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post #1 of 42 Old 07-19-2019, 01:04 PM - Thread Starter
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Stereo to mono cable suggestions

I have a single powered speaker. The source is a projector that has stereo auxiliary out. I have been using just one channel of the output to drive the powered speaker (JBL 306P).

But the max volume is still low. So I was wondering to find a circuit or cable that can combine both stereo channel into one. I was hoping that it will double the volume.

Do you have a suggestion?

If not, do you have a suggestion for a cheap (around $10) signal amplifier that can boost the signal before it to feed to the powered speaker?

Thanks in advance.

Last edited by SouthernCA; 07-19-2019 at 01:05 PM. Reason: Need Help.
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post #2 of 42 Old 07-19-2019, 02:53 PM
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Ah... no... generally Stereo to Mono Cable will not work because it is shorting the outputs together with no isolation, which is not good.

There are resistor Stereo to Mono that have a resistor Networks that prevents a dead short between the outputs, you can find this on a Google Image search -

Google-Image Search - Stereo to Mono Converter -

https://www.google.com/search?safe=o...4dUDCAU&uact=5

Not only will you see several wiring diagrams, but you will see several commercial device to accomplish this task. Most of the better ones will use a transformer.

https://www.amazon.com/MCM-Custom-50...dp/B07D4D919G/

https://www.monacor.com/products/pa-...isation/smc-1/

https://www.dhgate.com/product/stere...410969998.html

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post #3 of 42 Old 07-22-2019, 07:36 AM - Thread Starter
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Quote:
Originally Posted by bluewizard View Post
Ah... no... generally Stereo to Mono Cable will not work because it is shorting the outputs together with no isolation, which is not good.

There are resistor Stereo to Mono that have a resistor Networks that prevents a dead short between the outputs, you can find this on a Google Image search -

Google-Image Search - Stereo to Mono Converter -

https://www.google.com/search?safe=o...4dUDCAU&uact=5

Not only will you see several wiring diagrams, but you will see several commercial device to accomplish this task. Most of the better ones will use a transformer.

https://www.amazon.com/MCM-Custom-50...dp/B07D4D919G/

https://www.monacor.com/products/pa-...isation/smc-1/

https://www.dhgate.com/product/stere...410969998.html

Steve/bluewizard
Thanks Steve. I made one cable with 510 ohm resistors on each channel and 21k ohm to ground resistor as in one of the circuits shown here.

The problem is that the volume did not increase compared to just listening to one channel.

Any cheap voltage amplifiers that you can think of?

https://images.app.*******/dRFPcj2AH9f9P7mF8
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post #4 of 42 Old 07-22-2019, 08:04 AM
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Quote:
Originally Posted by SouthernCA View Post
I have a single powered speaker. The source is a projector that has stereo auxiliary out. I have been using just one channel of the output to drive the powered speaker (JBL 306P).

But the max volume is still low. So I was wondering to find a circuit or cable that can combine both stereo channel into one. I was hoping that it will double the volume.

Do you have a suggestion?

If not, do you have a suggestion for a cheap (around $10) signal amplifier that can boost the signal before it to feed to the powered speaker?

Thanks in advance.
Have you tried changing the input sensitivity on the JBL? It might be that the Aux out on the projector is outputting a low voltage signal and you are using the high voltage selection on the JBL. What brand and model projector is it? Also is it a standard like 3.5mm headphone style jack on the projector? if so you can get a long 3.5mm to 1/4 TRS cable or 3.5mm to XLR cable.
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post #5 of 42 Old 07-22-2019, 08:45 AM - Thread Starter
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Originally Posted by liffie420 View Post
Have you tried changing the input sensitivity on the JBL? It might be that the Aux out on the projector is outputting a low voltage signal and you are using the high voltage selection on the JBL. What brand and model projector is it? Also is it a standard like 3.5mm headphone style jack on the projector? if so you can get a long 3.5mm to 1/4 TRS cable or 3.5mm to XLR cable.
Yes. The JBL speaker switch is set to max sensitivity.

Yes, it is a headphone jack type of stereo 3.5 mm connector on the projector.

It is BenQ 1070 ST projector.

Do I need to build or buy a simple voltage amplifier? Any op-amp based will work.
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Quote:
Originally Posted by SouthernCA View Post
Yes. The JBL speaker switch is set to max sensitivity.

