Combing channels from a 3.5mm stereo jack to mono

[Greg C.]

Several of you have mentioned that you don't want to use up 2 channels of your mixer (understandable) for music playback from your iPod/iPad/MP3 player/laptop/etc. So far, I haven't found a cable pre made on the market that does proper resistive summing of the left and right channels. There are plenty that don't like this common Hosa cable. They merely short the left and right hots together. Though you're device may have some protection from burning out the output driver of your headphone jack, it's not ideal. At minimum it can result in distortion, at worst it can result in damage to the output. I'm sure many of you have read "Why Not Wye", that pretty much explains it all. If you don't feel like building such a cable, you might consider something like the IsoPod. There are also DIs on the market that will properly sum line output to mono made by Whirlwind, Radial, etc. FWIW.

[RoadRanger]

http://www.pimfg.com/Product-Detail/PVS-582-PT
Works great!

[WK154]

So what's wrong with a $4.55 cable that gives you the option to go one or two DL channels with an iPad by flipping a switch (software) for mono or stereo? If your devise doesn't have this ability (stereo to mono) I can see the benefit of other solutions.
http://www.bhphotovideo.com/c/product/846982-REG/Hosa_Technology_HMP_003Y_REAN_3_5_mm_TRS.html

[RoadRanger]

It's pretty common for a band to have stuff they want to play (break music and/or tracks) on an iPhone, MP3 player, or whatever and I don't want to have to go into it to set it to mono. BTW that transformer thing I linked has a REALLY short cord but you can just use a regular XLR cord to extend it out to wherever it need to be - I generally prefer whomever owns it to operate it instead of me fumbling with it. That way it's not my fault if it's messed up .

[Greg C.]

http://www.pimfg.com/Product-Detail/PVS-582-PT
Works great!

There we go, I knew I has seen a couple of different solutions out there. Just couldn't track them down. This isn't unlike the Whirlwind device, a lot less expensive though. I wonder how good the transformer is as far as LF saturation goes...

[Keyboard Magic]

I don't know if you can get ART Pro Audio Gear everywhere, but here's another option to check out if anyone's interested? The price is Canadian, and maybe a little expensive? It might be worth a look just the same.

http://www.long-mcquade.com/11048/Pro_Audio_Recording/Mic_Preamps_DI_Boxes/ART_Pro_Audio/ART_Stereo_Multi-Media_Interface_to_Single_Mic_Input.htm

 

[stevegarris]

Wow - a lot of great choices here - Thanks Greg!

The Whirlwind unit looks nice, but $50 is a lot after seeing the $12 cable from PI.

I had looked and and considered the ART unit at one time.

I'm going to order the PI unit today.

[Greg C.]

I suspect the Whirlwind model has a better transformer which means flatter frequency response and less distortion - especially with hotter input levels. Typically the cheapy transformers, like in cheap DIs and line level isolation transformers, tend to saturate at lower frequencies and add distortion. But the PI probably works fine based on Road Ranger's observation.

[stevegarris]

I suspect the Whirlwind model has a better transformer which means flatter frequency response and less distortion - especially with hotter input levels. Typically the cheapy transformers, like in cheap DIs and line level isolation transformers, tend to saturate at lower frequencies and add distortion. But the PI probably works fine based on Road Ranger's observation.

I'll let you know, I've got one coming.

[stevegarris]

I suspect the Whirlwind model has a better transformer which means flatter frequency response and less distortion - especially with hotter input levels. Typically the cheapy transformers, like in cheap DIs and line level isolation transformers, tend to saturate at lower frequencies and add distortion. But the PI probably works fine based on Road Ranger's observation.

I'll let you know, I've got one coming.

OK - Last night I did a quick test. I found the Beatles recording that always sounded funny on playback (disappearing guitars, weird instrument levels changes). Tried both my Radio Shack stereo to mono adapter, and the PI transformer cable.

Neither cable fixed the weird sound on this recording, which I believe is a bad mp3 file. The Radio Shack cable sounded best, with excellent bass and clarity. The PI cable really sounded bad in comparison. I left my Radio Shack cable in the rest of the night, playing recorded music for a small dinner party we were having. Everything coming through it sounded fantastic.

I'm going to do some additional testing, but my preliminary report is that the PI "DJ" transformer cable is no better than a simple adapter, and perhaps worse.

[Greg C.]

OK - Last night I did a quick test. I found the Beatles recording that always sounded funny on playback (disappearing guitars, weird instrument levels changes). Tried both my Radio Shack stereo to mono adapter, and the PI transformer cable.

Neither cable fixed the weird sound on this recording, which I believe is a bad mp3 file. The Radio Shack cable sounded best, with excellent bass and clarity. The PI cable really sounded bad in comparison. I left my Radio Shack cable in the rest of the night, playing recorded music for a small dinner party we were having. Everything coming through it sounded fantastic.

I'm going to do some additional testing, but my preliminary report is that the PI "DJ" transformer cable is no better than a simple adapter, and perhaps worse.

It sounds like the file might be shifting stuff in and out of phase left relative to right. When in full stereo, you wouldn't notice it so much in the acoustic domain. But when summed electrically, it cancels before it makes it out to the speakers.

[cupojoe]

new dl1608 user - forum lurker until now

We use an iphone into the dl1608 for music to start sound checking and for breaks.   I also went the DI box route to get it to one channel :

 http://www.musiciansfriend.com/pro-audio/rapco-horizon-stl-1-stereo-line-direct-box?source=3WWRWXGP&gclid=Cj0KEQjwpvufBRCwzp_zyqfkhrcBEiQA8b-SHFJ1nXlwrbtEWmZsiCHUlEzQlWoHBgbni88BitGtjZ8aAvDQ8P8HAQ&kwid=productads-plaid^82226234787-sku^336017000000000@ADL4MF-adType^PLA-device^c-adid^51870555867

It works great with left and right inputs down to one XLR out (XLR B channel in mono mode).    I also use phantom power so I wanted that separation.  However, I'd totally opt for a simpler cable solution if anyone has a less cumbersome suggestion than a DI box.   

[thedrums]

However, I'd totally opt for a simpler cable solution if anyone has a less cumbersome suggestion than a DI box.   

http://www.sweetwater.com/store/detail/ISOPOD

[gtrdudes]

For what it's worth I've made the hosa type cable. Left and right (tip and ring of the 1/8") to the hot (tip of the 1/4"). Used it for two years now with no problems.  I've used iPhones, iPods, etc... 

If it works, Wye fix it.

[cupojoe]

However, I'd totally opt for a simpler cable solution if anyone has a less cumbersome suggestion than a DI box.   

http://www.sweetwater.com/store/detail/ISOPOD

Thanks.   I hadn't seen that before... Slick.