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

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Comments

  • dcluleydcluley Posts: 2
    edited December 2013
    So, after a couple of days playing with this, I have found that the new woofer has caused my speakers to noticeably distort when listening in "direct" mode. I am not sure what is causing this, but the switch seems to have caused it. Perhaps the switch caused the already power hungry Lsi15's to be even more power hungry and my amp is not up to snuff. Perhaps it is my Pre-Pro, which I am also looking to upgrade. (I have an Emotiva UMC-1 with a UPA-5. . . love the UPA-5, UMC-1 has always been suspect IMO). The system sounded great always before the switch in direct mode, so I am leaning to switch them back out and maybe try again after I get enough money to upgrade my pre-pro and get some Monoblocks or Reference 2 channel to run the LSi's in front stereo mode and 7.1 mode.

    Any thoughts or experience on this from others? Could the switch cause more harmonic distortion or overdraw an amp, or is it just my setup?
  • ematthewsematthews Posts: 27
    edited December 2013
    Not sure about this swap. I have had mine on for some time and I think something with the speakers or this swap is
    causing my Emotiva XPA-2 amp to fault... I will be sending the amp back for the third time next week..
    AS a note. I tried to put the stock woofers back on last night and I could not get them off. I used Mortite as a gasget. I pulled the bass plate/stand off and the treminal post off and tried knocking them out with a wood stick.. They will not come out.
    I am at a point of selling or trashing these speakers. It's to bad, the mid range and highs are lovely on these. Bass sucks.
    Really disappointed right now.
  • zeppelin2zeppelin2 Posts: 13
    edited December 2013
    ematthews wrote: »
    AS a note. I tried to put the stock woofers back on last night and I could not get them off. I used Mortite as a gasget. I pulled the bass plate/stand off and the treminal post off and tried knocking them out with a wood stick.. They will not come out.
    I had the same problem. I was finally able to pry the driver out of the cabinet using medical forceps. I stuck them into one of the screw holes and was able to pry the thing loose. Care must be taken as the tool can slip and easily scratch the wood veneer!

    http://www.medical-supplies-equipment-company.com/files/media/images/Backhause-Towel-Forceps-525-1.jpg
  • ematthewsematthews Posts: 27
    edited December 2013
    Ha. I tried a dental pick and broke it... These things are super stuck..
  • skrolskrol Posts: 2,596
    edited December 2013
    I have the DB840 in my LSi15's and drive them all day long with either my Parasound HCA-800II or even my Denon DRA-835R receiver. Perhaps it is the amp.

    I agree that the mids through highs are fantastic but the bass can be a bit boomy. I much prefer the bass response of my RTA-11TL's, everything else it is the LSi's. I never heard them with the stock sub. In my case, I believe that the bass is mainly due to placement but I have limitations where I can position them. I am wondering if some sort of sound absorption would work.
    Stan

    Main 2ch:
    Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Monster HTS3600-MKII, Grado SR-225i

    HT:
    Denon AVR-888, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW10, Marantz UD5005, Panasonic TC-P42S60

    Other stuff:
    Denon: DRA-835R, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, TSi100; Pioneer: CT-6R, PL-530; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, Polk: RM7, Parasound C/PT-600, HCA-800ii
  • jon sjon s Posts: 922
    edited December 2013
    I have a pair of modded LSi15s as well... I don't have any issues with amps with the speakers... I have used a Pioneer SC-67, Onkyo TX-NR906, Marantz PM-7200, Acurus DIA100 and a Sony TA-8650 with no issues... Something must be wrong with your amp...

    The DB840s do sound tighter than the stock, which tended to be a bit boomy. Never regretted the swap...

    Question: Are you sure you have the DB840SVC? If you have the DB840DVC and have it wired incorrectly, you could be set up for a 2-ohm load which would trip up most amps. Unfortunately, the alternative is to wire them in series (8-ohms) but the SVC model is the one you really have to use...
  • ematthewsematthews Posts: 27
    edited December 2013
    jon s wrote: »
    I have a pair of modded LSi15s as well... I don't have any issues with amps with the speakers... I have used a Pioneer SC-67, Onkyo TX-NR906, Marantz PM-7200, Acurus DIA100 and a Sony TA-8650 with no issues... Something must be wrong with your amp...

    The DB840s do sound tighter than the stock, which tended to be a bit boomy. Never regretted the swap...