Yes, it is a headphone jack type of stereo 3.5 mm connector on the projector.

It is BenQ 1070 ST projector.

Do I need to build or buy a simple voltage amplifier? Any op-amp based will work.
Maybe try switching the JBL to lower sensitivity. But lower the volume first. If the projector isn't sending enough voltage on the AUX out then having the JBL at high sensitivity means it is barely getting any signal hence barely any volume. I looked on line and couldn't find an output voltage for the AUX out. You might shoot BenQ an email or give them a call. Also you might make a post in the projector forum and see if anyone knows the output voltage.
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Combining stereo to mono can cause cancellations due to out of phase info in the stereo mix. If done, you need a simple consumer line level mixer with gain. I don't know of one for $10.

Question is, why mono? Stereo would be much better sounding. JBL 306P is a nice speaker, why not use two in stereo?

Speaker has input sensitivity switch, it should be set to -10, not +4. I'm surprised the aux out of the projector won't drive the speaker loud enough. If it's a headphone jack, does it have a level control?

FYI, mixing to mono may gain you 6 dB (double the voltage), that's with tones and depends on how you combine the signals. If it's through a mixer with pan pots, it depends on the pan pot. You need 10 dB to "double the volume". You probably won't gain much by just mixing music to mono and may have phase cancellations. If the input sensitivity is set to -10, the level on the speaker is max and it's not loud enough, the output of the projector is not high enough or there is a problem somewhere. Cable wired correctly for unbalanced to balanced (RCA to TRS or TS)?
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post #8 of 42 Old 07-22-2019, 12:27 PM
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Originally Posted by SouthernCA View Post
Thanks Steve. I made one cable with 510 ohm resistors on each channel and 21k ohm to ground resistor as in one of the circuits shown here.

The problem is that the volume did not increase compared to just listening to one channel.

Any cheap voltage amplifiers that you can think of?

https://images.app.*******/dRFPcj2AH9f9P7mF8
Your image link didn't work. Plus given that part of the link as been replaced with ******* I suspect this forum will not allow links to that site.

There are low cost Amplfiers on Amazon as well as low cost Pre-Amplifiers, but I think you would still need a Stereo In to two Mono Out Adapter. Keep in mind that you can't really drive a Active Powered Speaker with an Amp, you pretty much need some type of Pre-Amp.

Does the Projector also have Optical Audio Out? Most modern devices do. Though consider that most Optical Audio Outs do not respond to the TV/Projector Volume Control, so the external device (Amp/Pre-Amp) needs to have its own Volume Control, and preferably a Remote Control.

There are low cost (more or less) Pre-Amps like this, but these are really DACs with a Volume Control -

https://www.amazon.com/Fosi-Audio-Co...dp/B07G2NQYLX/

No RCA Inputs, just Optical/Coaxial/USB.

Again a common Amp won't drive Active Powered Speakers, so you need some type of Pre-Amp to drive a speaker like that.

How is it you ended up with a single speaker connected to a Projector? That seems a very limited system. Though I won't presume to spend your money, it seems if you can afford a Projector you can afford a second speaker, and your reasons might have to do with something other than money.

What you really need is something like this -

https://www.amazon.com/Edifier-R2000...dp/B07RZWL77H/

https://www.amazon.com/Edifier-R2000...dp/B016PAWJYS/

A 5" Active Speaker with Analog (RCA) and Optical Inputs, Bluetooth, and a Remote Control. If you look on this page, you will see several lower cost speakers from Edifier -

https://www.amazon.com/s?k=edifier+s...f=nb_sb_noss_1

https://www.amazon.com/Edifier-R1280...dp/B0719C132V/

Though the Edifier R1280DB have 4" bass drivers, but have Optical, RCA, Bluetooth, and Remote Control.

I'm not sure how good it is, but this PYLE Pre-Amp does have a Remote Control -

https://www.amazon.com/Pyle-Rack-Mou...dp/B01MFET2UG/

Though I am making recommendation by speculating on your motives. Mostly assuming you have a very limited budget.

If you are not on a Starvation Budget, then perhaps this is the Pre-Amp you need along with a second speaker -

https://emotiva.com/collections/pre-...roducts/pt-100

Many people have built very basic TV systems based on this compact Pre-Amp -

https://www.crutchfield.com/p_022WXC....html?skipvs=T

It is a Pre-Amp with a Single AUX (RCA) input and Single Optical Input, but it also has Network Streaming. Which is nice.

