Can Monitor 4A's be wired in series?

Dennis47
Dennis47 Posts: 65
edited April 2007 in Speakers
I have an extra set of Polk Monitor 4 Series 2 speakers I would like to
connect to my existing rear surround Monitor 4A speakers. I presently
have a Carver TFM-15 (100 wpc) powering the 4A's on the "A" speaker
curcuit and a Polk SW6 (8-ohm) Subwoofer on the "B" circuit. The amp
is connected to a Carver HR-752 receiver via a Carver Z coupler. This
allows me to adjust the rear speakers and sub volume with the TFM-15
imput level controls. The TFM-15 manual states it is designed for
continuous use with 4-ohm or 8-ohm speaker impedance. If two sets of
speakers at 8-ohm in parrallel represent a 4-ohm total load what is the
impedance of a set of 4A's (8-ohm) and 4 series 2 (8-ohm) in series?
I can have a 4-ohm load on one of the amps speaker circuits as long as
the other circuit is not engaged.

The reason I want to use series wiring rather than parrallel is two-fold:
1) I want to have use of, at least on occassion, the SW6 sub which I
could do by simply disconnecting the speaker wire "jumpers" from the
second set of Monitor 4's.
2) The rear speakers are located in the middle of my living room on stands
behind my sofa and I do not want two additional exposed long speakers
wires to them.

I might mention, typically at the volume these speakers will be played,
the TFM-15 amp meters indicate a very low reading of 03 to 5 wpc load
at 8-ohms.

The other thought I had was to check and see (maybe on the Carver Forum
website) if it is possible to connect both the SW6 sub and the Carvrer Z
coupler/TFM-15 amp to the rear speaker terminals of the receiver.

Anyone have a solution or alternatives to this problem....?????:confused:

Thanks,
Dennis47
PL 4000 II / PL 400 II x2 / PL 5100 II / PL 6000 II
PL 7000 II / PL 1000 w/JDV mod x2 / PL 1100 II
Carver C-1 / C-11 / C-4000t / M-1.0t (MKII opt 002)
M-1.5t x2 / TFM-15 / TFM-22 x2 / TFM-24 x2
TFM-45 x2 / HR-752 / DPL-33 / TD-1400 / TD-1700
TDR-2400 / TX-12 / DTL-100 / SDA-490t
Thorens 316 / Roberts 770X x2 / ADC SS3 MKII
Polk SDA SRS / Polk SDA SRS 2.3 (XO upgrade)
Polk SDA-2B (XO upgrade)
Polk Monitor 12 & Monitor 5jr
Polk Monitor 10B (XO upgrade)
Polk Monitor 7C (XO upgrade)
Post edited by Dennis47 on

Comments

  • heiney9
    heiney9 Posts: 25,217
    edited April 2007
    My biggest question is why? What do you hope to accomplish? It would certainly work from an electrical standpoint, but sonically I don't see how it's going to make much of a difference, unless you are spreading them out along the rear to cover a much larger open space.

    Originally I was picturing them stacked or side-by-side, maybe I have the wrong picture :)

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
  • Dennis47
    Dennis47 Posts: 65
    edited April 2007
    H9,

    The Monitor 4's would be stacked. I am hoping this will expand the vertical
    soundstage on the rears. Another reason is my front channel SDA-2B's and
    front surround channel Monitor 7's overwhelm the single pair of 4A's.

    My goal is to have both pair of monitor 4's and the SW6 sub functioning
    as rear channel speakers operating at the same time with some sort of
    volume control such as I have with the TFM-15 imput level controls.
    The way I calculte it that would be 4-ohms (4A's & 4 series 2 speakers)
    and 8-ohms (SW6 sub), but that is not recommended for this amplifier.

