according to this: http://www.madisound.com/catalog/product_info.php?products_id=8232
"If you put the tweeter a little off to the side, then the distance from the tweeter dome to each side of the cabinet is different. This will spread out this edge refection over a wider frequency range, so you don't have a bigger problem at a certain frequency."
"In order to further reduce edge reflections, you should consider routing the speakers into the cabinet until they are flush with the cabinet face."
Also you could put some felt padding around the tweeter to reduce reflections off the baffle... Beyond that, you might have to start playing with the x-over components....
"If you put the tweeter a little off to the side, then the distance from the tweeter dome to each side of the cabinet is different. This will spread out this edge refection over a wider frequency range, so you don't have a bigger problem at a certain frequency."
"In order to further reduce edge reflections, you should consider routing the speakers into the cabinet until they are flush with the cabinet face."
Also you could put some felt padding around the tweeter to reduce reflections off the baffle... Beyond that, you might have to start playing with the x-over components....
http://www.htguide.com/forum/showthread.php4?t=26856
If this link is accurate, then this speaker is made to be played against the wall since no BSC was accounted for. Meaning if you place the speaker away from the wall, you won't get enough low end (or too much high end).
If this link is accurate, then this speaker is made to be played against the wall since no BSC was accounted for. Meaning if you place the speaker away from the wall, you won't get enough low end (or too much high end).
What is the woofer XO point?
How steep is the woofer LP?
Could be the woofer is adding to the listening range and not the tweeter that is hot.
One crude test I can think of is to use an equalizer, and wire only woofer / tweeter in turn (through the respective crossover and putting in a nominal resistor in replace of the other driver), and see if the sibilance is coming more from the tweeter or woofer.
PS: I have a similar problem at the moment!
David.
How steep is the woofer LP?
Could be the woofer is adding to the listening range and not the tweeter that is hot.
One crude test I can think of is to use an equalizer, and wire only woofer / tweeter in turn (through the respective crossover and putting in a nominal resistor in replace of the other driver), and see if the sibilance is coming more from the tweeter or woofer.
PS: I have a similar problem at the moment!
David.
Hi GOWA,
salas posted this very useful piece of information on this post:
http://www.diyaudio.com/forums/showthread.php?postid=1239638#post1239638
My ears certainly don't listen flat and I think my new speakers which measure flat, on-axis at 1 meter yet have 1 - 2dB more output in the 2 - 6KHz region over my tower speakers are way too forward / bright.
My designs from now on will be to tilt this down. I've noticed Zaph does this via a shelving circuit before tweeter XO circuit (a resistor and low value inductor in parallel wired in series with the tweeter) as an alternative to mucking with L-Pads.
David.
salas posted this very useful piece of information on this post:
http://www.diyaudio.com/forums/showthread.php?postid=1239638#post1239638
My ears certainly don't listen flat and I think my new speakers which measure flat, on-axis at 1 meter yet have 1 - 2dB more output in the 2 - 6KHz region over my tower speakers are way too forward / bright.
My designs from now on will be to tilt this down. I've noticed Zaph does this via a shelving circuit before tweeter XO circuit (a resistor and low value inductor in parallel wired in series with the tweeter) as an alternative to mucking with L-Pads.
David.
My first question would be--exactly what do you mean by sibilance?
I am normally think of this as s's ssounding quite ssssnaky like when Sssoixsssie Ssssioux ssssssang "Trussst in me". (an awesome cover, BTW).
I have heard this from a lot of speakers and it was always caused by a resonance peak from the woofer. I had some Audax HM100CO's that were horrible. Frankly, I'd be a bit surprised to find this coming from the p18's. (Also deeply dissappointed, as I love the sound of p17's used as bass woofers, and I was pinning my hopes on that p18 as a future replacement.)