I would really like an explanation as to how and why you came up with this particular system? Benq Projector and a single JBL 306 Studio Monitor?

Again, assuming you are not starving, there are many much better solutions to a Stereo system for your projector.


Steve/bluewizard

Last edited by bluewizard; 07-22-2019 at 12:54 PM.
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post #9 of 42 Old 07-22-2019, 02:39 PM - Thread Starter
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Originally Posted by liffie420 View Post
Maybe try switching the JBL to lower sensitivity. But lower the volume first. If the projector isn't sending enough voltage on the AUX out then having the JBL at high sensitivity means it is barely getting any signal hence barely any volume. I looked on line and couldn't find an output voltage for the AUX out. You might shoot BenQ an email or give them a call. Also you might make a post in the projector forum and see if anyone knows the output voltage.
The JBL switch is set to give max SPL.
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post #10 of 42 Old 07-22-2019, 02:52 PM
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The JBL switch is set to give max SPL.
Yes and no but aren't you saying its not giving you much volume?
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post #11 of 42 Old 07-22-2019, 03:00 PM - Thread Starter
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Yes and no but aren't you saying its not giving you much volume?
Yes, at max volume it only produces about 75 dB at 1 meter.
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post #12 of 42 Old 07-22-2019, 03:03 PM - Thread Starter
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Originally Posted by Rex Anderson View Post
Combining stereo to mono can cause cancellations due to out of phase info in the stereo mix. If done, you need a simple consumer line level mixer with gain. I don't know of one for $10.

Question is, why mono? Stereo would be much better sounding. JBL 306P is a nice speaker, why not use two in stereo?

Speaker has input sensitivity switch, it should be set to -10, not +4. I'm surprised the aux out of the projector won't drive the speaker loud enough. If it's a headphone jack, does it have a level control?

FYI, mixing to mono may gain you 6 dB (double the voltage), that's with tones and depends on how you combine the signals. If it's through a mixer with pan pots, it depends on the pan pot. You need 10 dB to "double the volume". You probably won't gain much by just mixing music to mono and may have phase cancellations. If the input sensitivity is set to -10, the level on the speaker is max and it's not loud enough, the output of the projector is not high enough or there is a problem somewhere. Cable wired correctly for unbalanced to balanced (RCA to TRS or TS)?
Yes Rex. The problem is either JBL amp is weak ( below specs) or the projector is not giving enough voltage signal. I checked with my iPhone and my Galaxy S7 and s4. The signal level and thus the speaker volume is the same. U checked with my Bluetooth receiver: same. Also checked with an optical to audio aux converter: same signal strength and same speaker volume.

The problem seems to be in the JBL speaker. But tech support says it is working as intended.
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post #13 of 42 Old 07-22-2019, 03:13 PM - Thread Starter
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Originally Posted by bluewizard View Post
Your image link didn't work. Plus given that part of the link as been replaced with ******* I suspect this forum will not allow links to that site.

There are low cost Amplfiers on Amazon as well as low cost Pre-Amplifiers, but I think you would still need a Stereo In to two Mono Out Adapter. Keep in mind that you can't really drive a Active Powered Speaker with an Amp, you pretty much need some type of Pre-Amp.

Does the Projector also have Optical Audio Out? Most modern devices do. Though consider that most Optical Audio Outs do not respond to the TV/Projector Volume Control, so the external device (Amp/Pre-Amp) needs to have its own Volume Control, and preferably a Remote Control.

There are low cost (more or less) Pre-Amps like this, but these are really DACs with a Volume Control -

https://www.amazon.com/Fosi-Audio-Co...dp/B07G2NQYLX/

No RCA Inputs, just Optical/Coaxial/USB.

Again a common Amp won't drive Active Powered Speakers, so you need some type of Pre-Amp to drive a speaker like that.

How is it you ended up with a single speaker connected to a Projector? That seems a very limited system. Though I won't presume to spend your money, it seems if you can afford a Projector you can afford a second speaker, and your reasons might have to do with something other than money.

What you really need is something like this -

https://www.amazon.com/Edifier-R2000...dp/B07RZWL77H/

https://www.amazon.com/Edifier-R2000...dp/B016PAWJYS/

A 5" Active Speaker with Analog (RCA) and Optical Inputs, Bluetooth, and a Remote Control. If you look on this page, you will see several lower cost speakers from Edifier -

https://www.amazon.com/s?k=edifier+s...f=nb_sb_noss_1

https://www.amazon.com/Edifier-R1280...dp/B0719C132V/

Though the Edifier R1280DB have 4" bass drivers, but have Optical, RCA, Bluetooth, and Remote Control.

