JBL 308P MKII Studio Monitor Review

[respice finem]

Depends on the painting. Some will be just an angled "reflector" (those behind glass), some rather (weak) diffusers (like oil paintings), a few could absorb a bit (watercolor on canvas). Generally a "porous absorber" can be anything... porous. And having some air between it and the wall increases "efficiency".

Choosing & Using Porous Absorbers

The choice of materials for acoustic treatment is paramount. We find out what different types of absorber can and can’t achieve.

www.soundonsound.com

 

[Robbo99999]

Thanks for the hints!
I will try it first with the speakers only (without RoomEQ, without subwoofer).
I saw that I'd need the mic for RoomEQ. Seems interesting to experiment with it but I'm not sure yet if I'll try it. However, if I do not try it I will not know if I would hear a positive effect. The same for the subwoofer.

Behind the listener position half of the wall is brick, the other half is plasterboard. A larger framed painting on that wall, as mentioned in a comment above.

Getting a mic is the first step into the rabbit hole, lol! What I mean is you'll probably think the speakers sound great once you've got them setup in your equilateral triangle you have talked about......and once you've put the HF Trim Switch on the back of the speaker to -2dB(minus). It's only once you measure them and then play about with optimising them that you may notice iterative improvements, but sometimes RoomEQ can make it sound worse in some cases.......ignorance can be bliss! But to be honest, you'll be a long way ahead of most people by getting those speakers (proven good here on ASR by the measurements), and setting that HF Trim Switch to -2dB(minus). See how you go once you've got them in there!

 

[Roddy]

My left speaker turns on automatically from standby. I unplugged the xlr going to it, and it still did, so it's not a signal issue. Has anyone else had the same problem. I searched the thread, and it seems people had issues with them not turning on. Mine always turned on with a high enough volume signal from the xlr, and practically any signal from the rca.

 

[Blumlein 88]

My left speaker turns on automatically from standby. I unplugged the xlr going to it, and it still did, so it's not a signal issue. Has anyone else had the same problem. I searched the thread, and it seems people had issues with them not turning on. Mine always turned on with a high enough volume signal from the xlr, and practically any signal from the rca.

I have 3 in a surround system. One fails to come on now and then. Turn it off and on and it comes to life. Don't have a solution for it. Happens rarely enough fortunately for me not to worry much about it. I considered putting a timer on it to turn it off and then on once each day or once per week.

 

[DavidMcRoy]

I have 3 in a surround system. One fails to come on now and then. Turn it off and on and it comes to life. Don't have a solution for it. Happens rarely enough fortunately for me not to worry much about it. I considered putting a timer on it to turn it off and then on once each day or once per week.

I have nine JBL 305P MKIIs in mothballs and one or two of them had that's issue occasionally. Rebooting works, but so does reseating the XLR plug, like maybe a transient wakes them up? Who knows? The four JBL LSR305s (predecessors to the 305P MKII) that remain in use for Dolby Atmos height speakers have never done that that I can recall.

 

[Blumlein 88]

I have nine JBL 305P MKIIs in mothballs and one or two of them had that's issue occasionally. Rebooting works, but so does reseating the XLR plug, like maybe a transient wakes them up? Who knows? The four JBL LSR305s (predecessors to the 305P MKII) that remain in use for Dolby Atmos height speakers have never done that that I can recall.

I had three of the LSR305s (1st gen) that I replaced with the 308's mk II when I moved to a larger space. None of them ever did this either. I haven't checked maybe the 1st gen never went into sleep mode.

 

[Blumlein 88]

@Roddy @DavidMcRoy
This might be helpful. Some versions of the MK II manual don't have this. Apparently some early Mk II speakers didn't either. In any case, you can disable the Standby feature. Or if it is disabled you can turn it on.

 

[DavidMcRoy]

@Roddy @DavidMcRoy
This might be helpful. Some versions of the MK II manual don't have this. Apparently some early Mk II speakers didn't either. In any case, you can disable the Standby feature. Or if it is disabled you can turn it on.

