Double 2 channel stereo setup?

If all goes well I will soon have a 1200sqft garage next to my house and I was thinking of what I could use to annoy the neighbors with loud music :)

I've got a pair of RTi12 and RTi38 speakers I thought I could stick in the various corners. The question then became what to drive them with. I've given away all my old receivers and I always wanted to see how nice the RTi12s could sound with some raw power.
I was thinking of wiring both pairs up to a Wyred4sound STI 500 v2 if I can find one used for a good price. The RTi38s say they can take upto 150watts so not sure how close to blowing them out I might come (no huge loss if they go).
Anyone want to talk me out of it?
In use: Polk LSi15s (sub upgrade), LSiC, LSi9s SVS PB 10 ISD connected to Onkyo TX-NR777. VR3 crossover upgrades ordered for fronts and center.
Collecting dust: Polk RTi12s, CSi 6A, RTi38s

Comments

  • learner
    learner Posts: 8
    I am driving two pairs of speakers, RTA12 and B&W DM603 S3 with Marantz PM8004 integrated amp which has A/B speaker capability. I mostly run the B&W alone, occasionally running both depending on the type of music and recording.
  • F1nut
    F1nut Posts: 49,708
    aggie113 wrote: »
    If all goes well I will soon have a 1200sqft garage next to my house and I was thinking of what I could use to annoy the neighbors with loud music :)

    I've got a pair of RTi12 and RTi38 speakers I thought I could stick in the various corners. The question then became what to drive them with. I've given away all my old receivers and I always wanted to see how nice the RTi12s could sound with some raw power.
    I was thinking of wiring both pairs up to a Wyred4sound STI 500 v2 if I can find one used for a good price. The RTi38s say they can take upto 150watts so not sure how close to blowing them out I might come (no huge loss if they go).
    Anyone want to talk me out of it?

    Stupid is as stupid does.
    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

  • codycatalist
    codycatalist Posts: 2,662
    If you're going for loud you'd probably get it with your idea. I'm not against it.

    Will it be the best sounding or placed system... No but we don't always want that and it sounds like you just want loud sound.

    Keep an eye out for cheap Cerwin Vega too, now those speakers can get loud.
    Just a dude doing dude-ly things

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  • mhardy6647
    mhardy6647 Posts: 32,926
    edited August 2019
    I don't quite get what the OP wants to do -- if the goal is two-channel stereo with four speakers, I would think :p that the best solution would be to use one stereo preamp and split the output to two appropriately capable power amps.

    Something like the 'serving suggestion' in this old Heathkit catalog (the one at the bottom right). This is a 'quad' (four-channel) preamp, but one could do the same thing with a stereo preamp. Indeed, many stereo preamps have dual outputs to drive two stereo power amps :)

    12590982023_ffe212c1bf_b.jpgmodulus by Mark Hardy, on Flickr


    This is the Heathkit AA-1640 power amp of the mid-1970s (FWIW).

    9954266836_6020350e4b_b.jpgAA-1640 by Mark Hardy, on Flickr
  • learner
    learner Posts: 8
    Marantz PM8004,5,6 have A/B speaker feature. You can run both simultaneously. Has more than enough power to rock you garage.
  • Kex
    Kex Posts: 4,892
    learner wrote: »
    Marantz PM8004,5,6 have A/B speaker feature. You can run both simultaneously. Has more than enough power to rock you garage.
    Many receivers have A/B capability, but they still have the exact same power source available for A+B as they would with only A capability (usually, there’s only a single power transformer, with very few exceptions).
    Alea jacta est!
  • mhardy6647
    mhardy6647 Posts: 32,926
    edited August 2019
    Kex wrote: »
    learner wrote: »
    Marantz PM8004,5,6 have A/B speaker feature. You can run both simultaneously. Has more than enough power to rock you garage.
    Many receivers have A/B capability, but they still have the exact same power source available for A+B as they would with only A capability (usually, there’s only a single power transformer, with very few exceptions).

    And actually it's worse than that because traditionally/historically, the A/B/A+B speaker selectors will connect both sets of speakers in parallel. The load impedance of A + B speakers connected in parallel will be the reciprocal of (the sum of the reciprocal impedance of the "A" speaker systems + the reciprocal impedance of the "B" speaker systems); i.e., Ztotal = 1/(1/Za + 1/Zb).

