T2 rock speakers, 1 Polk Audio Sub 10 subwoofer, 1 Russound DPA-6.12 distribution amp (6 bridged channels with 100 watts per channel), and an Outlaw ICBM. This LINK is what I was trying to do. Now, I have three blown amplifier channels and the sound seems a bit tinny, apparently lacking sufficient base and madrange transitions. If anyone has any suggestions as to what went wrong, it would be greatly appreciated. Let's begin with the blown amp channels and end with the thin sound.

Blown Amp Channels:

I split my zone 2 output for inside and outside use. The outside portion was connected to the ICBM and then connected to a Russound DPA 6.12 (e.g. 12 zones with 50 watts per channel). At the Russound amp, I bridged 4 of the channels to boost them to 100 watts, then I connected each of the ICBM's L and R main outputs to a single 100 watt bridged channel on the Russound amp, and I also connected each of the ICBM's L and R subwoofer outputs to a single 100 watt bridged channel on the Russound amp.

I connected each of the main L and R channel speaker wires to the L and R RK8T2 speakers, respectively. The RK8T2 has two sets of positive and negative wires (as it has two tweeters and can be configured as a single speaker providing a stereo signal) so, according to the wiring diagram for mono operation, I connected all the positive wires from the amp and speaker together and connected all of the negative wires from the amp and speaker together. When powered up, the RK8T2 speakers seemed to work fine (although the sound seemed a little thin, but more on that later).

I connected the Sub10 subwoofer. The Sub 10 is a dual voice coil ("DVC") speaker with two sets of positive and negative speaker wires. At the time of connecting up the Sub 10, I didn't know that DVC speakers have special connection issues. But, according to the wiring diagram, I connected the L channel amp positive and negative wires to one set of the positive and negative wires from the Sub 10, and similarly, I connected the R channel subwoofer positive and negative wires to the other set of positive and negative wires from the Sub 10 (could this setup have been problematic?). The ICBM subwoofer switch was set to stereo (not mono) (could this setup have been problematic?).

In any event, when I powered up the system, I got a low "boom" "boom" "boom" coming from the sub, and the sub amp channel lights blinked on and off. I quickly turned off the system, but noticed I had a blown amp channel. Since I had 2 other chanels I could use, I kept going! Not knowing what happened, I unconnected, checked, and reconnected all the connections (this time to another amp channel), did some internet research, and read the sub and amp manuals again. I turned on the system and the same "booms" occurred and blew another amp channel. I then checked things again, and even checked each sub voice coil by checking that sound would come out as each one was connected independently to a single channel. I reconnected again, not sure exactly what happend, but I blew a third channel! Therefore I was down to 3 channels on the amp, so I gave up trying to connect two subwoofer speaker wires. Accordingly, I changed the ICBM subwoofer connection to mono from stero, connected only one of the sub outs from the ICBM to the last remaining sub in channel on the amp, and connected all the positive wires from the amp and sub together and connected all of the negative wires from the amp and sub together. When I repowered up the system, it seemed to work, but the sub seems thin (perhaps because it is not run only on 100 watts; but then perhaps not!).

What went wrong? And what, if anything, is still wrong?

Thin Sound:

Before I set the system up, I jerry-rigged my RK8T2 speakers by connecting them to my Outlaw 7700 with 200 watts feeding each speaker and using 50' of 14 guage wire for each speaker. They seemed to sound incredible, even when outside and without the benefit of the subwoofer (but that was a week ago). Now that I have them set up as noted above (now with only bridged 100 watts per channel and with 150' of 10 guage wire) they sound a bit tinny (lacking mid range and base extension--whether or not the subwoofer is hooked up or bypassed by the ICBM). Could the 100 watt difference in amplifiers and the Outlaw verses the Russound amps make that much of a difference?

Of course, I may just be imagining things as I am frustrated right now--so my perceptions could simply be compromised. And, I am too frustrated to do a direct A/B comparison by jerry-rigging my 7700 again directly to my RK8T2 speakers; that will have to wait for another time when I can take a fresh look at things.

If the Outlaws can offer any guidance on what I did wrong and/or whether there may be a problem with the Sub 10, and/or how I might be able to improve the sound (including because I am operating my sub with with only 1 line connection between the ICBM and the amp), that would be greatly appreciated!

Ed

Blowing out amp channels like that makes me wonder if there was a wiring issue at the sub (positive and negative touching).

Go to ground zero and start over without making the system so complicated. Unbridge the amp to eliminate that wiring as a source of failure. I would take out the ICBM and the sub for starters and hook up the speakers to make sure the Russound amp is fine with your speakers. You probably blew some fuses in the down channels. If I am reading your post correctly it sounds like you are feeding the output of the Russound amp to the sub input. Normally powered sub inputs are not amplified before the sub. I would think the sub outs from the ICBM would go right to the sub, not to the amp. Connect the sub to the main sub output and test to make sure it works correctly. I would then connect the sub very carefully per the manual. Make sure all your connections are clean and keep the volume way down. Test the system with the ICBM out of it.

Gonk and XenonMan, thanks for weighing in on this.