View attachment 258657

Thanks very much. I'll file this away and give it a shot the next time I need to use them.

 

[Philbo King]

@Roddy @DavidMcRoy
This might be helpful. Some versions of the MK II manual don't have this. Apparently some early Mk II speakers didn't either. In any case, you can disable the Standby feature. Or if it is disabled you can turn it on.

View attachment 258657

Never knew this! Thanks. Mine have never gone into standby, maybe they don't have it.

 

[Roddy]

Thanks. That's a lot of steps to do what an extra button could've done. I'll see if it fixes it. The standby feature is essential to me due to the high noise floor. They would be perfect, and I don't intend to sell them, but using them as PC monitors I can hear the hissing when they're on and not playing, and all I can think of is my next upgrade.

@Roddy @DavidMcRoy
This might be helpful. Some versions of the MK II manual don't have this. Apparently some early Mk II speakers didn't either. In any case, you can disable the Standby feature. Or if it is disabled you can turn it on.

View attachment 258657

 

[respice finem]

Probably the simplest solution is to disable auto standby and use a "main switch" like in a recording studio. Or leave it on and use the central switch anyway, before going to sleep etc. Some studio monitors (like the Neumann KH 310A) don't have auto standby at all, despite considerable idle power consumption. They are meant to be switched off after their "work day".

 

[FrantzM]

Probably the simplest solution is to disable auto standby and use a "main switch" like in a recording studio. Or leave it on and use the central switch anyway, before going to sleep etc. Some studio monitors (like the Neumann KH 310A) don't have auto standby at all, despite considerable idle power consumption. They are meant to be switched off after their "work day".

Which is what I did. I use a Smart outlet for the LSR308. They have a delay on so they don't "TUMP" after power is applied to them.

Peace.

 

[respice finem]

Which smart outlet do you use? (asking because of the potentially high switch-on current).

 

[FrantzM]

I h

Which smart outlet do you use? (asking because of the potentially high switch-on current).

I have success with a variety of smart switches/outlet.
Currently using these from Kasa:

No issues whatsoever. There are 2 versions, I use the Apple HomeKit version, it is more expensive
Currently:
One of these Outlets has a refrigerator on it. I suppose the fridge start up pull is at least a thousand watts. It runs however at 128 Watts. No Issue after 6 months +.
Another has: 2 LSR 308 + (2 x SUB 1500) on it. No issue. Even with spirited level of music in my admittedly , small room (3.2 x 5 x 2.8 meters), Power consumption never goes over 60 watts total. Class D rules! .
I have also use Wemo smart Outlets, for more than a year on the LSR 308. These weren't power monitoring though. They were moved to the LSR 305 and other stuff in the house... have been working for more than 2 years. No issue.

====
To be back On-Topics: I can't stop recommending the LSR308. These have convinced me that, these days one can have great sound at a reasonable price. I use them with a pair of cheap subwoofers the Dayton SUB-1500 and control the subs with a miniDSP 2x4, REW, Audyssey MultEQ-X ... Denon AVR-X3400 H .. Total cost inthe USA for all this is less than $2500.oo . In small room, it is difficult to do better. Full range: I reach 19 Hz in my room. I am utterly satisfied...

Peace.

 

[Robbo99999]

Thanks. That's a lot of steps to do what an extra button could've done. I'll see if it fixes it. The standby feature is essential to me due to the high noise floor. They would be perfect, and I don't intend to sell them, but using them as PC monitors I can hear the hissing when they're on and not playing, and all I can think of is my next upgrade.

I agree that I wouldn't want them on my desk either (either side of the PC monitor), but they're fine for me in the living room. I switch mine on & off manually at the end of the day, I disabled the auto standby because sometimes they wouldn't switch themselves off.

 

[Roddy]

I agree that I wouldn't want them on my desk either (either side of the PC monitor), but they're fine for me in the living room. I switch mine on & off manually at the end of the day, I disabled the auto standby because sometimes they wouldn't switch themselves off.

