Tweeter sibilance

[fatpiggy]

I have just upgraded my crossovers tweeter capacitors in my RT 12's and I now have a sibilance issue which is driving me mad.I used a Dayton 200v 10uf 1% Audio capacitor with a .01 400v bypass film foil capacitor.I used the same values as the originals.The added bypass was suppose to improve the top end.

I have installed all new drivers.
The tweeters are SL5001's but I also tried SL6001's trilamanites but still have the problem.I removed the bypass capacitor and still have the horrible ssss's in voices.Is it the tweeters Dayton capacitor the tweeters thenselves or something else.Both speakers have the problem.When I change over to my other speakers no problem so its not my reciever amp, CD player or room accoustics.Both speakers have installed the original sponge packing in the enclosures.No change to the internals or drivers all stock.

I dont know if these RT12's had an sibilance issue from new as all the drivers and crossovers were blown before I started the rebuild.Both power resistors were blown.I replaced the blown resistors with the original values same type.Figured I would up grade the tweeter capacitors to something better.

I going to remove the new Dayton Audio Capacitors and install the old Polk capacitors and see if that solves the problem.Anyone had this issue.

Fatpiggy

[dacoupedeville]

I`m pretty sure all new components will need time to burn in. I know the sonicaps I installed in my 3.1`s took a while to sound their best...days. I used dayton in another xo upgrade and it was only hours before a significant improvement. I think even the tweeters will need 24 hours or so before they settle in. Poke around this forum and others have said the same, the more time passes, the better they should sound.

[fatpiggy]

Hi dacoupedeville ,
Thanks for the reply.I didnt think anyone was going to reply to my thread.I have been hammering these speakers for days now hoping they will settle down.However I think I have a woofer tweeter mismatch on my hands.

I am going to get new original tweeters that came with these speakers SL5501's and see if that makes any difference.There seems to be alot of difference in the frequency ranges of these tweeters as well as SPL output ratings.I think the sibilance is being caused by SPL output not matching the woofesr SPL output.

Listed is the specs for the tweeters I have you can see they vary allot in frequency ranges and SPL output .I think if you install a tweeter that is not SPL or frequency matched with your woofers crossovers you will get sibilance issues.

The SL 5501's tweeters are the original tweeters that came with these speakers however the schematic for the RT12 lists the SL 5001.So I bought the SL5001 tweeters thinking they were the correct tweeters.Both the SL 5001 and SL 6001 tweeters have sibilance.If the original SL5501's tweeters still have sibilance I will have to modify the crossovers and try and dampen down the output to get rid of the hissing on voices.

I have had fun these last few days padding out the listening room is see if reflections were the cause of the issue.No joy their.Its the tweeters for sure, the woofers sound great nice and smooth.I disconnected the tweeters and no sibilance there.

Anyway thanks for your comments.I keep hammering these speakers till I get the new SL5501 tweeters, maybe they will settle down over the next few weeks.Im going to see if hooking them up to a bigger amp fixes the problem just waiting for some new cables to arrive.

SL5501

* Size / Type = 3.750" Dynamic Balance® polymer dome tweeter
* SPL = 90 db @ 1w/1m
* Wattage = 45 Watts RMS / 90 Watts Peak
* Polymer dome tweeter
* Response = 2.5 kHz. to 20 kHz.
* Weight = 1 pound ea.
* Magnet = Shielded
* VC = 1" ( 25 mm)
* Ohms = 8 ohms

SL5001

* Size / Type = 3.750" Dynamic Balance® poly dome tweeter
* SPL = 92 db @ 1w/1m
* Wattage = 40 Watts RMS / 80 Watts Peak
* Polymer dome tweeter
* Response = 1.5 kHz. to 21 kHz.
* Weight = 1 pound ea.
* Magnet = UnShielded
* VC = 1" ( 25 mm)
* Ohms = 8 ohms
SL6001

* Size / Type = 3.75" Tweeter Dynamic Balance® Trilaminate Dome
* SPL = 91 db @ 1w/1m
* Wattage = 45 Watts RMS / 90 Watts Peak
* TriLaminte Dome Tweeter
* Response = 1600 Hz. to 25 kHz.
* Weight = 1 pound ea.
* Magnet = Un-Shielded
* VC = 1"
* Ohms = 8 ohms


Fatpiggy

[fatpiggy]

I got a new set of SL5501 tweeters installed and the sibilance isnt as bad, Its allot better however I think the issue is the resistors and possibly the Dayton capacitors I used in the crossover upgrade causing the sibilance.Next step is to replace the new crossover parts and install new original POLK parts and see if it cures the issue.

Fatpiggy

[ben62670]

The cap brand is not the issue. I would try removing the bypass cap. They are mostly for use with lower quaility caps. Please define what you mean by sibilance?

[fatpiggy]

I removed the Dayton bypass cap in the first instance.Sibilance is the pronounced Hiss when words spoken with SS's Cha ect most noticed with female voices.Does it on music, movies and TV.My RTi25's dont do it my Centre CSi 245 dosnt do it.Just these RT 12's I rebuilt.The crossovers had blown 2k 5 watt sandcastle resistors.I replaced the resistors with Xicon sandcastle resisitors same value.I removed the Mylar tweeter capacitors and installed 1% 10uf Dayton capacitors same values as the orignal mylars just higher voltage rated from 100v to 200volt.The rest of the crossovers are stock.The speaker are all new and stock

woofers MW7010 tweeters SL5501's.The cabinets have the original foam installed no change to the internals of the cabinets.

Fatpiggy

[ben62670]

Is that a typo "5k"?
Also how many hours do you have on the new caps?

[fatpiggy]

Yes its a typo 2K resistors , I just edited my post.I have about 50 hours on these speakers since the rebuild.Thinking maybe I need a larger amp.Im driving them with rotel 100watts.

Fatpiggy

[ben62670]

The amp is plenty powerful. Also 2k is wrong. It maybe 2r as in 2ohms not 2,000ohms.

[fatpiggy]

Ok,Thanks for picking that up for me Ben. So the problem is incorrect resistor size.The resistor I put in is 2K 5 watt.Silly me...so what would a 2k ohm resistor do to my tweeters will it blow the tweeter coils.Should I not use these speakers till I get the right resistors.What do you recommend as the best resistors to use, Mills? otrher sand castle types.larger wattage like 10 watts.

Thanks

Fatpiggy

[F1nut]

With a 2000 ohm resisitor, you shouldn't have any highs at all.

[ben62670]

It will not blow the tweeters, but will raise the XO point very high. You want a 2ohm 12watt Mill's. Sand cast is junk. Use a non inductive resistor if you can't find Mill's.

[fatpiggy]

Well I do have sound coming out of the tweeters but I really need to crank the volume on the amp up to get any sound output .All the highs have bad sibilance its all the voices sounds swiss and hiss.When I say crank I mean 1 o'clock I wouldnt dare go past 60% on my amp.I think the 2000k resistor in the circuit is also damping down the wattage getting to the woofers as they sound like there not getting enough power and sound garbled with the volume control down low.Well Im glad Ben picked up the issue.You know I tested these resistors with my multi meter and they measured up 1.97k I wasnt thinking they should have measured only around 2 ohms.Boy I can sure get stupid.So more than likely I can run the Tri Laminite tweeters like I wanted too originally.I'll be happy about that.

Fatpiggy

[fatpiggy]

Thanks for that Ben.I'll see if I can chase a couple of Mills from Madsound.I owe you one.

Fatpiggy

[ben62670]

Madisound doesn't have the value you need. Can you order from here?
http://www.parts-express.com/pe/psho...rtnumber=005-2

[fatpiggy]

I cant get parts from Parts Express as they have a min charge of $50 US for orders out of the states plus crazy shipping charges..Its a pain getting stuff through them.I will have to see if my friend can order them for me and post them on as he lives in the states.

Thanks for all your help Ben.Cheers

Fatpiggy