need advice or opinions on this

leftwinger57

After that long winded thread of Isrealboy's speakers catching fire and then I went into why weren't they better protected by either in line fuses or the poly switches I had heard so much about that just bothered me. Now Tony, Inspidel and some others informed me that they are for tweeter protection for the most part and Jesse gives me his classic 2 word response "they're nasty".So I called Polk C/S and spoke at length to Alex this time he said yes the switches are free and I'll send them out to you. Well they came today and it's not what I expected at all ,I thought a switch like a slider or an on/off something or other .No they are like resistors, more looking like 1/2 Daddy Long Leg spiders.Now comes the good part since I have the original sl /silver domes do I just for a control example cut out the old switches and see if I do hear anything different or better or because they are 36 y/o tweets it would not matter to cut out the old switches.Then when the RDO-194s come sometime in late fall/winter do I use them or not?
Meanwhile the new vinyl is spinning and nothing will be touched until I either hear from you dudes/dudettes or just make a decision on my own......

cnh

Dude! You worry to much. Just keep your amp in good shape. Have it checked out every so often and you'll be fine! I've run TONS of old A$$ vintage speakers, amps, receivers and I have NOT once had anything "burn" up on me! And considering some of the stuff I have, that's saying SOMETHING!

If anything is going to fry some speakers it's probably going to be my Adcoms (545, 555). But they haven't yet. They have no relays, no protection of any kind and can spike to the point of making those poly switches TOYS that could never handle the voltage surge!

cnh

heiney9

No sort of fuse of poly switch will prevent what happened to Isrealboy. That was a major malfunction somewhere beyond just playing them loud. Think large amounts of DC of which no speaker protection fuse, circuit or poly can prevent.

What happened is rare so don't stress over it.

H9

boston1450

+ 1 How often do you hear about this kind of issue. Use you own judgement when playing around with volumes or wrong applications. Even Brand New speakers have problems thats why there are CLAUSE's in place on items with Warranty's. to protect the seller from wrongfully usage.

tonyb

Agreed, what happened in the other thread is far outside the norm. As far as the poly switches go, if you like what you hear, leave well enough alone. They do go bad over time and since you have some on hand, whats to worry about ? The chances that you experience the same thing is about the same as a meteor falling on your head. Don't go out and buy a Helmut now either.

markamerica

I must concur with the other respondents: If they're not giving you issues, leave 'em alone. The situation Israelboy encountered was a rarity, and there may be more issues with amplification or something else in his case.

Mark

leftwinger57

I get what you guys are saying. Either I speak a different language then you guys or just to long winded but I'm not over reacting to anything. I got some free switches . A few/many people here said these poly switches are the bane of the tweeters in SDA 2Bs. So if they are so bad and since I have the original tweeters I was just wondering whether or not to cut them out. I have no problems at all w/ my amp forget all that other stuff, I think I asked a direct enough question after prefacing the thread with something that happened w/ another dude.Tony and I might be wrong on this but weren't you one of the nay sayers concering these said swithches I believe "they interfere w/ the signal path".Since I thought my SDA 2Bs sounded pretty damn good when I brought them home and never thought they could sound any better then I heard the landslide of people saying they can be that much better if you do these mods and I did in fact do the Dynamatting and floor deadening because it was also free and do hear a better bass response at lower levels.Please forget about the fire scenario I am way past that, it wasn't me, and I have no intention of blowing anything up ever and has nothing to do w/ my amplification....

heiney9

LW, your question and ramblings have been addressed hundreds of times here on CP, use the search feature and you'll learn more than you ever thought

H9

F1nut

Lew, remove the poly switches on your crossover boards and either replace them with a jumper or a 0.5 ohm 12 watt Mills resistor to compensate for the resistance of the poly.

westmassguy

leftwinger57 wrote: »

I get what you guys are saying. Either I speak a different language then you guys or just to long winded but I'm not over reacting to anything. I got some free switches . A few/many people here said these poly switches are the bane of the tweeters in SDA 2Bs. So if they are so bad and since I have the original tweeters I was just wondering whether or not to cut them out. I have no problems at all w/ my amp forget all that other stuff, I think I asked a direct enough question after prefacing the thread with something that happened w/ another dude.Tony and I might be wrong on this but weren't you one of the nay sayers concering these said swithches I believe "they interfere w/ the signal path".Since I thought my SDA 2Bs sounded pretty damn good when I brought them home and never thought they could sound any better then I heard the landslide of people saying they can be that much better if you do these mods and I did in fact do the Dynamatting and floor deadening because it was also free and do hear a better bass response at lower levels.Please forget about the fire scenario I am way past that, it wasn't me, and I have no intention of blowing anything up ever and has nothing to do w/ my amplification....

