SDA clone?

nhhiep
nhhiep Posts: 877
edited August 2012 in Vintage Speakers
Just sitting here wondering if anyone successfully clone any of the SDA speakers? considering how rare they're, why not make your own?
Looking at my 1C now, I can see that it's possible to make it thinner by shaving an in or two on each side, then move the PR to the side or back. Use thicker MDF because my 1Cs feel very hallow when tap on them, unlike Lsi9s.
also make it all wood all around to make it more wife friendly.
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  • evhudsons
    evhudsons Posts: 1,175
    edited July 2012
    There are too many reasons why a speaker is designed just so. Too many variables involved. I had the same question in my mind and found many threads with this same question. MDF is by far the best property at least for the main cabinets, and then use a veneer on the outside. That is for sound qualities. The SRS2 that I have now is MDF, but it does have caps on the top and bottom of real wood so I assume that providing you left the cabinet as it is and simply added caps you would have in view a wood speaker while keeping the MDF design and acoustic properties.
    I think if you simply had crossovers and drivers but no cabinet, it might be ok to try something similar but new, but I wouldn't change preexisting speaker. Right now I am in possession of 1c crossovers, inductors, and some spare drivers. I thought about the same thing in building a similar cabinet and making a 1c pair. Now that I have the srs2 I will probably just find a happy home for my leftover stuff.

    My advice would be to reveneer in nice wood, and do other upgrades besides the cabinets. For instance add some acoustic foam, upgrade crossovers, tweeters, sda cable, etc.

    Check out VR3's sticky thread on upgrading SDA's:

    http://www.polkaudio.com/forums/showthread.php?133384-All-the-Polk-SDA-upgrades-located-in-one-place!
    Polk Audio SDA CRS+ crossover 4.1TL by Trey/VR3 (Rings and custom stand by Larry)-Polk Audio SDA SRS2 crossovers by Trey/VR3Parasound HCA1500aYamaha rxa-3070 with musicast-Celestion SL6S presence,- sl9 surround backNHTsuper1's surroundMagnepan SMGParasound 1500pre- Sofia "Baby" tube amp - Monitor Audio Silver RX2 Marantz 2230/B&Kst140Technics 1200mk2 Gamertag: IslandBerserker I am but a infinitesimally small point meeting the line of infinity in the SDA universe
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  • chandler9a
    chandler9a Posts: 878
    edited July 2012
    Sounds like a cool idea but I believe others have talked about this and have found that it's harder to do than you would think, something to do with the angle of the front baffle. I know very little about speaker box design so I'm sure others will chime in. I like the idea of an all wood speaker rather than the cloth however. Maybe a nice veneer? Could get expensive I'm sure.
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  • nhhiep
    nhhiep Posts: 877
    edited July 2012
    I don't think money is an issue here because I've seen many members here keep making updates to their SDAs. At some points, it's probably cheaper to build from scratch than keep making updates
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  • F1nut
    F1nut Posts: 50,548
    edited July 2012
    There was a member that built his own version of the 1C's. They sounded like absolute crappola.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • Conradicles
    Conradicles Posts: 6,081
    edited July 2012
    It can be done. Costly, but it can be done.
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  • Mr. Bubbles
    Mr. Bubbles Posts: 736
    edited July 2012
    Careful! Before this thread is over I predict you will be condemned for blasphemy!

    My personal opinion however, is that it would be easily possible to recreate the SDA effect in a personal design or custom build. However just getting the SDA effect is only a small part of the equation. Moving passives, changing box dimensions, using newer more up to date drivers, etc, could all be possible and probably effective but when you consider all of those pieces together to match the entire system and design a crossover from scratch to not only match those components but to also integrate the dimensional effect and get a good flat response along with very detailed sound, it could be very difficult and more expensive than finding a good pair of SDA's to begin with. Now if you use all of the original designs and simply build replica cabinets and use OEM drivers and crossover designs, you may could come out to the good.

    I believe your concept is good and modern drivers could even be an improvement (just like the RDO tweets). The cabinets could even be built focusing much more on using anti diffraction methods. Now notice i said "could". Just because you have better drivers and focus on some part of a design that was weaker before does not meant that the "whole system" will be as good as the previous "whole system". I personally would love to try this but unfortunately i do not have the necessary test equipment and or time for the proper R&D.
    If con is the opposite of pro, is Congress the opposite of Progress?!


