Single resistor in 2B TL x-over
Comments
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I would put them at 5-600 hours very conservatively, finished them 2 years ago almost to the day.
2 years ago and you are just now noticing something is wrong with the sound? What am I missing here?Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
2 years ago and you are just now noticing something is wrong with the sound? What am I missing here?
Been switching components and interconnects around, just recently I had acquired the B&K 200.2 amp about a month ago and the Ref 50 pre 2 months ago. Had been using the AVR's up till that point and the SQ has improved dramatically from there.
What I noticed tonight was a soft buzz coming from both tweeters only when the preamp was turned on, the amp alone it's dead silent, only noticed because I had my face right up to it making sure all the screws were tight. The buzz is sort of between a hiss and a buzz, level of buzz unchanged with the volume knob.
I changed back from the XLR to the RCA and the noise dropped slightly but still there, not sure if this is normal.
I had just wired two dedicated 20A circuits for the amp and Panamax power conditioner. Thought it could be a ground issue but changed to nearby outlets and same noise.
The sound quality isn't bad, it's just there's this slight level of harshness in the tweeter....I wish I could be more specific. Almost like there is a void in frequency response with male vocals in the low to mid range. Maybe it's not the tweeter but not enough midrange where the tweeter is overpowering the lack of mid range vocals.
I believe the cabinets are sealed fairly well, PR push test on both speakers yields about 3-4 sec for the mids to return but they do start returning right after I push on the PR, they don't wait but are slow to return. -
The buzz is sort of between a hiss and a buzz, level of buzz unchanged with the volume knob.
Ok, well a slight hiss from the tweeter isn't uncommon, although it's more common when using tube gear. I really don't know if that is typical of your B&K pre amp. You could rule out the pre amp causing the harshness issue by swapping in another pre amp, even an AVR hooked up to the B&K amp.
Changing interconnect brands could be the cause of the harshness, if in fact you did change brands.
It could also be that the new to you amp and pre amp are exposing an issue with your source. What is your source/brand/model?The sound quality isn't bad, it's just there's this slight level of harshness in the tweeter....I wish I could be more specific. Almost like there is a void in frequency response with male vocals in the low to mid range. Maybe it's not the tweeter but not enough midrange where the tweeter is overpowering the lack of mid range vocals.
It could be the new mid-drivers. Some have reported that they don't sound as good as the originals.I had just wired two dedicated 20A circuits for the amp and Panamax power conditioner. Thought it could be a ground issue but changed to nearby outlets and same noise.
A ground loop isn't your problem. However, I would suggest you plug the amp into the wall instead of the Panamax.I changed back from the XLR to the RCA and the noise dropped slightly but still there, not sure if this is normal
Now, that is unusual as it should be the other way around.I believe the cabinets are sealed fairly well, PR push test on both speakers yields about 3-4 sec for the mids to return but they do start returning right after I push on the PR, they don't wait but are slow to return.
That's exactly what they are suppose to do, it's not the problem.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
I don't know if this has anything to do w/ the TL mod or not but I was told by EVERYBODY to pull those poly switches out"nasty" was the word that comes to mind. I did and soldered in Mills 0.5 resistors and that's as far as my confidence will let me go. I will say the way GMCMAN laid out his resistor is outstanding work, mine are kinda standing at attention trimmed of course but I like his look better.In my letter to Trey whcih I already wrote I said" if my work does not come up to your standards on the Mills then just redo them".I think he will just redo do them to cover all the bases.When they will go out, maybe for another month or 2.I will say I did not hear any difference but after the change out but if it helps to protect the new RDO-194s then let it ride.2chl- Adcom GFA- 555-Onkyo P-3150v pre/amp- JVC-QL-A200 tt- Denon 1940 ci cdp- Adcom GFS-6 -Modded '87 SDA 2Bs - Dynamat Ext.- BH-5- X-Overs VR-3, RDO-194 tweeters, Larry's Rings, Speakon/Neutrik I/C- Cherry stain tops Advent Maestros,Ohm model E
H/T- Toshiba au40" flat- Yamaha RX- V665 avr- YSD-11 Dock- I-Pod- Klipsch #400HD Speaker set-
Bdrm- Nikko 6065 receiver- JBL -G-200s--Pioneer 305 headphones--Sony CE375-5 disc -
Not to beat a dead horse, but I did some research on this a while back. If you review the schematics for the Monitor line, in most cases when a fuse was changed to a Polyswitch, the value of the resistor down stream was dropped by .3 or .5 ohms to compensate. It's not consistent however. The one SDA which could be compared, was the 1 vs 1A. Removal of the Zobel network aside, the switch from fuse to Polyswitch resulted in the resistor value downstream being dropped by .5 ohms. Changing the value of the downstream resistor that has the 5.8uf shunt cap needed for the TL Mod, may alter the crossover point and slope, whereas removing the Polyswitch and installing a resistor affects the overall SPL level of the Tweeter, without affecting the crossover. I always keep that separate. Yes it's an additional resistor that must be purchased, but it allows you to tweak the overall Tweeter level without affecting anything else.Home Theater/2 Channel:
Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
dhsspeakerservice.com/ -
Difficult to quote on this phone so I will answer as best as I can.
Source is Denon 2910, I have other players to try but not stellar units.
I will try a different pre to rule anything out.
I do have the amp on one 20A circuit and Panamax on the other.
No polyswitches used, I have the boards returned to how the picture shows them with the .5 mills.
Pics were when I had completed them, I do have hot glue covering the inductors.
The part abkut the 5.6 vs the 5.8 is where I'm very curious about the crossover point and slope, could possibly play a part. -
Source is Denon 2910
I had a 2900 float thru here years ago, which I found to be bright/harsh on the top end.The part about the 5.6 vs the 5.8 is where I'm very curious about the crossover point and slope, could possibly play a part.
That's not it. You tested the cap and found it was 5.8uF. Even if it was a 5.6uF, it's well within the original +/-10% of the original caps.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
I had a 2900 float thru here years ago, which I found to be bright/harsh on the top end.
Also, IIRC...the 2910 was definitely not an upgrade to the 2900. I believe I remember the last CD player comparison done here and the tester found the 2910 to be bright as well.
So I pulled out my old Sony DVP-S550D DVD player from a box and hooked it up with the digital coax.... low and behold, the harshness is gone. Granted this player isn't the last word in detail but Peter Gabriel's vocals reclaimed their rasp and not an ear-piercing shrill from the 2910. With the Sony it's almost like there is a thick bed sheet stretched across the width of my room in front of the speakers but nonetheless it's more pleasant to listen to than the 2910.
Turn the volume up and it's not as bad, the 2910 is excellent at movies but for audio there lies the weakness. I think if I had to pull the trigger on a CD player it would be the Opera CD 120 if one came around at a good price.westmassguy wrote: »whereas removing the Polyswitch and installing a resistor affects the overall SPL level of the Tweeter, without affecting the crossover. I always keep that separate. Yes it's an additional resistor that must be purchased, but it allows you to tweak the overall Tweeter level without affecting anything else.
The lower value resistors actually didn't change the harshness level too much like you stated, just the volume, (SPL) probably would have sounded good with this Sony but I'm going to keep the .5 in there as it balances the mids very well, now it's just a matter of hunting down a decent CD player. -
Let me clarify, the Sony sounds more neutral and has the absence of harsness that the 2910 provides....as well as the bedsheet.
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There ya go, it all starts with the source.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk
