NEED HELP WITH SDA CRS

MOJO1227

These are the 1984 version crs, blade/blade, dual tweets/external fuses

PROBLEM: Balance control full rht = Lft speaker dimensionals don't work.

with balance full left = All left speakers work and right dimensional work..

with balance centered = All speakers work, left and right. (wtf?)

Performed resistance chech per sda handbook = checks good

Interconnect cable checks good via resistance test.

Have both pair opened up and everything LOOKS good. Also swapped woofers around, no help.

Also noted .... when hooking up my test unit to my CRS+, everything test as it should per balance control

codycatalist

Sounds like a woofer is out of phase. Pop em out and make sure, your symptoms are in the manual. I believe it also lists how to make sure they are in absolute phase.

MOJO1227

Hmmmm .... makes sence. Blue and black wires to mids are positive and white wires negative. I know I am ok there, so far as the speakers go .... Wondering if somewhere along the way the interconnect wires going to the crossovers got swapped? The wiring diagram is not the best and shows rht spkr only .... but the left spkr should be reversed, if I am thinking clearly.

THANKS FOR THE INPUT .... I shall check.

westmassguy

However the wires from the blade/blade socket are connected on one, reverse it on the other.

MOJO1227

CORRECTION ... balance full RIGHT, I lose BOTH left and right dimensional speakers

... balance full LEFT, All dimensionals work
... balance CENTERED ALL speakers work, but just does not sound right

Reversed phase from blade/blade interconnect on left speaker, no help.

Iam LOST ... Any thoughts???

NOTE: Passive subs removed for testing

Schurkey

Unplug the SDA interconnect, repeat test. I'm curious how the speakers react to the "full right...centered...full left" movement of the balance control.

How do you know the dimensional drivers are "working" and not just vibrating in sympathy to the other drivers? Also, I'm thinking these speakers are new enough to have bass going to the dimensional drivers in addition to the SDA signal. The dimensional drivers shouldn't be "dead" if the source material has reasonable bass in it.

Does the SDA cable have continuity on both wires?

MOJO1227

SDA cable checks good.
Removed passive radiators to prevent excessive vibration.
Hell, I even pulled mids out of enclosure to verify/swapped as well(no slipped Magnets)
Balance at center the Left channel has more "depth" of sound, I guess one might call it.
I even swapped interconnect wires in speaker black/white(checking 180 phase).

Then I ditched the interconnect and broke out my test/jumper leads bypassing interconnect socket. hooked it up in phase and out of phase

I'll repost test with interconnect removed ..... BRB

MOJO1227

WITH INTERCONNECT REMOVED ....

Balance L- mid/tweet on left, no dimensional
Right - mid/tweet on right, no dimensional
Center - mid/tweet on left and right, no dimensional

I am over looking something some how ..... going to swap mids on rht speakr to make damn sure (again) that rht dimensional is working!!!!

MOJO1227

Swapped mids on right speaker ... BOTH work.

TO BAD THE SCREW DRIVER SLIPPED AND TORE ONE OF THE SURROUND GASKETS!!!!
Grrrrrrrrrrr .....

Schurkey

MOJO1227 wrote: »

WITH INTERCONNECT REMOVED ....

Balance L- mid/tweet on left, no dimensional
Right - mid/tweet on right, no dimensional
Center - mid/tweet on left and right, no dimensional

Do you mean the mid/tweet on the left side of the left speaker; and the mid/tweet on the right side of the right speaker are working without the SDA interconnect?

Have you verified that the + and - cables from the amplifier to each speaker are connected properly?


Bummer about the screwdriver slipping. Is this a torn surround, or the gasket that seals the driver to the cabinet? Some folks have patched rips of the surround using rubber cement. A search on this forum might yield some ideas.

MOJO1227

Correct .... Test unit is carver pre amp/ amp (pristine cond).

Connection polarity correct, beyond a doubt.

Hell, I've worked avionics systems for the last 30 yrs! Once upon a time worked the back shop for Eastern Airlines repairing Nav, Comm. and Auto flt black boxes., component level .... looooong time ago. Have forgot plenty, but still know my way around, or so I thought. lol ....

