Quicksilvers 120s with kt150s
Amplifier recommendations for 86 dB Sensitivity Speakers
Hi,
I’m considering a pair of Technics SB-G90M2, they have good specifications on paper; however, my only concern would be their 86 dB sensitivity.
My current amplifier is Cayin A100t, which according to its specs, outputs 70 watts into 8ohms. the Technics are 4 Ohms; so, I assume my Amp could deliver 100-140 Watts into 4 Ohms. Unfortunately, I couldn’t find more accurate information about my amplifier, and it only shows the output power at 8 Ohms equipped with KT-88 output tubes (mine came with EL-34s), therefore, it’s unclear what the real output powerat 4 ohms is.
Wondering if this tube amplifier would be a good match for these more demanding 86 dB speakers? I’m aware of impendence fluctuations and I know the Amp can drive them just fine, but I am not sure if 100 watt per channel -assuming that’s what my Amp can deliver into 4 Ohms- would be enough for these speakers to make them sound as intended, meaning, good sound quality.
(I don’t nor am planning to listen at high volume but have a larger room with high ceilings).
Below are the specs.
Many thanks,
Technics SB-G90M2 Speakers
- Type: 3-way floorstanding speaker with bass reflex
- Woofer: 2 x 16 cm
- Midrange: 16 cm
- Tweeter: 2.5 cm
- Sensitivity: 86 dB
- Impedance: 4 ohms
- Frequency range: 33 Hz – 90 kHz (-10 dB)
- Crossover frequencies: 500 Hz, 3400 Hz
- Maximum power handling: 200 W
- Recommended amplifier power: 40-200 W
- Dimensions and weight: 111.4 x 29.2 x 36.6 cm / 35 kg
Cayin A100T Integrated Tube Amplifier
Power output: 70 watts per channel into 8Ω (stereo)
Frequency response: 10Hz to 65kHz
Total harmonic distortion: 1%
Input sensitivity: 480mV (line)
Signal to noise ratio: 89dB (line)
Speaker load impedance: 4Ω to 8Ω
Valve complement: 8 x KT88, 2 x 12AU7, 2 x 6CG7, 1 x 12AX7
Dimensions: 440 x 210 x 397mm
Weight: 29kg
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- 46 posts total
Importantly and often overlooked is the profile of the impedance curve. These curves can vary typically from 2 to 25 ohms across the entire frequency range.
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I would not consider the speakers that you mention, 86db at 4 ohms is really hard to drive.....as so many have already mentioned. It would greatly limit your amplifier options now and into the future. You would need bigger, high current, high wattage, expensive amplifiers......and basically eliminating tube amplifiers unless you own a Brinks truck full of cash. There are literally many dozens of amazing speakers that would be better choices in that price range. Spend $5,000 or $6,000 on speakers, and you'll most likely save much more |
@retiredaudioguy Its important to keep in mind your numbers reflect a distance of 1 meter. |
@atmasphere You make a very good point. That got me wondering about the "real world" drop off. A point source, in free space, will be subject to an inverse square law reduction in intensity. My listening point is about 4 metres from the speakers so that would imply a 12dB reduction. I did an experiment. To avoid issues from there being two speakers I disconnected the right speaker (with the amp OFF) and hooked up a 4 ohm 25 watt resistor and played an A4 (441 Hz) test tone WAV file at an upper mid volume level of 80dB at 1 metre. Free space, point source calculation would then predict 68dB at my seat. The measured spl was about 76dB. I tried this at various frequencies and waveforms and there were differences from frequency dependent room reflections etc. and found drops of about 3 to 6 dB. My room is untreated but probably has typical reflectivity, so I suspect that as a rule of thumb one can subtract 4dB from the stated efficiency of speakers and have some approximation of dB/watt at 12 feet. |
- 46 posts total