I'm not sure how good it is, but this PYLE Pre-Amp does have a Remote Control -

https://www.amazon.com/Pyle-Rack-Mou...dp/B01MFET2UG/

Though I am making recommendation by speculating on your motives. Mostly assuming you have a very limited budget.

If you are not on a Starvation Budget, then perhaps this is the Pre-Amp you need along with a second speaker -

https://emotiva.com/collections/pre-...roducts/pt-100

Many people have built very basic TV systems based on this compact Pre-Amp -

https://www.crutchfield.com/p_022WXC....html?skipvs=T

It is a Pre-Amp with a Single AUX (RCA) input and Single Optical Input, but it also has Network Streaming. Which is nice.

I would really like an explanation as to how and why you came up with this particular system? Benq Projector and a single JBL 306 Studio Monitor?

Again, assuming you are not starving, there are many much better solutions to a Stereo system for your projector.


Steve/bluewizard
I had read a lot about the quality of these JBL 306 speakers and bought one just to test. They were cheap and good for that price but did not have the SPL quoted on the spec sheet. The sound quality was also kind of poor - but ok for the price.

I was setting a temporary projector in my bed room and thought I could use these to save space.

And then thought that if I can combine moth channels, I may be able to increase the volume somewhat.

So as Paul Harvey used to say: now you know the rest of the story.
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post #14 of 42 Old 07-22-2019, 03:19 PM
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Combining stereo into mono won't make it any louder unless somebody has mixed the sound to heavily shift certain elements to the left or right channel (which can happen, but is very rare).

I don't think anybody has asked, but is there a volume control on the BenQ projector and is it set to maximum?
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post #15 of 42 Old 07-22-2019, 03:24 PM
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Originally Posted by SouthernCA View Post
I had read a lot about the quality of these JBL 306 speakers and bought one just to test. They were cheap and good for that price but did not have the SPL quoted on the spec sheet. The sound quality was also kind of poor - but ok for the price.
I don't think the problem has anything to do with the cheapness of the speaker. Even lower-end speakers should go quite loud (they might not sound that great loud, but they will go loud). If it isn't getting loud, the problem is almost certainly the fault of the output feeding line-level signal into the JBL. Unless the JBL is defective, it can't be anything else than an input signal that is too low.
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Originally Posted by SouthernCA View Post
Quote:
Originally Posted by liffie420 View Post
Yes and no but aren't you saying its not giving you much volume?
Yes, at max volume it only produces about 75 dB at 1 meter.
Right the point of the selector switch is for input of different voltage that's why I asked if you tried switching it to the low voltage signal. If your feeding a speaker expecting 10 volts with say 5 volts its max spl is lower because its compensating for a low voltage signal. I may have missed where you tried switching to the lower voltage input but if you haven't give it a shot
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post #17 of 42 Old 07-22-2019, 04:06 PM
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I had read a lot about the quality of these JBL 306 speakers and bought one just to test. They were cheap and good for that price but did not have the SPL quoted on the spec sheet. The sound quality was also kind of poor - but ok for the price.
That is not consistent with everything else everyone else says about the JBL 306. These should be fine speakers for the money, very clear with a very large sound stage.

https://www.sweetwater.com/store/det...studio-monitor

Quote:
I was setting a temporary projector in my bed room and thought I could use these to save space.

And then thought that if I can combine moth channels, I may be able to increase the volume somewhat.

So as Paul Harvey used to say: now you know the rest of the story.
Try BOTH Sensitivity Settings - +4db and -10db - Set the Speaker volume to roughly 9. Start with both Bass and Treble set to 0db.

There must be some kind of read out on the Project, or that the projector projects on to the Screen for the Volume Setting - What is that setting? For example 6 out or 10, or 60 out of 100, or however your volume control is calibrated.

What you are saying does not seem right, the JBL 300-Series would probably be considered best in its price class for active speakers.

Does the Projector have any other outputs? Most likely an Optical, we might consider that as an option. Do you have an Amp that has Pre-Amp out? Do you have any type of Pre-Amp to drive the speaker with? You might even be able to drive the speakers with a Smart Phone, though that is perhaps not the best. You could Drive the speakers with a Computer to test them out.

