If you have the choice, which would you choose and why?
Price not in consideration.
Speakers are Harbeth 30.2
Room is 40 square meters.
Open plan rectangular 10 by 4 meters living-room, dining-room and kitchen.
Speakers on long wall In living-room.
2.5 meters to seating position.
2 meters apart.
Music singer songwriter.
Source only Tidal.
thx in advance for the recommendation.
2 questions
Will one amplifier be enough?
Second question.
Maybe you have been reading the tread benchmark vs quad vs hypex.
If not in summary.
In a conversation with mister Alan Shaw, he stated that if I blow up my speaker caused by The amplifier I loose warranty.
Nice speakers!
The Harbeth 30.2 has a sensitivity of 87 dB at 2.828Vrms.
The maximum sinusoidal output of the AHB2 is 28.28 Vrms. This is exactly 20 dB higher than 2.828 Vrms. It is 100 W into 8 Ohms.
The maximum output of the AHB2 in bridged mono is 56 Vrms which is 26 dB higher than 2.828 Vrms. The AHB2 delivers 380 W at 0.0003% THD into 8 Ohms which is almost a 4x increase in power. 1% THD is over 400W.
This means that you can play 6 dB louder in bridged mono with the AHB2 and you will have almost exactly 4 x the power available to drive your speakers.
Let's do the math:
In stereo mode, the AHB2 will drive each speakers to a peak SPL of 87 + 20 = 107 dB SPL at full power at 1 m in an anechoic space.
With two AHB2 amplifiers, the power into each speaker will be almost exactly 4 times as high, and the peak SPL will be almost exactly 6 dB higher. 107 +6 = 113 dB SPL at full power at 1 m in an anechoic space.
As a general rule of thumb, the 1 m anechoic SPL will be close to the SPL that you will experience in your living room when listening to a pair at a normal listening distance. You are further away than 1 m, but listening to two speakers in a partially reflective room. I have found this rule of thumb gives reasonable results.
The crest factor of the music will reduce the average SPL to something that is 12 to 18 dB lower than the maximum sinusoidal level.
Given a crest factor of 8 (moderate mastering), the average level will be 18 dB - 3 dB = 15 dB lower than the maximum sinusoidal level. 107 - 15 = 92 dB SPL (average) for stereo and 113 - 15 = 98 dB SPL (average) for mono. The music power will be ((10^(-15 dB/20))^2)*100 W = 3.16 W stereo and 12.6 W mono.
Given a crest factor of 6 (more aggressive mastering), the average level will be 12 dB - 3 dB = 9 dB lower than the maximum sinusoidal level. 107 - 9 = 98 dB SPL (average) for stereo and 113 - 9 = 104 dB SPL (average) for mono. The music power will be ((10^(-9 dB/20))^2)*100 W = 12.5 W stereo and 50.3 W mono.
As you can see from the calculations, given the relatively high 87 dB sensitivity, you will probably find that stereo operation will give you enough output. Bridged mono will give you an average level of 104 dB SPL with 113 dB SPL peaks when playing pop music. This is very loud.
If you listen to recordings with very little compression (high crest factor), you may want two amplifiers.
The Harbeth 30.2 is rated for music power of up to 150 W, so you are safe, even at a crest factor of 6.
The AHB2 has a protection system that monitors the output of the AHB2. This monitoring system is not in the signal path. It simply shuts the amplifier down if an unsafe event occurs. There are several unique features of this system that protect speakers:
The AHB2 monitors THD and if it exceeds 1%, it shuts the amplifier down to protect the speakers. The AHB2 only produces 0.0003 % THD at full power. The 1% THD protection will only occur when the amplifier is driven into clipping. An over-driven amplifier is the leading cause of tweeter failure. This cannot happen with the AHB2. The THD detection will shut the amplifier down before you damage your tweeters.
The AHB2 monitors the DC output of the amplifier and shuts the output and power supplies down if DC is detected on the speaker outputs. DC can destroy a woofer. If the output stage of an amplifier is damaged, the most common result is DC on the speaker outputs. This can never happen with the AHB2.
The AHB2 electronically mutes on turn on and off. There is no relay in the signal path. There is no risk of damage due to a failed relay. The electronic mute system is also designed to be fail safe.
Other protections include monitoring of the output current and detection of short circuits. The AHB2 is bullet proof and it is designed to provide extraordinary protection for speakers.
If you play a high-amplitude sinusoidal test tone into your speakers, the AHB2 could burn them out. If you play music, you will not be able to cause damage (assuming the 150 W music rating is realistic).