SDA's modded w/ active woofer
NeilGabriel
Posts: 1,487
http://minneapolis.craigslist.org/dak/ele/1920428376.html
turned passives into active drivers...what do you think?
turned passives into active drivers...what do you think?
Post edited by NeilGabriel on
Comments
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Part of me cringes when I read that. I wonder what the sonic cost was to pumping up an already great low end?Lovin that music year after year.
Main 2 Channel System
Polk SDA-1B,
Promitheus Audio TVC SE,
Rotel RB-980BX,
OPPO DV-970HD,
Lite Audio DAC AH,
IXOS XHA305 Interconnects
Computer Rig
Polk SDA CRS+,
Creek Audio 5350 SE,
Morrow Audio MA1 Interconnect,
HRT Music Streamer II -
so he can replace 12" passive radiators with active woofers but he can't take a picture of it and post it with his CL ad???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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wayne3burk wrote: »so he can replace 12" passive radiators with active woofers but he can't take a picture of it and post it with his CL ad???
lol. probably for a good reason. -
Sad. Most likely didn't know how to set them up properly to get good bass with the passives.____________________________________________________________
polkaudio Fully Modded SDA SRS 1.2TLs + Dreadnaught, LSiM706c, 4 X Polk Surrounds + 4 X ATMOS, SVS PB13 Ultra X 2, McIntosh C2300, Marantz AV7704, Bob Carver Crimson Beauty 350 Tube Mono Blocks, Carver Sunfire Signature Cinema Grande 400x5, ADCOM GFA 7807, Panasonic UB420, Sim Audio Moon 380D DAC, EPSON Pro Cinema 6050 -
failLiving Room 2 Channel -
Wiim Ultra. Jolida CD player. Fiio k11 R2R DAC, XTZ as300 Edge amp. Focal Cobalt 826 towers,
Upstairs 2 Channel Rig -
Classe Audio 5 Preamp, DIY1200as2 Icepower Amp x 2, Wiim pro streamer and Topping E70 Velvet DAC, California Audio Labs DX1 CD player, Polk LSi15's with MM840 woofer upgrade.
Studio Rig - Scarlett 18i20(Gen3) DAW, Schitt Saga 2 preamp, Topping a90 headphone amp, Mac Mini, Audiophonics Hypex NC252m amp, Polk r200's -
Why is this an issue? Lots of people here do modifications that alter the original design (for example, swapping in new inductors that lower the DCR). While I will personally admit that adding an active driver in place of the passive seems like a pretty bad idea, perhaps this person loves the extra bass. Subjective preference is what matters, right?
Moreover, at least this modification actually makes a real difference! -
I see you've been brainwashed by John's page too."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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I think it's a plain vanilla bad idea. If you install active woofers, I think you would need to port the cabinet. I also wonder how he integrated the new woofers into the 2-way crossover design.The world is full of answers, some are right and some are wrong. - Neil Young
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Why is this an issue? Lots of people here do modifications that alter the original design (for example, swapping in new inductors that lower the DCR). Moreover, at least this modification actually makes a real difference!
I think it is an issue because the PR is integral to the movement of the normal drivers. Having a big 12" active driver is going to create abnormal air pressure inside the cabinet that will interfere with the existing drivers, severely damaging the sound, if not the drivers. There is a reason that most cabinets with mixed speaker sizes are generally ported: cone travel of the smaller drivers may be exceeded by the large drivers displacement.
On the bright side, he still has the passives, but he may have damaged the mids with his mod.
I also think the sda bass is a little weak by modern standards, because the dynamic range of entertainment has grown since their introduction. If you want the full range of modern bass, get a sub.The secret for harvesting from existence the greatest fruitfulness and greatest enjoyment is to live dangerously. - Nietzche -
I think it is an issue because the PR is integral to the movement of the normal drivers. Having a big 12" active driver is going to create abnormal air pressure inside the cabinet that will interfere with the existing drivers, severely damaging the sound, if not the drivers. There is a reason that most cabinets with mixed speaker sizes are generally ported: cone travel of the smaller drivers may be exceeded by the large drivers displacement.
On the bright side, he still has the passives, but he may have damaged the mids with his mod.
I also think the sda bass is a little weak by modern standards, because the dynamic range of entertainment has grown since their introduction. If you want the full range of modern bass, get a sub.
Funny!!! my SDA's have no problem with tight Bass.. WEAK??? Please..:rolleyes: there will never be a sub in my system.... No need for it.. -
Yep that would be the most important thing. I suspect not a lot of design effort was put into it,but hopefully he isn't just running the new woofer unfiltered and in parallel with the mid bass's up to the 2k- ish crossover point.:eek::eek:I also wonder how he integrated the new woofers into the 2-way crossover design. -
Of course, what you're saying is completely correct. My point was that people do all sort of modifications which may or may not improve things, with the only criteria being that its subjectively better. I agree that its highly doubtful that adding an active driver is a good idea, but who am I to sayI think it is an issue because the PR is integral to the movement of the normal drivers. Having a big 12" active driver is going to create abnormal air pressure inside the cabinet that will interfere with the existing drivers, severely damaging the sound, if not the drivers. There is a reason that most cabinets with mixed speaker sizes are generally ported: cone travel of the smaller drivers may be exceeded by the large drivers displacement.
On the bright side, he still has the passives, but he may have damaged the mids with his mod.
