highs cut out with sda2bs

scottyboy76

Was listening for first time with audiosource pre, marantz monos, grounding box and cables jerryj12 loaned me.

After 3 or 4 songs the highs went muddy and then dropped almost entirely out while the rest played on, jumped up and turned down the preamps volume knob, highs came back in.

Turned everything off, turned out the lights and ran and hid like gollum when the wraiths came through.

Exxagerating a bit on our reaction, but my new to me sdas are now shut down until further advice, both from anyone and especially my new friend jerryj12 who sold them to me and has held my hand through all of this as i am new to sdas and mono hookups to them.

Could i have almost cooked the tweets?, not a huge deal, although im certainly not wealthy i am going to do the tl upgrade, the highs are really very irritating at rock volume.

thanks anyone.

ben62670

Sounds like you are pushing them pretty hard. I have heard those speakers at pretty high levels with no issues. There is however a protection device in them called a PolySwitch that with age gets more sensitive and trips easily. If you are one to drive them hard I would contact Polk CS and let them know you are a member and ask for new ones. It does require some soldering, but if you are going to do the TL upgrade it can be done then. When I do XO's for Polkies I usually just bypass the PolySwitch which gives slightly better sound but offers no tweeter protection. If you are one to push the speakers real hard I would not recommend bypassing the PolySwitches.
Congrats on my favorite SDA's
Ben

dorokusai

Polyswitch sounds like a good suggestion. I don't think Polk is offering these anymore....tho' you may catch a friendly. I'd bypass them personally and try not to relive the rock concert you remembered years ago with empty beer bottles on the table. Only to recall you never went and you wake up smelling smoke.

scottyboy76

I had forgotten reading posts about that switch.

Im thinking more and more that i will get jerry to come up to the n. georgia mountains and do my upgrades instead of letting the local repair guy.

I will have to make it worth his time with world class meat loaf or fresh mountain trout with beurre blanc sauce, and maybe a ride on the blue ridge railroad, because i sure cant impress him with my audio gear after visiting and listening to just a little of his stuff.

scottyboy76

After doing the tl upgrade, would the switch be less necessary

dorokusai

I always bypass it unless asked not to do so and it has nothing to do with the tweeter as it does your listening habits and gear.

ben62670

After the XO upgrade the current is still the same as before.
You can use these
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-810
Or these
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=071-258
I agree with Doro. Bypassing is the best, but if you know you push things a little too much then don't do it without protection.
Ben

dorokusai wrote: »

I always bypass it unless asked not to do so.

Edit:me too.

dorokusai

Ben makes me rock hard about tweeter protection device links.

scottyboy76

i think i might possibly leave it in place, stairway to heaven and levee breaks off same album, and gimme shelter always take away my control of volume knob, would love to get peak sound quality out of these guys, but cant afford to be replacing the replacement tweeters with our budget.

dorokusai

scottyboy76 wrote: »

i think i might possibly leave it in place, stairway to heaven and levee breaks off same album, and gimme shelter always take away my control of volume knob, would love to get peak sound quality out of these guys, but cant afford to be replacing the replacement tweeters with our budget.

That's fine, then either upgrade it with a new one per Ben's link or high quality in line fuse it. If you're prone to lose it from time to time, you need it.

ben62670

reported

dorokusai

ben62670 wrote: »

reported

Damn, it appears I continually choose the wrong thing to say. I'll crawl back in my hole Ben.

ben62670

It was a spammer I reported silly

inspiredsports

scottyboy76 wrote: »

i think i might possibly leave it in place, stairway to heaven and levee breaks off same album, and gimme shelter always take away my control of volume knob, would love to get peak sound quality out of these guys, but cant afford to be replacing the replacement tweeters with our budget.

Scott,

Ben TL'd my SDA 2B crossovers for me in November '08, and I elected to have polyswitches removed.

I've spent a lot of time upgrading components since then and have a modest system, but a very pure signal.

I generally listen under 80db, but I have generated a clean, sustained 105+ db as measured by my calibrated Exotech SPL meter at 10' back in a 26X30X8' room with Zeppelin/AC/DC/Rush/Pink Floyd/etc.

I think they will go louder without popping the tweets, but that is approaching just plain earbleed levels and there's really no reason for it.

I will say that my SDA SRS II's seem a tad more comfortable at that high a level, but the 2B's are my favorites.

The polyswitches do degrade sound a bit, so I offer the above to help you decide.