    So... if the "A" speakers have a nominal impedance of 8 ohms and the "B" speakers have a nominal impedance of 8 ohms, the nominal load (Ztotal in my little equation above) seen by the amp with A+B speakers in parallel is 4 ohms. If A is 8 ohm and B is 4 ohm, then Ztotal = 1/(1/8 + 1/4)= 1/(3/8) = 8/3 = 2.67 ohms

    See where this is going? No place good, unless the amplifier in question is designed and built to handle low impedance loads without self-immolation. :/

    ... and it's actually even a bit worse than that, because the impedance of almost all real-world loudspeakers varies with frequency, and the nominal impedance is rarely the minimum impedance. If the minimum impedance of a loudspeaker occurs in the mid-bass region, it can be harder still on any given amplifier than the nominal impedance rating might lead one to believe.

    :|

  • mhardy6647
    mhardy6647 Posts: 32,926
    edited August 2019
    Here's a classic hard to drive loudspeaker, for example -- the Infinity IRS Beta :p
    https://www.stereophile.com/content/infinity-irs-beta-loudspeaker-measurements

    Two sets of these in parallel on most stereo receivers or amplifiers would be pretty much guaranteed to be fatal to the receiver/amp in question. B)

    id3z2w9656d7.png
    "Fig.1 Infinity IRS Beta, impedance magnitude of woofer tower (top above 500Hz) and midrange/treble panel (2 ohms/vertical div.)"

    c5amfmehffbu.png
    (borrowed image :) )
  • Kex
    Kex Posts: 4,892
    mhardy6647 wrote: »
    Kex wrote: »
    Many receivers have A/B capability, but they still have the exact same power source available for A+B as they would with only A capability (usually, there’s only a single power transformer, with very few exceptions).

    And actually it's worse than that because traditionally/historically, the A/B/A+B speaker selectors will connect both sets of speakers in parallel. The load impedance of A + B speakers connected in parallel will be the reciprocal of (the sum of the reciprocal impedance of the "A" speaker systems + the reciprocal impedance of the "B" speaker systems); i.e., Ztotal = 1/(1/Za + 1/Zb)...
    :s I’ll take your word for it! :D:#:p
    Alea jacta est!
  • It is a metal garage (wood framing) so sound quality isn't critical. Power is more for driving the speakers loud without distortion hurting them. Amp has been purchased already now, so now looking at something like a Bluesound node 2i for providing access to most of the music. If I'm truly in danger of killing the amp or hurting the speakers by driving them at 4ohms instead of their rated 8 by running them together than I'm sure I could get by with just the RTi12's... I'm not really sure if that's what garnered the "stupid is as" comment as the poster seemed happy to just roll that grenade in and leave.
    In use: Polk LSi15s (sub upgrade), LSiC, LSi9s SVS PB 10 ISD connected to Onkyo TX-NR777. VR3 crossover upgrades ordered for fronts and center.
    Collecting dust: Polk RTi12s, CSi 6A, RTi38s
  • BlueFox
    BlueFox Posts: 15,251
    aggie113 wrote: »
    If all goes well I will soon have a 1200sqft garage next to my house and I was thinking of what I could use to annoy the neighbors with loud music :)

    1200 square foot garage! That’s bigger than my house. Why use cheap speakers in such a mansion?

    Lumin X1 file player, Westminster Labs interconnect cable
    Sony XA-5400ES SACD; Pass XP-22 pre; X600.5 amps
    Magico S5 MKII Mcast Rose speakers; SPOD spikes

    Shunyata Triton v3/Typhon QR on source, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • F1nut
    F1nut Posts: 49,708
    I didn't leave.
    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

  • mhardy6647
    mhardy6647 Posts: 32,926
    edited August 2019
    F1nut wrote: »
    I didn't leave.

    @F1nut never leaves B)
    aggie113 wrote: »
    It is a metal garage (wood framing) so sound quality isn't critical. Power is more for driving the speakers loud without distortion hurting them. ...

    IF that's the goal, I would throw my support behind the notion expressed by
    codycatalist Get yourself some high-sensitivity loudspeakers and go crazy.

    Personally, I'd steer well clear of Cerwin-Vegas, though -- they're pretty awful sounding loudpeakers (relative to my taste), with very few exceptions. Loud, though -- yes, indeedy.

    A 1200 ft^2 space would be ideal for, e.g., a pair of Klipsch LaScalas or Altec Nineteens (or, even better, Altec A5 or A7 Voice of the Theaters). Big JBLs would also not be inappropriate.

    Use the right tool for the job.

