JBL 306P MK II Review (Studio Monitor)

[F1308]

No but thats absolutly no reason why 25khz should destroy them faster than15khz.

It will all be dependant on the material and its natural resonance.

 

[tomtoo]

It will all be dependant on the material and its natural resonance.

Oh come on.

Edit says: The only reason tweeters can be destroyed by ultrasonic is that you can hear nothing and give out of this reason to much power.

 

[infinitesymphony]

Please, has anyone measured the reported hiss ?

I don't think we have a measurement for the LSR306P MkII yet. The Hiss List shows:

JBL LSR305P MkII - 28.5 dBA
JBL LSR308P MkII - 30.0 dBA

Because these designs are so similar it would be reasonable to assume until measurements are taken that this model will fall somewhere in that range. So, not great, but not the worst.

 

[dfuller]

No. If 5khz not destroy a bass in a second why should 25khz destroy a tweeter in a second? Hope you can explain?

Tweeters have far less thermal mass in the voice coil (or whatever analogue) than a woofer or midrange driver, and woofers/midrange drivers are designed to take a lot of energy (bass needs much more energy input to reach the same SPL, plus tweeters have to be lighter and quicker reacting than a woofer or midrange driver). So while the woofer or midrange may be unhappy in terms of sound quality, you're not likely to destroy them with a high level 5KHz signal.

No but thats absolutly no reason why 25khz should destroy them faster than15khz.

It wouldn't. 15KHz and 25KHz at high level will wreck a tweeter the same way. The voice coil wires aren't heavy enough to deal with sustained continuous high power. The point is that you can't hear 25KHz. There's little if any reason to allow a lot of energy up there.

 

[F1308]

I don't think we have a measurement for the LSR306P MkII yet. The Hiss List shows:

JBL LSR305P MkII - 28.5 dBA
JBL LSR308P MkII - 30.0 dBA

Because these designs are so similar it would be reasonable to assume until measurements are taken that this model will fall somewhere in that range. So, not great, but not the worst.

Thank you.
And the frequency the hiss is enjoying us with ?
Any idea ?
I mean: typically powered loudspeakers have an unwanted hissing in the range....

 

[dfuller]

Thank you.
And the frequency the hiss is enjoying us with ?
Any idea ?

It's white noise or something close to it.

 

[tomtoo]

Tweeters have far less thermal mass in the voice coil (or whatever analogue) than a woofer or midrange driver, and they're designed to take a lot of energy (bass needs much more energy input to reach the same SPL, plus tweeters have to be lighter and quicker reacting than a woofer or midrange driver). So while the woofer or midrange may be unhappy in terms of sound quality, you're not likely to destroy them with a high level 5KHz signal.
It wouldn't. 15KHz and 25KHz at high level will wreck a tweeter the same way. The voice coil wires aren't heavy enough to deal with sustained continuous high power. The point is that you can't hear 25KHz. There's little if any reason to allow a lot of energy up there.

Absolutly ok. Thats the danger with ultrasonic its not that the tweeter can stand the high frequence. Its you cant hear and overpower the tweeter.

 

[F1308]

Oh come on.

Edit says: The only reason tweeters can be destroyed by ultrasonic is that you can hear nothing and give out of this reason to much power.

Or may be you simply blew the candle too much !!!

https://www.lansche-audio.com/products/plasmatweeter/

 

[infinitesymphony]

And the frequency the hiss is enjoying us with ?
Any idea ?

Not yet, but that's a request I brought up in the Hiss List thread because, like our earlier discussion, I believe the timbre of the hiss can potentially influence its perception:

I wish we had spectral measurements of the hiss for each speaker beyond a simple dBA measurement because I think it's possible that different people may find different kinds of hiss to be more or less tolerable. Most of the hiss spectra will be similar to a colored noise profile but I think most people would prefer pink noise over white noise, for example.

 

[tomtoo]

Or may be you simply blew the candle too much !!!

https://www.lansche-audio.com/products/plasmatweeter/

Realy expensive way to light a cigarette.

 

[F1308]

Not yet, but that's a request I brought up in the Hiss List thread because, like our earlier discussion, I believe the timbre of the hiss can potentially influence its perception:

Good thing.
Then we could possibly compare that not at all important hissing at -28/-30 dB with those to-die-for-harmonics at -83 dB.

 

[F1308]

Realy expensive way to light a cigarette.

Oh, come on...10000000 Hz harmonics are there !!!

 

[tomtoo]

Oh, come on...10000000 Hz harmonics are there !!!

Oh thats a lot of zeros. Even Bats would quit there.

 

[F1308]

Not yet, but that's a request I brought up in the Hiss List thread because, like our earlier discussion, I believe the timbre of the hiss can potentially influence its perception:

We could even make a patent granting every single buyer a Niagara-Falls-like-ultra-relaxing hissing !!!!
At the risk of many not playing music ever on them !!!! So relaxing, why bother ?
Hey, I find the hissing outstanding...what could be done to increase its loudness ?

 

[waynel]

Good thing.
Then we could possibly compare that not at all important hissing at -28/-30 dB with those to-die-for-harmonics at -83 dB.

Now you are confusing acoustic levels with an arbitrary relative level on a random plot (that you provided)

 

[posvibes]

Being a totally convinced and converted LSR305p MkII fan (the bass is jaw droppingly good) I recall Armirm saying they may be worth a re-measure after the added bells and whistles to his test rig might be in order.

I listen in the far field, not loud and the only alteration I make is playing with the -2db or 0db HF trim not sure which I prefer (so 2db or not 2db that is the question).

What amazes me is that such good sound can be had from such inexpensive speakers. There is a dissertation for a Phd. from Harvard Business School marketing awaiting on all the implications of the LSR 305p for Capitalism and the class divide in the Audiophile community (or some such thing).

Love this site.

 

[RayDunzl]

Please, has anyone measured the reported hiss ?
I mean, frequency and level heard after playing music at say 55-65 dB and stopping it to get the measurement ?

Probably similar to this:

Broadband above 1500Hz, and a broad peak around 16khz

https://www.audiosciencereview.com/forum/index.php?threads/jbl-lsr-308-in-the-house.1066/#post-27832

 

[GeorgeBynum]

It is a $10,000 ruler....

Engineers and architects call them scales.<g>

 

[andreasmaaan]

It is a $10,000 ruler....

Ha! For some reason I thought the cost was more like $30k... Am I mistaken there?

 

[Tom C]

Seems like anyone who actually owns these is quite satisfied with what they received for the money spent. I am one of those. There is audible distortion, but not overly objectionable at low listening levels. There is audible hiss, but not to distraction, and I use them as desktop speakers for my PC workstation. Whether or not you’ll be happy with these probably depends a lot on how fussy you are.
I’d like to apply the EQ correction. Sorry I’m such a rube, but is it as simple as loading the file posted by @Maiky76 into JRiver DSP? Is there a post somewhere that explains the process in detail?

Bump
Someone?
Anyone?
Bueller?