Print

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

[Glen Hansen]

North of Phoenix is the Tonto   (fools)  national forest. I have had great experiences using home type speakers and low budget pa speakers there. Classic rock with nobody around to say tun it down. Ac power source Tripp lite 1800 power inverter not a pure sine wave. Inverter will run crown cts 1200 amp into clipping no problem,but there is a buzz in the power supply heard at the amp not in speakers. My setup will consist of cd player rca connections to a dbx 1321 then xlr out to a passive xlr pre amp then 100 ft xlr to to the speakers. Power cords 50 ft 10 awg 2 25 ft 12 awg. I wanted minimum voltage drop and flexibility to position the speakers correctly. I hope for a good stereo image as the primary goal . Speaker stands are 6 ft to 10 ft crank ups. I took the plunge without a demo for the jbl srx 835p. Any advice to get the best sound there will only a few people listening. Is there a minimum distance between the speakers ? Without subs should I just skip all of remote control    eq features?

[Nathan Riddle]

North of Phoenix is the Tonto   (fools)  national forest. I have had great experiences using home type speakers and low budget pa speakers there. Classic rock with nobody around to say tun it down.

Ac power source Tripp lite 1800 power inverter not a pure sine wave.
Inverter will run crown cts 1200 amp into clipping no problem, but there is a buzz in the power supply heard at the amp not in speakers.

My setup will consist of cd player rca connections to a dbx 1321 then xlr out to a passive xlr pre amp then 100 ft xlr to to the speakers.

Power cords 50 ft 10 awg 2 25 ft 12 awg.
I wanted minimum voltage drop and flexibility to position the speakers correctly.

I hope for a good stereo image as the primary goal.

Speaker stands are 6 ft to 10 ft crank ups.

I took the plunge without a demo for the jbl srx 835p.

Any advice to get the best sound there will only a few people listening?

Is there a minimum distance between the speakers?

Without subs should I just skip all of remote control eq features?

First, welcome!

You didn't ask a question, but the inverter will probably be fine. Just calculate your energy density for 1/8 power usage on the speakers for min (worst case) run-time.

Good buy on the 835p.

60deg triangle is the preferred stereo setup for studio work. So if your people are 10ft away, then the speakers should be 10ft apart.

You don't NEED the 1321 EQ, but if you wanted to change on the fly without a mixer you could use it.

The JBL's have ethernet DSP control, that would be the best method. Though that means running more cables.

[Glen Hansen]

Power source. The prius charges its 12 volt battery from its high voltage battery . When the high volt battery needs to be charged the engine will auto start then shut off when acceptable charge is reached. Really cool.
I wish I could find a more open space than this https://youtu.be/QQdXaSuEP_A  . No sub playing in the car just pan a sonic 8 inch alinco coaxial speakers. Some of the trails have loose gravel and I do not want to get stuck. Looks like I should get the ethernet DSP control. And have a backup passive system on standby.  I cant wait to get these up and running jbl already did all the tweaking with the built in amps.
 



 

[Stephen Kirby]

What is the music?  And what is the relationship of the audience to where the speakers are.  You mention stereo image.  Is this playback of recorded music?  Unless the audience can be confined into a relatively narrow area about the same distance away from the speakers as they are spread apart, you won't get much of an image.  In live sound, people are usually spread out at least as wide as the stage is.  There are occasional debates on here on the relative merits of stereo vs. trying to get the same mix to every listening position.  You'll have to define the objective a little better.

I don't know about putting 835s way up in the air.  They're kind of meant to be basically full range boxes.  Again, it depends on the audience configuration.  Sitting, standing, in a bowl?

[Glen Hansen]

The music will be cd classic rock pink floyd ,ELP, Sabbath, stones etc.  Im the audience my girlfriend might join me might not. I will be camping out and enjoying music. When I had cheap 15 inch 2 way speakers they sounded way better on stands compared to on the ground. The last times I listened to music outdoors torturing bang and olufson rl 60.2  I really wanted the speakers to be way higher than ground level or 4 feet off the ground on stands. As far as speaker placement I will use my past experience and experiment. Toe them in move closer together further apart etc. I might loose bass? by having them higher off the ground but bass is not my goal. Im not after felt thump to make my day.  https://youtu.be/QQdXaSuEP_A
I will update when I test these. Thanks for the help.
 

