Getting the full SDA Effect from Polk L800 Speakers

[kevintomb]

the phase shift isn’t the head shadow compensation. The head shadow compensation is a roll-off in the response to mimic the head shadow. Which follows a first order Low pass filter. They mixed that with the off-axis angle of the array drivers.

the system works exactly as advertised. There is no conspiracy here. The L-R/R-Lsignal replayed from the right distance of the opposite side cancels crosstalk. It’s that simple.

they provided me with their own measurments including crosstalk cancelation. I did the same but the results were a bit iffy (Largely my own difficulty in measuring it). They measured upwards of 20dB of XTC. I couldn’t replicate it but I also don’t have the right measurement gear. They used a HATS. I now have a head worn measurement microphone that should allow better measurements and plan to revisit it in the future.

The actual "system" or set up is EXTREMELY simple. It is really just the Hafler circuit. It is not complex at all.

Polk talks it up to sound like far more than it is. I mean it does what they say and all, but through a VERY simple wiring hook up, that anyone at home could do with 2 spare speakers wired across the positive terminals of the Left and right amp outputs.

I think some of the detractors of this SDA effect, simply see it for what it is. A very simply hafler circuit with speakers placed on the outboard sides of the regular left and right drivers.

Not a bash at the idea, but it is not nearly complicated at all.

It works great for Binaural recordings and SOME classical stuff that was made with simple mic set ups. For studio recordings, there never was a real sound stage to try to replicate. It was all intentionally placed electronically, and does not benefit for accuracy, but at times can sound more impressive and fun.

 

[kevintomb]

Ah, well I was referring to your use of the wording gimmick and makes no sense at all. It did work quite well for me and I agree that it is more apparent on binaural recordings.

FYI, I sold polk years ago, and owned several of most models from the 80s and SDA speakers also. I was simply never able to really believe it was a better sound, but just an exaggerated stereo image.

I have also worked in studio with recordings for a few churches, and intimately knew the mic set ups in studio and in a few church sanctuaries. The recordings when played at home using my SDA speakers of the time, were simply NOT realistic to what I heard in person.

Not to beat a dead horse, but it was a nice effect, enjoyable and so on, but I always felt like it was taking away, not enhancing the sound, but adding something artificial to make it less natural.

 

[shadyJ]

FYI, I sold polk years ago, and owned several of most models from the 80s and SDA speakers also. I was simply never able to really believe it was a better sound, but just an exaggerated stereo image.

I have also worked in studio with recordings for a few churches, and intimately knew the mic set ups in studio and in a few church sanctuaries. The recordings when played at home using my SDA speakers of the time, were simply NOT realistic to what I heard in person.

Not to beat a dead horse, but it was a nice effect, enjoyable and so on, but I always felt like it was taking away, not enhancing the sound, but adding something artificial to make it less natural.

Anything that uses stereo panning or stereo imaging would benefit from cross-channel cancellation, not just binaural and traditionally mic'd classical. Many studio recordings have all kinds of stereo soundstages. It's not as if studio recordings are only in mono or hard panning left/right.

 

[kevintomb]

Anything that uses stereo panning or stereo imaging would benefit from cross-channel cancellation, not just binaural and traditionally mic'd classical. Many studio recordings have all kinds of stereo soundstages. It's not as if studio recordings are only in mono or hard panning left/right.

Benefit?

Not as to sounding more realistic or natural.

The SDA creates a VERY real soundstage with minimal miking, but a very fake soundstage with studio recordings.

The ideal placement and image are baked INTO studio recordings.

 

[Golfx]

Benefit?

Not as to sounding more realistic or natural.

The SDA creates a VERY real soundstage with minimal miking, but a very fake soundstage with studio recordings.

The ideal placement and image are baked INTO studio recordings.

Like many who replied above (which you are encouraged to read) they too had a quick bias against the review as presented. It was adequately discussed and their views countered. Not sure how many minds were changed.

 

[kevintomb]

Like many who replied above (which you are encouraged to read) they too had a quick bias against the review as presented. It was adequately discussed and their views countered. Not sure how many minds were changed.

Yeah I read the whole thread. Seems some like SDA and do not understand it, and some bash it, not understanding it also.

I understand what it is supposed to do, but it is all based on a flawed premise, that recordings are all made in a way that they are not.

I have owned SDA speaker, and even enjoyed them, but simply felt it created an artificial fake soundstage. Impressive and fun, sure, but not realistic, at least with the recordings I made myself and knew intimately.

Not to bash on Polk, but it was great marketing to create and idea to solve a problem that was never really a real problem.

