Recent Polk 705/707 discounts a result of poor design?

Came across a post on audioholics from a speaker designer that the reason for the recent massive discounts of the Polk 705/707 LSiM line is the result of a major design flaw. That is placing two crossovers below 400Hz at 100Hz and 300Hz stressing avr's and requiring large amounts of amplification, possibly leading to component failure. Is it really an engineering feat or is there some truth to this? I'm new to high fi audio so thought I would post this here and some brighter minds can help shine some light on this.


Quoting:

"You need to drop these speakers like a hot potato. The whole design concept is flawed and insane.

Now we have a lunatic who has presented a speaker with not just one crossover below 400 Hz but two. (100 Hz and 300 Hz)

Now I have designed speakers for years. I can tell you that there is no way you can make a safe speaker like that, let alone a decent one, with a passive crossover solution. I say that categorically, there is no way. I have to work with the same laws of nature as Polk. To even consider this, which is a bad idea anyway as the crossover points are too close together, you would need at least three amps with active crossovers.

Inevitably the stress on the receiver or power amp are going to be horrendous with passive crossovers with those specs.

There is a very high probability the crossover is actually in resonance, a very bad situation for amps driving them. However if you cobble together a contraption like that, you will be far too stupid to spot a detail like resonance.

Do not connect your receiver to a speaker like that. It will vastly shorten its life, if it has not already.

The cynic in me leaves to believe that now Polk and Denon Marantz are the same company, they are deliberately trying to boost the market for replacement receivers.

The is the most egregious concept for a speaker I have seen to date."

URL:

https://forums.audioholics.com/forums/threads/need-help-with-polk-lsim-705-and-yamaha-rx-2030.115444/

Comments

  • DSkipDSkip Posts: 16,281
    My best advice is to be skeptical of anyone claiming to be an expert unless they have legitimate references. Even then, some ‘experts’ I know are completely misguided and I can’t stand talking anything audio with them.

    If the design of the lsim series was troublesome to amplifiers, don’t you think there’d be a pile of complaints on google?
  • F1nutF1nut Posts: 43,074
    The tlsguy has no idea what he's talking about, none. Even says they aren't 4 ohm loads when in fact they are. BOZO!!!
    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

  • DaveHoDaveHo Posts: 2,490
    I've seen some of the nonsense he's posted over the years, he's an idiot. That said, IMHO the xover freq from MW to the Cassini drivers is too low. I run them full range for music & am always concerned about bottoming out the MW. Enough so that I feel it's holding back what the speaker should be capable of.
  • EmlynEmlyn Posts: 2,528
    edited December 3
    I would not drive a pair of 707s with a receiver unless it was 4 ohm stable anyway. That would be insane and horrendous at high volume.

    Even if the receiver is stable a high current separate amp is recommended. Those speakers were not designed to be run by lightweights, and neither is the new Legend line. A Parasound A23 handles the LSiM line just fine without any unusual heat buildup, although they sound better with an A21.
    1. Polk LSiM707, 704C, 703; Dual SVS SB2000 subwoofers; Marantz SR7011 receiver; Parasound A23 amp; Oppo 205; Sony 65" 4K TV; FIOS; PS Audio Power Plant Premier; MIT S2 cables
    2. JM Labs Electra 920.1; Sonic Frontiers Line 3 Preamp; Classe Model 25 amp; Sony HAP-Z1ES; Oppo 105D; Music Hall MMF7 and Acoustech phono pre; PS Audio Power Director; MIT S1 Cables
    3. Polk LSiM703; Parasound JC2BP and A21; Sony 48" 4K TV; Wyred4Sound DAC 2; Oppo 203; Squeezebox Touch; MIT S3 cables
  • VR3VR3 Posts: 23,550
    Lol...
    - Not Tom

    "No, that's silly talk. Dude, you can't possibly be this audio dumb so quit the act." - Doro
  • msgmsg Posts: 5,045
    Wow, that guy sure is talented with hyperbole. I wonder if he practiced reciting that in the mirror before posting.
    I disabled signatures.
  • mrlorenmrloren Posts: 2,141
    Wow!