[Steve Ferreira]

The music will be cd classic rock pink floyd ,ELP, Sabbath, stones etc.  Im the audience my girlfriend might join me might not. I will be camping out and enjoying music. When I had cheap 15 inch 2 way speakers they sounded way better on stands compared to on the ground. The last times I listened to music outdoors torturing bang and olufson rl 60.2  I really wanted the speakers to be way higher than ground level or 4 feet off the ground on stands. As far as speaker placement I will use my past experience and experiment. Toe them in move closer together further apart etc. I might loose bass? by having them higher off the ground but bass is not my goal. Im not after felt thump to make my day.  https://youtu.be/QQdXaSuEP_A
I will update when I test these. Thanks for the help.

All this just for you and maybe your girlfriend in a park camping?

[Nathan Riddle]

All this just for you and maybe your girlfriend in a park camping?

Some people just want good clean loud sound 

[Stephen Kirby]

A common question here when people ask about gear is whether the OP is trying to create a business or just have a really big stereo to play with.  This is probably the first thread I've seen where the objective really is to have a big loud stereo.

For a limited audience stereo set up remains the same regardless of scale.  Spread the speakers around 2/3's the distance to the listening position.  Typically the HF would be around ear height.  Which would depend on how flat the area is.  Raising the speakers lessens early reflections off the ground and may add a sense of space, but at the cost of not having a realistic soundstage.

[Dave Garoutte]

But I don't quite get why you would go to the wilderness just to blast your stereo.  Isn't peace and quiet the point?

[Glen Hansen]

A common question here when people ask about gear is whether the OP is trying to create a business or just have a really big stereo to play with.  This is probably the first thread I've seen where the objective really is to have a big loud stereo.
------- Ok I would equate big as a wide stereo field. With a bit of luck have a very accurate detailed stereo experience.  You guys know better than me most vocals are centered on recordings for me the wider the speakers maintaining the center vocals is  a positive for me. ---------
Give me some time to set these speakers up and I will make a video and in the video hopefully I can answer some questions.

 

[David Morison]

But I don't quite get why you would go to the wilderness just to blast your stereo.  Isn't peace and quiet the point?

No reason one can't do both - hike/fish/mountainbike/canoe/whatever by day, crank some tunes up in the evening sounds like a perfectly reasonable way to spend a weekend.

[Steve Ferreira]

No reason one can't do both - hike/fish/mountainbike/canoe/whatever by day, crank some tunes up in the evening sounds like a perfectly reasonable way to spend a weekend.

I guess it will keep the wildlife away from him as well.

[Len Zenith Jr]

I guess it will keep the wildlife away from him as well.

I don't know about that. Around my club, music tends to attract a lot of cougars.

[Luke Geis]

Unless you have a really good inverter, you will probably always find some amount of hash in the speakers power supply which will often be audible in one way or another. Usually the speakers will hum or buzz, but as you experienced, the speakers were clean, but the amps power supply was less than happy.

With the SRX's I don't think you will have too much of a problem. I believe the SRX utilizes a SMPS which should handle the hash from the inverter, but I could be wrong. A test is usually the only way to find out.

As for where to place the speakers? Usually on a stand. There is a sweet spot. The idea is to get the HF drivers at or around ear level and as close to the ground as possible to reduce bounce. The issue is that when placed close to the ground, the bass content is usually increased due to coupling. To reduce this you have to get the speaker off the ground. The height off the ground will tune the frequency at which it decouples and begins to cancel again ( as it comb filters with the reflection or floor bounce from the original sound ). If the speaker is essentially dead below 40hz and strong above 100hz, the ideal height would be where it decouples from 100hz, but is close enough that it couples at 40hz and below. This would mean that an ideal range would be right around 5' to 7' in the air. This would decouple most of the energy above about 80hz and everything below that would still have reasonable coupling to the ground. The higher the speakers are in the air, the more airy and spacious they will sound. The closer to the ground the more direct and punchy it will sound.

As to width apart? This one is simpler. As mentioned before you want to be about as far away from the speakers as they are apart from each other. As you cross the point where you are further away from the speakers as they are from each other, you begin to loose stereo imaging and the speakers start having more obvious comb filtering. The same goes for being closer than they are together. If you are closer to the speakers than they are apart, you can more easily hear the comb filtering with small movements. 

Have fun.