Gonk, as for your comment about the wiring issue at the sub, I was initially thinking the same thing. That is why I double checked and triple checked the wiring connections and did internet research about dual voice coil ("DVC") sub (and the various wiring options and pitfalls). But, after I blew the third channel on the amp, I checked that each set of positive and negative wires at the sub produced some sound out of the sub, and then I said screw it, connected all the positive wires together and then connected all the negative wires together between the last amp channel and the sub (with the ICBM now in mono and only one of two input wires from the ICBM feeding the single subwoofer amp channel and the single positive and negative wire to the sub), turned it on, and crossed my fingers. Sound came out of the sub; and nothing bad happened. But the bass does seem to be thin--although I am not sure based on my frustration. Therefore, given the lack of problems when all the positive wires were hooked together and all the negative wires were hooked together from the single sub wire from the amp to the dual set of wires from the sub, I am just not sure anymore that the wiring in the sub is wrong. As such, I am wondering also if the stereo setting on the ICBM was problematic because I read that DVC subs are sensitive to minor variations in signal as could happen between right and left stereo hookups and thus mono settings are preferrable. But the sub manual doesn't mention any such concern and it suggests connecting stereo wires from the amp to the two different coils on the DVC sub!

XenonMan, as for your comment about going back to basics, I believe that is a good idea, including unbridging the amps and unconnecting the ICBM. Hell, I blew so many channels, why not risk some more as the amp has to go in to be repaired anyway--besides if I unbridge the amps, I have more channels to try the stereo sub hookup again. But, one point I need to clarify is that the Atrium 10 sub is not powered, it is passive--it just has two voice coils with two sets of positive and negative wires, one set for each voice coil (4 speaker level wires total--2 positive/2 negative--with no line level inputs). Therefore, any additional thoughts given that the sub is not powered?

Also, when do I give up and send the sub back to get it checked? Before starting from scratch with the wounded amp, or after I go back to basics with the wounded amp? Same question about when to send the sub in to get checked and/or fixed? I know I am probably well past those ponts; but right now, I am so frustrated that I am not sure what to think and I am not sure how I am going to boil things down to figure out the problem(s).

Again, thoughts from the Outlaws would be greatly appreciated.

Ed.

Hook up one voice coil at a time to a C cell battery + and touch the - side to the battery. Listen for the hiss of the speaker in the sub. It will tell you if the voice coil is intact. It won't hurt the speaker and it will tell you a lot. I doubt if you hurt the sub with the other excursions. I would then hook up a single voice coil to the sub out of the ICBM.

This looks like it might be the issue here. If you have the amp set up for bridge/mono then the L+ amp output will have the positive waveform on it and the R+ will have the inverted waveform. If you then have the positive of one sub voice coil attached to the amp L+ and the other voice coil positive attached to the amp R+ then you've set the sub voice coils up to cancel each other. We've had a number of conversations where I work (work is slow at the moment) and we really don't see why this would cause the amp to blow. Maybe others can shed some light.

A typical correct setup for the sub/bridged amp would have only two wires going to your amp from the sub: Positive on the sub going to L+ on the amp and negative on the sub going to R+ on the amp. The two voice coils on the sub can be connected in series or parallel. Choose which ever configuration your sub and amp support. Your amp will drive between a 4-8 Ohm load. So if your voice coils are 4 ohms each hook them in series. If your voice coils are 8 ohms each hook them in parallel. (I looked but couldn't find the info on your sub.)

EEman, your first sentence accurately describes my Russound DPA-6.12 amp wiring diagram. But, your second sentence does not seem to follow what I wrote in the text you quoted from me. I am using 4 amp channels, bridged down to two amp channels and arbitrarily designating one of the bridged channels left and one of the bridged channels right, and each separate amp channel has its own positive and negative wire connections (as if I was going to use two separate speakers each one connected to its own bridged amp channel. But in this case I am just using both bridged channels to hook up to two different voice coils of one physical sub (which I undertand should appear for all intents and purposes of making connections as if I were connecting up two separate speakers). In any event, the designated L amp channel positive and negative connections (which in the bridged mono configuration are the L+ and R+, respectively) are connected to the first sub's coil positive and negative; and the R channel postive and negative connections (again, at the amp they are the L+ and R+, respectively) are connected to the second sub's coil positive connection: Therefore L channel's L+ is connected to the first coil's positive, and the L channel's R+ is connected to the first coil's negative; and similarly the R channel's L+ is connected to the second coil's positive, and the R channel's R+ is connected to the second coil's negative. Therefore, unless I am missing something, I believe I hooked it up correctly, both in terms of the manual's wiring diagram and your suggestions of how it should be hooked up with no crossing of negatives and positives. What I do note, however, is that you also suggest (or intimate) that the sub should be hooked to the amp with only one channel and one set of positive and negative speaker wires not two channels and two sets of positive and negative speaker wires. If I did that, I would have the two positives from the sub and one amp positive connected and two negatives from the sub and one amp negative connected; and with that I would effectively loose a channel and the associated power. With all this explanation, do you still think I set it up wrong? If so, I guess I am still missing something.

Ed.

Try this link out and read it all the way through. It sounds like wiring your amp the way you describe may be the problem. Hope it helps.

http://www.adireaudio.com/Files/DualVoiceCoilDrivers.pdf