setting up SDA's/possible problem

[snotpmah]

Hi Guys,

Well I've finally started getting some "big boy" equipment. Recently picked up an H-K AVR335 to go with my SDA 2a's. Also connected an Onkyo M-501 amp to drive them, an H-K TS-14 sub and 3 small H-K surrounds. The major issue I'm having is that vocals, especially female, seem in the background- even Chaka Kahn, Mariah, Celine, Norah. Sounds like they are singing at the far end of a long tunnel-spacey, echo-y and distant. Well-recorded instrumentals sound good though. The i/c cable is working, as I get the opposite dimentional driver working when I turn the balance control. I have a multi meter, and have started going through the SDA troubleshooting guide here. Very confusing though. Seems I get no resistance between the i/c sockets 1 and 2 (large and small blades) for instance. Any ideas appreciated. This is driving me f-n crazy! Before I attempt to hook up the other speakers or HT modes, I want to sort out my mains and 2 channel first.

All drivers seem to be working, as well as the tweeters with no noticeable distortion. I reset the AVR to factory specs. so I've not fooled with any settings yet. AVR is set to pure stereo surround off mode, and all tone controls are flat.

I'm in Sarasota, so if any S. Florida guys are out there, I'd be willing to bring the speakers to you to help diagnose. You are also welcome to stop by me, and I'll provide lunch, dinner, whatever you want. Just need a little guidance here...

Thanks,
Bob

[michaeljhsda2]

What listening mode is the AVR set at? Sounds to me like it is set to "hall" or "auditorium" etc. Is there a setting for 2 channel only?

[treitz3]

^^^try that and if it doesn't work, reset the unit to factory settings^^^

Are your connections hooked up in phase correctly?

[snotpmah]

Thanks for replying.

I reset the AVR and it's set to dry 2ch. stereo, "surround off" mode. (No hall effect)
Connections are good and in phase.
Someone suggested the mids might be out of phase, so I'm trying to loosen. Screws are almost impossible to get off, so leads me to believe they have never been touched?

[stubby]

Is the center image (voices) centered between the speakers, or are they smeared across the stage?

This is kind of a long shot, but your tweeter protection (polyswitches) may be in bad shape. They can severely limit tweeter output and cause all kinds of imaging anomolies.

stubby

[nooshinjohn]

great advice stubby... removing the polys from my 2.3's really opened them up.

[snotpmah]

Stubby,

I just played Norah Jones' CD. It sounds like she is centered right in front of me, with the guitar off to the right, and piano to the left. Her voice still sounds "hollow". You would think on that type of recording the vocals should be way in front.

BTW, I ordered the RDO 194's today. I'm sure it won't fix this issue, but I am looking forward to less listening fatigue, because it's pretty bad right now.

[Joe08867]

How far apart do you have the speakers set up? You want a pyramid shape for the listening position. Say 10 feet apart and 10 feet to the center of the listening position. If you are to close to them or way to far away say 15 foot or more from them, they will sound more and more hollow or distant.

also, How are they placed? Are they square with the listening position or do you have any toe-in at all? SDA's are not to be Toed in at all. This will effect the speakers and you will lose sound quality.

How far from the side and back wall are they placed. This can affect the bass response and make other frequencies seem weak.

[sda2mike]

all of the above plus: check your speakers internal wiring..you could have a driver or 2 out of phase..i'm spkg from experience there is a sticky for your speaker's wiring diagram

[Schurkey]

While there are many possibilities; you've already been given good advice.

That said, use your ohmmeter to verify that there is no resistance between the negative terminals of your receiver.

My SDA 1Bs sounded TERRIBLE until I connected a jumper wire between the negative terminals of my amplifier. A mere 20 ohms of resistance on an otherwise "common ground" amplifier made the speakers unlistenable.

There is a Polk-authored paper describing ohmmeter tests (and specifications) that can be made to SDA speakers. That paper can be downloaded from this web site.
http://www.polkaudio.com/forums/atta...9&d=1268334955

[snotpmah]

Thanks for helping me through this process...

I'm a little leary of opening them up just yet. I'll try the easy stuff first. I am in a perfect 9ft. listening "triangle", and speakers are square and currently 4 in. from back wall. I've tried them right against wall also with no real difference. I'll check for resistance between the neg. posts of both my receiver and the amp. How much resistance is acceptable?

I'll report back my findings.

[snotpmah]

Well I measured resistance at .5 at both the receiver grounds, and the amp grounds.

If no other easy suggestions, I guess I'll start unscrewin'.

Wish me luck...

[OldmanSRS]

1. Which components/speakers are new to you, ie. has any of this stuff worked fine in any other combination?

2. It would be very helpful to break the problem in half. Can you try another set of speakers or another source/amp.

3. If other speakers play well, then the issue is likely related to the Polks. If not then it's the components upstream.

4. Do the Polks sound normal or at least better with the IC removed, ie. female voice positioned between the speakers with no hollow sound?

