Voice echo

Commander7716

I have a Pair of SDA 2 speakers that I did the crossover upgrades awhile back. I love the detail they have now, but i have noticed that voices seem to have an echo and are more back than up front. When I unplug the SDA cable the voices come back up front and the echo is gone. This became really noticeable when watching the NCAA tournament recently. You could hardly hear the sportscasters behind the crowd and players voices. Again, when I unplugged the cable, they came back up front. Is this normal or should I be looking for a problem somewhere? I appreciate any help anyone can give!

mhardy6647

sounds like the midrange signal is out of phase someplace - it sounds like you are hearing the "R minus L" difference signal.

EDIT: Just to be clear - the comment above is strictly generic; I don't know anything about the SDA speakers, so the issue might be more subtle or more or less complex.

dudeinaroom

IS this with all music? Is it just with the TV all or all other sources?

11tsteve

This only started after the crossover updates? I assume you are using an A/V receiver?

Commander7716

It is noticeable in all music that have lyrics. Not noticeable in instrumentals. Some music is more noticeable than others and I have tried another amp. It does seem to be only coming from the midrange dimensional array driver as mhardy suggested. When listening up close, it seems that all sounds coming from it have echo and are a little distorted.

11tsteve

Did you do the crossover work? Is it possible that perhaps a pair of caps with differing values got used to make a single value, or perhaps tyhe driver wires got soldered out of phase?

Commander7716

Let's say that I didn't notice it when I first got the speakers. i was anxious to do the upgrades so did not have much listening time on the original CO. I am using a rotel RTC-850 preamp with a Parasound HCA-750A amp. My music is thru my PC with a Prodigy HD2 sound card. The sound card is where I have been spending my effort as I thought thought that it was the culprit until I heard the same thing from the TV that does not go thru the PC. I have listened to music channels from the cable provider and hear the same thing.

TennMan

What brand capacitors were used in your crossover upgrade? I just did some upgrades to my amp recently and found that all capacitors of the same value, 68pf in this case, are not created equally. One of the capacitors I tried had a 3D/reverb effect that was interesting but not desireable.

Commander7716

Sorry for the delayed response, I had to check everything on the crossovers to make sure it was all good. I used clarity cap for the high and daytons for the mid, When I ordered them I specified them to match the tolerances. As I was listening close to the speakers, I noticed that there was not much gain from the dimensional mids, is that normal.

Commander7716

Just noticed something else, when I turn the volume down on one channel, the volume comes up on the other channel. This effect only happens when in SDA, very strange!

TennMan

I don't think the brand of your caps is your problem. A lot of people have used them with good results.

Have you checked all your connections closely to make sure the polarity from the amp all the way to the drivers is correct? First, I would disconnect the IC cable and speaker wires, then connect a 1.5 volt flashlight battery (observing polarity) to the speaker terminals momentarily and watch to see if both the MWs move outward at the same time. If that checks out good make sure your speaker wires are connected from the amp to the speakers with the correct polarity. Speaker polarity is extremely important for SDAs to work properly.

westmassguy

These are SDA-2s, with 3 woofers? Not 2As or 2Bs? They are 2nd generation, and have split crossovers. The upper half connects to the lower half with a black and white wire. Make sure they're both connected the same and with the correct polarity. If memory serves, there's a white wire connected to one of the spade connectors, so the white wire from the upped section goes there. Double check the wires coming from the blade/blade interconnect socket. Both wires attach to the upper half, but one should be reversed. Also make sure you have a good connection at the IC socket. The IC cable in the 1st through 3rd generation carries signal both ways through separate conductors.

TennMan

Maybe the solution could be as simple as disconnecting the dimensional tweeter? Just wondering because of the post that was made in another thread.

westmassguy

Very true Ronnie. I was going to suggest that after the wiring was double checked