[Glen Hansen]

Unless you have a really good inverter, you will probably always find some amount of hash in the speakers power supply which will often be audible in one way or another. Usually the speakers will hum or buzz, but as you experienced, the speakers were clean, but the amps power supply was less than happy.

With the SRX's I don't think you will have too much of a problem. I believe the SRX utilizes a SMPS which should handle the hash from the inverter, but I could be wrong. A test is usually the only way to find out.

As for where to place the speakers? Usually on a stand. There is a sweet spot. The idea is to get the HF drivers at or around ear level and as close to the ground as possible to reduce bounce. The issue is that when placed close to the ground, the bass content is usually increased due to coupling. To reduce this you have to get the speaker off the ground. The height off the ground will tune the frequency at which it decouples and begins to cancel again ( as it comb filters with the reflection or floor bounce from the original sound ). If the speaker is essentially dead below 40hz and strong above 100hz, the ideal height would be where it decouples from 100hz, but is close enough that it couples at 40hz and below. This would mean that an ideal range would be right around 5' to 7' in the air. This would decouple most of the energy above about 80hz and everything below that would still have reasonable coupling to the ground. The higher the speakers are in the air, the more airy and spacious they will sound. The closer to the ground the more direct and punchy it will sound.

As to width apart? This one is simpler. As mentioned before you want to be about as far away from the speakers as they are apart from each other. As you cross the point where you are further away from the speakers as they are from each other, you begin to loose stereo imaging and the speakers start having more obvious comb filtering. The same goes for being closer than they are together. If you are closer to the speakers than they are apart, you can more easily hear the comb filtering with small movements. 

Have fun.

Wow thanks for the great response.
I will definitely research comb filtering.
 

[Luke Geis]

Comb filtering is something that cannot be eliminated ( unless you go to a single source of sound ) and is just part of the game. The only real way to reduce the audible effects of it is to be 100% equidistant from each speaker and don't move. Since that is not possible ( practically speaking ) it is just easier to understand that it is happening.

The height of the speaker off the ground is probably the only real thing you can do to tune out floor bounce or coupling. Floor bounce is when the signal from the speaker literally bounces off the ground and back up at you. The bounce is a tangent of the direct sound and will arrive later in time ( out of phase ) which causes comb filtering. The frequencies and the amount of the effect relative to the listening position can be tuned by adjusting the height of the speaker. This gets us to problem #2 though. If placing the speaker directly on the ground all but eliminates floor bounce, its side effect is coupling of low frequencies. Typically all frequencies that are essentially omni directional will couple and create addition because the floor acts as an infinite baffle, halving the space, which effectively doubles the audible power. This means that energy from about 250hz and below has a 3db boost in output. This may or may not be of detriment to some. Typically, modern speakers have a fair amount of low end boost built in, giving the speaker a bigger and more desired sound. The SRX is rather linear ( flat in frequency response ), but still has a low end hump ( relative to its midband frequency response ) that will give the speaker a more DJ smile type sound when placed on the ground. This can be tuned out with a shelving filter, but this leads us to part 3 of what effects the sonic character of the speaker.

The height of the speaker off the ground will determine what frequencies will decouple. The question then is what frequencies do you want it to decouple from and how much floor bounce can you live with? The floor bounce gives the sound an airiness, or liveliness that some prefer. Much like open back headphones, it makes the speaker sound open and live with more realness. Too much of a good thing is still too much though. Some prefer a more direct and closed sound. When the speaker has less time to interact with the world around it, the sound you hear most, is the sound of the speaker. This gives the speaker a more direct and punchy sound, that is less lively and more accurate ( within reason ).

As you can see it is kind of a compromise between what you want, what you have and what you can do to get closer to where you want. The SRX is designed as it is to work basically standalone. This means you don't need crossovers or other DSP to get it to sound amazing. It has more DSP in it than most units anyway. You just need to get it up and talking with the control app or Architect software and you can tune to your hearts content.

[Glen Hansen]

I unboxed them hours ago . They are a tight squeeze to fit in the prius. The stands will have to wait until I get a roof rack. Slight buzz when tested on inverter from the amps nothing really coming through the speakers --- crown cts were 3 to 10 time worse. Should be an interesting evening as temps will be around 99 until the sun goes down.

