NEW 1.2TL's need break in?

rduval
rduval Posts: 16
edited March 2004 in Speakers
Strange as it sounds...I just bought a pair of NEW 1.2's. They have been stored since new, these are the ones from Ebay about a month ago. When they arrived you could tell...they ARE brand new. Boxes, spotless, everything

They came with the TL upgrade kit complete with new crossovers, documentation, etc, which I installed.

So here's the scoop..

I have had (and still have) a pair of the original (non 1.2's) SDA SRS's. I LOVE the bottom end of these speakers but always found the high mids and highs bite so I bought these new 1.2TL's.

Problem is the new ones sound VERY different. The highs and upper mids are much smoother, not as spikey as the originals which is great. But they don't have the same really low bass! They're punchier but the bass doesn't extend waaayyyy doooowwwnn like the originals. I have both sets side by side so I can make an A-B comparison and it's very obvious.

So, I know this sounds strange because nobody's had a "new" set in over a decade but do they need a break-in period or are the 1.2TL's just that different from the originals?

Rick
Post edited by rduval on
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Comments

  • F1nut
    F1nut Posts: 50,722
    edited February 2004
    If you were sitting still for the last 12 years or so, you might need to loosen up a bit before being your best. ;)
    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

  • cds
    cds Posts: 28
    edited February 2004
    Rick,

    A thought…

    Since you had to install new crossovers along with the tweeters, it is possible that while wiring all the LF drivers you may have switched the polarity somewhere putting the bass drivers out of phase in one of the speakers.

    This would be similar to wiring a pair of speakers out of phase at the speaker terminals. I know it’s a pain, but you may have to go through each one and check.

    Since you have the original SDAs, you could open one to double check your connections.

    Let us know what you find.
    Carl
  • rduval
    rduval Posts: 16
    edited February 2004
    If I remember correctly all the plugs on the crossover are polarized so I don't think it would be possible to switch them around.

    I know on the tweeters that they had one large and one small terminal so I didn't screw that up for sure. I didn't actually have to unplug any wires from any speakers other than the tweeters so I can't see that as being the problem but I'm going to pull the crossovers just to be sure.

    Rick
  • cds
    cds Posts: 28
    edited February 2004
    OK Rick, if you’re saying that the TL upgrade required just changing the tweeter section of the crossover then let’s assume the LF drivers were wired correctly at the factory.

    Here’s something I came across on a “defective” pair of SDAs I looked at years ago. The plastic red and black binding post nuts will come off if unscrewed all the way. On these “defective” speakers, someone had put the colored nuts on backwards so when the owner connected the amp using terminal colors, he was wiring one of them out of phase. The label on the back shows the positive and negative terminals that should agree with the colors.
  • hoosier21
    hoosier21 Posts: 4,413
    edited February 2004
    Or just play them for a while and let them break in.
    Dodd - Battery Preamp
    Monarchy Audio SE100 Delux - mono power amps
    Sony DVP-NS999ES - SACD player
    ADS 1230 - Polk SDA 2B
    DIY Stereo Subwoofer towers w/(4) 12 drivers each
    Crown K1 - Subwoofer amp
    Outlaw ICBM - crossover
    Beringher BFD - sub eq

    Where is the remote? Where is the $%#$% remote!

    "I've always been mad, I know I've been mad, like the most of us have...very hard to explain why you're mad, even if you're not mad..."
  • RuSsMaN
    RuSsMaN Posts: 17,986
    edited February 2004
    heh heh heh
    Check your lips at the door woman. Shake your hips like battleships. Yeah, all the white girls trip when I sing at Sunday service.
  • Tour2ma
    Tour2ma Posts: 10,177
    edited February 2004
    Is the comparitive set up fair? That is are both the 1.2's in or outside of the SRS's?
    More later,
    Tour...
    Vox Copuli
    Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb

    "Death doesn't come with a Uhaul." - Dennis Gardner

    "It's easy to get lost in price vs performance vs ego vs illusion." - doro
    "There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
  • RuSsMaN
    RuSsMaN Posts: 17,986
    edited February 2004
    Why would it matter?

    Stereo image, etc, sure - but low bass response - nah. He could set them in the middle of the room facing each other, and they should have decent low end.

    BIG waves brotha, Tsunami style.

    Cheers,
    Rooster
    Check your lips at the door woman. Shake your hips like battleships. Yeah, all the white girls trip when I sing at Sunday service.
  • Tour2ma
    Tour2ma Posts: 10,177
    edited February 2004
    Two words: Corner loading...
    More later,
    Tour...
    Vox Copuli
    Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb

    "Death doesn't come with a Uhaul." - Dennis Gardner

    "It's easy to get lost in price vs performance vs ego vs illusion." - doro
    "There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
  • rskarvan
    rskarvan Posts: 2,374
    edited February 2004
    Rick,

    I ALMOST bought these speakers out from under you. (I know I saw them first - I hestitated). You got a FABULOUS deal there. If you become unhappy with the 1.2TL's, let me know. I'll take them off your hands.

