HydrogenAudio

CD-R and Audio Hardware => Audio Hardware => Topic started by: TooSteep on 2012-02-09 18:44:12

Title: Hooking up PC to powered speakers with XLR?
Post by: TooSteep on 2012-02-09 18:44:12
Hello all:

I believe I am about to come in to possession of a pair of powered DJ speakers. I believe they have XLR connectors on the back.

What is the simplest method of connecting my PC to them and controlling the volume from my desk, strictly for playback (no recording)?

Right now, I have an external 24-bit USB box, with analog RCA outs that I run into my amplifier that sits on a shelf at the side of my room. The amp has a simple little remote control that I use from my desk to control the volume on my stand-mounted monitors. I keep the volume control in Windows and on Foobar set to maximum - assuming (hoping?) that it gives me maximum bit depth for the music.

Is there a 'de facto' standard method around here for hooking up to Active pro-audio gear?

Thanks.
Title: Hooking up PC to powered speakers with XLR?
Post by: punkrockdude on 2012-02-09 19:05:40
Be sure that the output that the sound card puts out does not exceed the input the speakers can take. For example if your sound card output +21 dBU and your speakers accepts up to let's say +18 dBU then you might get clipping since the sound card can output 3 dB more than your speakers can recieve. If hope I have got it right. If not, someone else will correct me.

Check your active monitors that any eq shelves on the back is set to their 0 positions to start with to have an unaltered sound. Regards.
Title: Hooking up PC to powered speakers with XLR?
Post by: DVDdoug on 2012-02-09 19:17:08
Quote
I believe I am about to come in to possession of a pair of powered DJ speakers. I believe they have XLR connectors on the back.
Virtually all computer speakers are powered/active.    Just make sure those are line-level inputs, not microphone inputs.

The XLR is normally a balanced connection (two "push-pull" signal wires plus a ground).  But, with the appropriate adapter, you can connect unbalanced (computer or "RCA") signals.   

If you know how to solder, this page[/u] (http://www.rane.com/note110.html) has all of the information about mixing & matching balanced & unbalanced connections.  There are "more adavanced" ways of converting between balanced & unbalanced connections involving transformers or active adapter boxes, but these are usually not necessary for home use.

Quote
I keep the volume control in Windows and on Foobar set to maximum - assuming (hoping?) that it gives me maximum bit depth for the music.
It's generally a good idea to keep the strongest signal possible though the audio-chain.  But, any loss of bits/resolution at low listening levels is at levels you can't hear anyway.    Essentially the same thing happens with analog...  i.e. The signal-to-noise ratio is reduced when you lower the volume, but hopefully the noise is below the threshold of hearing and at low levels, you can't hear the little low-level details.    The "damage" happens only when you reduce the level (analog or digital) and then re-amplify it.

And, any noise you hear from the active speakers will be more noticeable if you reduce the volume digitally.  (The analog gain control on the speakers may reduce the signal and noise together).    But hopefully, you won't be hearing noise from the speakers and this won't be an issue
Title: Hooking up PC to powered speakers with XLR?
Post by: dumdidum on 2012-02-09 19:23:58
well, there are volume controls for studio monitors (e.g., tc electronic level pilot). there are also variations of these that come with a remote.

however, the problem with those volume controls/monitor management devices from your perspective is that they come with balanced ins and outs. i mean, you could go from your 24-bit interface into a DI box to a volume control and finally to your monitors. but that's a bit convoluted as a solution, you'd have to add two pieces of gear.

alternatively, you could purchase an audio interface with balanced outputs. or maybe the monitors have RCA inputs. (in fact, most DJ monitors do.) also, some DJ monitors include a volume control (e.g., pioneer s-dj05/08)
Title: Hooking up PC to powered speakers with XLR?
Post by: punkrockdude on 2012-02-09 19:41:02
however, the problem with those volume controls/monitor management devices from your perspective is that they come with balanced ins and outs. i mean, you could go from your 24-bit interface into a DI box to a volume control and finally to your monitors.
Isn't a DI box' intention to convert a high Z to low Z?
Title: Hooking up PC to powered speakers with XLR?
Post by: dumdidum on 2012-02-09 20:06:13
Isn't a DI box' intention to convert a high Z to low Z?

