DB840 sub in LSI15's replace the stock 8"driver!!!!!

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Comments

  • cbow8
    cbow8 Posts: 306
    edited April 2012
    nice mod guys. this is very tempting. been almost a month^^^has anyone tried different subs????
  • stretchl
    stretchl Posts: 1,334
    edited September 2012
    Damn, I just read this thread

    http://www.polkaudio.com/forums/showthread.php?123136-SDA-Driver-Seals-Original-Foam-vs.-Mortite-vs.-Armaflex-Foam&highlight=mortite

    What has become of this DarqueKnight?

    That's quite a set of data he posted!
    “Anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that 'my ignorance is just as good as your knowledge.'
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    Visuals
    https://media.illinois.edu/journalism/ledford-charles-stretch
    bit.ly/stretchonphotojournalism
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  • dorokusai
    dorokusai Posts: 25,573
    edited September 2012
    The only Polk subwoofer that fits, is the db series. We tried to get an SR series subwoofer to fit but the magnet structure is too big and the Power Port becomes a problem. I'm sure you could find similar sized subs to the db and they would work but that was the subwoofer we actually played with in a chamber, tested and worked on in-house, to see if it would work as a better driver choice.

    Mark
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • mesquitehead
    mesquitehead Posts: 312
    edited September 2012
    I ended up using the gaskets on the replacements and left out the moretite and they fit fine. I did use all the screw holes though. I used Dynamat extreme on the woofer frames and also wrapped the ports. I notice a much fuller and substantial low end and I think it helps the overall sound of the 15's sound blend better from the high to low end.
    photo (8).JPG
    "Thats great... but how does it sound"
    http://www.burginmcdaniel.com/

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    Yamaha RX-A820 (networked with wireless bridge), Carver M-1.0t, Carver TFM-35, Carver C-1, Polk SDA1c's (x2 pair), Polk RTA 8tl's, Polk RTA 11tl's, Polk Monitor 5, Polk CS 400, Polk PSW 650, Rega Planar 3, Sony DVPNC555ES SACD/DVD, Panny 65" Plasma, Roku

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  • jon s
    jon s Posts: 905
    edited September 2012
    Question... When I disassembled the OEM woofer from the cabinet, the white lead was + and the yellow lead was -. But the leads have different sized connectors... If I fit the connector by size, the polarity is reversed. Did anyone else notice this? If so, how did you resolve it? Did you solder the connectors on correctly?

    Connecting the wires by size gave me a very slight increase in bass so I am assuming that the polarity is incorrect.
  • jon s
    jon s Posts: 905
    edited September 2012
    Aargh... my mistake, the wiring is correct... But I do not notice any increase in overall bass response, it actually sounds less... The bottom extension appears deeper, but the midbass response seems reduced. Some music that had thumping bass now sounds subdued but goes lower. Depth seems to have improved.

    The mortite I bought from Home Depot was kind of dried out... it had a crumbly texture... is that normal?
  • Drenis
    Drenis Posts: 2,871
    edited September 2012
    I dont think it`s supposed to be dried out. Also remember drivers need some time for break in.

    But everyone says its better so you be the judge.
  • EndersShadow
    EndersShadow Posts: 17,517
    edited September 2012
    It's less boomy which is what your describing. Your getting accurate bass for once. Turn it up and it's got more than enough bass.

    Trust me I know.

    What are you powering it with power wise and source wise?
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • halo71
    halo71 Posts: 4,567
    edited September 2012
    Anyone that has upgraded to the db woofers and still have the stock woofers laying around and wanna get rid of them please PM me. I would like to get 6 more of them for a "project".
    --Gary--
    Onkyo Integra M504, Bottlehead Foreplay III, Denon SACD, Thiel CS2.3, NHT VT-2, VT-3 and Evolution T6, Infinity RSIIIa, SDA1C and a few dozen other speakers around the house I change in and out.
  • Phred_t
    Phred_t Posts: 1
    edited September 2012
    I'll have 4 of the stock 8" drivers available at the end of this week after I upgrade all mine.
  • halo71
    halo71 Posts: 4,567
    edited September 2012
    I pm'd you Phred.
    --Gary--
    Onkyo Integra M504, Bottlehead Foreplay III, Denon SACD, Thiel CS2.3, NHT VT-2, VT-3 and Evolution T6, Infinity RSIIIa, SDA1C and a few dozen other speakers around the house I change in and out.
  • PSOVLSK
    PSOVLSK Posts: 5,021
    edited September 2012
    pm'd you Gary.
    Things work out best for those who make the best of the way things work out.-John Wooden
  • sk88
    sk88 Posts: 158
    edited October 2012
    A bit off topic --- has anyone thought of or tried DB1040 on Lsi25? I'd be very interested to hear the results.
    • Online - Focal Solo6 BE, Polk PSW10, Focusrite Saffire Pro 24 DSP, Lenovo x220t
    • Music/HT - Lsi25, Lsi9 (Vr3), Lsi7, LsiC, Pioneer SC-68 & BDP-62FD, PS3
  • dorokusai
    dorokusai Posts: 25,573
    edited October 2012
    We had problems with the simple idea of just using the larger version, on the larger version. It's more than a few issues including proper clearance of the power port and cabinet volume were just two problems. The volume isn't a huge issue but it became a project that had more work involved and it wasn't just a drop in replacement like the smaller model. It was abandoned and I'm not aware of anyone doing this mod, nor would I suggest it unless you had the money and time. Just my opinion.