    Monitor 5Jr, Monitor 5, RTA12, RTA 15TL, SDA 2A, 1c, SRS 2, 1.2TL, CRS, Atrium.
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  • Face
    Face Posts: 14,340
    edited July 2012
    Keep the cabinet dimensions and driver locations/spacing the same, and the crossover won't change. Otherwise you may end up with something that sounds like crud.
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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  • Joe08867
    Joe08867 Posts: 3,919
    edited July 2012
    Even shaving an inch or two off the sides would still make these quite large by today's standards. It would still be about the width of two monitor 70's and Moving the PR would only weaken the low end response. It's in front for a reason. I am not saying it can't be done but you would seriously have to play around to get it right.
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  • TennMan
    TennMan Posts: 1,266
    edited July 2012
    nhhiep wrote: »
    Just sitting here wondering if anyone successfully clone any of the SDA speakers? considering how rare they're, why not make your own?
    Looking at my 1C now, I can see that it's possible to make it thinner by shaving an in or two on each side, then move the PR to the side or back. Use thicker MDF because my 1Cs feel very hallow when tap on them, unlike Lsi9s.
    also make it all wood all around to make it more wife friendly.
    As you can see by my signature line, I like to experiment. Be forewarned that you are going to catch hell and will be told that it won't work. I'm surprised that h9 has not already chimed in to condemn the thought of even doing such a thing. Don't let any of that discourage you. It's normal for that to happen here when you start to think outside the box a little.

    When I presented the idea of using CRS+ internal parts in 10b cabinets here on the forum I was quickly given a tongue lashing filled with unsubstantiated technical reasons why I would never get the SDA sound from that combination, along with a few other comments intended to make me feel stupid for wanting to do such a thing. However, I didn't let that dissuade me from wanting to come up with a hybrid of the CRS+ and 10b that would have the best qualities of both speakers. I think I accomplished that. I have the SDA sound of the CRS+ and the better bass (to me) of the monitor 10b. I've listened to them daily for months now and I'm very happy with them.

    I didn't stumble upon the idea of a hybrid speaker by accident and I didn't just throw a bunch of parts together. I studied schematics for a lot of speakers before deciding it should work. CRS+, SDA2b and monitor 10b speakers have a lot in common and share a lot of the same components.

    I say go for it and build what your vision is of a modern pair of SDAs. I recommend that you stick with the same driver spacing to maintain the SDA sound unless you are able to calculate and build a set of crossovers to match something different. If you like the sound of the bass coming from the side and/or rear of the cabinet go for that too but I personally prefer the PR to be forward facing. It is probably a psychological thing but for me the bass coming from the front seems to have better impact and clarity.

    By all means do it and have fun experimenting. Keep us posted on how it goes.
    • SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
    • Crossover upgrades by westmassguy
    • Marantz 1504 AVR (front speaker pre-outs to Adcom 555)
    • Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS
    • Pioneer DV-610AV DVD/CD player
    • SDA CRS+ · Hidden away in the closet
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  • Toolfan66
    Toolfan66 Posts: 17,237
    edited July 2012
    TennMan,

    What you did is not even close to what the OP wants to do.. I thought about this sometime ago as well but I didn't want to alter the design I just wanted a better more modern looking cabinet. what the OP is talking about doing is a complete waste of time IMHO!!
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  • evhudsons
    evhudsons Posts: 1,175
    edited July 2012
    the worst that you can do is be unhappy with the result. As Tool66 says it may be a waste of time. But, I like experiments and they fail more often than not, but sometimes you come out ahead and are happy. It's a hobby. The naysay advice is because of knowledge, experience, etc and they don't want you to just waste your time but if you know that, then you can also use their advice and knowledge and move forward with more of a chance of success.
    Polk Audio SDA CRS+ crossover 4.1TL by Trey/VR3 (Rings and custom stand by Larry)-Polk Audio SDA SRS2 crossovers by Trey/VR3Parasound HCA1500aYamaha rxa-3070 with musicast-Celestion SL6S presence,- sl9 surround backNHTsuper1's surroundMagnepan SMGParasound 1500pre- Sofia "Baby" tube amp - Monitor Audio Silver RX2 Marantz 2230/B&Kst140Technics 1200mk2 Gamertag: IslandBerserker I am but a infinitesimally small point meeting the line of infinity in the SDA universe
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  • wayne3burk
    wayne3burk Posts: 939
    edited July 2012
    you can get the SDA effect without a passive radiator cant you?

    or is the passive radiator required because you're feeding the crosstalk cancelling channel to a second pair of mid-bass drivers?

    seems to me you could make a two way crosstalk cancelling speaker with a tweeter and a couple of mid/bass drivers and send the bass signal to a subwoofer.

    just a thought - obviously not based on any foreknowledge of polk design secrets or techniques....
    Yamaha RX-V2700, EMI 711As (front), RCA K-16 (rear), Magnavox Console (Center & TV Stand), Sony SMP-N200 media streamer, Dual 1249 TT =--- Sharp Aquas 60" LCD tellie
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  • Face
    Face Posts: 14,340
    edited July 2012
    The passive radiator replaces a port, that's all. But be warned, sometimes a PR is required due to a design calling for a very long port. As for making the cabinet shorter and sealed, that may work depending on the MW's T&S parameters, but it's likely there wouldn't be much bass output below 100hz.
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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  • nooshinjohn
    nooshinjohn Posts: 25,415
    edited July 2012
    Someday I will try this with planar drivers and a ribbon tweet...
    The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD

    “When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson
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  • Face
    Face Posts: 14,340
    edited July 2012
    John,

    Here are your mids: http://meniscusaudio.com/bg-neo10-p-1169.html

    As for a tweeter: http://meniscusaudio.com/bg-neo-3-pdr-p-449.html

    You will need a real woofer from 20-300hz though. Go active with DSP and have a ball.
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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  • Dawgfish
    Dawgfish Posts: 2,554
    edited July 2012
    I know a guy who actually built his own version of some SRS 1.2s. They actually didn't sound that bad regarding bass, mids, sda effect, soundstage,imaging, and detail. I did find them to be very bright however, but I think that was mostly due to his choice of amps and pre, which I have always found to be bright. It can be done, it will just take a lot of time and effort. In the long-run it would probably be a lot easier and cheaper to find a good used pair and modify them. I understand the pride that comes from having built something yourself however. As an avid fly fisherman/guide I build a lot of my own rods and tie most of my own flies. There is a certain fealing of pride that comes from using something you built with your own two hands.
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited July 2012
    nhhiep wrote: »
    Just sitting here wondering if anyone successfully clone any of the SDA speakers?

    Forum member beb62670 took a stab at it. You might want to get his insights.
    nhhiep wrote: »
    considering how rare they're, why not make your own?

    It is not as easy as you might think.
    nhhiep wrote: »
    Looking at my 1C now, I can see that it's possible to make it thinner by shaving an in or two on each side, then move the PR to the side or back.

    The width of SDA's was something that concerned polk for aesthetic reasons. If they could have made them thinner, they would have. The stereo and dimensional drivers have to be 6.5" apart to meet the design requirements. Each driver is 6" in diameter, so you are looking at a minimum width from one outside driver edge to the other of 18.5".
    nhhiep wrote: »
    Use thicker MDF because my 1Cs feel very hallow when tap on them, unlike Lsi9s.

    Polk put some thought into the redesign of the cabinets of 4th generation and above SDA's wherein they used a monococque structure with a minimum of interior bracing. The 4th and 5th generation cabinets may sound more "hollow", because they actually are more hollow. However, the 4th and 5th generation SDA cabinets are actually less affected by resonance caused by internally generated vibrations. The SDA 1C is a 4th generation model.
    nhhiep wrote: »
    ...also make it all wood all around to make it more wife friendly.

    Attractive real wood finishes are nice. I redid the wood finishes of 4 of my 5 SDA pairs.:smile:
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • nooshinjohn
    nooshinjohn Posts: 25,415
    edited July 2012
    Face wrote: »
    John,

    Here are your mids: http://meniscusaudio.com/bg-neo10-p-1169.html

    As for a tweeter: http://meniscusaudio.com/bg-neo-3-pdr-p-449.html

    You will need a real woofer from 20-300hz though. Go active with DSP and have a ball.

    Thanks man... I don't know when I will get around to it. My big Maggies with the new tube amps are amazingly SDA-like already.
    The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD

    “When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson
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  • Joe08867
    Joe08867 Posts: 3,919
    edited July 2012
    DarqueKnight wrote: »
    The width of SDA's was something that concerned polk for aesthetic reasons. If they could have made them thinner, they would have. The stereo and dimensional drivers have to be 6.5" apart to meet the design requirements. Each driver is 6" in diameter, so you are looking at a minimum width from one outside driver edge to the other of 18.5".

    That is not true in SDA1's or SDA2's, that is the case for the SRS and CRS lines.
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  • nspindel
    nspindel Posts: 5,343
    edited July 2012
    TennMan wrote: »
    When I presented the idea of using CRS+ internal parts in 10b cabinets here on the forum I was quickly given a tongue lashing filled with unsubstantiated technical reasons why I would never get the SDA sound from that combination, along with a few other comments intended to make me feel stupid for wanting to do such a thing. However, I didn't let that dissuade me from wanting to come up with a hybrid of the CRS+ and 10b that would have the best qualities of both speakers. I think I accomplished that. I have the SDA sound of the CRS+ and the better bass (to me) of the monitor 10b. I've listened to them daily for months now and I'm very happy with them.

    I think you are misrepresenting what happened here, I recall that thread. I believe that you were complaining that your CRS+'s didn't have much bass, and you wanted them in the 10B cabinets to improve that. If I remember correctly, you were told (and very accurately) that if you were not getting much bass from your CRS+'s that you were probably doing something else wrong, and that poor bass response can be improved by other means besides building something completely out of spec.

