# USB Soundcard for REW



## carmaniac13 (Jan 3, 2011)

I'm putting together my measurement rig to use with REW, which currently includes a Dayton EMM-6 calibrated from CSL.

I'm trying to decide on a USB preamp now, and I was hoping that REW Sound Card Database would offer some insight, but it hasn't really seemed to take off yet.

http://www.hometheatershack.com/forums/spl-meters-mics-calibration-sound-cards/52505-rew-sound-card-database.html

I think I've narrowed it down to the Tascam US-144 mkII, and the M Audio Fast Track Pro. I've been reading as much as I can about them, and they both seem pretty comparable. They both have multi-in multi-out and ASIO support, Phantom power, zero-latency headphone outputs, as well as SPDIF in/out, which is something extra I wanted so I can hopefully use it as a decent outboard soundcard for my laptop if the mood strikes.

The nitty gritty specs are very similar, based on what I've found published. The Tascam lists the response as 20-20k +0.5dB/-1.0dB, whereas the M Audio is 20-20k +/-0.1dB. Both should be fine and easily cleaned up by the REW calibration, but the M Audio might point to having better amplitude and phase response outside the rated bandwidth (specifically < 20Hz).

It seems there's a few people around here that have used Tascam, but has anyone tried out this M Audio? I'm open to suggestions as well if there's a product I'm overlooking.

Thanks for the help!


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## carmaniac13 (Jan 3, 2011)

Went with the Tascam. Got it for $109 minus a $15 mail in rebate. Couldn't pass that up compared to the $149 for the M Audio.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Too late to recommend the US-122 instead (it’s all over the Database thread; don’t know why it didn’t appeal to you). It’s cheaper than the 144 and AFAIK only lacks the firewire output, which isn’t needed for REW. Still, $95 is a really good price for the 144...

Regards,
Wayne


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## carmaniac13 (Jan 3, 2011)

Both are USB. The 144 adds S/PDIF in/out, which was something extra that I wanted so I can use the card for more than just REW measurements.


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## carmaniac13 (Jan 3, 2011)

Just wanted to give an update on this Tascam. I ran the soundcard calibration on it, using both the Headphone Output as well as the Line Out Output. Here are the phase/magnitude plots.

Using the Headphone Output:









Using the Line Out Output:








Tests were done using 96/24 sampling rate. Output signal at -6dB, input adjusted to -9dB. Had REW use the ASIO drivers and everything worked great!

-3dB responses:
3.3Hz - 39.753kHz for Headphones
4.4Hz - 45.787kHz for Line Out

I haven't done any speaker testing yet, hopefully I'll get to that this weekend.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Down less than 1 dB at 10 Hz and less than .5 dB at 30 kHz. With response like that, who needs a calibration file? 

Regards,
Wayne


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## chinni123 (Jan 8, 2012)

carmaniac13 said:


> Both are USB. The 144 adds S/PDIF in/out, which was something extra that I wanted so I can use the card for more than just REW measurements.


Does S/PDIF means using coax or fiber optic cable that was used to connect digital audio before hdmi came?

If so, does 144 suppports coax or fiber optic?

Does S/PDIF input/output means, audio receiver can be connected to sound card using this output for REC calibration?

Curious what is use of this beyond REC. I read that these USB sound cards are used for recording cd quality audio. I never knew all this stuff before researching room analyzer software. Appreciate little education.


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## Wayne A. Pflughaupt (Apr 13, 2006)

These interfaces are primarily used by musicians who want to record their instruments and / or voices straight to the computer. The (coax) digital output possibly could be used for REW (as a feed to the AVR), but wouldn’t offer any advantage over standard analog signals. It would merely introduce unnecessary “stuff” in the signal chain (i.e. digital / analog conversions on both ends).

Regards,
Wayne


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## carmaniac13 (Jan 3, 2011)

The 144 has a coax input/output pair that can be used for digital audio signals. The 144 supports both S/PDIF format as well as some AES standard that I'm unfamiliar with. The manual says it's used in professional audio.

As Wayne said, these interfaces are generally geared for musicians and recording techs for the purpose of music playback/recording. The 144 has two XLR inputs with phantom power for connecting microphones. It also has 1/4" line in's and a guitar preamp. In addition to that, it also has MIDI input and output, which allows for the connection of any MIDI device to record to the computer.

As far as recording quality, this device can record at much better than CD quality, if your computer has recording software and enough processing power. Standard CDs are 16/44.1KHz, and the 144 is capable of recording at up to 24/96kHz.

The digital inputs/outputs were a feature I did want on my card, but I don't use them with REW. When working in REW, I use the 144's onboard DAC/ADC and send analog outputs to the stereo and the loopback channel.

The digital out gives me the option to have a pure digital signal chain from my laptop to my receiver. Using the receiver's DAC would definitely be better than the one in my laptop. (The one in the 144 might be of comparable quality though)


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## chinni123 (Jan 8, 2012)

That cleared my understanding better. Thanks to both Wayne and carmaniac13. 

Wayne, I am glad to find somebody from Texas in the forum. I live in Dallas and studied in Houston. I came couple of times to Katy where Ikea located. I enjoy reading your posts.

carmaniac13, Can I ask where did you buy Tascom. It is good deal. I also plan to order one of the calibrated microphone from cross spectrum to use with device.


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## carmaniac13 (Jan 3, 2011)

I got it on amazon.com.

There are other less expensive options available, if you don't need all the features the 144 has. The Tascam 122 is one such option.


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## chinni123 (Jan 8, 2012)

carmaniac13 said:


> Both are USB. The 144 adds S/PDIF in/out, which was something extra that I wanted so I can use the card for more than just REW measurements.


Other than for REW, what else one can use this device. I guess one can record music program or an event better than cd quality. I don't know any other reason.

It seems SPDIF is useful if A/D conversion is better in receiver. Is it possible to send mp3 songs to receiver using spdif? 

That will help me to avoid using projector to listen to songs. Now, I have to turn on projector to traverse through folders to pick a file from hard drive connected to media player. If I use spdif, then I can listen songs from laptop.


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