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

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Comments

  • cokewithvanillacokewithvanilla Posts: 1,774
    edited March 2011
    Has anyone done something like this to the 25's?
  • DVOuSSDVOuSS Posts: 52
    edited March 2011
    i second that question...i feel that the subs are the weakest link in the 25s
    Living Room
    Toshiba 55" 240HZ LCD
    Onkyo TX-NR807
    Emotiva XPA-5
    HTPC
    Polk Audio LSi 25 - Mains
    Polk Audio LSiC - Center
    Polk Audio LSi 9 - Surrounds
    DSW microPRO 4000 x2 - Subs

    Media Room
    Mitsubishi 73" DLP
    Onkyo TX-SR875
    HTPC
    2 x JBL Urei S300 Amplifiers
    2 x JBL Urei S150 Amplifiers
    JBL Synthesis Three S3M - Mains
    JBL Synthesis Three S3HC - Center
    JBL Synthesis Three S3S - Subs
    JBL Synthesis Two S2A - Surrounds
  • EndersShadowEndersShadow Posts: 16,488
    edited April 2011
    Hate to revive a mostly dead thread, but curious as to if any of you guys think adding dynamat to the sub would be worth the effort? Also how many of you dynamatted the powerport tube inside the tower?
    "....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 sjon s Posts: 922
    edited April 2011
    ignore this...
  • dorokusaidorokusai Posts: 25,263
    edited April 2011
    Hate to revive a mostly dead thread, but curious as to if any of you guys think adding dynamat to the sub would be worth the effort? Also how many of you dynamatted the powerport tube inside the tower?

    The Dynamat suggestion was also suggested to me from the Polk Engineering department and part of what I originally posted here on the forum. I used simple weatherproofing mastic to dampen my tube but Dynamat would work just as well.
  • EndersShadowEndersShadow Posts: 16,488
    edited April 2011
    dorokusai wrote: »
    The Dynamat suggestion was also suggested to me from the Polk Engineering department and part of what I originally posted here on the forum. I used simple weatherproofing mastic to dampen my tube but Dynamat would work just as well.

    Thanks. I might do that since its pretty easy once you have it opened up anyway. That and I am buying about 36 sq ft of it for my car around the same time, so I might have some left over :wink:
    "....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)
  • love2listenlove2listen Posts: 172
    edited April 2011
    I put dynamat on the tube and on the basket of the new sub and it did make a difference, to my ears!!
  • dorokusaidorokusai Posts: 25,263
    edited April 2011
    I wouldn't be so concened with the basket on the dB series woofer since it's a car subwoofer and more rigid than the stock driver but it's easy enough to handle while it's all torn apart.
  • EndersShadowEndersShadow Posts: 16,488
    edited April 2011
    dorokusai wrote: »
    I wouldn't be so concened with the basket on the dB series woofer since it's a car subwoofer and more rigid than the stock driver but it's easy enough to handle while it's all torn apart.

    Any other secrets from the Polk Engineering department you can share without killing me afterward :eek::biggrin::tongue::wink:. Related to the LSi series of course 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)
  • Jer.WarJer.War Posts: 180
    edited April 2011
    I have also swapped the stock subs in the LSI15s for the DB series with satisfying results (figured I would ad my 2 cents). I did notice the basket on the DB subs were quite sturdy, but I also had a ton of dynamat hangin around so I figured what is the harm?? I also put a layer on the base (underside) of the LSIs, as well as the bass tube (the cardboard does benefit from so dampening). When you have the sub out, it wouldn't hurt to inspect the area where the wire enter the upper enclosure just to make sure there is a good seal. When I changed out my sub I did have to make a new gasket as others have, I used plain ol' butyl (I have access to lots) which is similar to mortite.
    While I was in the modding mood, I removed the upper drivers and dampened the baskets of those as well.
    These mods really tuned up the bass, now it is tighter and deeper than without these mods. The next biggest improvement I noticed other than the woofer swap was proper spiking and leveling (I put it off for a while, but man what a difference).

    [The Ever-Evolving System

    LSI15's (PNF Symphony cabels, modded X-Over and subs), LSIC, LSI7's, Rega Apollo CDP (PNF ICON ICs, modified PS cct.), Yamaha RXV-1700 w/ ipod dock, B&K REF200.2 (fronts) Samsung BDP-1600, XBOX360, Patriot Box Office Media Player, 42" Samsung LCD.
  • TouchOfEvilTouchOfEvil Posts: 989
    edited April 2011
    Glad more people are doing this mod with great success!!
    Living Room Rig:D
    Rotel RSP-1069/Rotel RMB-1095/Rotel-1072/Polk lsI15's W/modded xoverW/DBsubs/Polk LsiC/lsI7's/Klipsch sub-12"the weak link"/DLP Mitsubishi 65"
    Xbox360/PS3/WII
    M.Br. setup:)
    Emotiva MMC-1/Rotel RMB-1075/Polk BlackStone TL350's/Velodyne SPL1000/Samsung 51" Plasma
    Computer Rig:
    Rotel RB1050/Tannoy DC4's/Klipsch RW-10d/ImodIpod/HK AVR230 for now....
    Headphones-Ultrasone-HFI780's w/LittleDot MK Vamp Portables Panasonic HJE-900's
  • EndersShadowEndersShadow Posts: 16,488
    edited May 2011
    I just did the upgrade in my LSi 15's. Thought I would post some pics of the stock woofer v. the DB840.

    In the first two pics the stock woofer is on the left.

    I still need to create a gasket on the speakers but will do that on Saturday.
    "....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)
  • dorokusaidorokusai Posts: 25,263
    edited May 2011
    Another convert....ahhhh, I love it when it's more than a capacitor job. I'll never do another LSI15/25 again as I almost lost my sanity.
  • FaceFace Posts: 14,714
    edited May 2011
    dorokusai wrote: »
    Another convert....ahhhh, I love it when it's more than a capacitor job. I'll never do another LSI15/25 again as I almost lost my sanity.
    It is a headache to do one top to bottom.
    "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
  • dorokusaidorokusai Posts: 25,263
    edited May 2011
    I believe we're a club of 2 Mike.
  • EndersShadowEndersShadow Posts: 16,488
    edited May 2011
    dorokusai wrote: »
    Another convert....ahhhh, I love it when it's more than a capacitor job. I'll never do another LSI15/25 again as I almost lost my sanity.

    LOL...that along with cost are what are making me think thats a long term upgrade :smile:
    "....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)
  • jmosjmos Posts: 40
    edited September 2011
    Ordered mine today, will let you know how it goes.
    The lows have definately been an issue with my system, quite happy with the mids and highs but when I play a track with a mix of low freq sounds it gets really messy.

    Regards
    John
  • mole'mole' Posts: 3,160
    edited September 2011
    good reading/info in here for a soon to be LSi15 owner....
    mole'
  • jmosjmos Posts: 40
    edited October 2011
    5.jpg
    jmos wrote: »
    Ordered mine today, will let you know how it goes.
    The lows have definately been an issue with my system, quite happy with the mids and highs but when I play a track with a mix of low freq sounds it gets really messy.

    Regards
    John

    Finally got the new drivers in, very happy with the result considering the low cost and easy changeover.
    The bass is faster, tighter and clearer, I guess in time it should improve.
    The bass in RIDE ACROSS THE RIVER from DIRE STRAITS sounded so bad I often skipped the song now I can listen to it.
    I'm quite happy with the changeover, thanks for the great tips and help on this forum.
    Regards
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  • FaceFace Posts: 14,714
    edited October 2011
    The hardest part was probably removing the old grill, right?
    "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
  • jmosjmos Posts: 40
    edited October 2011
    Face wrote: »
    The hardest part was probably removing the old grill, right?
    Actually they pulled out quite easy?
    The image actually shows the rubber/plastic gasket still on the DB840, I did actually remove these once I had noticed them and remembered that they had to be removed.
  • BrasiliaflyerBrasiliaflyer Posts: 67
    edited January 2012
    Are you guys using the single or dual voice coil version of the DB840?
  • EndersShadowEndersShadow Posts: 16,488
    edited January 2012
    Are you guys using the single or dual voice coil version of the DB840?