yeah, usually it takes high impedance unbalanced and converts to low impedance balanced. they're also used to break ground loops. is there something deeper behind your question? that is, are you trying to say my suggestion of using a DI box is unreasonable?
Title: Hooking up PC to powered speakers with XLR?
Post by: punkrockdude on 2012-02-09 20:57:21
Isn't a DI box' intention to convert a high Z to low Z?

yeah, usually it takes high impedance unbalanced and converts to low impedance balanced. they're also used to break ground loops. is there something deeper behind your question? that is, are you trying to say my suggestion of using a DI box is unreasonable?

Did I make you upset?
Title: Hooking up PC to powered speakers with XLR?
Post by: TooSteep on 2012-02-10 02:30:21
Interface that takes USB input, outputs XLR and has a volume control?

It looks like these ones only have XLR inputs. So it seems that I want an interface that accepts a USB input, has an internal DAC, has XLR outputs, and has a volume control. I guess I could sit it on my desk and have a long run of XLR to the speakers.

Any suggestions on a good quality interface, with minimum extra features, and minimum processing in the volume control?

Thank you.
Title: Hooking up PC to powered speakers with XLR?
Post by: TooSteep on 2012-02-10 03:12:27
Passive Volume Attenuator

I just found this:
http://www.smproaudio.com/index.php/en/pro...llers/nanopatch (http://www.smproaudio.com/index.php/en/products/monitor-controllers/nanopatch)
http://www.amazon.com/SM-Pro-Audio-Passive.../ref=pd_cp_MI_0 (http://www.amazon.com/SM-Pro-Audio-Passive-Attenuator/dp/B000T9K8ZO/ref=pd_cp_MI_0)

I think it is exactly what I need. It appears that it will accept the unbalanced analog RCA outs from my USB DAC (I'll need an RCA-to-1/4" stereo TRS cable), and feed the active monitors using a 1/4" TRS-XLR speaker cable.

It's a lot of wires and boxes, but it should do the trick if I cannot find a USB-DAC/attenuator combo.

Title: Hooking up PC to powered speakers with XLR?
Post by: pawelq on 2012-02-10 04:05:14
Interface that takes USB input, outputs XLR and has a volume control?

For example, an M-Audio Fast Track Pro like on playing in front of me right now. It has TRS (not XLR) balanced outputs, but that's not a problem, you'll just get two TRS-to-XLR cables, like I did.


Fast Track Pro has analog volume control on line out (speaker) outputs, and separate analog volume control on headphone output. There are also unbalanced RCA outputs. It has some additional features, like microphone preamps with Phantom Power, but I did not mind getting them as the interface is rather cheap anyway (I think I paid ~$150 at B&H and got a free dynamic microphone as a bonus). Ultimately, I even used these Phantom Power preamps a few times.

Quality is not bad, the line out volume pot could be better. Sometimes it can slightly crackle when turned, and there is also a bit of channel imbalance but both only occur right above zero, extremely low levels, which I never use anyway. At low, normal, and high volume levels - no problems.

Rarely I experience problems with USB transmission, typically when graphic intensive operations are performed on the computer - tests on another computer suggest that this may be a pecular feature of my machine.

Headphone amp could produce a bit higher volume than it does with my low-sensitivity Sennheisers HD580; I guess it could be remedied if I powered the interface from a 9V power supply, not from 5V USB.


There are several other options, e.g., Lexicon Alpha, Alesis iO2 Express, PreSonus AudioBox USB, E-mu 0404 USB2.0.
Title: Hooking up PC to powered speakers with XLR?
Post by: Glenn Gundlach on 2012-02-10 05:20:29
Be sure that the output that the sound card puts out does not exceed the input the speakers can take. For example if your sound card output +21 dBU and your speakers accepts up to let's say +18 dBU then you might get clipping since the sound card can output 3 dB more than your speakers can recieve. If hope I have got it right. If not, someone else will correct me.