Any component in the signal path affects the voicing of the tweeter. The Polyswitches do protect the tweeters under certain conditions, but are not a foolproof, all encompassing protection device. They are resistive, and therefore affect whatever signal passes through them. They are a known source of distortion, their resistance changes over time, and not always equally between both speakers, that's why most here will advise removing them and inserting an audio grade resistor in their place, when doing a crossover upgrade. If you chose to leave them in, fine. If you choose to install the new ones Polk sent you, that's fine too. Do whatever you feel comfortable with. BTW, you can't just cut them out, you'll have an open circuit. If you insert a jumper, you'll increase the tweeter output slightly, and the speakers will sound hot or brighter than they were. Most of us put a 0.5 ohm resistor in place, but some also use a 0.2, or 0.3 ohm, all depends on personal taste.

leftwinger57

All right here's what's going to happen,Jesse all this time I was under the impression these switches were connected directly to the tweeters themselves and not on the x-overs, no body said other wise so I just pulled one of the tweeters and found this out.Now I do know how read a meter know some values but I have no intention of touching said x-overs ,that wil be VR-3s job when the time is right.So in closing when the 194s become available they will be put in and not another thing will be done.About the search feature I did try it for something else and it was worthless so I might as well bother you....(not f-1)

leftwinger57

Westmassguy, yours and Jesse's resonse, explanation and answer was what I was exactly looking for, not some moronic response from H-9.Thank you, at least you absolutely understood what the f%#k I was talking about..Jeez

tonyb

LW,

Yes, what I said was correct but only if you feel the sound has suffered from them. You don't have to switch them out if you don't feel a need. F1NUT explained what to do should you want to do it but given your limited expertise on these speakers I would suggest you let someone else do it for you. Maybe when you get the crossovers redone, do it all in one shot. Myself and others feel they degrade the sound some, what we are not eluding to is that they make the speaker sound like crap. Just that they will sound slightly better without them. Relax and enjoy them, all this is much to do over nothing.

heiney9

leftwinger57 wrote: »

Westmassguy, yours and Jesse's resonse, explanation and answer was what I was exactly looking for, not some moronic response from H-9.Thank you, at least you absolutely understood what the f%#k I was talking about..Jeez

Sorry LW, but I personally get tired of rehashing the same **** ad nausea year after year. Sometimes YOU need to put in a little effort if you want to learn. Glad others felt like rehashing for the thousandth time, me I rarely will anymore. I'm tired of the apparent laziness. Why should I take my time to answer if you won't take the time to get the answer when it has been all over CP forever?

Just my .02c

H9

Big Dawg

LW, the poly switch acts as a resistor most of the time, unless it is activated, when it acts as a switch. It automatically resets afterwards, but empirical evidence has shown that the poly switches degrade over time. The purpose of the poly switch is to protect your tweeters from peak signals which can be caused by distortion, often during musical peaks, when you are driving your amplifier beyond its ability (often somewhere between 50-75% of the volume knob). Thus the advice not to push the volume knob past 12:00. Generally, the better (more distortion free) your amp, the less critical that limit. If you find yourself often wanting to go over that limit, you need a better amplifier.

Since most folks here who have sda's also have invested in quality amplification, and since the poly switch absolutely adds colored resistance, most prefer to replace it with a jumper or small (equivalent or less) resistor according to their preference. However, if you like the sound with the 30 year old poly switches, you will like it at least as well with the new replacements, especially if you are worried that you might otherwise fry a tweeter.

Msabot1

As far as that burned driver goes....I think one of his loaded college buddys got jiggy with a bic lighter!

leftwinger57

Big Dawg, your in central Jersey like me. Maybe you should come over and see if my Adcom gfa 555 is good enough@ 200 per side. I do like your explanation of the switches themselves which has been gone over already also.Again nothing will be done except for the 194s if and when they return to stock. I will list my sig for so please leave me alone about my amp,sources or what I use, it all works and works well.

Big Dawg

The adcom is fine, no issues with it if it is operation to spec.

TennMan

Big Dawg wrote: »

The adcom is fine, no issues with it if it is operation to spec.

I have a gfa-555. How can you tell if it's operating to spec or not?

Schurkey

TennMan wrote: »

I have a gfa-555. How can you tell if it's operating to spec or not?

Given the age of a '555, I'd expect the same problems with the electrolytic capacitors as we see on crossovers. When the power supply electrolytics degrade, the amp will try to throw just as much voltage as when new, but the current capacity is reduced. End result is that it sounds "thin" at high power levels, getting worse with time.

I have no idea how you test for this "officially" but I suppose it involves setting up a dummy load of resistors and a capacitor to simulate a speaker, and then driving the load with an oscilloscope voltage and amperage probe connected.

TennMan

Thanks. I think mine sounds great. I was just wondering if there was routine maintenance on a 555 that others were doing that I didn't know about.

zingo

Twist the current polyswitch to short the leads and listen without them in the signal path. If you like the sound better with them in, install the new ones and your good to go. If you like the sound better without them, solder them shorted, replace them with a jumper or resistor as Jesse suggested.

BlueFox

I wonder how much difference a 1/2 ohm resistor will make to the sound, versus a piece of (good) wire?

F1nut

BlueFox wrote: »

I wonder how much difference a 1/2 ohm resistor will make to the sound, versus a piece of (good) wire?

Depends on your ears. I can hear the differences between a 0.5 ohm, a 0.68 and a .75 ohm resistor.

BlueFox

Interesting. It is amazing how even the most minor change can affect the sound.

F1nut

Yeah, it is. I started with a 1 ohm (killed the top end) and worked down to a .22 (IIRC) and ended up liking the .5 the best. Another example of a small change making or breaking the sound, moving the speakers one half inch further away from the back wall resulted in sonic bliss.