Greg

gdb

Go with fuse protection, you can afford to replace a fistful of them for about $5.00 ! Plus they don't deteriorate/weaken with time, they're a go/no-go thing.

inspiredsports

gdb wrote: »

Go with fuse protection, you can afford to replace a fistful of them for about $5.00 ! Plus they don't deteriorate/weaken with time, they're a go/no-go thing.

But they do affect the signal path and resulting sound quality.

george daniel

Try replacing the poly's with a .5 ohm 12 watt resistor,,while you are in there poking around,might as well do the tl mod with new/improved caps,, then I would replace your amp(s) with something that can supply more current to them.A 40 watt tube amp would be perfect.Good luck with your new aquisition

Oh,, careful with that volume,,,,Eugene.

scottyboy76

Im tempted to go the better sound quality route.

Im over 50, married, havent had a beer in years, dont even smoke a peace pipe anymore, so if i abuse these sdas after jerry has helped me get so much farther into quality audio than i ever thought i would, then i deserve what i get.

By the way, about how much am i looking at for the tl upgrade gear, parts only.

Im about to look around the site in case there are posts already laying it out.

pitdogg2

ben62670 wrote: »

After the XO upgrade the current is still the same as before.
You can use these
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-810
Or these
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=071-258
I agree with Doro. Bypassing is the best, but if you know you push things a little too much then don't do it without protection.
Ben



Edit:me too.

Ben wouldn't the poly be .90 in those? I know the .85 is real close but that .75 is a little low isn't it?

danger boy

which marantz mono's are you using? SDA's don't like mono block amps esp if you use the interconnect cable.. bad juju can happen.

scottyboy76

jerryj12 kindly loaned me his ai-1 and cable and showed me how and why to use it.

great guy, treated me like a lifelong friend the day he met me.

ben62670

pitdogg2 wrote: »

Ben wouldn't the poly be .90 in those? I know the .85 is real close but that .75 is a little low isn't it?

The other option would be 1.1 amps so I would prefer to have them slightly underated.

dcoil

inspiredsports wrote: »

Scott,

I will say that my SDA SRS II's seem a tad more comfortable at that high a level, but the 2B's are my favorites.

Greg

Hey inspiredsports - I have a pair of SRS and 2B's. Can I ask why you say the 2B's are your favorites?

inspiredsports

dcoil wrote: »

Hey inspiredsports - I have a pair of SRS and 2B's. Can I ask why you say the 2B's are your favorites?

In my opinion, they are just perfectly balanced with incredibly clean and revealing treble.

The single (single point source) tweeter may be the deciding factor. Once the signal is divided between low pass and high pass sections of the crossover, nothing else is introduced to into the high signal path to dole out the signal between multiple tweeters.

Obviously, the 2B's 12" passives can't produce quite as much bass as the SRS II's 15"ers, but it's very close, and the SRS II's do throw a slightly wider soundstage. I should also share that I mentioned 105+ db for the 2B's in a post above where the SRS II's produce 113+ db under the same parameters.

They are both excellent, but I gravitate to the 2B's about 60/40.

On3s&Z3r0s

@Ben (or anyone else who cares to answer), I don't mean to hijack the thread, but I'm leaning toward pulling the poly's out of my 2B's when I do a TL upgrade (I've had them for about 6 months and never experienced a cut-out of any sort). When you say "bypass" do you mean remove and replace with a jumper?

Thanks!

On3s&Z3r0s

inspiredsports wrote: »

In my opinion, they are just perfectly balanced with incredibly clean and revealing treble.

The single (single point source) tweeter may be the deciding factor. Once the signal is divided between low pass and high pass sections of the crossover, nothing else is introduced to into the high signal path to dole out the signal between multiple tweeters.

I'd say you're spot on about the single tweeter. I haven't ever owned a pair of the big SRS, but I've heard a couple in different spaces. In large spaces they seem to do alright, but in some smaller spaces or those with harsh acoustics I think they can be overkill. I was talking to another CP member offline who had owned at least one of the SRS models (can't remember exactly which) and the 1C's and 2B's, and out of all of them he expressed a preference for the 2B's (or at least he said he felt they had the most potential in his somewhat smaller space).

I own a pair of the original SDA 2's and the 2B's. The original 2's have a dimensional tweeter (not an extra tweeter in a series array as with some of the SRS models), and after having a hard time deciding whether to buy the 2B's I was amazed at how much better they were.

I'm sure many of the SRS models could bury my 2B's in the right space and paired with the right equipment, but for my space I think they're about as good as I could do from the SDA lineup.