    That was a strange read. Polk made the LSiM line for what 9 years? They sold a lot of them over that time, figure there would be many reports on them if they were bad and cooking AVR's.

    One thing I read in that thread is the OP was bi-amping with an AVR, oops. Yeah and wondered why they sounded bad.

    I like my 705's, sound great and have a decent amp powering them.
    When I was a kid my parents told me to turn it down. Now I'm an adult and my kids tell me to turn it down.

    Family Room:
    Samsung UN75RU710DFXZA,
    Denon AVR-X4400H, Emotiva XPA3 GEN3
    Oppo BDP-93,Sony UBP-X800BM, WD Live HUB.
    Main: Polk LsiM 705
    Center: Polk LSiM 704C
    Front High/Rear High In-Ceiling Polk 80F/X RT
    Surrounds: Polk S15
    Sub: HSU VTF3-MK5

    Bed Room;
    Marantz SR5010, BDP-S270
    Main: Polk Signature S20
    Center: Polk Signature S35
    Rear: Polk R15
    Sub: HSU STF-2

    Working Warehouse;
    Sony 2100ES AVR, Sony DVP-NS3100ES for disc
    Cerwin Vega AT-12 (blasters) Advent Prodigy (listening)
    Old sony 12" Sub
    Mini tower PC with 400GB of music
  • MuchiemanMuchieman Posts: 35
    Seriously? Guy’s, AH has a lot of Dealers that hang out on that forum. Most of them won’t even recommend Polk speakers. But yet they’ll surely Chastise anyone that does. There seems to be a hand full that stick together.
  • pitdogg2pitdogg2 Posts: 14,882
    edited December 3
    Muchieman wrote: »
    Seriously? Guy’s, AH has a lot of Dealers that hang out on that forum. Most of them won’t even recommend Polk speakers. But yet they’ll surely Chastise anyone that does. There seems to be a hand full that stick together.

    I actually find most "dealers" will recommend lines that are more profitable to them.
  • mrlorenmrloren Posts: 2,141
    edited December 3
    Muchieman wrote: »
    Seriously? Guy’s, AH has a lot of Dealers that hang out on that forum. Most of them won’t even recommend Polk speakers. But yet they’ll surely Chastise anyone that does. There seems to be a hand full that stick together.

    True it is AH after all. Most people there hate Polk for some reason.

    I was reading a thread where this guy was bragging about having over $20k into his system and only spent $200 on interconnects and speaker wire. Gee wonder how it would sound if he spent a few bucks on some AQ or BJC.

    There was this video from Gene where he was saying all anyone needs is Monoprice cable. Then he pulls out a Pair of Kimber cable the run about $900 a pair.

    When we use to have retail stores I'd go in for a listen. Most of the time sales people would bash Polk, I'd ask why. Almost every time I got a blank look.

    To bash the LSiM like this, a line that sold for years is just obnoxious to say the least. I could see if it was a new line but one that has been out for years. Nope that guy got his little bit of compensation for his little under sized body part (brain that is).
    When I was a kid my parents told me to turn it down. Now I'm an adult and my kids tell me to turn it down.