Though there are similar speakers, many would consider the JBL a Best in Price Class Speakers, they are highly rated and should be giving you more than you claim you are getting. Now, we just have to figure out why?

Steve/bluewizard
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Originally Posted by bluewizard View Post
That is not consistent with everything else everyone else says about the JBL 306. These should be fine speakers for the money, very clear with a very large sound stage.

https://www.sweetwater.com/store/det...studio-monitor

Try BOTH Sensitivity Settings - +4db and -10db - Set the Speaker volume to roughly 9. Start with both Bass and Treble set to 0db.

There must be some kind of read out on the Project, or that the projector projects on to the Screen for the Volume Setting - What is that setting? For example 6 out or 10, or 60 out of 100, or however your volume control is calibrated.

What you are saying does not seem right, the JBL 300-Series would probably be considered best in its price class for active speakers.

Does the Projector have any other outputs? Most likely an Optical, we might consider that as an option. Do you have an Amp that has Pre-Amp out? Do you have any type of Pre-Amp to drive the speaker with? You might even be able to drive the speakers with a Smart Phone, though that is perhaps not the best. You could Drive the speakers with a Computer to test them out.

Though there are similar speakers, many would consider the JBL a Best in Price Class Speakers, they are highly rated and should be giving you more than you claim you are getting. Now, we just have to figure out why?

Steve/bluewizard
That is why I bought one just to test. They were told to be too good for the price. And you know when something is too good to be true, it generally is.

For its price I would have been shocked if they were any better than they turned out to be.

I have tried them with smartphone output, projector output, and Bluetooth receiver output, every time assuming that there must be something wrong with the input. But now, we have to accept that these speaker may be defective that JBL does not want to accept. Oh well. It was an experiment and they do currently serve a purpose. The volume is less but acceptable. And I did not buy two of them. Thank God.
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post #19 of 42 Old 07-22-2019, 11:44 PM
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That is why I bought one just to test. They were told to be too good for the price. And you know when something is too good to be true, it generally is.

For its price I would have been shocked if they were any better than they turned out to be.
...
As I said, what you are saying is inconsistent with everyone else who has heard or reviewed this speakers. So either your expectations are exceedingly out of balance, there is something wrong with your system/settings, or there is something wrong with this speakers. Did you mail-order or buy from a dealer? If a dealer, take it back and have them try it out to make sure it is operating properly.

Here is a Sound Demo, how does that rate compared to what you heard?


And here is the person doing the demo's review of the speaker -


They sound incredibly clear to me.

Steve/bluewizard
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As I said, what you are saying is inconsistent with everyone else who has heard or reviewed this speakers. So either your expectations are exceedingly out of balance, there is something wrong with your system/settings, or there is something wrong with this speakers. Did you mail-order or buy from a dealer? If a dealer, take it back and have them try it out to make sure it is operating properly.

Here is a Sound Demo, how does that rate compared to what you heard?

https://www.youtube.com/watch?v=v8omh4hEgoM

And here is the person doing the demo's review of the speaker -

https://www.youtube.com/watch?v=QNDH4bgKwZc

They sound incredibly clear to me.

Steve/bluewizard
Yes. They do. I have been perplexed too. But after talking with JBL customer support a few times, I had to give up. How much time can I spend on a sub $100 powered speaker?

Now I am trying to use them the best I can.
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post #21 of 42 Old 07-23-2019, 08:33 AM
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Originally Posted by SouthernCA View Post
The JBL switch is set to give max SPL.
It's supposed to be set at -10db by default, which is the more sensitive setting according to the OM. It might be worth checking the recessed switch to confirm that the factory didn't screw up and set it to +4db. If it is a refurbished unit (seems difficult to get this monitor for under $100), then maybe the prior owner switched it from the default.

It would definitely be worth trying the other setting regardless of what it looks like it is set to. It's not always clear on those recessed switches which mode is which. The drawing in the owner's manual appears to show the "raised" part of the switch on the +4 setting, which is confusing because the default setting is supposed to be -10 (either they are showing it in the non-default setting of +4, or the -10 setting looks like it's on +4 (at least in that OM drawing)).