 

[Sam780]

Enjoyed the review and the banter that went along with it. This is more of a question than an opinion. I currently have a pair of KEF 104/3 powered by a McIntosh MC2600. One, is the amp appropriate for these speakers, and two, would these offer a substantive improvements over the KEF 104/3 that are complemented by a Velodyne ULD-12 sub woofer.

 

[Golfx]

Enjoyed the review and the banter that went along with it. This is more of a question than an opinion. I currently have a pair of KEF 104/3 powered by a McIntosh MC2600. One, is the amp appropriate for these speakers, and two, would these offer a substantive improvements over the KEF 104/3 that are complemented by a Velodyne ULD-12 sub woofer.

Your amplifier seems gorgeous and can drive anything. Yes it is a class AB and will do fine driving these speakers. I believe they are on sale currently and so too is the L400 center which this website also gave a more that outstanding review. You can contact Matthew Poes by private message to see what he would recommend versus your current speakers. Or perhaps @shadyJ will chime in?

 

[Sam780]

Your amplifier seems gorgeous and can drive anything. Yes it is a class AB and will do fine driving these speakers. I believe they are on sale currently and so too is the L400 center which this website also gave a more that outstanding review. You can contact Matthew Poes by private message to see what he would recommend versus your current speakers. Or perhaps @shadyJ will chime in?

Thank you for the quick reply and the fine compliment. Now it's all about trying to figure out what I am going to do with the 104's if I do pull the trigger on a pair of L800's. Thanks again. Enjoy the rest of the weekend (whats ever left). Stay safe and healthy.

 

[Golfx]

I gifted my previous speakers to my sons and sons in law. Got great street cred from my wife for doing so.


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[shadyJ]

Enjoyed the review and the banter that went along with it. This is more of a question than an opinion. I currently have a pair of KEF 104/3 powered by a McIntosh MC2600. One, is the amp appropriate for these speakers, and two, would these offer a substantive improvements over the KEF 104/3 that are complemented by a Velodyne ULD-12 sub woofer.

I would say that the Velodyne sub couldn't add much to the L800s. Ditch the sub. The L800s have really good deep bass performance, so if you were going to add a subwoofer, it would have to be a pretty substantial one. The ULD-12 is not an improvement over what the L800s can already do in bass.

 

[Golfx]

I would say that the Velodyne sub couldn't add much to the L800s. Ditch the sub. The L800s have really good deep bass performance, so if you were going to add a subwoofer, it would have to be a pretty substantial one. The ULD-12 is not an improvement over what the L800s can already do in bass.

Thanks for joining in Shadyj! It is Sunday and you are helping. That is nice.

BTW @Sam780 Shadyj is the audioholics’ s primary speaker reviewer, James Larson. You struck forum gold.


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[Sam780]

Thank you for the reply and the information. I guess if I do get the L800 I can test them with and without the ULD-12. It would be an interesting test, at least for me. I have the current setup since around 1991 and I just recently started to listen to it again. Life and other hobbies kind of got in the way. Thanks again.

 

[kevintomb]

I would say that the Velodyne sub couldn't add much to the L800s. Ditch the sub. The L800s have really good deep bass performance, so if you were going to add a subwoofer, it would have to be a pretty substantial one. The ULD-12 is not an improvement over what the L800s can already do in bass.

Yeah 4-10" woofers will do quite well.

Although I do see the -3db point of the Polk is rated at 32 Hz.
So there is room for better deep bass to some extent, but I think that would depend on the person and the type of music they tend to listen to, and the room situation.

With that said however, the ULD-12 Subwoofer is rated down to 20 hz at -3db, so in comparison at least on paper, the Velodyne goes quite a bit lower than the -3db figure of the polk.

Velodyne ULD-12 Subwoofer Review price specs - Hi-Fi Classic

www.hifi-classic.net

To me, a tough call honestly. Having heard the ULD-12, albeit many years ago, it was quite impressive deep bass wise, with the right music choices. I mean, almost unreal deep bass.

 

[davidscott]

FYI, I sold polk years ago, and owned several of most models from the 80s and SDA speakers also. I was simply never able to really believe it was a better sound, but just an exaggerated stereo image.

I have also worked in studio with recordings for a few churches, and intimately knew the mic set ups in studio and in a few church sanctuaries. The recordings when played at home using my SDA speakers of the time, were simply NOT realistic to what I heard in person.

Not to beat a dead horse, but it was a nice effect, enjoyable and so on, but I always felt like it was taking away, not enhancing the sound, but adding something artificial to make it less natural.

What did you think of the 7Bs? I had a pair of those back in the early/ mid 80s and they had some of the most realistic vocals that I ever heard. Couldn't take much power though I had to replace one or both tweeters twice.