If the damn wiring diagrams would only indicate wire numbers or at least colors! I would know what I am looking at .... Oh well.

Thanks for all the help, sincerely .... off to the shop they go. I give up!

F1nut

Which Carver amp as some are not common ground.

MOJO1227

Carver amp M-1.0t .... but I was using them to drive my 2.3's, until I incorporated the "dreadnaught".
Besides, I have a set of CRS+ that work as advertised, per say when hooked up. So I know there is no prob. with my pre and amp.
I see Crown Royal in my very near future!!!

Schurkey

Schurkey wrote: »

MOJO1227 wrote: »

WITH INTERCONNECT REMOVED ....

Balance L- mid/tweet on left, no dimensional
Right - mid/tweet on right, no dimensional
Center - mid/tweet on left and right, no dimensional

Do you mean the mid/tweet on the left side of the left speaker; and the mid/tweet on the right side of the right speaker are working without the SDA interconnect?

MOJO1227 wrote: »

Correct

Switch speakers right-for-left. The right-side drivers of the right speaker are the dimensional drivers. The left-side drivers of the left speaker are the dimensional drivers.

MOJO1227

Got that ... outboard speakers are dimensional. Both drivers good .....
Hmmmmmmmm .... just hit me, wondering I never did swap the tweeters.
Because BOTH dimensional tweeter and driver fail to work with balace full right on right speaker.
I should have added that detail to this post long ago.
Anything thing to that?

Schurkey

If the balance is adjusted "full right", there's no left-channel signal to provide an SDA signal to the right speaker. You should have right channel info coming from the right speaker's "stereo" drivers, and you should have right-channel SDA signal coming from the left speaker's SDA drivers.

If the right speaker SDA drivers are powered at all--and it doesn't seem that they are when the balance is full right--it's because they're getting "sub-bass drive" via the SDA inductor, so they reproduce bass only. I would have expected a silent tweeter, and bass only from the right speaker SDA mid-woofer.

Am I correct in thinking these speakers are new enough to get bass drive as well as SDA signal at the SDA mid-woofer driver?

westmassguy

The 84' CRSs do not have the sub-bass drive circuit. There should be no sound from the dimensional woofer or tweeter. There may be sympathetic movement of the dimensional woofer, but that's it.

MOJO1227

One thing is for sure .... When balance is CENTERED the left channel sound is different from the right. Call it more depth, bass, I don't know, though seems to me both should be equal.
NOTE: Speaker placement is the same on both, regarding wall distance etc ...

That led me down the quick L/R balance check .... Anyway, I dropped off to a shop today.

Jeeez ... Been working avionics systems 25 years, Hell, I once even repaired the black boxes to the component level with Eastern Airlines. I've forgotten much since then.

I shall post my findings .... stupid as them may be, for I have no shame!!! lol ..

Again, thanks to all. Much appreciated!

EndersShadow

@MOJO1227

FYI: Sent you a PM on a different matter

TennMan

I may have missed this being done but it would be a good idea to use a flashlight battery monetarily connected to each speaker to see if all the drivers are moving together in the same direction.

VSAT88

Please post back, I need to know !

leftwinger57

To bad about the slippery screw driver syndrome. Been there and did that to a #6502 driver when replacing older ones in my M7s. Polk had sent me 2 drivers by mistake and I was honest w/ them and they said keep it I was under warranty. Why, I complained about 2 things. You need an electron microscope to see the plus or minus sign on the back of the basket on lug bar ( no more red dots) and not warning customers about trimming the rubber around the basket screw holes. I told them I learned that here and some kind of waning note should be dropped into the box when shipping raw speakers. Not everyone belongs to this here forum...

MOJO1227

UPDATE: Sorry for the delay, as life threw me a curve ball .....

Anyway, without further to do. As it turned out NOTHING was wrong with the CRS. Upon building up speaker connectors, myself and Mr. Crown Royal decided we would do it together, how can one go wrong ..... WELL, apparently I crossed the the leads on one pair, so they were out of phase.

Stupid is as stupid does ... and I know better, or so I thought!

Thanks to all for the support.

VSAT88

Done that myself, more than once. I get in a hurry and miss the mark sometime. Really glad you got it all straight.