    - ronskarvan@aol.com
  • cds
    cds Posts: 28
    edited February 2004
    Two words: Corner loading...

    Yes, that was another thought. Back in the days when audio magazines tested SDAs, I remember some reviewers commenting that the low end was very position sensitive. Something like if they were too close together the bass would mask the higher frequencies and if too far apart, the bass would disappear.

    Because room placement can be a big factor, have you swapped the positions of your original SDAs and the TLs? If it is room resonance related and you accurately relocate each pair, the symptom should transfer to the older set.


    Cheers
  • rduval
    rduval Posts: 16
    edited February 2004
    Ok...to reply to eveyone at once...

    Actually the binding post caps WERE reversed and I fixed it according to the labels on the back...

    ...They are set up inline, 1.2TL's on the inside 5ft centre to centre, originals on the outside with 1" between the old and new. Both pairs 1ft from the back wall and both have spikes...

    ...Corner loading, true but even at low levels the difference is painfully obvious so I don't think that corner loading would be the culprit. I do agree that there is a bass sweet spot from a placement point of view. and neither pair are in it at the moment because both are equally as close to it as possible...

    Damn I'm frustrated by this!


    Rick
  • Tour2ma
    Tour2ma Posts: 10,177
    edited February 2004
    How far are the SRS's from the corners? I'd swap either the left or right 1.2 and SRS.

    That said, seems we skipped some basics along the line like:
    - are all the MW's in the 1.2's functioning?
    - are the 1.2's well sealed so their PR is in fulll play?

    Probably others that are even more potentially insulting... Sorry if I did, but I'm feeling your pain...
    More later,
    Tour...
    Vox Copuli
    Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb

    "Death doesn't come with a Uhaul." - Dennis Gardner

    "It's easy to get lost in price vs performance vs ego vs illusion." - doro
    "There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
  • cds
    cds Posts: 28
    edited February 2004
    Rick,
    Disconnect the SDA cable and reverse the polarity on one of the new ones.

    Does that make the bass better or even worse?

    Carl
  • madmax
    madmax Posts: 12,434
    edited February 2004
    To save a lot of effort looking for the correct polarity on all the woofers take a little 9V battery and with the speaker completely disconnected from everything else connect the + side of the battery to the + side of the speaker and - side of the battery to the - side of the speaker. The 4 inner speakers should pop out about 1/8th inch or so. Check both speakers.
    madmax
    Vinyl, the final frontier...

    Avantgarde horns, 300b tubes, thats the kinda crap I want... :D
  • bikezappa
    bikezappa Posts: 2,463
    edited February 2004
    ****'in A relpy Madmax. I will remember that trick.
    Simple
    Quick
    Accurate
  • dorokusai
    dorokusai Posts: 25,577
    edited February 2004
    I did that battery trick and heard music.....
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • madmax
    madmax Posts: 12,434
    edited February 2004
    The battery trick is quick, easy and safe. It does assert a 20 watt pulse onto the woofer if it is fully charged (new) so obviously on higher power speakers it can cause no harm. I have used it on the smallest of speakers without harm as well. As for the tweeter it will only make a small click because the series capacitor will block the dc voltage. (the click only happens when you charge the cap, afterwards you will not hear it).

    This is only a guess but I bet if he hooked up the SDA cable the SDA speakers in the opposite speaker would pop in when you touch the battery terminals.

    madmax
    Vinyl, the final frontier...

    Avantgarde horns, 300b tubes, thats the kinda crap I want... :D
  • Tour2ma
    Tour2ma Posts: 10,177
    edited February 2004
    Originally posted by dorokusai
    I did that battery trick and heard music.....
    Then you're improving since most of the time you just hear voices...


    (Damn you're on a roll... )
    More later,
    Tour...
    Vox Copuli
    Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb

    "Death doesn't come with a Uhaul." - Dennis Gardner

    "It's easy to get lost in price vs performance vs ego vs illusion." - doro
    "There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
  • cds
    cds Posts: 28
    edited February 2004
    A 9 volt battery will work, but it doesn’t have much current capacity driving into a low impedance load. Across that kind of load, the actual voltage probably drops to a couple volts.

    In a pinch, I’ve used an alkaline 1.5V AA, C, or D cell. A good cell will easily drive the cones out and the voltage is not high enough to cause any driver issues.

    BTW, in the 1.2’s and 2.3’s both the Stereo and SDA arrays are DC coupled to the binding posts. Therefore, all the MW drivers will move forward if the battery is connected + to red and – to black.

    If the results are the same in both speakers, the internal crossover phasing is correct
  • madmax
    madmax Posts: 12,434
    edited February 2004
    Originally posted by Tour2ma
    Then you're improving since most of the time you just hear voices...