I recently measured some SDA2Bs, and the bass response actually has a +4dB peak at 65Hz, which can lead to an impressive and/or boomy sound depending on the room. But I think your point is that the rapid roll-off below the passive tuning frequency (the SDA2B is down -10dB at about 32Hz) means they don't really capture the lowest octave most HT buffs are used to.I also think the sda bass is a little weak by modern standards, because the dynamic range of entertainment has grown since their introduction. If you want the full range of modern bass, get a sub. -
One of the problems with very deep bass (below 30Hz) is that traditional floorstanders have started their -12db/-24db per octave roll-off by then. Although room gain can help in the 20Hz range, the presence of room modes and suckout will leave the in-room response looking pretty bad. So, I think the only way to have clean bass response in the < 30Hz range is to have multiple subs with an active filter (like the FBQ2496, for example).TOOLFORLIFEFAN wrote: »Funny!!! my SDA's have no problem with tight Bass.. WEAK??? Please..:rolleyes: there will never be a sub in my system.... No need for it.. -
Nose candy?Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
Thanks
Ben -
Hey Ben!-Kevin
HT: Philips 52PFL7432D 52" LCD 1080p / Onkyo TX-SR 606 / Oppo BDP-83 SE / Comcast cable. (all HDMI)B&W 801 - Front, Polk CS350 LS - Center, Polk LS90 - Rear
2 Channel:
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Taken from a recent Audioholics reply regarding "Club Polk" and Polk speakers:
"I'm yet to hear a Polk speaker that merits more than a sentence and 60 seconds discussion."
My response is: If you need 60 seconds to respond in one sentence, you probably should't be evaluating Polk speakers.....
"Green leaves reveal the heart spoken Khatru"- Jon Anderson
"Have A Little Faith! And Everything You'll Face, Will Jump From Out Right On Into Place! Yeah! Take A Little Time! And Everything You'll Find, Will Move From Gloom Right On Into Shine!"- Arthur Lee -
TOOLFORLIFEFAN wrote: »Funny!!! my SDA's have no problem with tight Bass.. WEAK??? Please..:rolleyes: there will never be a sub in my system.... No need for it..
Well, you have demonstrated an excellent technical capacity to improve the frequency response of SDA's
It is unfortunate that more people have not been exposed to that mod. I am looking forward to upgrading my 1C's with rings some day soon, so I too can eschew the sub during music listening! For HT, I still expect to use a sub, because the separate channels necessitate it. The secret for harvesting from existence the greatest fruitfulness and greatest enjoyment is to live dangerously. - Nietzche -
My SDA's don't see HT duty..
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Agreed but response into the 30's should suffice for music unless your a pipe organ fan.One of the problems with very deep bass (below 30Hz) is that traditional floorstanders have started their -12db/-24db per octave roll-off by then. -
Why is this an issue? Lots of people here do modifications that alter the original design (for example, swapping in new inductors that lower the DCR). While I will personally admit that adding an active driver in place of the passive seems like a pretty bad idea, perhaps this person loves the extra bass. Subjective preference is what matters, right?
Moreover, at least this modification actually makes a real difference!
Can we flush this **** yet?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 -
Or post 90s Kraftwerk, or Juno Reactor, etc.Agreed but response into the 30's should suffice for music unless your a pipe organ fan. -
1. Keyboard WarriorCan we flush this **** yet?1. A Person who, being unable to express his anger through physical violence (owning to their physical weakness, lack of bravery and/or conviction in real life), instead manifests said emotions through the text-based medium of the internet, usually in the form of aggressive writing that the Keyboard Warrior would not (for reasons previously mentioned) be able to give form to in real life. -
"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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Many of us have met him, you couldn't be more wrong.
Yeah, he's an **** in real life, too
Active woofer in a spot meant for a passive is a bad idea, unless you port the cabinet (and tune the port). Plus, as others have said, the crossovers are not designed for this.
The SDA's were designed to be MUSICAL speakers, NOT HT speakers. They're not intended to crumble your foundation with LFE explosions. In an HT environment, yes, they probably should have reinforcement from a sub. In music... not necessary.Ludicrous gibs! -
The SDA's were designed to be MUSICAL speakers, NOT HT speakers. They're not intended to crumble your foundation with LFE explosions. In an HT environment, yes, they probably should have reinforcement from a sub. In music... not necessary.
As soon as I get out of school and get my own house, a 2 channel room is certainly in the cards. I am jealous of you guys that have the space to let these monsters really sing! Some of the pics of setups on here are completely drool-worthy. *sigh* Until then, double duty for the SDA's...The secret for harvesting from existence the greatest fruitfulness and greatest enjoyment is to live dangerously. - Nietzche -
So He's not allowed to have an opinion?

Since when did trolling become justified as having an opinion?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 -
Trolling?I guess our definitions of that term are vastly different.Unless I've missed something I don't see anything I would consider trolling.
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Come on Fred, his question as to why this is an issue should have been your first clue.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 -
While I think most of us disagree with his statement but if thats considered trolling then we are all guilty of similar comments.While I'm obviously in the minority I did find the info in his SDA measurement thread interesting and informative but he took a few unwarranted shots in jibbies from some.At the risk of sounding like his defense attorney it does'nt sit well with me that a new member and IMO knowledgable one gets pissed on for offering up some performance data....his question as to why this is an issue...







