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TORII with Headphones and Harbeth Speakers (Read 1699 times)
Steve Deckert
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If the 1st watt
sucks why continue?

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TORII with Headphones and Harbeth Speakers
05/23/17 at 23:43:36
 
Quote:
OK, so I'm interested in the Torii MKIV for a rig driving Harbeth P3ESR. I have only one stumbling point... To have all the functionality I desire (in a home office) I would need either a preamp output (to connect to an external headphone amp) or a headphone 1/4" jack itself. That is, I want both my sources (DAC and Turntable) connected to both of my transducers (speakers and headphones).

Could this be accommodated?

Thanks!


Thank you for asking!  Two problems... MKIV has too much power for good headphone jack performance and too little power for Harbeth speakers which when converted to a 1 watt / 1 meter sensitivity are about 81dB.  That's 10dB below the recommended minimum.  Below is the performance with the Harbeth/Torii MK IV combination.

1 watt =     81dB @ a distance of 1 meter.
2 watts =   84dB
4 watts =   87dB
8 watts =   90dB
16 watts=  93dB
25 watts=  95dB.

For every meter of distance greater than 1 meter, subtract 3dB.


An alternative approach would be using the 4 watt Mini-Torii with headphone jack paired with the DM945/6 speakers.

1 watt =     94dB @ a distance of 1 meter
2 watts =    97dB
4 watts =   100dB

The last Mini Torii that went out replaced an Audio Note 300B amplifier driving similarly efficient Audio Note speakers and the owner is quite happy.  The DM945/6 speakers are over twice as fast as the Harbeth with the same silky smooth tone, so they too could be an upgrade.

Thanks,

Steve
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Robcan
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Re: TORII with Headphones and Harbeth Speakers
Reply #1 - 07/22/17 at 22:19:56
 
Hi,
Some questions about this thread, if I may?
1) What is meant by "fast" ?
2) I have a pair of B&W 802 D ( the version just superceded ) with a sensitivity of 90 db. Used in a room approx 20 ft long x 12 ft wide, vaulted ceiling.
I rarely play above 1/4 volume with a Bryston 3B NRB 120 wpc. AR LS15 preamp.

If I understand your amp selection chart the Torii Jr or Mk 4 would be sufficient.

However, B&W recommend a minimum of 50 wpc? I realize I am likely only using 15 to 20 wpc during most listening, so, why need a 50 to 500 wpc?

One of my first stereo systems was Telefunken V250 25 wpc class A amp, into 4 ohms, driving a pair of very efficient Telefunken speakers.

I had amazing sound from that system in the 70's.

Thanks
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Steve Deckert
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If the 1st watt
sucks why continue?

Posts: 3369
Re: TORII with Headphones and Harbeth Speakers
Reply #2 - Yesterday at 04:20:10
 

Fast is the time it takes for the speaker cone to change direction.  The higher the mass of the cone, the harder it will be to stop it from moving in one direction and start it moving in the opposite direction.  Efficient speakers have cones that are low in mass, in extreme cases almost 10 times lower.

A high mass cone requires an amplifier with a lot of power and damping (negative feedback) to help control the cone from overshoot.

There are only two reasons for high mass speakers cones.... makes the driver resonate in a small box and has less peaky response or is more immune to colorations from the enclosure due to the the damping effect of thicker cone material. It's the easy way out.

Part of the speaker power recommendation could come from losses in the crossover that are hard to resolve on paper, and or the damping factor needed to keep the speaker from sounding muddy in the bass.  This damping factor is typically found in push-pull amps with negative feedback in the 50watt or higher range.


-Steve


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Robcan
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Re: TORII with Headphones and Harbeth Speakers
Reply #3 - Yesterday at 23:41:20
 
Thank you for your information.

In the interim, I purchased a Mark Levinson 532H, 300 wpc.

The reasons for this are:

1) extremely good reviews, on both private sites and "advertiser driven"

2) a damping factor of 4000

3) comments from others who have my exact speakers in their system, and have experimented with numerous amps

I can say that I am listening to my collection of music, some of which I bought on vinyl over 40 years ago, and I hear background instruments and voices that are new to me. The voices often surprise me with their lifelike sound, and I can easily understand many lyrics that, on further thought, I realize I could not understand due unless I focused.

I assume the damping factor is a major factor.

I will be biwiring my speakers next, I think I have picked the low hanging fruit..
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Lin
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Re: TORII with Headphones and Harbeth Speakers
Reply #4 - Today at 17:00:50
 
"I assume the damping factor is a major factor."

Anything above 20 is meaningless. Smiley

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