Which SDAs are these?

[Emlyn]

I bought another pair of pre-owned SDAs today. The owner's manual that originally came with the speakers indicated they were SDA-2A speakers, but the picture on the manual doesn't look exactly like the speakers below. The SDA driver is an MW6511, built in October 1987, the "regular" mid-driver is an MW6503 built in October 1988 and stamped "Engineered for CRS" on the back. The owner thought they were SDA-2As and sold them as such but they seem to be SDA-2Bs. So, what are these really?

The speakers had been sitting unused for a few years, but I got them cleaned up pretty well I think. And, no the cleaning did not involve the use of Armor All. ;)

[Emlyn]

The works:

[hotwheelman]

Naked pics please.:D How about a rearend shot too. Never mind I see you beat me to the post.:D

[hotwheelman]

They look to be b's. How much you bag em for?

[Emlyn]

I picked these up locally for $350 today. Except for a couple of minor imperfections on the tops, these are perfect. I guess these must have been built back in the days when Polk tossed whatever manual they had printed in the box as the speakers were going out the door.

Thanks.

[F1nut]

I agree with Mike, those are 2B's. I doubt that the manual was a mistake by Polk, it's more likely that the original was lost and someone replaced it with the wrong one.

[RuSsMaN]

Two Bee

[F1nut]

Or Not Two Bee

[HBombToo]

soon @ bombers...

say a prayer for Troy's Father all.

Henry

[dorokusai]

Nice pick Emlyn.

[Emlyn]

Thanks all. Chuck (aka Madmax) opened my ears to SDAs. He hooked me up with the 2.3TLs that are behind the 2Bs.

The 2A manual says the nominal impedance is 5 ohms but doesn't say the recommended amplifier output range. Anyone know the specs on the 2Bs? I'll likely run the 2Bs with a Parasound A23 amp (125 into 8 ohms, 200 into 4 ohms).

[F1nut]

Overall Freq. - 15Hz to 26kHz
-3 dB - 38Hz to 20kHz
Nominal Impedance - 6 ohms
Efficiency - 89.7 dB
Power - 30-350 wpc


Call Polk CS and ask for a manual.

You'll find that the 2B's aren't even close to the 2.3TL's, but not bad for a second system.

[RuSsMaN]

Originally posted by F1nut
You'll find that the 2B's aren't even close to the 2.3TL's, but not bad for a second system.

I disagree to a degree. The 2B's (in most rooms) actually throw a better overall 'SDA' image. I've always thought the smaller SDA's did a better job at the actual stereo image than the bigger ones.

The larger models do have a 'presence' about them, and obviously more authority in the low-end dept.

-Russ

[HBombToo]

Originally posted by dorokusai

Hey Henry, how about you stay focused on your own gear?

Not following you here Mark...

h

[BobMcG]

These are actually what could be referred to as "second generation" 2B's. (Most common.) In addition, they are also the "studio version" of the 2B.

AND: At least with my two (then new) pairs of 2B's...
The 2B's owner's manuals were indeed 2A manuals with their picture on the cover but came with a separate (loose and easy to misplace) addendum to discribe the features of the newer 2B model.

In my personal opinion:
Although I have a great fondness for the 2B's, I've found the 1C's better at doing everything the 2B's do and the 2.3's even better yet. In all catagories.

[RuSsMaN]

Not knocking the bigger models at all, I ended up with the SRS-2 as my 'choice' SDA speaker.

I guess my preference with SDA leans more towards a 'point source' in the imaging dept (fewer, closely spaced drivers), vs a psuedo transmission line / array.

Cheers,
Russ

[BobMcG]

Hey there Russ!

I hear ya.

I've found the SDA effect is also influenced greatly by the speaker size to room size ratio. The SDA I get from my CRS+'s is incredible, and they produce very enjoyable bass too. They are in a much different environment than (the rooms that house) my other, larger SDA's though. They are in a much smaller room which has a lower, angled ceiling. In this setting the small SDA's really shine.

[F1nut]

I have to disagree about them being the "studio" version. The studio did come in black only, but the cabinet more closely resembled the 2A with the inset base.

[BobMcG]

It's quite possible I have missed some of the varieties of the SDA's of the past.
However, the studios I've seen of the 2nd generation (final) 2B's were "basically" standard 2B's without the cloth wrapped pannel sides glued on. And of course a bit different black ash-like tops and bottoms to make up the difference. If you look closely at any standard 2B you'll see that under the external clothed side panels are the black ash-like sides. If you look under the oak end caps you see black ash-like there too. The studios are basically a "stripped down" standard which is why they weigh and cost a bit less. The first generation 2B's did have the extended bottoms to them similar to but not exactly like the 2s and 2As. (They didn't have the short pedestal on the very bottom.) Here is the first version of the 2B.
With all of the changes Polk made to some of the SDAs it's hard to know if you've seen them all.

[F1nut]

Whew, too many damn versions! I'll take another look at my Studio 2B's the next time I get to my folks house.

[Emlyn]

Based on everyone's help, a description and pictures I found in an old catalog (after Matt lost his lab coat and started appearing with a Ferrari Testarossa), and the dates on drivers, the speakers appear to be SDA 2B Studio speakers from around late 1988 or 1989. I haven't seen another picture exactly like the speakers I have, but they are clad in black ash vinyl as described in the catalog. Bob is right in that they seem to be "stripped" versions of the late design standard SDA 2B. The cosmetic cabinet differences are that the late standard SDA 2B had cloth side panel attachments and hardwood tops and bottoms, looking just like smaller versions of the standard SDA 1Cs. My version has vinyl cladding on the tops and sides, four strips of MDF to form a small pedestal base (very cheap), and two strips of black stained wood stuck on the front at top and bottom to mimic the appearance of the standard version. From what I understand from the catalog Polk also made a studio version of the SDA 1Cs at this time, but I haven't seen real life examples of those yet.

So, I now know the SDA 2s are a couple of years younger than I had assumed when I bought them and they have the drivers they should have. They'll eventually go in my office once I clear some space for them.

Thanks for the help.

[dorokusai]

If you find a FrankenPolk....it will most likely be an SDA model :)

[madmax]

After you get a taste of that SDA sound you become like a crack addict. Congrats on the new pair!

My friends have been teasing me for years saying I am trying to collect them all. If you don't watch they will take over your whole living space. :)

madmax