    Mark
    Polk Audio CS
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • sk88
    sk88 Posts: 158
    edited October 2012
    I appreciate your reply. No, I am not brave to try.
    • Online - Focal Solo6 BE, Polk PSW10, Focusrite Saffire Pro 24 DSP, Lenovo x220t
    • Music/HT - Lsi25, Lsi9 (Vr3), Lsi7, LsiC, Pioneer SC-68 & BDP-62FD, PS3
  • dorokusai
    dorokusai Posts: 25,573
    edited October 2012
    Plus, honestly, I don't even like the LSi25 so I would put forth no more effort than I already have. The fact you can drop-in and plug in the LSi15/dB Series woofer is just the sweetest deal ever. The mod has been done here over a dozen times, it works and I've yet to hear any complaints.

    It all stemmed from an email I sent to Engineering many years ago about, "What would you do to mod the LSi series?". And the first model out of the response was the LSi15. The exact driver was immediately mentioned and a couple smaller issues that were also passed on and can be found in the threads about this modification.

    Clearly, they had messed around with this idea and if you have ever met the folks from that area of Polk HQ, they like to try things and test theories. If they didn't we wouldn't be here and we wouldn't even care about this in the first place. These folks love their job and they love to push the envelope, even if its simple things.

    That's why Polk Audio has such a following here and why they(HQ) think its weird when we want autographs on vintage drivers, literature and sometimes even body parts when we get the chance to do tours in Baltimore(2005/ 2008/ 2012....am I getting the years' right guys?). Other manufacturers started doing stuff like this YEARS after we started to do it and make it painfully public. Suck it Carverfest.

    Mark
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • Drenis
    Drenis Posts: 2,871
    edited October 2012
    dorokusai wrote: »
    Other manufacturers started doing stuff like this YEARS after we started to do it and make it painfully public. Suck it Carverfest.

    Hahaha! Thanks for the great morning laugh Mark.
  • PubFiction
    PubFiction Posts: 105
    edited December 2012
    Are there any other options besides the polk replacement for this driver that anyone has found? I am not a fan of their look.
  • EndersShadow
    EndersShadow Posts: 17,517
    edited December 2012
    PubFiction wrote: »
    Are there any other options besides the polk replacement for this driver that anyone has found? I am not a fan of their look.

    You can't see it once you put the cover back on. Plus the subs face sideways so you shouldn't see them regardless lol
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • PubFiction
    PubFiction Posts: 105
    edited December 2012
    well mine are positioned so you can see them and I liked to keep the grill off.
  • F1nut
    F1nut Posts: 49,708
    edited December 2012
    If you are watching the drivers when listening, you are NOT listening.
    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

  • Drenis
    Drenis Posts: 2,871
    edited December 2012
    PubFiction wrote: »
    well mine are positioned so you can see them and I liked to keep the grill off.

    You either have way to extreme of a toe in or like F1nut says, you're doing it wrong. Why do you dislike using the grill?
  • Face
    Face Posts: 14,340
    edited December 2012
    PubFiction wrote: »
    well mine are positioned so you can see them and I liked to keep the grill off.
    I guess you're SOL then.
    "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
  • PubFiction
    PubFiction Posts: 105
    edited December 2012
    Lots of people like to have the grilles off I don't get the big deal? They dont really add much to the look other than provide a cheap cover up for bad looking or gaudy speakers. But its fine, obviously their is not a known alternative.
  • F1nut
    F1nut Posts: 49,708
    edited December 2012
    Grills serve a few purposes that you seem unaware of. First and foremost, they are an integral part of the speaker's acoustical design. They keep dust and grim off the drivers. They keep little fingers from poking. So, put your grills back on.
    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

  • Face
    Face Posts: 14,340
    edited December 2012
    If you're serious about finding another sub that has the same parameters, this is what you want to look for: http://www.polkaudio.com/products/db840

    Be advised, you will probably end up with another car sub which will either look similar or much more gaudy.

    Resonant Frequency 49 Hz
    Xmax
    Xmax Linear .51 inch/13 mm (peak to peak)
    MMS 67g
    BL 10.3 Tesla Meters
    CMS 157.6 Micro Meters
    Recommended Enclosure Sealed/Ported/Bandpass
    SD 35.65 sq inch/ 230 sq cm
    VAS .42 cubic feet/11.9 L
    QTS .6
    QES .6
    QMS 14.1
    Diameter 8" (20.32cm)
    Cut-Out Diameter 7 1/8" (18.10cm)
    Nominal Impedance 4 ohms
    Efficiency 85 dB
    "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
  • cbow8
    cbow8 Posts: 306
    edited December 2012
    i hooked up my lsi15s today. they have crossover mods and the db840. sound good to me. its about the perfect blend for a nice rich sound without being boomy and annoying. i dont think id want anymore bass from that model of speaker. db840 is plenty of sub for this application.im running somewhere around 850 watts to them and havent heard any distortion or sign of being a weak link. those are my thoughts about this mod. thanks guys have a happy new year!!
  • zeppelin2
    zeppelin2 Posts: 13
    edited May 2013
    Can we get some long-term impressions from those that made the db840 swap?

    Has anybody reverted back to the stock woofers?
  • EndersShadow
    EndersShadow Posts: 17,517
    edited May 2013
    Lol the lack of posts after doing the mod are due to the members enjoying music too much to post lol.

    They sound MUCH better. I sold off my stock woofers and haven't looked back.
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • jon s
    jon s Posts: 905
    edited May 2013
    changing the woofes made the bass a lot tighter... The original drivers tended to be a bit boomy.