    Question: Are you sure you have the DB840SVC? If you have the DB840DVC and have it wired incorrectly, you could be set up for a 2-ohm load which would trip up most amps. Unfortunately, the alternative is to wire them in series (8-ohms) but the SVC model is the one you really have to use...

    Thanks
    I checked and the are the SVC ones so no issue here.. I will keep an eye on my amp and send it back to Emotiva if there is more
    problems. Good thing it has a 5 year warranty.
  • dorokusaidorokusai Posts: 25,100
    edited December 2013
    One negative doesn't change the actual recommendation from Polk Audio. Not everyone will experience the same thing but 50+ have....whatever.

    When I worked for Polk we did this change in the chamber vs stock and it was an improvement.

    -d
  • ematthewsematthews Posts: 27
    edited January 2014
    Not sure what I did but just an update. I turned off my sub and disconnected it from the entire system..Moved my connections to Full output. And moved my speakers in about
    two inches... I am getting some good sound now...
    I also switched the speakers out and tried a few others I had... And to be honest, I didn't know how good these actually were... The other two speakers didn't have as much bass and the highs were very bright... These Polk's are good!
    Trial speakers
    Klipsch RF82
    Infinity P363
  • skrolskrol Posts: 2,596
    edited February 2014
    Caution on sub woofer selection!

    I did not realize that Polk made an 8" DXi series until I saw their boxed DXi108 sub (it is a dvc). They also have raw DXi 8" sub (DXi804 svc and dvc) that does not show up on the web page but does appear in the DXi series Owners Manual. Here is where the confusion sets in. Comparing the specs of the DB840 svc to the DXi804 svc, as listed in each ones Owners Manuals, they look identical. However, the specs on the web site "Spec" tab for the DB840 svc are different from what is listed in its OM. Usually, I would be suspicious of the web site specs and believe the OM. However, in this case I suspect that the web is correct and the OM is wrong. I have an email into Polk CS to sort out which is correct.

    When I do a speaker cabinet simulation using the LSi15 sub cabinet dimensions and OM specs for the DB840, things don't look right. They look better when I use the web site specs.

    Bottom line, the DXi804 is likely NOT a good replacement for the LSi15 sub. Stick to the DB840.

    Stan
    Stan

    Main 2ch:
    Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Monster HTS3600-MKII, Grado SR-225i

    HT:
    Denon AVR-888, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW10, Marantz UD5005, Panasonic TC-P42S60

    Other stuff:
    Denon: DRA-835R, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, TSi100; Pioneer: CT-6R, PL-530; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, Polk: RM7, Parasound C/PT-600, HCA-800ii
  • skrolskrol Posts: 2,596
    edited February 2014
    To make things even more complicated, I have a sales literature sheet for the DB series which has yet different specs for some of the parameters while others match the OM and others match the web. Take heart, some are actually consistent across all three sources.
    Stan

    Main 2ch:
    Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Monster HTS3600-MKII, Grado SR-225i

    HT:
    Denon AVR-888, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW10, Marantz UD5005, Panasonic TC-P42S60

    Other stuff:
    Denon: DRA-835R, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, TSi100; Pioneer: CT-6R, PL-530; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, Polk: RM7, Parasound C/PT-600, HCA-800ii
  • xcapri79xcapri79 Posts: 5,273
    I did it several years ago near the beginning of this thread. Once the woofers have broken in, they sound great and are still sounding great.