    I'm hesitant to try this connection even at low volume with the TFM-15.
    PL 4000 II / PL 400 II x2 / PL 5100 II / PL 6000 II
    PL 7000 II / PL 1000 w/JDV mod x2 / PL 1100 II
    Carver C-1 / C-11 / C-4000t / M-1.0t (MKII opt 002)
    M-1.5t x2 / TFM-15 / TFM-22 x2 / TFM-24 x2
    TFM-45 x2 / HR-752 / DPL-33 / TD-1400 / TD-1700
    TDR-2400 / TX-12 / DTL-100 / SDA-490t
    Thorens 316 / Roberts 770X x2 / ADC SS3 MKII
    Polk SDA SRS / Polk SDA SRS 2.3 (XO upgrade)
    Polk SDA-2B (XO upgrade)
    Polk Monitor 12 & Monitor 5jr
    Polk Monitor 10B (XO upgrade)
    Polk Monitor 7C (XO upgrade)
  • mhardy6647
    mhardy6647 Posts: 33,998
    edited April 2007
    Two (nominal) 8 ohm speakers in series will give a nominal resultant impedance of 16 ohms.

    It is fine to wire two speakers in series. Your amp (assuming a direct-coupled, SS amp) will deliver less power into the resultant load. Also, remember that all components of the first impedance (inductive, capacitive, and resistive) will be "felt" by the second -- i.e., it may sound different than the same two speakers in parallel.
  • heiney9
    heiney9 Posts: 25,217
    edited April 2007
    I say give it a try, it can't hurt anything. I'd hook 'em in both series and parallel to see if you notice a difference. You may or may not get the result you want.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
  • zingo
    zingo Posts: 11,258
    edited April 2007
    I agree with heiney9. There is no harm in trying. I'm not saying that convention is everything, but if stacks of identical speakers made a big difference, I feel that we would see it more. On the other hand, nothing looks better than a big stack of speakers with the grills off and all those drivers showing their teeth!
  • Dennis47
    Dennis47 Posts: 65
    edited April 2007
    I finally had the chance to experiment with the rear speakers and am
    very satisfied with the results thanks to H9 and mhardy6647. I have
    the 4 series 2's (w/SL1500 tweeters) and the 4A's (w/RDO202-1 tweeters)
    wired in series and the SW6 sub wired in parrallel. I really can't tell any
    difference in the power usage on the Carver TFM-15 amp meters. The
    sound, I assume because of the two different tweeter types, is much
    improved and the vertical soundstage is greatly extended. The results
    are much better than I had hoped for.

    I am using SDA-2B's powered by a Carver M-1.5t for the front channels,
    Monitor 7C's powered by a 100 wpc Carver HR-752 for the front surround
    channels with the Holographic circuit engaged and the above mentioned
    Monitor 4's for the rear surrounds with the ambient control engaged.
    The Polk and Carver sound great together! The soundstage is incredible
    with both sets of front speakers and the rears playing all together. I've
    been thinking about a set of SDA SRA-2.3's or 1.2's bi-amped with
    another Carver M-1.5t. I just can't imagine how good that would sound.
    I just recently acquired the Polk SDA-2B's and Monitor 7C's so I'll just
    take my time enjoying them while I dream about the SDA SRS's.

    Thanks again for the advise. :cool: :cool: :D
    PL 4000 II / PL 400 II x2 / PL 5100 II / PL 6000 II
    PL 7000 II / PL 1000 w/JDV mod x2 / PL 1100 II
    Carver C-1 / C-11 / C-4000t / M-1.0t (MKII opt 002)
    M-1.5t x2 / TFM-15 / TFM-22 x2 / TFM-24 x2
    TFM-45 x2 / HR-752 / DPL-33 / TD-1400 / TD-1700
    TDR-2400 / TX-12 / DTL-100 / SDA-490t
    Thorens 316 / Roberts 770X x2 / ADC SS3 MKII
    Polk SDA SRS / Polk SDA SRS 2.3 (XO upgrade)
    Polk SDA-2B (XO upgrade)
    Polk Monitor 12 & Monitor 5jr
    Polk Monitor 10B (XO upgrade)
    Polk Monitor 7C (XO upgrade)