Differences between SDA2 SDA2a and SDA2b?

fafner

Some where along the way I read what the differences were between the SDA2, SDA2a, and SDA2b models but I know no longer remember what they are. Can someone please remind me?

Also, on the rear text panels of the SDA2's are all only identified as SDA2 or do the 2a's and 2b's have that designation on the back?

Thanks.

fafner

cnh

Well, I'll start this off and the old timers can add their expertise or correct my errors.

The SDA 2 has 3 mid drivers and dimensional tweeters (or 2 tweeters). The SDA 2As have just 2 mid drivers (dimensional) and one tweeter. The SDA 2Bs have the same configuration as the 2As but the mid drivers are not identical. The dimensional driver is a different number from the normal driver....can't remember the numbers. Most of the SDA 2s including the As and Bs, have the SL2000 silver dome tweeter. There is also the question of veneers...vinyl vs. real wood...most noteworthy on the 2Bs.

Visually, there is a lot of variation between the various models and MANY different versions of both the As and the Bs.....the most common B is the one with the wood slab top and bottom which most As do not have.

Someone can take it from here.....?

cnh

F1nut

Post a pic.

comfortablycurt

As cnh said, the original SDA 2's had three midwoofers, and two tweeters each. The tweeters were setup in the same stereo/dimensional style array as the midwoofers. Later research showed that the SDA effect wasn't really necessary with the tweeters, and in many ways it actually sounded better without dimensional tweeters. There are many on here that use and love their dimensional tweeter equipped SDA's though. I've never heard any, I'd love to. The original 2's came with either the SL-1000 or the SL-2000, depending on the time of production.

The 2A's have two MW6510 midwoofers, and a single SL-2000 tweeter.

2B's also have two midwoofers, but use two different ones. Each speaker had one MW6511 and one MW6503. Along with a single SL-2000 tweeter.

All the different iterations of the SDA 2's used 12" passive radiators.

Earlier 2B's were blade/blade, while later 2B's were pin/blade.

There were several variations in the cabinets as well. The original 2's and 2A's had pretty similar style cabinets. All wood grain finish, and they were mounted on "pedestals". I believe the cabinets for the 2A's are 5-6" shorter though, due to not having the third MW. The 2B's cabinets are pretty similar to the SDA 1C style cabinets. Cloth sides and wood caps on the top and bottom.




SDA 2-
http://www.polksda.com/ebay/5739934917_SDA2.pdf

SDA 2A-
http://www.polksda.com/ebay/5727020283_SDA2A.pdf

SDA 2B-
http://www.polksda.com/ebay/5751672872_SDA2B.pdf


There were also studio versions of the 2B's, which were all black. I'm not sure if there were studio versions of the 2A's or original 2's.

There was also an overlapping period between the 2A's and 2B's. Some of the very earliest 2B's have 2A style cabinets. I've never heard of a 2A with a 2B style cabinet though.



I've got a pair of 2A's...and I love them. I've got worn out polys in need of replacement at the moment though...so my Monitor 7A's are pulling active duty currently.

Regarding the markings on the back...I'm not sure. I'll double check tomorrow, but I'm pretty sure my 2A's just say SDA II on the back.

fafner

Thanks for the comments. I have 3 pairs and they all have just one tweeter and two midwoofers, so they are either 2a's or 2b's. All three pairs have simply SDA 2 printed on the back. So the issue is to determine which they are. Is there a specific way to tell what the midwoofer models are? Also was there any reason to believe that one or the other either sounded "better" than the other. In other words was the pairing of different midwoofers supposedly an improvement..either overall or for the SDA effect.

Thanks again. Wow this really is a great forum, isn;t it

fafner

F1nut

Post a pic.

chandler9a

fafner wrote: »

Thanks for the comments. I have 3 pairs and they all have just one tweeter and two midwoofers, so they are either 2a's or 2b's. All three pairs have simply SDA 2 printed on the back. So the issue is to determine which they are. Is there a specific way to tell what the midwoofer models are? Also was there any reason to believe that one or the other either sounded "better" than the other. In other words was the pairing of different midwoofers supposedly an improvement..either overall or for the SDA effect.

Thanks again. Wow this really is a great forum, isn;t it

fafner

It is my understanding that the SDA 2b's are better but thats not to say the 2a's are bad speakers, I have a pair and LOVE them.

As others have mentioned above, the 2a's will have MW model 6510 and the 2b's will have one 6503 and one 6511 in each cabinet ( I believe those are the correct models) so if you just pull one out of each cabinet you should be able to tell.

Aaron

fafner

F1nut wrote: »

Post a pic.

Of what? Please tell me how that will help with whether they are 2a's or 2 b's? Are my descriptions not clear?

fafner

fbm211

As F1 said, post a pic---of the speakers.He and others can tell you what you have by looking at the speakers.

heiney9

fafner wrote: »

Thanks for the comments. I have 3 pairs and they all have just one tweeter and two midwoofers, so they are either 2a's or 2b's. All three pairs have simply SDA 2 printed on the back. So the issue is to determine which they are. Is there a specific way to tell what the midwoofer models are? Also was there any reason to believe that one or the other either sounded "better" than the other. In other words was the pairing of different midwoofers supposedly an improvement..either overall or for the SDA effect.