If it is from a resonance peak in the woofer cone, the best way to eliminate it is to use a lower crossover point. I see from the schematic you posted that they haven't used baffle step compensation. I personally like a much larger inductor in front of the woofer, which can provide baffle step compensation without an extra network. (I learned of this from George Short's Northcreek website.)
JJ
I am normally think of this as s's ssounding quite ssssnaky like when Sssoixsssie Ssssioux ssssssang "Trussst in me". (an awesome cover, BTW).
I have heard this from a lot of speakers and it was always caused by a resonance peak from the woofer. I had some Audax HM100CO's that were horrible. Frankly, I'd be a bit surprised to find this coming from the p18's. (Also deeply dissappointed, as I love the sound of p17's used as bass woofers, and I was pinning my hopes on that p18 as a future replacement.)
If it is from a resonance peak in the woofer cone, the best way to eliminate it is to use a lower crossover point. I see from the schematic you posted that they haven't used baffle step compensation. I personally like a much larger inductor in front of the woofer, which can provide baffle step compensation without an extra network. (I learned of this from George Short's Northcreek website.)
JJ
GOWA,
Salas is helping me tame my Wharfedales I'm using as an experiment... refer post:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=104960
He suggests in my case (see my at listening position, off-axis measurements) a 6KHz peak is suspect and taming that should help a lot. Refer the contained graph. Mine is not so much a sibilance problem but just a general brightness. I do find more detail is coming through from my wharfedales. It must be in part to:
a) a better tweeter (Seas 27TBFC/G in the Wharfedales vs. the old Peerless HDS 812687 in the towers)
b) better phase tracking (measured) through the crossover when measured on-axis and tweeter phase reversed.
The "flat is inaccurate" post seems to suggest at typical listening distance and off-axis - one should target a 2dB droop per decade above 200Hz. I interpret this as 2dB down at 2,000Hz and 4dB down at 20,000Hz.
My tower speakers which I laughed at (and others have - as they are the AR.com DIYs) have a noticeable droop between 3 and 5KHz when measured on axis at 1m, but they nicely level out at listening position. They don't droop though and I find them forward sounding... so what salas says definitely seems to be on the mark with my (limited) experiences and worth trying.
HTH,
David.
Salas is helping me tame my Wharfedales I'm using as an experiment... refer post:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=104960
He suggests in my case (see my at listening position, off-axis measurements) a 6KHz peak is suspect and taming that should help a lot. Refer the contained graph. Mine is not so much a sibilance problem but just a general brightness. I do find more detail is coming through from my wharfedales. It must be in part to:
a) a better tweeter (Seas 27TBFC/G in the Wharfedales vs. the old Peerless HDS 812687 in the towers)
b) better phase tracking (measured) through the crossover when measured on-axis and tweeter phase reversed.
The "flat is inaccurate" post seems to suggest at typical listening distance and off-axis - one should target a 2dB droop per decade above 200Hz. I interpret this as 2dB down at 2,000Hz and 4dB down at 20,000Hz.
My tower speakers which I laughed at (and others have - as they are the AR.com DIYs) have a noticeable droop between 3 and 5KHz when measured on axis at 1m, but they nicely level out at listening position. They don't droop though and I find them forward sounding... so what salas says definitely seems to be on the mark with my (limited) experiences and worth trying.
HTH,
David.
Thanks to all for your input. There is much information here for me to consider. Because this x-over came from a company that I have much faith in (Madisound), I am going to rebuild these x-overs in the hope that in my rush to build, I made some stupid mistake.
www.madisound.com
www.madisound.com
SY said:
It may well be. In the recording chain, in the replay source, in the amplification, in the cabling. I have even listened to classic valve versions adding sibilant or else 'fizzy' treble. Especially ones made in former East Germany. The thing is that if the speaker has some (even minor) issue in the 4-8kHz octave, it will be amplified to too obvious levels. Simple test I suggest, is to plug a pair of known to be smooth headphones to the system, and see if the same amount of sibilance is there in the chain before the speakers. Then we know better where to look.
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