    He only hears the music when he connects the battery to his head, not the speakers. (just wanted to clear up this one point).
    Vinyl, the final frontier...

    Avantgarde horns, 300b tubes, thats the kinda crap I want... :D
  • rduval
    rduval Posts: 16
    edited February 2004
    Ok, here's where I'm at...

    I thoiught I'd try swapping the crossovers..just to see if the bass followed the crossovers. Unfortunately the original do not have plugs like the 1.2's & TL's, everything is soldered onto the board so it's no so easy. To complicate matters the slip on lugs for the tweeters are different so I stopped there for a moment.

    One thing I noticed inside the originals vs the 1.2's is that the originals have a LOT more bracing. I mean A LOT! ANy thoughts on if this has something to do with it?

    Also the original crossover is massive compared to the 1.2's. It barely slips through the access hole! That's got to have something to do with the sound! Not that size alone matters, just that they are very different.

    I think the next step for me is just to try the TL tweeters in the originals. Anybody done that? Any comments?

    One positive note for anyone who folloed the old thread regarding using 2 carver M1.0t's in mono mode, you'll remember that the feedback blew them both up becuase they are not common ground. Somebody suggested that running a common ground cable betweeen the negative terminals might do the trick...it did! That's all I needed to do..$500 lesson to repair them but they're great now.


    Rick
  • Tour2ma
    Tour2ma Posts: 10,177
    edited February 2004
    Glad to hear about the amps...

    Your comment on the bracing really surprises me. One of the things I have read here is how much Polk improved the stiffness of their flagship model as it progressed from the SRS trhough the 1.2 to the 1.2 tl. I always took that to mean more and better bracing... Just doesn't jive with you're observations.

    Please post some pics if and when you can...
    More later,
    Tour...
    Vox Copuli
    Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb

    "Death doesn't come with a Uhaul." - Dennis Gardner

    "It's easy to get lost in price vs performance vs ego vs illusion." - doro
    "There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
  • cds
    cds Posts: 28
    edited February 2004
    The bracing observation is interesting. I suspect Polk determined that the benefit realized with the original bracing would not be noticed by most users and reduced it in subsequent cabinets as a cost cutting measure. Funny, I’ve never seen the original cabinet but adding more bracing on the newer models always came to mind whenever I’ve had them open.
    Any difference caused by cabinet wall resonance would be noticed at higher volumes but it would not cause a lack of bass. At low volumes cabinet bracing should not be a factor.

    The difference in the crossover is also interesting but I also suspect it may be a result of design refinement. For example, earlier SDA designs contained more “stuff” because Polk originally had the dimensional function using both woofers and tweeters. Later versions eliminated the tweeter portion of the array.

    I don’t have access to a schematic of the original so I can’t compare it to the newer models, but I don’t think I’ve ever read a review on the 1.2 models that noted a lack of bass. There has to be something else wrong.

    Do you have access to any type of signal source other than music? If not test equipment, how about a test CD with tones? If you could play a steady 30 – 40 Hz tone and observe the amplitude of the woofer cone movement at a specific volume setting, that may help.

    Have you done the battery test and compared the cone movement of the two versions? There should not be much difference unless one of the new crossovers is screwed up.

    Another little detail is that the cabinet should be sealed. A significant air leak somewhere will effect the low frequency response. Did you install gaskets under each tweeter? You should also be able to compare the cabinet air seal by pressing a MW driver down, releasing it and comparing how quickly it returns to the rest position. If it snaps right back, there is an air leak in the cabinet. Obvious leaks spots are the bass brace and 4 mounting feet holes. Be sure things are screwed in to them.

    Keep us posted.
  • rduval
    rduval Posts: 16
    edited February 2004
    The only internal cabinet structure where the newer ones seem more "sophisticated" is that the internal walls are grooved into a large checkerboard pattern . This is not done on the originals. Perhaps, from an engineering point of view, this creates many "I" beams and makes the cabinet stiffer? maybe?

    On the crossovers, there are an extra 4 or 5 larege electrolytic caps and the coils, and as you can see 2 of the coils are MUCH bigger. Maybe it's same amount of wire, just a larger form?

    I haven't done the battery test yet, just haven't gotten around to it but I will. I'm reasonably confident that they're ok though. It's not that they lack bass, they have LOTs of puch it's that what they have is upper bass where the originals have low, ground rumbling, rattles your teeth out bass. Subwoofer bass. It's smooth and it's sweet and it goes waaaaaaaaaay down. I really wish the old crossovers had the plugs like the newer ones, it would have made it so easy to try.

    Cabinets are as well sealed as the originals. If you press in on the bass radiator all upper drivers come forward. If you hold the bass radiator until the 6" normalize then release it take about 3 or 4 secs to come back, about the same as the originals.

    I'm beginning to wonder if the really low sub-bass was deliberatly tuned out of the speakers in the later models to prevent damage by under-powered systems?

    Rick
  • rduval
    rduval Posts: 16
    edited February 2004
    Oh and for those interested I've also included the pic of my current setup so you can see how everything's layed out. The old ones are on the outside, the 1.2TL's in the middle.

    Rick
  • hoosier21
    hoosier21 Posts: 4,413
    edited February 2004
    how much have they been played? I mean has your original question about break in been ruled out?
    Dodd - Battery Preamp
    Monarchy Audio SE100 Delux - mono power amps
    Sony DVP-NS999ES - SACD player
    ADS 1230 - Polk SDA 2B
    DIY Stereo Subwoofer towers w/(4) 12 drivers each
    Crown K1 - Subwoofer amp
    Outlaw ICBM - crossover
    Beringher BFD - sub eq

    Where is the remote? Where is the $%#$% remote!

    "I've always been mad, I know I've been mad, like the most of us have...very hard to explain why you're mad, even if you're not mad..."
  • wallstreet
    wallstreet Posts: 1,405
    edited February 2004
    Just leave em just like that.:eek:
  • rduval
    rduval Posts: 16
    edited February 2004
    OK!!! SOME SUCCESS!!!

    1) I did the battery thing...SOB..they were reversed! So I changed the colored caps but when I get a minute I'm gonna fix them in the cabinets..so far so good.

    2) Found out the when the negatives of the 2 carvers are bridged YOU GET MONO! SERIOUSLY! I had to bridge them for the old ones but since the 1.2's have the transformer interconnect I don't need to. Wow, soundstage really opened up.

    3) Since I was **** around with the cabling I changed the speaker cables from the Monsters I was using to the AudioQuest Slates I had bought. WOW WHAT A DIFFERENCE! Bottom end opened up, mids were sweeter, etc. The 1.2's still aren't quite as full as the originals but they're close.

    So right now...I'm pretty happy...sorry to disappoint all of you who sent me private emails offering to buy them ;) .

    Only problem at the moment is that one of the Carver 1.0's that I just had rebuilt started making a crackling sound so I'll take it back tommorow to get them to go over it again so I'm running on one amp now for the right "pair" (yep I'm running all 4 at the moment but the old ones are only the bottom end since the 1.2's are so much sweeter...) and I'm running my 1.5t for the left.

    Anyway...thanks so much for everyones help...couldn't have got it sorted out without ya...

    Rick
  • cds
    cds Posts: 28
    edited February 2004
    Rick,
    Gee, I wish I had a main speaker setup that looked like that.... Dream on.

    From your picture, the originals are on the outside and closer to the wall. As any pair of speakers approaches the room corners, the boundary / corner effect becomes more pronounced.

    If you had posted your picture stating you had two pair of identical brand X speakers as shown and asked which pair would produce higher levels of bass, the answer would be the outer ones. They are nearer the corners and thus benefit from room boundary reinforcement. If I were doing a speaker response test using a SPL meter in your setup, I would expect higher levels of low frequency from the outer pair…. all other things being equal.

    Question, have you swapped the TL’s to the outer position?
    It may be that both are producing nearly the same low bass amplitudes, but the room boundaries are reinforcing it better with the originals, and the result is more “shake the floors and your bones” bass. Room tuning via speaker placement can be really critical in some installations.

    Without a schematic of the original crossover it’s hard to speculate what the difference represents. The larger coils could simply be the fact that they are wound with larger gauge wire. This should not be noticeable at low frequencies unless you are testing them at very high volume levels.

    The crossover should be out of the picture for really low frequency because it is DC coupled to the drivers.
    A quick check with the battery should show all 8 drivers moving forward or backward. If for example the SDA connection in the crossover were open in one of the TL’s, only the 4 stereo drivers would move forward with the battery. At very low frequencies, this would reduce your effective cone area.

    Also, if one or more of the 6.5's were wired out of phase, that would screw up the low end. If they have the same size spade lugs, it would be easy to do.

    Your check for cabinet leaks sounds fine, and since the cabinets are the same size, the only other “tuning” variable effecting low frequency would be the response characteristics of the 6.5” drivers and the passive radiator. Polk could have changed something, but since they don’t disclose the individual driver specifications you would have to swap all the 6.5’s and the radiator to see.

    The easiest experiment at this point would be to:

    1) Check each TL with a flashlight battery to verify all the 6.5 drivers are functioning in phase and

    2) Swap the speaker positions, placing the TL’s on the outside.


    If you lived closer, I’d offer to drive over and get those crummy TL’s out of your hair. Hey, why not put the SL3000’s and crossovers in your original SDA’s and have the best of both worlds? Then sell all the rest of the bone pile to me for scrap…. Well I can dream can’t I?

    Cheers