  • Viking64
    Viking64 Posts: 6,646
    edited August 2019
    This is one of the few home audio occasions where I would recommend a Crown amp. :p
  • Viking64 wrote: »
    This is one of the few home audio occasions where I would recommend a Crown amp. :p

    And JBL pa speakers.
    2 channel: Anthem 225 Integrated amp; Parasound Ztuner; TechnicsTT SL1350; Vincent PHO-8 phono pre; Marantz CD6005 spinner; Polk SDA2BTL's; LAT International speaker cables, ZU Mission IC's and power cables all into a PS Audio Dectet Power center.

    Other; M10 series II, M7C's, Hafler XL600 amp, RB-980BX, Parasound HCA-1500 amp , P5 preamp, all in storage. All vintage Polk have had crossover rebuilds and tweeter upgrades.

    The best way to predict the future is to invent it.

    It is imperative that we recognize that an opinion is not a fact.

    Imagine making politics your entire personality.
  • mhardy6647
    mhardy6647 Posts: 32,926
    edited August 2019
    Viking64 wrote: »
    This is one of the few home audio occasions where I would recommend a Crown amp. :p
    Viking64 wrote: »
    This is one of the few home audio occasions where I would recommend a Crown amp. :p

    And JBL pa speakers.

    Now yer talkin'.

    14306081432_c5bf0732a4_b.jpgdumpdivehifi by Mark Hardy, on Flickr

    Actually a DC-300 would be even better, but I don't have one of those.
    No JBL monitors, either :p

    On the other hand, for a big garage, there's always the nuclear option. :)
    https://www.behringer.com/Categories/Behringer/Power-Amplifiers/Portable/NX6000D/p/P0CHX#googtrans(en|en)


    y39eecnxszgy.png

    avfsqzfg0kyw.png

  • mdaudioguy
    mdaudioguy Posts: 5,165
    In my modest 400-ish square foot garage, I have a pair of Polk Monitor 10 speakers driven by a vintage Pioneer Elite stereo integrated amp, and it's more than enough. I'd dare say it'd fill a garage twice the size..., maybe even thrice.
  • learner
    learner Posts: 8
    mhardy6647 wrote: »
    Kex wrote: »
    learner wrote: »
    Marantz PM8004,5,6 have A/B speaker feature. You can run both simultaneously. Has more than enough power to rock you garage.
    Many receivers have A/B capability, but they still have the exact same power source available for A+B as they would with only A capability (usually, there’s only a single power transformer, with very few exceptions).

    And actually it's worse than that because traditionally/historically, the A/B/A+B speaker selectors will connect both sets of speakers in parallel. The load impedance of A + B speakers connected in parallel will be the reciprocal of (the sum of the reciprocal impedance of the "A" speaker systems + the reciprocal impedance of the "B" speaker systems); i.e., Ztotal = 1/(1/Za + 1/Zb).

    So... if the "A" speakers have a nominal impedance of 8 ohms and the "B" speakers have a nominal impedance of 8 ohms, the nominal load (Ztotal in my little equation above) seen by the amp with A+B speakers in parallel is 4 ohms. If A is 8 ohm and B is 4 ohm, then Ztotal = 1/(1/8 + 1/4)= 1/(3/8) = 8/3 = 2.67 ohms

    See where this is going? No place good, unless the amplifier in question is designed and built to handle low impedance loads without self-immolation. :/

    ... and it's actually even a bit worse than that, because the impedance of almost all real-world loudspeakers varies with frequency, and the nominal impedance is rarely the minimum impedance. If the minimum impedance of a loudspeaker occurs in the mid-bass region, it can be harder still on any given amplifier than the nominal impedance rating might lead one to believe.

    :|

    I have no problem driving pairs of B&W DM603 S3 and RTA12C with Marantz PM8004 at high volume.
  • No one seems to care at this point, but the hardware is already set.
    In use: Polk LSi15s (sub upgrade), LSiC, LSi9s SVS PB 10 ISD connected to Onkyo TX-NR777. VR3 crossover upgrades ordered for fronts and center.
    Collecting dust: Polk RTi12s, CSi 6A, RTi38s
  • mhardy6647
    mhardy6647 Posts: 32,926
    edited August 2019
    aggie113 wrote: »
    No one seems to care at this point, but the hardware is already set.

    Well, if all of the hardware's set, you've got what you're gonna get, sort of by definition.

    EDIT: It seems to me that you asked for advice, you got advice, and you're not particularly interested in (or convinced by) the advice you got here. That's certainly your prerogative, but at this point I'd opine that you are pretty much on your own. Good luck & have fun!


    Post edited by mhardy6647 on