Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Guy Graham]

Man you guys are nasty to newcomers. You wouldn't say that in person, or maybe you do, in which case, I rest my case.

That setup looks awesome. Congrats on your new 835's.

If someone told me they were 835s in person, I would ask why they don't look like that particular cabinet?

If I saw that room, I would query the unusual setup and in particular the potential acoustic problems.

I wouldn't say these things rudely, but they're pretty obvious points for anyone with an inquisitive mind.



Sent from my GT-I8160

[Scott Hofmann]

Agreed. 

Sound here is WAAAY down the list after dealing with the safety (and liability) issues. 

First:  make it safe
Second:  make it safe
Third:  make it safe

Edit:

Chain is not acceptable for flying loads overhead.

Where are the safeties?

If chain is not acceptable for flying loads overhead, what do you make of chain motors for arena rigging and trim chains on theatre battens?
Or did you mean to say that the chain as pictured is not acceptable?

[g'bye, Dick Rees]

If chain is not acceptable for flying loads overhead, what do you make of chain motors for arena rigging and trim chains on theatre battens?

I believe there are several issues here:

APPROVED chain is OK for lifting, but I believe once the load is in place there needs to be additional suspension and safeties in place to bear the load.

The chain in the picture appears to be plain old hardware store chain which should have a label on it stating "not for overhead lift".  The point is, it's worth checking.

Lastly, I've seen "engineering firms" do the most outrageous stuff.  One, when called back to add safeties to an un-rated OSB box suspended by plain old eye bolts in the SIDES of the cabinet,  simply added hardware store chain looped through the handles of the cabinet. 

I would suggest the OP have their insurance company verify anything these engineers are approving.

[Jamin Lynch]

Disclaimer: I'm not a professional rigger.

I've read, devices designed for lifting loads, such as chain hoists,  must use load rated grade 8 chain.

I believe load rated grade 5 chain is ok for static loads.

Maybe a pro rigger will school us.

I would argue properly rigged chain and suspension hardware for a static speaker suspension would be safer than cable. I've seen one fail before.

[David Allred]

If someone told me they were 835s in person, I would ask why they don't look like that particular cabinet?

If I saw that room, I would query the unusual setup and in particular the potential acoustic problems.



Sent from my GT-I8160

Looks to be horns in.  More energy on the floor (people) than on the walls.  Given the box (room) probably the most advantageous.

[Guy Graham]

Looks to be horns in.  More energy on the floor (people) than on the walls.  Given the box (room) probably the most advantageous.

Apologies - I clearly posted in haste. I couldn't see key details on my phone, such as the SRX8xx characteristic cabinet shape.

Whilst JBL don't specify how wide a frequency bandwidth the 60° x 40° pattern control covers, I guess that deployment and with those mounting points in that room, is probably the best - given the limited information we have to go on.

From the details on their website, I think JBL have been remarkably clever with the SRX835p loudspeaker. They might have used the unpowered STX835 as a platform, with a rotatable mid / high section providing increased versatility, when mounted in different orientations.

However the powered box really saves a lot of weight: 38.6kg, vs 58.1kg for the more expensive and unpowered STX alternative!

Looking at the specs - JBL appear to have done something quite impressive, way beyond any phenomenal weight-saving achievement. Of course one assumes that in good faith, their specs are all true, and of course are all measured consistently across their different product lines (to allow potential customers to make fair and valid comparisons).

The quoted peak SPL figure for the STX835 is 134dB. The cheaper powered SRX835p is rated at 137dB peak SPL. Increased output capability, whilst decreasing many beneficial metrics.

If we assume JBL flattered the STX specs by measuring when biamped with ideal iTech HD power amps - the powered SRX box manages to get louder whilst also getting lighter and using fewer drivers.

In that light, the lack of facility to rotate the mid and high driver sections can surely be forgiven?

Likewise the SRX828p has benefited from a similar witchcraft-like sprinkling of JBL magic. Not only is the powered box cheaper than the STX equivalent, it goes down lower, is lighter and has a peak rated SPL that is 3dB higher!

Having glanced at the dimensions, I think JBL haven't just beaten their own competition - they're going after Hoffman's iron law as well...


Sent from my GT-I8160

[Trevor Crowe]

I personally didn't take the claimed 137db rating very seriously. This weekend I will tweak the onboard DSP and see if I can remove the harsher highs. It's likely just a break in issue as well. That said, the 3 way clarity in the midrange is phenonminal. It went way beyond volumes the old 4 QSC K12's could do with no sign of compression.

[Ivan Beaver]

I personally didn't take the claimed 137db rating very seriously. This weekend I will tweak the onboard DSP and see if I can remove the harsher highs. It's likely just a break in issue as well.

You must remember that the "peak" rating is just that. And at 1M

Average music has a dynamic range of 15dB or so.

So when any loudspeaker is producing "peak" output, the average SPL you would measure or perceive is quite a bit lower.

And then as you get a little bit away-the level drops even more.  33' is a 20dB loss.

So running at maximum output and you are 20' away the "average" level would be closer to around 100dB.

So the peak specs are not "lying" but they are not telling you what you "expect".

This goes for any loudspeaker.

[Trevor Crowe]

In our 500 seat church, the 4 old QSC's would audibly compress at around 90db from the sound board, at the back(~90 feet) and turn to mush!
The two srx play cleanly past that, with dynamics to spare. Instruments remained seperated. For me, that's what I'm listening for, not 'how loud it will go', which seems to be what all the user reviews in the pro audio world talk about.

[Trevor Crowe]

Got it sounding really good today. Went around the room with REW. Noticed there is a huge tonal shift towards the lows in the stock setup. Sounded muffled and bass heavy. The Rew brought it back, but corrected to be a little too bright (like it was showing 6db down in the highs, when it really is around 3db correction.

[ProSoundWeb Community]