Hello everyone! It has been a while.

Last time I was here, I had just replaced the (2x) EL-70 drivers in my Planet10 microTowers with (2x) Pluvia 7.2HD. At the time, I had trouble deciding whether to go with series or parallel wiring. The EL-70s were nominal 4ohm, so I originally went with series wiring for nominal 8 ohm total. However, the Pluvias are nominal 6 ohm, so I had the conundrum of choosing 12 ohms (series) or 3 ohms (parallel).

Ultimately I chose the lazy way (12ohms, series) because the speakers were already wired that way and my Tubelab SSE has 4, 8 and 16 ohm taps (went with the 16 ohm taps and it sounds excellent).

Trouble is, now these speakers do not get along at all with my "Wiener" TPA 3118 Amp. When I ordered it, I selected the 4 ohm output filter configuration and it is fairly well-known that the results can be pretty terrible if these amps are played with inappropriate speaker loads, especially such a massive mismatch of 4 ohms vs. 12 ohms and especially when the rising impedance curve of these "naked" drivers makes matters in the top end exponentially worse for the Wiener (not so much for the SET!). This isn't just theoretical - it sounds horrific.

gmarsh, designer and builder of the "Wiener", concluded that a Zobel is a fantastic addition to flatten the impedance and help get the best from the Wiener. I grabbed his code from that post and started playing with it in GNU Octave. (Thanks Gary!) The only way forward to get these speakers to work with the Wiener Amp is to go for parallel wiring, and I might as well add the Zobel while I am at it. The simulations I have done in GNU Octave, with some help from an online Zobel calculator have made this all pretty straightforward.

Question #1: The Pluvia 7HDs wired in parallel will have an ReVc of 2.7 ohms (nominal 3 ohms impedance). This will not be ideal for the 4 ohm tap on my SET, nor the 4 ohm target load of the Wiener Amp.

Question #2: Right now the naked speakers running in series (12 ohms nominal, no Zobel) are a very nice match with my SET.

Any feedback will be very much appreciated! Thanks.

Last time I was here, I had just replaced the (2x) EL-70 drivers in my Planet10 microTowers with (2x) Pluvia 7.2HD. At the time, I had trouble deciding whether to go with series or parallel wiring. The EL-70s were nominal 4ohm, so I originally went with series wiring for nominal 8 ohm total. However, the Pluvias are nominal 6 ohm, so I had the conundrum of choosing 12 ohms (series) or 3 ohms (parallel).

Ultimately I chose the lazy way (12ohms, series) because the speakers were already wired that way and my Tubelab SSE has 4, 8 and 16 ohm taps (went with the 16 ohm taps and it sounds excellent).

Trouble is, now these speakers do not get along at all with my "Wiener" TPA 3118 Amp. When I ordered it, I selected the 4 ohm output filter configuration and it is fairly well-known that the results can be pretty terrible if these amps are played with inappropriate speaker loads, especially such a massive mismatch of 4 ohms vs. 12 ohms and especially when the rising impedance curve of these "naked" drivers makes matters in the top end exponentially worse for the Wiener (not so much for the SET!). This isn't just theoretical - it sounds horrific.

gmarsh, designer and builder of the "Wiener", concluded that a Zobel is a fantastic addition to flatten the impedance and help get the best from the Wiener. I grabbed his code from that post and started playing with it in GNU Octave. (Thanks Gary!) The only way forward to get these speakers to work with the Wiener Amp is to go for parallel wiring, and I might as well add the Zobel while I am at it. The simulations I have done in GNU Octave, with some help from an online Zobel calculator have made this all pretty straightforward.

Question #1: The Pluvia 7HDs wired in parallel will have an ReVc of 2.7 ohms (nominal 3 ohms impedance). This will not be ideal for the 4 ohm tap on my SET, nor the 4 ohm target load of the Wiener Amp.

**Should I add an extra 1 ohm of resisance?**(could be accomplished by adding a 2 ohm 10W resistor in series with each driver).Question #2: Right now the naked speakers running in series (12 ohms nominal, no Zobel) are a very nice match with my SET.

**Will rewiring as proposed and adding a Zobel screw that all up?**Any feedback will be very much appreciated! Thanks.

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