Quote:
Originally Posted by SouthernCA View Post
I have tried them with smartphone output, projector output, and Bluetooth receiver output, every time assuming that there must be something wrong with the input. But now, we have to accept that these speaker may be defective that JBL does not want to accept. Oh well. It was an experiment and they do currently serve a purpose. The volume is less but acceptable. And I did not buy two of them. Thank God.
Did you have volume on your smartphone/projector set to max when you tested it? Even inexpensive powered monitors will go very loud -- and $199 list for a powered monitor isn't "cheap" at all in terms of what you can get these days in that price range. I just put Edifier powered monitors, that were only $120 for the pair, in my brother-in-law's house and they go very loud (and sound very good also).

It doesn't cost the manufacturer anything more to make the internal preamp gain more sensitive. As a result, virtually all powered speakers will go a lot louder than 75db's. Cheap speakers may not sound as great loud as the drivers and amp are strained, but they will go very loud. The much more expensive part of the JBL's internal hardware are the power amplifiers, the internal preamp that drives those internal amps costs literally nothing in comparison to the power amps. There is no way JBL would spend the money on biamped 56 watt amplifiers for the LF & HF drivers and then have limited gain on the internal preamp that doesn't allow that 112 watts to be used. It's not possible. The only possibility would be a major design error, but if that was the case, we would have heard about it. There are nearly 500 reviews on Amazon, virtually none are complaining about them being too quiet.

I feel confident there are only 3 possibilities:

1. You happened to get a defective JBL speaker and should get a replacement
2. The cable you are using to test inputs is defective or has a built-in volume control that is set to a low level
3. If neither the JBL nor the cable is defective, then the recessed sensitivity switch is set wrong on the JBL or the volume on the input source (projector, smartphone,...) is set too low (which seems impossible given multiple sources tested -- though you haven't specifically stated that you had volume set to max on these devices).

If JBL is telling you that 75db is "normal", escalate the support case and demand a new speaker. It's good that you tempered your expectations base upon price, but I think you've taken that a bit to the extreme because low volume is not a symptom of any cheap or moderately priced powered monitor.

Last edited by pjp; 07-23-2019 at 11:41 AM.
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post #22 of 42 Old 07-23-2019, 12:33 PM
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The way the projector describes the output voltage is counter intuitive. So, flip the switch to get MORE output. Then, look into getting a second speaker!

EDIT: Read it wrong, my bad! Switch is on the JBL.

It's a VIRTUAL channel unless stated otherwise.

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post #23 of 42 Old 07-23-2019, 12:51 PM - Thread Starter
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Quote:
Originally Posted by pjp View Post
It's supposed to be set at -10db by default, which is the more sensitive setting according to the OM. It might be worth checking the recessed switch to confirm that the factory didn't screw up and set it to +4db. If it is a refurbished unit (seems difficult to get this monitor for under $100), then maybe the prior owner switched it from the default.



It would definitely be worth trying the other setting regardless of what it looks like it is set to. It's not always clear on those recessed switches which mode is which. The drawing in the owner's manual appears to show the "raised" part of the switch on the +4 setting, which is confusing because the default setting is supposed to be -10 (either they are showing it in the non-default setting of +4, or the -10 setting looks like it's on +4 (at least in that OM drawing)).







Did you have volume on your smartphone/projector set to max when you tested it? Even inexpensive powered monitors will go very loud -- and $199 list for a powered monitor isn't "cheap" at all in terms of what you can get these days in that price range. I just put Edifier powered monitors, that were only $120 for the pair, in my brother-in-law's house and they go very loud (and sound very good also).



It doesn't cost the manufacturer anything more to make the internal preamp gain more sensitive. As a result, virtually all powered speakers will go a lot louder than 75db's. Cheap speakers may not sound as great loud as the drivers and amp are strained, but they will go very loud. The much more expensive part of the JBL's internal hardware are the power amplifiers, the internal preamp that drives those internal amps costs literally nothing in comparison to the power amps. There is no way JBL would spend the money on biamped 56 watt amplifiers for the LF & HF drivers and then have limited gain on the internal preamp that doesn't allow that 112 watts to be used. It's not possible. The only possibility would be a major design error, but if that was the case, we would have heard about it. There are nearly 500 reviews on Amazon, virtually none are complaining about them being too quiet.