    Some of my equipment includes the following:
    Adcom: GCD CD Player, GFP Preamp, GFA Amp; Audio-Technica: Turn Tables; Denon: HD Radio Tuners;
    Emotiva: XSP, XPA, UPA; RSP, RPA, ERC, Stealth; Focal: Chorus Speakers;
    Harman Kardon: Receivers; Jolida: Integrated Tube Amp; Marantz: Tuners;
    McIntosh: C Preamps, MA Integrated Amps, MX Processors, MC Amps, MHT, MCD CD Players, MR Receivers, LS Speakers;
    Mirage: OMD Speakers; MM and S Subwoofers; Parasound PHP Preamp, HCA Amp;
    Pioneer: SC AVRs, BDP Blu Ray Players;
    Polk Audio: LSi, LSiM, RTi, RTIA, RM, Signature, Monitor Speakers, DSW, PSW Subwoofers;
    Sony: HD Radio Tuners; Technics: SL Turntables, Equalizers; Yamaha: Tuners;
  • mikeyb128mikeyb128 Posts: 2,456
    Have to agree. Did this mod with vr3 fortress crossovers, and these speakers continually blow my mind. I like them as much or more than my lsim system. My friends are always surprised that nice sound comes from a pair of polks...
    2 channel:
    Bryston 4B3, Bryston BDA3, Cary SLP03, Shanling CDT1000SE with parts conneXion level 2 mods, Nottingham analogue ace space 294, soundsmith Carmen MKii , Eastern Electric minimax phono pre, Core power technologies balanced power conditioner, Akiko Corelli power conditioner with Akiko Audio HQ power cable, Nordost heimdall 2, Frey 2, interconnects, speaker and power cables, Focal Electra 1028 BE 2, Auralic Aries mini, Black diamond racing cones, ingress audio level 1 roller blocks, JL Audio E110 with Auralic subdude, Primacoustics room treatments.
    Theater:
    Focal Aria 926,905,CC900, SVS PB ultra x2. Pioneer Elite SC85, Oppo BDP93, Panamax M5400PM, Minix neox6, Nordost Blue heaven LS power cables.

  • ZLTFULZLTFUL Posts: 4,166
    kevintomb wrote: »
    What gets me, is often when upgrading to better parts, the values actually "change", from what stock is, even when mimicking the rated values.

    Uh...ok...
    So you're saying an 8uf cap of one brand isn't the same rating as an 8uf rating of another? Now I would agree to an extent based on +/- percentage but within 5%, human ears aren't going to hear a difference.

    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
    2 Channel: Silverline Audio Sonatina MKI, Monitor 5 Series II, DIY Seas based bookies
    LR 2 Channel: LSi7, DSW-MP2000
    HT: JTR Triple 8 LCRs, DIYSG Volt 8LX Surrounds, DIYSG Volt 6LX Atmos, 6 SI HT-18D2 Subs
    Guest BR 2 Channel: Swans D1080MKII
    Deck: Pyle BT Speaker pair with upgraded woofers
  • xcapri79xcapri79 Posts: 5,273
    edited May 2015
    ZLTFUL wrote: »
    Now I would agree to an extent based on +/- percentage but within 5%, human ears aren't going to hear a difference.
    Unless it has to do with interconnects, then the difference would be night and day. Right? ;)

    The advantage of using higher spec. components is that they will be closer to the design spec. and this should result in an incrementally improved performance and/pr longer life. The results will vary of course depending on the application.


    Some of my equipment includes the following:
    Adcom: GCD CD Player, GFP Preamp, GFA Amp; Audio-Technica: Turn Tables; Denon: HD Radio Tuners;
    Emotiva: XSP, XPA, UPA; RSP, RPA, ERC, Stealth; Focal: Chorus Speakers;
    Harman Kardon: Receivers; Jolida: Integrated Tube Amp; Marantz: Tuners;
    McIntosh: C Preamps, MA Integrated Amps, MX Processors, MC Amps, MHT, MCD CD Players, MR Receivers, LS Speakers;
    Mirage: OMD Speakers; MM and S Subwoofers; Parasound PHP Preamp, HCA Amp;
    Pioneer: SC AVRs, BDP Blu Ray Players;
    Polk Audio: LSi, LSiM, RTi, RTIA, RM, Signature, Monitor Speakers, DSW, PSW Subwoofers;
    Sony: HD Radio Tuners; Technics: SL Turntables, Equalizers; Yamaha: Tuners;
  • ZLTFULZLTFUL Posts: 4,166
    Explain how a 2 ohm, 5% tolerance resistor can measure 2.5 ohm just because it is mounted in a speaker?
    You logic is confusing at best. Are you telling me that when I order a 2 ohm resistor that when I mount it on the crossover board, it will magically change to a different spec?
    Just measured a 22.5 ohm resistor...on a crossover board...it measured 22.53 ohms...which is within tolerance for a Mills MRA12...so where is this magical resistance chance happening?
    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
    2 Channel: Silverline Audio Sonatina MKI, Monitor 5 Series II, DIY Seas based bookies
    LR 2 Channel: LSi7, DSW-MP2000
    HT: JTR Triple 8 LCRs, DIYSG Volt 8LX Surrounds, DIYSG Volt 6LX Atmos, 6 SI HT-18D2 Subs
    Guest BR 2 Channel: Swans D1080MKII
    Deck: Pyle BT Speaker pair with upgraded woofers
  • F1nutF1nut Posts: 38,143
    Explain how a 2 ohm, 5% tolerance resistor can measure 2.5 ohm just because it is mounted in a speaker?

    This should be interesting.



    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."


  • nbrowsernbrowser Posts: 6,879
    edited May 2015
    F1nut wrote: »
    Explain how a 2 ohm, 5% tolerance resistor can measure 2.5 ohm just because it is mounted in a speaker?

    This should be interesting.



    I got front row tickets....wanna sit up there when this plays out? lol
    Living room: Samsung UN55KU7000 4K UHD HDR 55 inch TV, Marantz CD6004, Pro-Ject Debut Carbon, Parasound zPhono, Mac Mini, Oppo BDP-93, XBox One S 2Tb, Kenwood DPX792BH car deck for radio purposes, Marantz SR5010 AVR, Parasound HCA-1200II, Front SDA 2 modded with Larrys Rings and RD0-194-1 tweeters, Rear Onkyo SKF-4800 Towers, Center CSiA6, BOOM Tannoy TS2.12 Sub, Audioquest Evergreen interconnects just about everywhere except from AVR to amp, MIT Terminator 4, MIT AVT3 speaker cables with extra terminals covered up Monitor 5 Jr+ in the wings for a center channel.
  • ohskigodohskigod Posts: 6,483
    Boys boys boys

    Put the soldering irons down, climb your basement stairs, walk out your front door, and get some sunshine. Lol
    Theater - Polk 9500 surround bar. simple elegant win
    2 Channel -
    Anthem Pre 2l, Jolida JD100 CD player, CAL Sigma DAC, Carver m4.0, Polk LSi9 w external modified Crossovers (thanks Trey!)
  • ZLTFULZLTFUL Posts: 4,166
    kevintomb wrote: »
    Perhaps explained poorly!

    All I was trying to say, is that the stock components often measure different than their labeled values.
    I have not measured any huge variations, but read a few threads, where variations were far larger than the 5-10% Variances labeled on the Stock parts.

    That makes WAY more sense than your original postulation.
    Measuring that same 22.5 ohm resistor in the stock circuit does show a greater than 5% tolerance. But I would also expect that considering that part has an unknown life over the last 24ish years and has clearly degraded over time.

    Putting a new component in the circuit isn't really trying to replace it with a different value per say as much as it is returning the circuit to its original specs.

    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
    2 Channel: Silverline Audio Sonatina MKI, Monitor 5 Series II, DIY Seas based bookies
    LR 2 Channel: LSi7, DSW-MP2000
    HT: JTR Triple 8 LCRs, DIYSG Volt 8LX Surrounds, DIYSG Volt 6LX Atmos, 6 SI HT-18D2 Subs
    Guest BR 2 Channel: Swans D1080MKII
    Deck: Pyle BT Speaker pair with upgraded woofers
  • Airplay355Airplay355 Posts: 4,019
    I just did this mod myself. I found the DB drivers on amazon for $47.50 with free two day shipping (for Prime members). I picked up two before it became impossible to find new ones anymore. So, some notes...

    I read through some posts here and saw "dental pick", so I thought GREAT idea, and bought a literal dental pick. I see now that's not what people use. Turns out, it worked really well, especially for prying out the old driver. No cabinet damage and I didn't have to unscrew the bottom plate to push the driver out. I just lifted it right out.

    I have the newer version and the grill on one speaker was so stuck on, my wife insisted that it must be glued in place. It finally came off but not without a pea sized hole in the grill cloth. Unfortunate, but this grill cloth is fragile and there really was no other way to get it off. The second grill was more loose and came out with just a tiny hole from the dental pick I used to pry it out. This hole is much more tolerable. Grills are not forever, especially the stuff they used on this series.

    I did not like the idea of mortite or some kind of messy caulk gasket. I saw someone mention cutting the DB gasket and that's what I decided to do. I used a razor blade for all the trimming. First, I cut the gasket in half, as in I inserted the blade where the driver had been and cut along the circumference of the circle so I had two circle gaskets (frontal plane, I guess?). The top part has some decorative ridges in it, so I used the bottom. There was a small ridge on the outer rim, which I trimmed off. To get this gasket to fit into the hole, I cut it again (sagittal?) so that I could lay it in the hole and overlap an area where I cut. The overlap was trimmed off. This allowed me to align 3/4 of the holes with their original position. It also kept the driver in the original position instead of pushing it farther out. I replaced the four screws that were there originally and added 4 from the DB840. I used an impact drill and the screws went in like butter without any pre-drilling.

    The VC on the woofers I got was at the bottom based on logo orientation. If mounted with the logo up, the wires were smashed against the port and I didn't want any lose wires dangling around right by the port. So I decided to invert them and just leave the logo upside down. No one is going to see it, so I don't care at all. I'd rather that than risking buzzing wires inside the cabinet.

    My port didn't seem like cardboard. It was hard and rigid. I decided not to bother with the dynamat. Since I didn't use mortite I can always pop the driver out and add it later, but for now I left it out.

    The good:

    The bass is instantly tighter. I would go as far as to say I disliked the bass from the original speaker. It was sloppy and that makes sense once I got to feel the flimsy driver compared to the stiffer DB.

    Bass is slightly deeper but not too much. Mostly I was after tighter more controlled bass. That's what I got.

    The bad:

    For those with grills that are in way too tightly, you should be prepared to ruin them or at the very least, puncture the fabric and have a hole. The only way to get the tight ones out is by pulling from underneath (as far as I can tell).

    I feel like I've made a power hungry speaker even more power hungry. This is anecdotal of course. 7guq29am547y.jpg
    djq59hqo3xhb.jpg

  • mpitogompitogo Posts: 69
    What about a DB1040 SVC for an LSi25?
    Living Room Music-2.0
    Family Room Home Theater-7.2.2
    Office Home Theater-5.1
    Master Bedroom Music-2.0
    Patio Music-2.0
  • Airplay355Airplay355 Posts: 4,019
    Hard for me to say. The engineers at Polk were the ones who did the work to find out the sub was a great drop in replacement. I don't think they tried it with Lsi25s. The subs seem cheap enough where you could get them, try them out and return them if you didn't like them or dump them on craigslist.
  • Hey gang, I have followed this thread for years and, considering its age, dont feel too dumb by keeping it going to ask a question now. I have loved my 15s for many years, but the one nagging thing about them (to me anyway) was the upper bass rolloff. I could never really smooth it out so I just set the receiver to a high crossover, and handed most of the work to a pair of 10" Hsu subs. That helped quite a bit.
    I listen to a lot of light strings and female vocals, so deep extension has never been a real priority in lieu of smoothness. So just recently I was considering selling the speakers just because it has always seemed like a bandaid fix.

    Burning question now to is have you guys found the upper woofer crossover smoother with the replacement woofer? Or is this a complete replacement crossover thing?

    On another note at the other end of the frequency spectrum (and unrelated) the highs seem 'capped' for a lack of a better word that I can come up with. That one I can live with for now though.
  • K_MK_M Posts: 938
    The mod, involves changing the side mounted woofer (8") that has a decent bit less upper bass boominess. It is a great change "IF" this particular issue bothers you.

    It can be also helped by doing what you do, crossing a sub fairly high, and adjusting the level to your preference. There are ways to mod the crossover to also remove the "issue" of bass boominess also.

    Not sure how to answer about the "highs", they seem fairly good as is, but not too forward like many speakers are voiced.
    Lsi15, Lsi9, LsiC,Rta11t,M5jr+,M4,SDA 3.1TL, SDA SRS 2.3TL, Rti6....Still listing stuff, a work in progress.
    B+W-
    Epos-
    Infinity-
    Advent-

  • Thanks K_M, The highs shouldnt have entered the picture here as its not the topic. My mistake.
    Your description was enough for me to give this a try. I find the small Hsus blend nicely at the bottom, so that area of midrange is the only 'in my face' problem that I have that I was never able to fix.
  • Airplay355Airplay355 Posts: 4,019
    I found the mod helped with what I perceived as boomy bass. Extension is better, impact is better and the speaker sounds better when run full range. For HT they're crossed at 60hz so they really aren't doing much but for music, the full range abilities help out. I prefer not to use my sub with music unless I'm trying to annoy the neighborhood for fun.

    I find it to be a more cohesive speaker. I also figured that for $80, if I didn't like it, I hadn't wasted much.

    I don't have a problem with the highs at all. The tweeter is what draws me to this speaker. My wife and I were watching a movie the other day where a smoke alarm went off and we couldn't tell if it was in the movie or was our alarm. They're very accurate and extend plenty high for me :)
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