Review and Measurements of Benchmark AHB2 Amp

[sandeep_s300]

Wowzer... When recording the audio from a transducer (Microphone.) and then playback through a second transducer (Headphone or speaker.) the audio is changed.

So what? the recording of both A and B track is using the same microphone and listening using the same headphone . Both A and B should sound the same. Are they same or they aren't - that answer is the key to decision making and drawing conclusion .

 

[sandeep_s300]

It seems like a good approach: you can level match very precisely after the fact and use an automated ABX software to avoid any sighted bias. Be sure to always use the same playback conditions (same sound level, same speaker, same mic position and settings, etc.) not to introduce any other variables.

I am however wondering how good the recording side (mic, ADC, etc.) has to be in order to capture the very small differences that the two amplifiers may introduce?

I guess that apart of corner cases (e.g., close to saturation) there should be no to very little audible differences. I fear that the latter will be difficult to capture.

[edited typos]

Yes, when I do, it's late night after kids goto bed 75DB decibel listen and also record in parallel. The quality of microphone doesn't matter .. use iPhone if you don't have any professional mic .. it even picks up if someone has touched my door .. The key to it is , keep everything same and the only change factor should be the one that you are comparing. Oh , trust me, even with iPhone mic you can pick difference , if there is any difference. I could pick difference in female vocalist texture of her breath between the two recordings using two different components.

 

[gfinlays]

Does anyone tried the benchmark speaker cables (speakon) ? Just want to know your findings about them.

I haven't tried them per se, but I made my own cables using the Neutrik Speakons that Benchmark uses with the same Canare 4S11 cable. I build my own speakers, so have the Speakons at both ends. Very quick, easy, reliable connection. I much prefer them over bananas/spades/bare wire.

The 4S11 is a technically excellent cable with moderate capacitance and vanishingly low inductance due to its construction.

 

[antcollinet]

So what? the recording of both A and B track is using the same microphone and listening using the same headphone . Both A and B should sound the same. Are they same or they aren't - that answer is the key to decision making and drawing conclusion .

The problem is the difference between amps (forget about cables - there is nothing to detect) will be zero or so small it is almost impossible to hear - assuming you are not driving them into clipping.

It is almost impossible for a microphone and then additional transducers to reproduce those tiny differences in any sensible audible way through the additional distortion and noise of those devices.

 

[sandeep_s300]

The problem is the difference between amps (forget about cables - there is nothing to detect) will be zero or so small it is almost impossible to hear - assuming you are not driving them into clipping.

It is almost impossible for a microphone and then additional transducers to reproduce those tiny differences in any sensible audible way through the additional distortion and noise of those devices.

Have you tried it? Try it first and then let me know

All of us who participate (just within like minded friends ) , can pick differences .

I do agree with you that minor details won’t be captured and there will be loss of information . That is the trade off we do make to keep placebo effect , emotional bias out.

Also, when we do this test, it is basically to determine what stays and what goes to used market for sale . In Australia , we don’t have 30 days risk free trial system . So we can’t test anything in our own room , and as we all know what we hear in dealer showroom doesn’t prove anything by a big margin.

 

[Doodski]

So what? the recording of both A and B track is using the same microphone and listening using the same headphone . Both A and B should sound the same. Are they same or they aren't - that answer is the key to decision making and drawing conclusion .

I meant they both are changed and don't sound like the original.

 

[SIY]

Have you tried it? Try it first and then let me know

I've done a LOT of work with top quality mics and recording. Trying to use one to detect amplifier "differences" is like using a yardstick to measure a bacterium. If you want to use a recording technique, then level-match and blind test the differences, the right way to do it is to record the electrical signal at the speaker terminals (you can do that with any good ADC or interface, just use a two resistor voltage divider to keep the recorded voltages within the ADC range). Once you've captured the files, then use a program like DeltaWave. It can level match, time align, and allow you to do an ABX comparison.

 

[antcollinet]

Have you tried it?

Have you? Properly level matched and blind using something like deltawave?


Come back and try to convince me of your golden ears, and golden mics, when you have.

 

[sandeep_s300]

Have you? Properly level matched and blind using something like deltawave?


Come back and try to convince me of your golden ears, and golden mics, when you have.

And will I be rewarded after spending hours of my time to convince you? Will you fund my effort ? You asked me have you? Yes I have - countless times and we find the difference where there is a difference . Period.

My ears , my equipment, my budget , my test method , my results lol. If you haven’t don’t like to like on how I have done , then no point banging on the keyboard as it will achieve nothing for any of us .

 

[SIY]

And will I be rewarded after spending hours of my time to convince you? Will you fund my effort ? You asked me have you? Yes I have - countless times and we find the difference where there is a difference . Period.