5. If not, suspect a phasing issue. Remove the IC. Momentarily connect a 1.5V battery to each speaker with the battery+ to speaker+ and the - to -. Observe the MWs on each speaker. Do they all move the same direction by about the same amount? If any move opposite, then something inside is wired out of phase or the binding posts are marked wrong.

This should keep you busy for a while. Report the results and we can continue.

[snotpmah]

These speakers were a recent acquisition. They have the same issue with both of my current receivers. I swapped in two of the tiny surrounds, and I think the voice sounds more forward on those. They're so crappy it's hard to tell. With IC removed I hear a more narrow sound. I know the IC works because of my balance test (see original post), and they pass the battery test. One strange thing I noticed w/ battery test was rt. speaker went dead, then came back on a few seconds later. It did this a couple of times. The left side did not cut off when I held the batt. to it.

Next I'll try just switching to a smaller, carpeted room, to see if room acoustics has anything to do with it. Hey you never know!

Oldman, click this link and check out my post #74, in homage to your signature

http://www.polkaudio.com/forums/show...=117127&page=3

[Joe08867]

It isn't the room it is the polyswitches in your crossover.

If the speaker went out then came back on the Polyswitch tripped. It is like a circuit breaker for the tweeters. If it tripped from a battery they are bad and either need to be replaced or removed from the circuit all together with a jumper. Considering the speakers are 20 years old and electronic parts degrade over time this isn't abnormal. I have had to replace or remove polyswitches from every set of SDA's I have purchased.

If the tweeters are tripped you will not get much out of those speakers. And vocals (Especially female voices) will sound hollow and distant.

Sounds like you need to crack open those speakers.

[erniejade]

4. Do the Polks sound normal or at least better with the IC removed, ie. female voice positioned between the speakers with no hollow sound?

For some music mine do not sound right with the IC cable in place and i take it out for some of my cd's or LP's.

[snotpmah]

That poly suggestion makes sense to me. Before I start unscrewing everything, what's the easiest way to get to them?

Might be related- When I first got the H-K and amp, I thought it was strange that the receiver clipped once by istelf, and then again while hooked up through the amp. With my old inferior receiver, the system never clipped even at some pretty loud volumes.

Could the clipping be related to the polyswitches or some other faulty component in the SDA's?

While I'm in there, are there any other things I should check for??

[OldmanSRS]

It isn't the room it is the polyswitches in your crossover.

Could be, but...they only protect the tweeter. The MW's should still move when/if the poly switch trips. I find it hard to believe a poly switch would trip at only 1.5V DC. There's a 12uF cap in series with it in the XO that blocks the DC.

You need to look inside the speaker that trips and visually inspect the connections, inductors, and the XO components for loose solder joints and wires. Both speakers must pass the battery test, with all MW's moving and in phase before taking it to the next troubleshooting level.

Bob, Is that your FFR MkII? Who are you on FFCars.com?

Here's mine: http://www.polkaudio.com/forums/show...40719&page=116

And here: http://www.worldisround.com/articles/123897/index.html

[snotpmah]

Thank you.

So Greg, are you saying that during the batt. test the speakers should not cut out at all? Because the woofers ARE reacting correctly from my observation. I can try again w/ the left side, just to make sure that one doesn't cut off either. I only paid $220 for these; I'm just hoping I don't get in over my head while trying to bring them back within specs.

I'm on ffcars.com with the same user name. Haven't posted much since I sold it. Maybe audio is my new hobby for now...That last pic. was at the new owner's house next to his 'vette.

I love that second link you gave- very detailed info. there. All I have is a book full of sloppy notes and receipts, for the next build. Not sure which one I want to do next (maybe a small-block)

[OldmanSRS]

During the batt test they should not cut off. I've done this test many times on many Polks and none ever cut off. My advice is to open both speakers up, jumper out the polyswitches (look like a yellow or white chicklet with 2 wires coming out of the bottom) and like is said, give everything a thorough visual inspection.

Then we can move on with troubleshooting if you find everything is OK and they pass the batt test.

I can't believe you sold your car.

[snotpmah]

I had to sell it. I'm a realtor and things got pretty bad a few years ago.
I sold off my cars, motorcycle, boat, NC property, and multiple properties in FL just to keep from starving.

Such is life.


i'll start digging into these and let you know what I find...

[OldmanSRS]

Thank you.

Maybe audio is my new hobby for now...

It's my winter hobby and that's the primary reason I wear earplugs when I drive.

Sorry to hear about the market down there. That's rough.

[snotpmah]

Well I jumpered the poly's, and I seem to notice a difference with Norah Jones' CD. On some other vocal CD's less so. Maybe my other recordings are just not good. Just to be sure, does anyone have a suggestion for another song I could buy/download that features strong female vocals (dry, forward, no echo)?

Since I'm already inside these, what other upgrades can I do to them? Why stop now, right??

[OldmanSRS]

Alison Kraus "New Favorite" and many others by her.