Sibilance problem

[DerrickM]

Hi,

As per my recent posts, I made some crossovers for Dynaudio drivers. I followed Dynaudio's recommendation of 6dB @ 2800Hz for the woofers, and 12dB @ 2800Hz for the tweets. I used Butterworth, so +3dB rise in the crossover region was expected.

My problem is sibilance, or hissing of esses in certain tracks. I'm sure that these are in the source material to some degree, but I don't hear it on my studio monitors. It's not noticeable all the time; it's only bad on certain songs, and at high volumes. However, when it rears its ugly head its the only thing I can think about.

I'm worried that perhaps I've done something wrong or overlooked something when I built my crossovers.

I'm currently trying to EQ it out, but I'm already down -7dB at 7.5k and I don't want to ruin the sound.

For anybody that happens to be into American oldies, one particular track I'm really having problems with is "Ruby don't take your love to town" by whatever band Kenny Rogers had in the 60's.

The drivers in question are Dynaudio MW160 and MD100.

Can anybody shed some light on sibilance, and possible causes in my crossovers? I'll take another look with the RTA, but I didn't see any big peaks in the 3-8k region.

[Salas]

If the woofer retains delayed energy over 3k your 6dB crossover does not attenuate it enough. Go higher slope.

[Cameron Glendin]

Have you tried swapping the polarity to the tweeter? Pos to Neg and viceversa with the wireing of the tweeter.

Personally with 12 db x overs I tend to not mix the slopes. Thats my own preference. If the manufacturer recomends it really should work, perhaps a Linkwitz-Riley would work better for your aplication.

[DerrickM]

I have not tried swapping the tweeters, but I put polarity switches in the crossovers... so it's easy to try. Can that really cause sibilance? I tried both settings when I installed it, but I wasn't listening for sibilance at the time.

I also thought about switching the woofer to a 12dB slope, but I'd have to replace the coil and add a capacitor... that means essentially reworking the crossovers. I want to be certain I'm on the right track before going to that effort.

I have a .23mH coil on the woofer, and I didn't see an easy way to add a cap and make it 12dB... without replacing the coil too.

If I covered the woofers with paper or cloth, would I be able to tell if the hissing of the "esses" is coming from the woofers or the tweeters?

[Cameron Glendin]

our hearing is most sensitive in the broad 3k area so yes, small changes can make noticable differences.
As for reversing polarity, yes it does. The 12 db xover causes a slight phasing shift of 180 degres, usually best to wire neg to positive of the tweeter with a 12 db x over only. Personally I usually try both and decide myself.