Mine occasionally don't turn themselves off, or take more than the 15 minute standby time to turn off, but I've noticed the left one turning on anywhere from 1-3 times a day, when the PC it was connected to that's on daily was out of commission. At least it's my left one, my right one is against a wall with the back nearly impossible to reach.

Probably the simplest solution is to disable auto standby and use a "main switch" like in a recording studio. Or leave it on and use the central switch anyway, before going to sleep etc. Some studio monitors (like the Neumann KH 310A) don't have auto standby at all, despite considerable idle power consumption. They are meant to be switched off after their "work day".

Is that OK for speakers? Turning off at the mains highly unrecommended for PCs, consoles, and I presumed anything sophisticated like a DAC.

Also, the instructions look complicated, but they're quite easy.
- take pictures of your settings beforehand. turn off speakers.
- set all protruding switches (not the one you need a toothpick to get to) to the right.
- set volume to minimum.
- turn on. set all protruding switches to the left within 5 seconds.
- front flashes to signal standby turned off.
- return volume & settings to normal.
- repeat in opposite direction to turn standby back on.

right --> left (standby off)
left --> right (standby on)

I'll see if turning it off and on again a few times fixes it.

 

[Sal1950]

Is that OK for speakers? Turning off at the mains highly unrecommended for PCs, consoles, and I presumed anything sophisticated like a DAC.

There's no solid reason for that if the owner uses common sense.
With PC's, just make sure it's actually shut down and not just sleeping before cutting power..
The worse that can happen is the CMOS battery is dead and the PC will lose it's time setting.

 

[Robbo99999]

Mine occasionally don't turn themselves off, or take more than the 15 minute standby time to turn off, but I've noticed the left one turning on anywhere from 1-3 times a day, when the PC it was connected to that's on daily was out of commission. At least it's my left one, my right one is against a wall with the back nearly impossible to reach.

Is that OK for speakers? Turning off at the mains highly unrecommended for PCs, consoles, and I presumed anything sophisticated like a DAC.

Also, the instructions look complicated, but they're quite easy.
- take pictures of your settings beforehand. turn off speakers.
- set all protruding switches (not the one you need a toothpick to get to) to the right.
- set volume to minimum.
- turn on. set all protruding switches to the left within 5 seconds.
- front flashes to signal standby turned off.
- return volume & settings to normal.
- repeat in opposite direction to turn standby back on.

right --> left (standby off)
left --> right (standby on)

I'll see if turning it off and on again a few times fixes it.

I think it's fine to shut off your speakers, also your PC's. I don't think there's really a concern with this in terms of longevity. I suppose the idea is that temperature fluctuation can cause issues, but I don't think you have to be worried about that in PC's and speakers. My only initial concern with turning my speakers off manually each day was whether the switch would physically wear out, but after doing this for the past nearly 2 yrs the power switches on the back of the 308p feel very solid, I just think they're designed to switch on & off many many times, I'd say don't worry about it and just turn them off every day or maybe multiple times per day (although that's a pain, in which case I'd have the speakers on a seperate power switch that would turn them off both at the same time).

 

[respice finem]

Is that OK for speakers? Turning off at the mains highly unrecommended for PCs, consoles, and I presumed anything sophisticated like a DAC.

Good question. As these are studio monitors, I think they "have to bear it". In a studio setup, they are powered on (by a main switch) at the start of a working day, and off at its end. At least in the few studios I've seen so far. But as complexity grows, this may become a problem in the future, as it is already with PCs or smartTVs (which are also computers, essentially). Which in turn calls for reliably working standby...

 

[LTig]

Is that OK for speakers? Turning off at the mains highly unrecommended for PCs, consoles, and I presumed anything sophisticated like a DAC.

As long as the unit has a real mains switch and the manual of said unit does not mention any tasks the user has to perform before switching it off you can safely use any switch in the chain before the units mains switch. Well, I do.