 

[kevintomb]

What did you think of the 7Bs? I had a pair of those back in the early/ mid 80s and they had some of the most realistic vocals that I ever heard. Couldn't take much power though I had to replace one or both tweeters twice.

They were quite nice, especially for that time period! I also like the 5jr+ speakers and the Rta11t's.

As to power handling, yes for loud or really deep bass, they would peter out, somewhat quickly, after all you can only get so much bass out of one 6.5" woofer! Polk traded Decent deep bass, for moderately less power handling. Not so much how many watts you could use, but simply the woofers would run out of excursion easier.


Although in all honesty, pretty much everything Polk made back then, used either the same or VERY similar woofers and tweeters, so it was hard to stray from the basic sound they all shared.

Even the biggest models of the SDA line, were just the same woofers and tweeters (at first at least) as all the smaller monitor line. So they all shared a similar tonality. The larger ones would play louder and handle more power, and had deeper reaching bass.

 

[Patent guy]

Enjoyed the review and the banter that went along with it. This is more of a question than an opinion. I currently have a pair of KEF 104/3 powered by a McIntosh MC2600. One, is the amp appropriate for these speakers, and two, would these offer a substantive improvements over the KEF 104/3 that are complemented by a Velodyne ULD-12 sub woofer.

Hi Sam, I'm sorry to be tardy in replying, but I believe that McIntosh MC2600 amplifier isn't suitable in that you won't get the best SDA effect because it is the "balanced" type that Polk discourages for use with the L800. The exchanges about balanced amplifiers in this forum thread so far might be a bit confusing, but I can boil it down to this: Hypothetically, if the negative "-" terminal on either channel of your amplifier has a non-zero AC voltage you can measure (red VOM lead to terminal, black VOM lead to actual chassis ground) when in use, then the amplifier is "balanced". This means the negative terminal is not at chassis ground voltage (which is true for unbalanced outputs). Please Don't actually try this measurement unless you Know how to safely use a VOM and measure AC voltages. IIRC, your amplifier has McIntosh's autoformer outputs and I believe it is a "balanced" power amplifier of the type discouraged in the Owner's Manual and elsewhere.

 

[Sam780]

Hi Sam, I'm sorry to be tardy in replying, but I believe that McIntosh MC2600 amplifier isn't suitable in that you won't get the best SDA effect because it is the "balanced" type that Polk discourages for use with the L800. The exchanges about balanced amplifiers in this forum thread so far might be a bit confusing, but I can boil it down to this: Hypothetically, if the negative "-" terminal on either channel of your amplifier has a non-zero AC voltage you can measure (red VOM lead to terminal, black VOM lead to actual chassis ground) when in use, then the amplifier is "balanced". This means the negative terminal is not at chassis ground voltage (which is true for unbalanced outputs). Please Don't actually try this measurement unless you Know how to safely use a VOM and measure AC voltages. IIRC, your amplifier has McIntosh's autoformer outputs and I believe it is a "balanced" power amplifier of the type discouraged in the Owner's Manual and elsewhere.

Thanks for your comment. I decided to stay with the current setup, KEF104/2. I incorrectly stated that I had KEF104/3. Anyway, based on multiple reviews and the fact that the 104's are basically pristine and sound great with the MC2600 amp, I see no reason to spend another $5K on speakers that I really don't need. Thanks again to you and all the others who replied to my original inquiry.

 

[tjcinnamon]

Hi Sam, I'm sorry to be tardy in replying, but I believe that McIntosh MC2600 amplifier isn't suitable in that you won't get the best SDA effect because it is the "balanced" type that Polk discourages for use with the L800. The exchanges about balanced amplifiers in this forum thread so far might be a bit confusing, but I can boil it down to this: Hypothetically, if the negative "-" terminal on either channel of your amplifier has a non-zero AC voltage you can measure (red VOM lead to terminal, black VOM lead to actual chassis ground) when in use, then the amplifier is "balanced". This means the negative terminal is not at chassis ground voltage (which is true for unbalanced outputs). Please Don't actually try this measurement unless you Know how to safely use a VOM and measure AC voltages. IIRC, your amplifier has McIntosh's autoformer outputs and I believe it is a "balanced" power amplifier of the type discouraged in the Owner's Manual and elsewhere.

I have an Anthem 325 and a Rotel 981. Would the anthem work? I can’t tell if it’s single ended or balanced.
I love the speakers but I’m trying to maximize the effect.

the reason I ask is that I had the red terminal not fully hooked up and the SDA on the other speaker was not playing. But the “normal” speaker was. It was really weird

I’m just surprised that it would have that impact.

 

[paulgyro]

Would it be crazy to buy these speakers and not use the SDA tech? Seems they perform slightly better without SDA on but at the expense of amazing imaging.