    Single Voice Coil
    "....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)
  • makdownundermakdownunder Posts: 13
    edited January 2012
    whats the difference between the single and double voice coil?
  • EndersShadowEndersShadow Posts: 16,488
    edited January 2012
    whats the difference between the single and double voice coil?

    The fact you can wire it to be a lower ohm load or a higher one by itself. You want the Single Voice Coil since the stock woofer is a Single Voice Coil.
    "....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)
  • dorokusaidorokusai Posts: 25,263
    edited January 2012
    Face wrote: »
    The hardest part was probably removing the old grill, right?

    Sometimes they come out easy as pie, others are super jammed up in there.

    Just use caution when removing the old grills, be patient. The new drivers sound better and look even cooler don't you think? Thanks for the pics JMOS.

    Oh, and your welcome TOE, sorry that I neglected to catch you thank you about this so long ago. I worked with engineering on this modification years ago when we wondered if there was any easy stuff to do aside from xover modifications on the LSi series.
  • BeefJerkyBeefJerky Posts: 1,302
    edited February 2012
    Okay, I guess it's time to resurrect this thread again! I recently acquired some LSi15's thanks to our awesome member DMara. I decided to give this mod a try since the price was right, and from other's comments, I had nothing to lose. I got a set of db840's and some Mortite off of Amazon for right around $106 shipped. I also purchased a large box of Dynamat Xtreme since I want to do some noise reduction in my car, so I also put Dynamat on the outside of the port tube as Mark suggested. It only took about an hour to do the mod, and it was very straightforward.

    The results are very good. I just got them hooked up, and I can immediately tell how much tighter, cleaner and accurate the bass is. It also does seem to dig a bit deeper. I imagine it will only improve as the new drivers break in over the next few days. There also seems to be less port noise when playing loud, heavy bass notes; I assume this is due to the Dynamat.

    At any rate, I highly recommend this mod! It's easy and quite inexpensive.
  • jhracer3jhracer3 Posts: 87
    edited March 2012
    BeefJerky,

    Can you post a link to the mortite you bought? I saw they have a few options on Amazon, I was wondering which weight/thickness to go with.

    Thanks
  • EndersShadowEndersShadow Posts: 16,488
    edited March 2012
    jhracer3 wrote: »
    BeefJerky,

    Can you post a link to the mortite you bought? I saw they have a few options on Amazon, I was wondering which weight/thickness to go with.

    Thanks

    Another better (IMHO) option is Armaflex which you can buy at Lowes, Home Depot, ect. It comes off much easier and is easier to work with as well.

    Here is a review of the differences between mortite, armaflex, ect.

    Here is what it looks like: http://www.homedepot.com/h_d1/N-5yc1v/R-100539553/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=Armaflex&storeId=10051
    "....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)
  • Denon FrankDenon Frank Posts: 130
    edited March 2012
    When I did my DB840 upgrade I used a sharp blade and cut the gasket that came with the new speakers. Just take the gasket off the new woofers and slowly & carefully cut the gasket along the back edge where it has a seam (where it starts to curve from the flat edge with the mounting holes.) You'll end up with the thin part of the gasket that has the holes in it as you new mounting gasket. Just take your time and it works great. :smile:
    Frank

    Polk LSiM 703 mains on Skylan Stands
    Polk LSiM 704c center
    Polk FX500i surrounds
    Parasound 5250 Amp
    Oppo BDP-105 :smile:
    SVS PC Ultra tuned to 16hz
    Panasonic 65" Viera Plasma
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