    I'm in the middle of a CRS+ refurb right now, and let me tell you, they are not bass shy. Not in the least. If you weren't getting good bass out of these speakers, then the cause was likely correctable without putting everything in a different cabinet. That's not giving you hell, that's someone who's owned SDA's for 23 years giving you solid advice that you're free to follow or not.
    Good music, a good source, and good power can make SDA's sing. Tubes make them dance.
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  • motorstereo
    motorstereo Posts: 2,133
    edited July 2012
    If you'd really like to be properly crucified just mention that you're considering stacking some sda's.:evil:
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  • Face
    Face Posts: 14,340
    edited July 2012
    Stacking speakers=Cacophony of sound
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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  • motorstereo
    motorstereo Posts: 2,133
    edited July 2012
    Face wrote: »
    Stacking speakers=Cacophony of sound
    Couldn't agree more. It's funny that it only took Joe Armideo's simple straight forward explanation on stacking for me to understand that. My stacking crucificition really served no purpose other than to amuse me.
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  • TennMan
    TennMan Posts: 1,266
    edited July 2012
    nspindel wrote: »
    I think you are misrepresenting what happened here, I recall that thread. I believe that you were complaining that your CRS+'s didn't have much bass, and you wanted them in the 10B cabinets to improve that. If I remember correctly, you were told (and very accurately) that if you were not getting much bass from your CRS+'s that you were probably doing something else wrong, and that poor bass response can be improved by other means besides building something completely out of spec.

    I'm in the middle of a CRS+ refurb right now, and let me tell you, they are not bass shy. Not in the least. If you weren't getting good bass out of these speakers, then the cause was likely correctable without putting everything in a different cabinet. That's not giving you hell, that's someone who's owned SDA's for 23 years giving you solid advice that you're free to follow or not.
    Your recollection of the thread is incorrect. Here is the thread: http://www.polkaudio.com/forums/showthread.php?129598-Has-anyone-tried-this-before-SDA-CRS-10

    The tread didn't start out as a complaint about bass. I did say I thought the CRS+ bass was not as good as the 10Bs and I still believe that. The thread was started to see if anyone had already tried what I was considering doing. I received several replies from the same person in quick succession telling me it would never work. The highlight of those replies was, "You will end up with nothing but a mismatched mess.". Most of the reasons given for the project being a failure didn't hold water. The hybrid speaker project turned out to be a success in my opinion. Since I did my project couple of other members of this forum sent me PM telling me they also had positive results with building CRS+ 10B hybrids. They don't want to post on the forum about it to avoid going against the grain. I wish they would post about it here. Below is what one of them had to say in a PM:
    Thought I'd let you know I scored a pair of crossovers for 2As off eBay, and they are now sitting happily in my Monitor 10s. The 10s have mw6503s, which are very close to the 2As original mw6510s as far as the T/S parameters are concerned. I'd already done the RDO-194s, and they sound awesome. I put them side by side with my 2As, and the sound is indistinguishable between the two.

    Everyone can read through my original thread and decide for themselves is I was catching hell or not. I can tell you, from my point of view the idea of deviating from the norm was not welcomed by some of he members here.
    • SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
    • Crossover upgrades by westmassguy
    • Marantz 1504 AVR (front speaker pre-outs to Adcom 555)
    • Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS
    • Pioneer DV-610AV DVD/CD player
    • SDA CRS+ · Hidden away in the closet
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  • Mr. Bubbles
    Mr. Bubbles Posts: 736
    edited July 2012
    I believe the issue of SDA's being bass shy is a personal issue. Comparatively speaking all SDA's (at least the ones I've heard) are bass shy to my ears. Not in the quality area or by any means in the extension area, But in overall tonal balance they lack somewhat. I have come to terms with it being partly due to my personal hearing response, but also believe it is partly the speakers as well.
    If con is the opposite of pro, is Congress the opposite of Progress?!


    Monitor 5Jr, Monitor 5, RTA12, RTA 15TL, SDA 2A, 1c, SRS 2, 1.2TL, CRS, Atrium.
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  • nhhiep
    nhhiep Posts: 877
    edited August 2012
    BTW, does anyone know the XO points of the 1Cs?
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited August 2012
    50 Hz and 2000 Hz.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • nhhiep
    nhhiep Posts: 877
    edited August 2012
    50hz? you're joking right? with all the SDA thing, I think there are more than 2 XO points.
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  • pitdogg2
    pitdogg2 Posts: 25,441
    edited August 2012
    nhhiep wrote: »
    50hz? you're joking right? with all the SDA thing, I think there are more than 2 XO points.

    Wow questioning the guy that probably knows the most about SDA's besides Matt Polk:eek::eek:?
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  • drumminman
    drumminman Posts: 3,396
    edited August 2012
    pitdogg2 wrote: »
    Wow questioning the guy that probably knows the most about SDA's besides Matt Polk:eek::eek:?

    Yeah, that's a little surprising.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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