What causes an emphasis on 'cha' and 'sss' vocalizations?

[Wseaton]

Greetings all,

Was at a co-workers today for a BBQ, and he took take me for test spin with his prized home theater. Forgive me if I didn't get the name of his main speaker brand, but they were quite large, and featured a ribbon tweeter along with dome midrange and MTM arrangement with what I thought were kevlar mids being they were the typical yellow cloth texture. They we're not DIY but an american brand I'd never heard before. Trust me, one thing they weren't were Chinese knock-offs because the wood working was WAY too good and what he paid too ridiculous.

Anyways, while they had incredible detail and dynamics, I noticed that everytime a singer hit a 'cha' or 'sssssss', or similiar mouth vocalization, it was like the speaker over emphasized the response by several dB, and it grated on my skin. Heard this with several recordings, so it wasn't that particular source. My co-worker friend was oblivious to the problem, although in all honestly it was obvious my ears were more sensitive to playback defects than his.

The reason I'm posting this is I've heard this similiar problem before in speakers ranging from $1000, to $10,000, but it always seems more pronounced with bigger, more complicated driver alignments.

Is what I'm hearing caused by a particular crossover defect, or just a driver design in general? I figure our DIY veterans have perhaps caused this characteristic on purpose or not on purpose and can shed some light.

[phase_accurate]

Could as well be caused by the amp.

Regards

Charles

[Coolin]

The cause can be alot of things like metal drivers or bad quality cross over components that could also be reacting with each other. You wouldnt expect it but the amp is probably most likely.

[Samuel Jayaraj]

Pronounced 'ss', 'sh', 'ch' is known as sibilance and can be caused by any component in the audio chain. Sometimes the recordings themselves may be flawed by too bright a sound and excessive highs. It is pretty difficult to immediately pinpoint the cause in a complete system; however, cure can begin with better power chords, interconnects, speaker cable and then moving on to the electronics and finally speakers (since you say they are branded and highly priced, they should not be inherently so flawed).

[CLS]

If you got a RTA around, measure the frequency response.

Usually the peak(s) on the 6k~8kHz region would sound like this. I suspect the tweeter itself plays a major role.

[jdybnis]

Sibilance is caused by narrow peaks in the high frequency region. If you can do an in-room measurment start there. I'd look at the speakers before I'd start switching power cords. Before you even measure try listening with only one speaker playing at a time. If one of the tweeters or ribbons are broken it will be obvious which one.

[CLS]

Originally posted by jdybnis
... I'd look at the speakers before I'd start switching power cords. ...

Absolutely!

My experiences on power cords/wires/ even resistors/capcitors are relitively "minor" in such illness. They might be somewhat effective from "pretty good" to "perfect", but not on such case.

If the basic ain't right, peripherial can not give any helps.

[morbo]

Your description sounds to me like underdamped cone resonances in teh kevlar cone. Would this manufacturer happen to be using large kevlar woofers crossed to that dome? or be big on 'minimalist' crossovers?

[soongsc]

Maybe they were intentinally designed like that to make them sound different from accurate speakers? Some speakers in intentionally designed to produce feeling of a large sound stage, some are desigened with enhanced highs. Each could be designed to target specific customer tastes.

[speaker]

Originally posted by Wseaton
I noticed that everytime a singer hit a 'cha' or 'sssssss', or similiar mouth vocalization, it was like the speaker over emphasized the response by several dB,

I'd love to see the frequency plot for them. Could be a laid back midrange making the HF seem over-emphasized. Could be an amplifier clipping on the dynamic transients. Could be any of the things previously mentioned too.

I'd also pay heed to soonqsc, they could just be designed to sound like that. To an older customer with damaged hearing, they might sound more natural than speakers with a neutral tonal balance.

speaker