Check your active monitors that any eq shelves on the back is set to their 0 positions to start with to have an unaltered sound. Regards.


Every sound card I've run into over the years puts out 2 V p-p at 0dB Fs. Obviously there are specialty cards that do more but they're the exception rather than the rule. At work (broadcast, commercial duplication and post production) the common way to interface pro and consumer gear is to use a Henry Matchbox. There are of course others and the ambitious can build an equivalent since it's nothing more than opamps and a power supply. You'll find however that if your time is worth more than minimum wage it's cheaper to buy one ready to go but there is always the satisfaction factor.

http://henryeng.com/matchbox.html (http://henryeng.com/matchbox.html)

Title: Hooking up PC to powered speakers with XLR?
Post by: Arnold B. Krueger on 2012-02-14 13:20:43
Hello all:

I believe I am about to come in to possession of a pair of powered DJ speakers. I believe they have XLR connectors on the back.

What is the simplest method of connecting my PC to them and controlling the volume from my desk, strictly for playback (no recording)?

Right now, I have an external 24-bit USB box, with analog RCA outs that I run into my amplifier that sits on a shelf at the side of my room. The amp has a simple little remote control that I use from my desk to control the volume on my stand-mounted monitors. I keep the volume control in Windows and on Foobar set to maximum - assuming (hoping?) that it gives me maximum bit depth for the music.

Is there a 'de facto' standard method around here for hooking up to Active pro-audio gear?


About as close to that as there to a standard for interconnecting balanced and unbalanced equipment as there is would be this page on the web:

Rane Note 110 (http://www.rane.com/note110.html)
Title: Hooking up PC to powered speakers with XLR?
Post by: LocrianGroove on 2012-07-01 06:57:51
I also would like to connect my PC, as well as TV (with fixed volume level output) to active studio monitors.  I'd like to control volume via a handheld remote control (e.g. an IR type used in controlling A/V gear), without having to buy a receiver.  Basically a line level controller with a remote control for cheap is what I'm looking for.  Are these device available?
Title: Hooking up PC to powered speakers with XLR?
Post by: Roseval on 2012-07-01 12:52:22
Interface that takes USB input, outputs XLR and has a volume control?


Many USB DACs today do have volume control. We call it a DAC but a pre-amp with USB input is what they are
Have a look at Benchmark DAC1, Mytek, etc
http://www.thewelltemperedcomputer.com/HW/USB_DAC_Async.htm (http://www.thewelltemperedcomputer.com/HW/USB_DAC_Async.htm)
Title: Hooking up PC to powered speakers with XLR?
Post by: mzil on 2012-07-01 17:12:15
I believe I am about to come in to possession of a pair of powered DJ speakers. I believe they have XLR connectors on the back.

I bet they already have unbalanced inputs too, in which case you won't need to buy/make any adapter. What are they exactly?

XLR is a nice beefy connection useful in a professional setting like a stage or studio where equipment is constantly being connected and disconnected. Balanced runs also have a theoretical advantage that they are less prone to picking up any "common mode" noise, such as hum from extraneous noise generators, when used over long runs such as across a stage or across a studio, however for short range desktop use, where you connect once, let it sit that way for months or even years without disconnecting, and send the signal only a short distance, balanced connections have no real world advantage. It is a myth that they do. [Barring some unusual common mode noise source induced over that short run, which isn't likely.]
Title: Hooking up PC to powered speakers with XLR?
Post by: RonaldDumsfeld on 2012-07-01 22:18:47
As several correspondents have already observed, It makes sense to connect pro quality speakers to a audio interface from the same stable of pro gear producers. pawelq has made some good suggestions.

Quote
I'd like to control volume via a handheld remote


This is a bit more tricky. The only one's I know of atm come from leading supplier RME.

RME UCX (http://www.rme-audio.de/en_products_fireface_ucx.php)

Although the unit is not really dear compared to hi-fi grade gear I doubt many people would be prepared to pay $1,000+ plus for such a luxury.

However since where RME leads the herd tends to follow we can look forward to less expensive alternatives appearing in the coming months.