My ears , my equipment, my budget , my test method , my results lol. If you haven’t don’t like to like on how I have done , then no point banging on the keyboard as it will achieve nothing for any of us .

I've given you the basic outline of how to test whether your perceptions are accurate. It's up to you to do it- if you decide to try to do a good experiment with basic ears-only controls, you'll get lots of help and support here.

 

[antcollinet]

And will I be rewarded after spending hours of my time to convince you? Will you fund my effort ? You asked me have you? Yes I have - countless times and we find the difference where there is a difference . Period.

My ears , my equipment, my budget , my test method , my results lol. If you haven’t don’t like to like on how I have done , then no point banging on the keyboard as it will achieve nothing for any of us .

What effort are you expecting? Once you've done the recordings, it is "a few simple keystrokes" in deltawave to level match and ABX them.

My ears , my equipment, my budget , my test method

Fine - but if you use comparisons improperly controlled/blinded, then don't ask us to

trust me, even with iPhone mic you can pick difference

 

[sandeep_s300]

What effort are you expecting? Once you've done the recordings, it is "a few simple keystrokes" in deltawave to level match and ABX them.

The levels are matched pre recording . When can hear the difference in simplistic way, there is no point going next level to find more . Remember , I don’t have to go so deep as end user . Enjoy the music the way one perceives - it’s more biology and chemistry involved than just physics here In ASR people just looks through everything by the logics of physics . Anyway — I landed here to read the page 1 measurement before making the purchase and got into this thread . Out of here .

 

[sandeep_s300]

What effort are you expecting? Once you've done the recordings, it is "a few simple keystrokes" in deltawave to level match and ABX them.



Fine - but if you use comparisons improperly controlled/blinded, then don't ask us to

No one asked - scroll up. I said what I have plans to do and asked one question - about the benchmark speaker cables and speakon. Not sure why people has to respond everything else but not to what was asked and consume ASR bandwidth , storage and lengthy threads

 

[antcollinet]

The levels are matched pre recording

If by ear - or even acoustic dB meter - this is insufficiently accurate.

No one asked

Isn't that your post I quoted?

Not sure why people has to respond everything else but not to what was asked and consume ASR bandwidth , storage and lengthy threads

Because what we are primarily concerned with at AscienceR is promoting the evaluation of gear in scientifically valid ways.

 

[Frank Dernie]

My ears , my equipment, my budget , my test method , my results lol. If you haven’t don’t like to like on how I have done , then no point banging on the keyboard as it will achieve nothing for any of us .

Why did you ask a question from experienced and knowledgeable people then?

 

[yanm]

It is maybe good to explain @sandeep_s300 why the suggestions of knowledgeable members are key.

• Very precise level matching: our brain interprets small differences in sound level (say below 0.1 - 0.2 dB) not as difference in volume but as a difference in quality. The very slightly louder recording will be perceived as higher quality, better defining, etc, when in reality it is indeed only very slightly louder.
• On loudspeaker => mic approach: (I) both transducers are prone to high level of distortion (compared to a solid state amplifiers), which will likely mask any distortions coming from the amp, (II) modern amp and DAC are so quiet that ambiant noise (and mic own noise) is likely the parameter that will define the noise floor. In both cases, this has nothing to do with what you want to test (the amps).

In my opinion, improper level matching is often the main reason people hear “clear” difference between modern amps or DACs. When there are actual differences they should be very very small.

Hope this helps. Anyway, good luck with the tests and have fun!

 

[yanm]

No one asked - scroll up. I said what I have plans to do and asked one question - about the benchmark speaker cables and speakon. Not sure why people has to respond everything else but not to what was asked and consume ASR bandwidth , storage and lengthy threads

Our host tested both binding posts and SpeakOn connectors / cables, see https://www.audiosciencereview.com/...hmark-ahb2-review-updated-measurements.50844/. The SpeakOn cables have slightly better measurements but this will make no audible difference whatsoever (as it should be with any decently gauged cable and proper connectors).

 

[sandeep_s300]

What effort are you expecting? Once you've done the recordings, it is "a few simple keystrokes" in deltawave to level match and ABX them.



Fine - but if you use comparisons improperly controlled/blinded, then don't ask us to

is there an alternative to delta wave that can be used in Mac OS?

 

[yanm]

is there an alternative to delta wave that can be used in Mac OS?

People have reportedly successfully run deltawave on Linux using Wine. It could be worth trying wine + deltawave on MacOS… it’s a very long time since I’ve used Wine / crossover on my Mac, so I don’t know if this still work with modern MacOS.

 

[gfinlays]

The SpeakOn cables have slightly better measurements but this will make no audible difference whatsoever (as it should be with any decently gauged cable and proper connectors).

Definitely no audible difference, but the Speakons are very easy to connect/disconnect and they do look nice if you dig the slightly "industrial" aesthetic: