JBL 708P Review (Professional Monitor)

[Flaesh]

lol

BTW thank you again for this recording))

did you try the Youtube?

I won’t be able to compare in the foreseeable future

 

[Frank Dernie]

In the early days of CD HiFi News did a CD sampler with music samples and test tracks. @John Atkinson was still editor I think.
One of the tracks was called “the dynamic range of real life” iirc. The microphone was set up inside a roller-shutter garage and started with the tester talking outside. He then banged on the roller shutter door which was shockingly louder.

It is a fun disc, must look for mine…

 

[Flaesh]

IIRC member @gnarly tapped the plate with a fork and got high results; when I repeated the experiment, I got lower values; I forgot the exact numbers, sorry.

 

[JimWeir]

And show me! Do we have a thread on the forum about music recordings that have significant dynamic range?
We sometimes listen to Danley's https://www.danleysoundlabs.com/tom-danleys-mic-recordings/ and Katz's https://www.digido.com/portfolio-item/we-have-lift-off-now-in-surround/ with great pleasure, but that's not music

Here are two examples.

 

[JimWeir]

In the early days of CD HiFi News did a CD sampler with music samples and test tracks. @John Atkinson was still editor I think.
One of the tracks was called “the dynamic range of real life” iirc. The microphone was set up inside a roller-shutter garage and started with the tester talking outside. He then banged on the roller shutter door which was shockingly louder.

It is a fun disc, must look for mine…

Note that the brain doesn’t decode the maximum dynamics. Media like LP and Tape FM radio forced a limit on crest factor (the peak to RMS ratio. But even the essentially unlimited range of digital media has practical limiting used. Film and Broadcast industries have set the RMS loudness level at -18 or -20 dB full scale. With the digital format hard limited at 0dB (and practically -0.1 dB) leaving the maximum crest factor at the loudest portions of the recording at a 10:1 ratio.

 

[Ron Texas]

In the early days of CD HiFi News did a CD sampler with music samples and test tracks. @John Atkinson was still editor I think.
One of the tracks was called “the dynamic range of real life” iirc. The microphone was set up inside a roller-shutter garage and started with the tester talking outside. He then banged on the roller shutter door which was shockingly louder.

It is a fun disc, must look for mine…

We just call "roller shutters" garage doors because it's rare that anything else is used.

 

[RCAguy]

How could it not be? Distortion is a static measurement.

Generally I think distortion measurements are near worthless. Rate of change of distortion with increasing level may be more interesting, but nobody does that.

Distortion a “static,” “worthless” measurement? Not if the listener has the experience to relate %THD to his\her perception. Play a pure sine into almost any loudspeaker (the most prodigious generator of THD) and clearly hear a 2nd harmonic an octave higher and a 3rd higher by 1-1/2 octaves. Continuous, not static, and synamically level-dependent, these artifacts are the speaker’s deleterious “contribution,” unless the listener prefers the super-sized brightness of “euphonious distortion.”

 

[jhaider]

Distortion a “static,” “worthless” measurement? Not if the listener has the experience to relate %THD to his\her perception. Play a pure sine into almost any loudspeaker (the most prodigious generator of THD) and clearly hear a 2nd harmonic an octave higher and a 3rd higher by 1-1/2 octaves. Continuous, not static, and synamically level-dependent, these artifacts are the speaker’s deleterious “contribution,” unless the listener prefers the super-sized brightness of “euphonious distortion.”

Now try with music. If you succeed, write a paper and get audio-famous for it.

 

[dasdoing]

Yes, that is what I heard, I figured that could be an artifact generated from the microphone capture process.

BTW thank you again for this recording))

thank YOU for the Danley one. that finale one is literally a banger. I think the Discovery is better for midrange impact, even though there is tons of energy down there, too. The finale lets you test that "boom" impact way better.

 

[Flaesh]

"converted about 1% of that into sound!" - nice info about Saturn's η0, which corresponds to 92 dB\W, similar to a conventional subwoofer. The link from there https://acousticstoday.org/the-soun...nt-l-gee-tracianne-b-neilsen-and-alan-t-wall/ The article seems to confirm my amateurish assumptions.

 

[RCAguy]

Note that the brain doesn’t decode the maximum dynamics. Media like LP and Tape FM radio forced a limit on crest factor (the peak to RMS ratio. But even the essentially unlimited range of digital media has practical limiting used. Film and Broadcast industries have set the RMS loudness level at -18 or -20 dB full scale. With the digital format hard limited at 0dB (and practically -0.1 dB) leaving the maximum crest factor at the loudest portions of the recording at a 10:1 ratio.

Right, adding that -20dBFS in US (-18 in EBU) is must be calibrated to a sound level, usually 85SPL. (Also deemed “safe” by OSHA when exposed over an 8h shift.). Then Full Scale is 20dB higher, 105SPL per channel, that are relatively safe as these exposures are instantaneous (momentary) peaks.

Add that human sensitivity to sound level is frequency dependent. We’re “deafer” to lower levels of low frequencies. A frequent error is for producers to make mixing decisions monitoring at higher than 85SPL, baking in bass that sounds weak when played by consumers at lower level.

 

[John Atkinson]

In the early days of CD HiFi News did a CD sampler with music samples and test tracks. @John Atkinson was still editor I think.
One of the tracks was called “the dynamic range of real life” iirc. The microphone was set up inside a roller-shutter garage and started with the tester talking outside. He then banged on the roller shutter door which was shockingly louder.

It is a fun disc, must look for mine…

I produced the CD, with Martin Colloms and Tony Faulkner; the garage door recording was by Mike Skeet.

I ordered 1000 CDs from Denon at a landed price of 8 pounds sterling each. After the CDs arrived in July 1985 and were being sold by the Hi-Fi News Accessories Club, I got a memo from senior management that they had decided not to go ahead with the CD project after all. Fortunately for my job security, we had sold more than enough CDs to cover our costs

John Atkinson
Editor, Hi-Fi News & Record Review 1982-1986; Editor, Stereophile 1986-2019; Technical Editor, Stereophile 2019 onward

 

[beefkabob]

I produced the CD, with Martin Colloms and Tony Faulkner; the garage door recording was by Mike Skeet.

I ordered 1000 CDs from Denon at a landed price of 8 pounds sterling each. After the CDs arrived in July 1985 and were being sold by the Hi-Fi News Accessories Club, I got a memo from senior management that they had decided not to go ahead with the CD project after all. Fortunately for my job security, we had sold more than enough CDs to cover our costs

John Atkinson
Editor, Hi-Fi News & Record Review 1982-1986; Editor, Stereophile 1986-2019; Technical Editor, Stereophile 2019 onward

Please rip a FLAC version and share it with us. I know a lot of people who would absolutely love to have it.

 

[birkbott]

Anyone in this thread with experience using the AES input? The manual states you can adjust the trim from -24 to +24db but mine only go -24 to 0db so I’m running short on headroom.

I’m wondering if maybe there’s a firmware update but I don’t know what the procedure is for updating it.

 

[birkbott]

I’m using the AES out from a miniDSP SHD Studio.

 

[staticV3]

Anyone in this thread with experience using the AES input? The manual states you can adjust the trim from -24 to +24db but mine only go -24 to 0db so I’m running short on headroom.

I’m wondering if maybe there’s a firmware update but I don’t know what the procedure is for updating it.

The 708P has two different trim adjustments.
The Input Trim goes from -24dB to 0dB.
The AES Level Trim goes from -24dB to +24dB.

Are you sure that you're adjusting the AES Trim?

 

[birkbott]

Yes I’m sure, both max out at 0

 

[beefkabob]

I will double check later. I'm using AES input from an SHD studio. I seem to remember them going up to 0db on the AES part. I'm not sure if there's an additional volume control on mine. 0db is a proper max, though. It blows the doors off the barn with a track at full and has serious distortion sometimes. Also it compresses the sound a ton.

 

[birkbott]

I will double check later. I'm using AES input from an SHD studio. I seem to remember them going up to 0db on the AES part. I'm not sure if there's an additional volume control on mine. 0db is a proper max, though. It blows the doors off the barn with a track at full and has serious distortion sometimes. Also it compresses the sound a ton.

Yeah it’s weird, I was using it with Roon and it was ok but I’ve been trying Spotify connect directly to the SHD and it’s much quieter. I made sure volume normalization was disabled in the Volumio plug in. Not sure what other settings there are.

 

[beefkabob]

Yeah it’s weird, I was using it with Roon and it was ok but I’ve been trying Spotify connect directly to the SHD and it’s much quieter. I made sure volume normalization was disabled in the Volumio plug in. Not sure what other settings there are.

I don't use Spotify, but there are several places that can have volume controls Source device. Spotify app. Volumio. SHD. Speakers. If Windows is the source, there are volume controls in at least Windows and the SHD drivers. I'm not sure what syncs with what, and it seems to vary by software version. I turn windows to 100%, drivers to 100%, and playback software to 100% then use the SHD volume knob for actual volume. Literally 4 places to control volume, and I bet somewhere Windows has an extra volume control.