Thanks again. Wow this really is a great forum, isn;t it

fafner

We need to see a pic

Midwoofers have the model # printed on the magnet so they need to be pulled from cabinet to find out.

Yes, later 2B's sound better than earlier 2's.............that generally holds true for all SDA's. Later model improvements are very audible or what would be the use of improving them? Simplified x-overs (less parts to achieve better fidelity), better parts, better cabinets and an evolutionary improvement of the Stereo Dimensional Array properties.

H9

F1nut

fafner wrote: »

Of what? Please tell me how that will help with whether they are 2a's or 2 b's? Are my descriptions not clear?

fafner

Of your 3 pairs of SDA's. A picture is worth a thousand words.

fafner

F1nut wrote: »

Of your 3 pairs of SDA's. A picture is worth a thousand words.

Ok, here are pics I have of one pair; the color is deceiving since it is actually all black wood. I do not have pics of the other two pairs, however, one pair looks just like this one except the wood is a medium dark brown while the 3rd pair looks the same except it has a top and bottom piece of oak about 1 inch thick on both the top and bottom and the sides are not solid wood but are black cloth over a kind of fiberboard glued to the sides.

I hope that is helpful.

Thanks.

fafner

F1nut

Ok, now we're cooking with gas.

The pair in your pictures appear to be SDA 2B Studio versions. The platform at the base of the SDA 2A's is taller. Can't say for sure about the 2nd pair. The 3rd pair are SDA 2B's.

fafner

F1nut wrote: »

Ok, now we're cooking with gas.

The pair in your pictures appear to be SDA 2B Studio versions. The platform at the base of the SDA 2A's is taller. Can't say for sure about the 2nd pair. The 3rd pair are SDA 2B's.

Thanks a lot. Glad the pictures helped. Now my final question: Is there any difference between the 2B's and the 2B Studio's other than cosmetics?

Although I have owned two pairs of these since the mid 1980's, I have never delved so deeply into the different versions. So I am still in the learning phase

fafner

F1nut

No difference in the sound.

Glad to help.

comfortablycurt

F1nut wrote: »

Ok, now we're cooking with gas.

The pair in your pictures appear to be SDA 2B Studio versions. The platform at the base of the SDA 2A's is taller. Can't say for sure about the 2nd pair. The 3rd pair are SDA 2B's.

+1

The second pair sounds like either a pair of 2A's, or an early pair of 2B's, which used the 2A style cabinets for a short time.

As mentioned above, pull a midwoofer from one of the speakers. If it's a 6510, then they're 2A's. If it's either a 6503 or 6511, they're 2B's.

The drivers model number will be on the back of the magnet.

danger boy

signed by Matthew Polk
SDA 2b

comfortablycurt

danger boy wrote: »

signed by Matthew Polk
SDA 2b

Does the added weight of the ink in the signature have any impact on the bass performance? Lower extension? More output?:p;)

danger boy

comfortablycurt wrote: »

Does the added weight of the ink in the signature have any impact on the bass performance? Lower extension? More output?:p;)

in a word yes.. the sweet spot is much wider now :rolleyes:

fafner

Well, I think I have a couple of problems. The pair of SDA2's identified above as 2B Studios arrived...I purchased them on Ebay for a good price. The packaging looked great and I was happy to see UPS drop them off.

However, when lifting one of the two boxes I heard a distinct rattle, like a piece of wood or metal rattling around inside. I was not too concerned because I thought it was probably just the internect cable moving. The speaker itself wrapped in bubble wrap all around but when it was removed and I move it to a standing position, I again heard the same rattle. There was no cable inside that box and I not opened the second; there was no promise of a cable in the eBay ad.

I decided to hook it up to where one my other SDA2's was already located and listen to it.
First, I noticed that the interconnect cable was pin/blade which I was generally familiar with but had never seen. Any way, I connected the wires from the AVR and turned the system on. I immediately noticed that the "new" speaker was putting out much less volume than one it had replaced. I ran Speaker Setup on my AVR and had to reduce the volume significantly on the other 4 sda's and the rear 10's to equal what was coming from the "new" speaker.

I have already contacted the eBay seller to notifiy him and do not need any advice on what issue. I would like suggestions on (a) what might be rattling (b)why might this speaker be using significantly more power than the other 3 SDA's and (c) might these to be related.

I am aware of the dangers of buying something sight unheard but have never had a problem before. I am not worried about the money issue because I will get that back. What I am concerned about is if the "new" speakers are broken and if so can they be fixed.

Thanks for any thoughts you care to offer.

fafner

Conradicles

I would take off the passive radiator and look inside and see what is going on. We are here to help you! I have those same SDA-2B black studio speakers and they are a great speaker for the $.

fafner

Conradicles wrote: »

I would take off the passive radiator and look inside and see what is going on. We are here to help you! I have those same SDA-2B black studio speakers and they are a great speaker for the $.

As expected, the issue with the eBay seller has been mutually resolved. It is now a question of whether I can play detective and find out why these speakers don't work correctly. I do not have a lot of confidence that I can but a friend of mine is going to try and help me out.

A web search suggested that a slight modification of a standard RCA cable will suffice as a pin interconnect for these speakers (basically removing the outmost part of the connector) and that blade connector does nothing but help to keep the pin in place. Can anyone confirm this?

fafner

Tony M

Do you own a philips head screwdriver?

F1nut

First, I noticed that the interconnect cable was pin/blade which I was generally familiar with but had never seen.

You mean that you've never had the SDA interconnect cable hooked up to your regular 2B's!?!

As stated, you will have to open up your "new" speaker and take a look around. It won't be hard to find what's rattling around. Until you find out what it is, DO NOT use them.

sda2mike

danger boy wrote: »

signed by Matthew Polk
SDA 2b

did you carry the whole damn speaker with you to get it signed??? or just the PR?:p

sda2mike

fafner wrote: »

Well, I think I have a couple of problems. The pair of SDA2's identified above as 2B Studios arrived...I purchased them on Ebay for a good price. The packaging looked great and I was happy to see UPS drop them off.

However, when lifting one of the two boxes I heard a distinct rattle, like a piece of wood or metal rattling around inside. I was not too concerned because I thought it was probably just the internect cable moving. The speaker itself wrapped in bubble wrap all around but when it was removed and I move it to a standing position, I again heard the same rattle. There was no cable inside that box and I not opened the second; there was no promise of a cable in the eBay ad.

I decided to hook it up to where one my other SDA2's was already located and listen to it.
First, I noticed that the interconnect cable was pin/blade which I was generally familiar with but had never seen. Any way, I connected the wires from the AVR and turned the system on. I immediately noticed that the "new" speaker was putting out much less volume than one it had replaced. I ran Speaker Setup on my AVR and had to reduce the volume significantly on the other 4 sda's and the rear 10's to equal what was coming from the "new" speaker.

I have already contacted the eBay seller to notifiy him and do not need any advice on what issue. I would like suggestions on (a) what might be rattling (b)why might this speaker be using significantly more power than the other 3 SDA's and (c) might these to be related.

I am aware of the dangers of buying something sight unheard but have never had a problem before. I am not worried about the money issue because I will get that back. What I am concerned about is if the "new" speakers are broken and if so can they be fixed.

Thanks for any thoughts you care to offer.

fafner

when they delivered...DROPPED...my 2Bs, i too had that rattle...turns out, in BOTH speakers the board let go of the inductor AND the wires disconnected from it!:eek:

fafner

F1nut wrote: »

You mean that you've never had the SDA interconnect cable hooked up to your regular 2B's!?!

As stated, you will have to open up your "new" speaker and take a look around. It won't be hard to find what's rattling around. Until you find out what it is, DO NOT use them.

My existing SDA's have blade/blade interconncect cables.

I have also found an issue with the 2nd speaker of the "new" pair. The tweeter just seems to "buzz" and the 12" woofer doesn't seem to work at all. I am also going to open it up tomorrow.


fafner

fafner

sda2mike wrote: »

when they delivered...DROPPED...my 2Bs, i too had that rattle...turns out, in BOTH speakers the board let go of the inductor AND the wires disconnected from it!:eek:

Was that easy to fix? Again I have never looked inside any speaker except some old simple box speakers.

fafner

fafner

tony millard wrote: »

Do you own a philips head screwdriver?

I'm feeling more like using my sledgehammer.

fafner

Tony M

Please don't.

These speakers are real easy to fix since you'll have a huge hole to work through when you remove the ones' passive radiator.

The others' tweeter might have to be replaced but not until you look inside that one too. It might have some wires touching somehow. Doubtful but who knows.

You can look in them and relate what you see to the forum here. Pictures would help to if you have that ability to post them.I know some don't have digital cameras to assist in matters like this.

Those are great speakers, get em singin and rockin again.

fafner

tony millard wrote: »

Please don't.

These speakers are real easy to fix since you'll have a huge hole to work through when you remove the ones' passive radiator.

The others' tweeter might have to be replaced but not until you look inside that one too. It might have some wires touching somehow. Doubtful but who knows.

You can look in them and relate what you see to the forum here. Pictures would help to if you have that ability to post them.I know some don't have digital cameras to assist in matters like this.

Those are great speakers, get em singin and rockin again.

Thanks Tony. I do have a digital camera and will take pix of what we see inside. I am a total newbie in anything but listening to SDA's for over 20 years. I appreciate what help I have received so far and will continue to post my progress (or lack there of) until a moderater (or someone else) just tells me to shut the hell up.

fafner