I feel confident there are only 3 possibilities:



1. You happened to get a defective JBL speaker and should get a replacement

2. The cable you are using to test inputs is defective or has a built-in volume control that is set to a low level

3. If neither the JBL nor the cable is defective, then the recessed sensitivity switch is set wrong on the JBL or the volume on the input source (projector, smartphone,...) is set too low (which seems impossible given multiple sources tested -- though you haven't specifically stated that you had volume set to max on these devices).



If JBL is telling you that 75db is "normal", escalate the support case and demand a new speaker. It's good that you tempered your expectations base upon price, but I think you've taken that a bit to the extreme because low volume is not a symptom of any cheap or moderately priced powered monitor.
You are probably correct about my giving up too early. But for $100, how much time could one spend?

And this was a new unit from Guitar Center. By the time I was done with JBL customer support, the return window had closed.
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Quote:
Originally Posted by RayGuy View Post
The way the projector describes the output voltage is counter intuitive. So, flip the switch to get MORE output. Then, look into getting a second speaker!
What do you mean? I don't see any switch in BenQ 1070 projector.
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post #25 of 42 Old 07-23-2019, 01:16 PM
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Quote:
Originally Posted by SouthernCA View Post
Yes. They do. I have been perplexed too. But after talking with JBL customer support a few times, I had to give up. How much time can I spend on a sub $100 powered speaker?

Now I am trying to use them the best I can.
Again, what you are saying goes completely counter to what everyone else is saying. Given that you paid less than $100 for a $200 speakers, the speakers is somewhat suspect. Was it Used? Where did you get it?

I would suggest you go down to a Musician Supply Store and listen to the JBL 305 or 306, I think your experience will be very different than what you are experiencing at home.

While you are there check out the Mackie MR524 and MR624 -

https://www.sweetwater.com/store/det...studio-monitor

https://www.sweetwater.com/store/det...studio-monitor

Though I think for a home theater system, the Edifier are a better choice.

If you want to add a good but compact system to your projector, then take a look at the Edifier Speaker, all of which are available on Amazon -

https://www.edifier.com/us/en/shop?p...eatures_group=[[%22bookshelf%20speakers%22]]

NOTE: apparently the Forum doesn't like square brackets in a web link, so cut and past this -

edifier.com/us/en/shop?product_type=Speakers&features_group=[[%22bookshelf%20speakers%22]]

Or just go to Edifier.com, select Products, then select Bookshelf Speakers.

Specifically at the R2000DB ($249/pr) and the S2000Pro ($399/pr) -

https://www.edifier.com/us/en/speake...th-optical-rca

https://www.edifier.com/us/en/speake...tudio-monitors

If you think you might prefer a 2.1 system then look at the Edifier S350DB ($299/set) -

https://www.edifier.com/us/en/speake...kers-subwoofer

All have Aux or 2xAux Input, Optical Inputs, some have Coaxial Inputs, Bluetooth, Remote Control.

Klipsch also makes an Active Speaker with Remote -

Klipsch R-51PM - Phono/Aux, USB, Optical, Bluetooth, Remote - $499/pr -

https://www.klipsch.com/products/r-5...wered-speakers

https://f072605def1c9a5ef179-a0bc3fb...-Sheet-v03.pdf

You said you paid less than $100 for the speakers, but one has to wonder why when the common selling price is $200? I suspect this is not a good speaker which is why it sold so cheap.

Given that, in general, the JBL 306 is a top performer in its price class, one of several things has to be wrong -

- Something isn't kosher with the output of the Projector.
- Setting on the Speaker are not correct.
- The Speaker itself is bad.


There are several questions you have not answered which would be helpful in us understanding the problem -

- Where did you get this speakers so cheap?
- What is the volume setting of the Speaker?
- What is the volume setting of the Projector?
- What Cable, Connectors, and Cable Adapters are you using?


Again, I suggest you find a GOOD JBL 306 to listen to somewhere on some other system, I think you will be impressed.

If you have Headphones, plug those into the Projector and see how it sounds. That would tell us something. Though we would have to work out what it tells us once we hear the results.

Something is wrong somewhere, because what you are saying is absolutely inconsistent with everything everyone else in the world is telling us.

Steve/bluewizard

Last edited by bluewizard; 07-23-2019 at 03:48 PM.
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post #26 of 42 Old 07-23-2019, 01:36 PM
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Just for reference, here is a link to what I assume is the correct projector - BENQ W1070 -

https://www.benqdirect.com/w1070-refurb.html#

Steve/bluewizard
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post #27 of 42 Old 07-23-2019, 01:51 PM
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Quote:
Originally Posted by SouthernCA View Post
You are probably correct about my giving up too early. But for $100, how much time could one spend?

And this was a new unit from Guitar Center. By the time I was done with JBL customer support, the return window had closed.
You don't need to be within the return window. The only reason "returning" is important is if you got the wrong model. The model you selected is a great speaker -- there is zero chance that it won't be great and loud for what you want to use it for. Guitar Center's return window is only 30 days, JBL's warranty should be much longer than that. Either you are using it wrong (which we can help you fix), or it is defective (in which case JBL is obligated to replace it under warranty).

Please answer the questions that have been asked of you to help determine exactly what's wrong.

Specifically:

1. What happens to volume when you flip the JBL input sensitivity to the opposite direction of what it is currently set to? It doesn't matter what you think it's set to, try the opposite setting -- this is by far the most likely cause of the problem.

2. Do you have the volume control of the BenQ and the smartphone set to maximum volume?

3. Are you using the same 3.5mm cable for all the inputs you tested and have you tried a different cable to make sure it's not defective?

If none of the above addresses the volume issue, the speaker is defective and you have an "open and shut" case to get a warranty replacement from JBL, but the first thing to do is to provide answers to the 3 questions above.
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post #28 of 42 Old 07-23-2019, 02:33 PM - Thread Starter
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Quote:
Originally Posted by pjp View Post
You don't need to be within the return window. The only reason "returning" is important is if you got the wrong model. The model you selected is a great speaker -- there is zero chance that it won't be great and loud for what you want to use it for. Guitar Center's return window is only 30 days, JBL's warranty should be much longer than that. Either you are using it wrong (which we can help you fix), or it is defective (in which case JBL is obligated to replace it under warranty).



Please answer the questions that have been asked of you to help determine exactly what's wrong.



Specifically:



1. What happens to volume when you flip the JBL input sensitivity to the opposite direction of what it is currently set to? It doesn't matter what you think it's set to, try the opposite setting -- this is by far the most likely cause of the problem.



2. Do you have the volume control of the BenQ and the smartphone set to maximum volume?



3. Are you using the same 3.5mm cable for all the inputs you tested and have you tried a different cable to make sure it's not defective?



If none of the above addresses the volume issue, the speaker is defective and you have an "open and shut" case to get a warranty replacement from JBL, but the first thing to do is to provide answers to the 3 questions above.
1. Have tested both positions of the JBL speaker switch

2. BenQ projector output volume is controlled by BenQ remote and is set at the max.

3. I have used two cables. In one case I just used one channel of the stereo to feed the power speaker and in other case used the cable I made by combining two channels into one by using 510 ohm series resistance and 21k ohm resistance to ground.

Volume did not change either way too much.
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post #29 of 42 Old 07-23-2019, 02:58 PM
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Quote:
Originally Posted by SouthernCA View Post
1. Have tested both positions of the JBL speaker switch

2. BenQ projector output volume is controlled by BenQ remote and is set at the max.

3. I have used two cables. In one case I just used one channel of the stereo to feed the power speaker and in other case used the cable I made by combining two channels into one by using 510 ohm series resistance and 21k ohm resistance to ground.

Volume did not change either way too much.
Did the volume change a lot when you flipped the sensitivity switch? If not, that is likely a huge hint about what is defective with the monitor. If you've duplicated the same thing with a phone, also at max volume, that eliminates the source as a possible issue and you have more than enough justification for JBL to provide a replacement under warranty. Is it still under warranty? If it was a "floor model" sale (I'm also trying to figure out how you got it for under $100), I'm pretty sure that Guitar Center's floor model sales still include full factory warranty.
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post #30 of 42 Old 07-23-2019, 03:23 PM - Thread Starter
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Did the volume change a lot when you flipped the sensitivity switch? If not, that is likely a huge hint about what is defective with the monitor.


Yes it did change. It went down.

If you've duplicated the same thing with a phone, also at max volume, that eliminates the source as a possible issue and you have more than enough justification for JBL to provide a replacement under warranty. Is it still under warranty?

If it was a "floor model" sale (I'm also trying to figure out how you got it for under $100), I'm pretty sure that Guitar Center's floor model sales still include full factory warranty.

Not a floor model. It was in sale last Christmas. I am not supposed to mention price. So I am not mentioning it.
See my answers above.
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