    Family Room:
    Samsung UN75RU710DFXZA,
    Denon AVR-X4400H, Emotiva XPA3 GEN3
    Oppo BDP-93,Sony UBP-X800BM, WD Live HUB.
    Main: Polk LsiM 705
    Center: Polk LSiM 704C
    Front High/Rear High In-Ceiling Polk 80F/X RT
    Surrounds: Polk S15
    Sub: HSU VTF3-MK5

    Bed Room;
    Marantz SR5010, BDP-S270
    Main: Polk Signature S20
    Center: Polk Signature S35
    Rear: Polk R15
    Sub: HSU STF-2

    Working Warehouse;
    Sony 2100ES AVR, Sony DVP-NS3100ES for disc
    Cerwin Vega AT-12 (blasters) Advent Prodigy (listening)
    Old sony 12" Sub
    Mini tower PC with 400GB of music
  • MuchiemanMuchieman Posts: 35
    pitdogg2 wrote: »
    Muchieman wrote: »
    Seriously? Guy’s, AH has a lot of Dealers that hang out on that forum. Most of them won’t even recommend Polk speakers. But yet they’ll surely Chastise anyone that does. There seems to be a hand full that stick together.

    I actually find most "dealers" will recommend lines that is more profitable to them.

    Well said, it is why I posted up. I just find that the person that said Polk's LSiM line on AH forum would say Polk put out a design a FlagShip line with a flawed design. Polk’s LSiM line has a proven record of Excellent reviews with Pro testing not to mention a lot of very happy customers. If my apartment was bigger I’d surely have a pair of the 705’s sitting in my living room.
  • mpitogompitogo Posts: 364
    I chimed in. Not sure it will help much but someones gotta represent.
    Living Room Music-2.0 Polk L800 | McIntosh C47 | McIntosh MC452 | Denon DP-2500A | Oppo BDP-103 | iTunes Laptop via USB
    Family Room Home Theater-7.2.2 (Atmos) Polk LSiM 707, 706c, Dual DSW microPRO 3000, LSiM 702 F/X [x4], RC65i | Marantz SR7009 | Rotel RB-1590 [FL/FR] | Sony UBP-X800 4K | Xbox One S 4K | AppleTV 4K | HTPC | Sony 75” XBR X850D 4K
    Office Home Theater-5.1 Polk RT55, CS400, PSW450, f/x 500 | Onkyo TX-SR705 | Xbox 360 MCE | AppleTV | Samsung 55”
    Office Music-2.0 KEF Q100 | Sansui AU-6900 | Topping DX7s | Sansui FR-1080
    Master Bedroom Music-2.0 Totem Hawk | McIntosh MA-5200
    Patio Music-2.0 Polk Atrium8 | AMC 2445 bridged
    Airplay zones: Family Room (HDMI), Master Bedroom (Optical), Office (HDMI), Living Room (Optical), SR7009 (AVR direct) and Patio (analog). MacMini iTunes multi-stream to any, combo or all.
    Spares: Polk LSi25, LSiC, CS300, T15, Martin Logan Motion 40, Klipsch RP-600M, Dynamo 500, Rotel RA-1570, Denon AVR-4802R, Onkyo DX-C540, DVP-S500D, PS HX-500, PASS ACA (kit) Class A balanced monoblocks
    Maintenance: Pro-Ject VC-S Record Cleaning Machine
  • vmaxervmaxer Posts: 4,482
    mpitogo wrote: »
    I chimed in. Not sure it will help much but someones gotta represent.

    I had to go read the thread, glad I’m not a member there.

    (That I remember)
    Pio Elete Pro 520
    Panamax 5400-EX
    Sunfire TGP 5
    Micro Seiki DD-40 - Lyra-Dorian and Denon DL-160
    PS Audio GCPH phono pre
    Sunfire CG 200 X 5
    Sunfire CG Sig 405 X 5
    OPPO BDP-83 SE
    SDA SRS 1.2TL Sonicaps and Mills
    Ctr CS1000p
    Sur - FX1000 x 4
    SUB - SVS PB2-Plus

    Workkout room:
    Sony Bravia XBR- 32-Inch 1080p
    Onkyo TX-DS898
    GFA 555
    Yamaha DVD-S1800BL/SACD
    Ft - SDA 1C

    Not being used:
    RTi 38's -4
    RT55i's - 2
    RT25i's -2, using other 2 in shop
    LSI 15's
    CSi40
    PSW 404
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!