[Chrysander 'C.R.' Young]

Glen, I have to admit that I am not certain whether you are trolling us or are just an eccentric fellow who likes listening to music really loudly out in the wilderness.  I would be very curious to see some pics or videos of your system in the wild.  Good luck and let us know how things work out!

[Steve Ferreira]

I don't know about that. Around my club, music tends to attract a lot of cougars.

 

[Glen Hansen]

Set up speakers about 70 ft. away maybe 40 feet apart on ground.
Everything sounding pretty good turned up the volume a bit and inverter went dead? Any other time my inverter shut off was running high amp power tool and then tripping the low battery volts alarm. Inverter was cool and fan was not running so it was probably drawing the low 1/3  of whatever 2 amps per speaker. I hooked up the eq and cut all the low end under 100 that helped a bit but still had some cut outs. My inverter is a tripp lite 1800 watt non sine over 6 years old.  Looks like I will be buying a new inverter any suggestions?



How do they sound ? Way better than I thought. Everything is well balanced bass treble etc. no real need to make any adjustments.
Theres no dead spot between the speakers unless the recording is that way. https://youtu.be/p89kAp4rzBE this was almost like there was not 2 speakers more like they did not exist, side to side full almost wrap around in front and to the sides not behind me.  These speakers do not project forward and slap you in the face with sound. The stage is in between the 2 speakers.

[Glen Hansen]

Up on stands https://youtu.be/3SAz2PaBI4k yes it is a poor video.  They actually sounded better on the ground ? My new pure sine wave 1500 watt inverter is working really good no buzz on the power supplies. Running the speakers around 200-++ ish watts on the inverters watt meter not real accurate with an led light hooked up showed a dimming on the beat of the music. I may try adding another prius battery that I have to see if it makes an improvement in power overall.  Next outing will be speakers on ground so moving them will be easier.
I plan on running cds through a laptop to a passive preamp = easy volume control in the dark. I installed audio architect today and I am wondering if to change eq settings on the fly while music is playing is there a procedure to adjust both speakers - eqs at the same time ? Same thing for volume ?
I called jbl pro and they said we dont have a laptop here hooked up to anything and if you use the app. Ok thanks for your help app ok its cool got it. I ordered  2 100 ft. cat5 shielded cables so I will be able to monitor remotely + possibly eq on the fly safely.  I would also like to warm up or turn up the human voice bring the vocals out a tad. These speakers seem to be extremely sensitive to small eq changes.
If using the audio architect is too complicated for a rookie like me is there a simple stereo eq download  that someone can suggest ?
Pink floyd live at pompeii is on its way the new version 2017.

quote
As for where to place the speakers? Usually on a stand. There is a sweet spot. The idea is to get the HF drivers at or around ear level and as close to the ground as possible to reduce bounce.
I know this will sound kinda crazy but a cheap laser may help me get these hf drivers leveled to my listening position. Also toe in or out. Then to make all of this even more complicated.
Tilting the speakers to get all of the point of origin drivers time aligned. Or maybe jbl already did that

[Luke Geis]

I'm not surprised you prefer the sound of them on the ground. They should sound more direct and have more bass response. In the video it is hard to tell, but the speakers look to be at least a good 6' up in the air? The listening position is above them at least from the vantage you were at. All this means is that you were not in the " ideal " location at that time.

The MF/HF driver has a coverage pattern in that model of 60* X 40* which doesn't mean much other than a good percentage of the speakers output is to some degree controlled. You should not need to " splay " the speakers at all if you are in the ideal listening location mentioned in earlier posts. Will it help? I would guess that it probably won't make much difference at the listening distance you seem to be shooting for. If you were really close and the speakers also really close together, then yes splaying them would help.

At further distances the point of incident is less consequential. The coverage of the speaker will spread out and at some point even moving several feet any given direction will have you fully within that coverage and the resultant sound of that single speaker should not change. This assumes a single speaker and no comb filtering. As soon as the second box is in the equation comb filtering will be very real.

I don't think you will have to get crazy with time alignment. If the speakers are on the same plane and you seat yourself anywhere close to the middle of them, you should be able to simply move around and tell if you are in a good spot.

[Chrysander 'C.R.' Young]

Glen,

Thanks for the update.  You are officially not a troll.  Perhaps a bit eccentric by my own very biased standards, but you seem to have successfully made a lot of noise in the wilderness using some PA speakers.  Excellent choice of music. 

Good luck and safe travels.

[ProSoundWeb Community]