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ISDN and Source-Connect Explained for Voice Actors

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This post is an updated version of the original article, which was first published on February 5, 2008.

For anyone new to the voice over industry, or to this tech, ISDN in the simplest terms is a digital connection that voice actors and their clients use to come together in a recording session. It supports the transmission of voice (a conversation) and data (a recorded voice over file) at the same time. Through ISDN, a client is able to record studio quality audio live as the talent performs the voice over, rather than have the voice actor send over an audio file after the fact.

It’s as if the voice actor was recording in a client’s in-house studio.

The main benefits of ISDN are:

  1. The talent has little to no follow up work with a client after a recording session through this digital connection because all of the work is completed in the session.

  2. The client is able to provide in-the-moment artistic direction, eliminating the need for retakes and any back and forth communications. They get exactly what they need, with no further delay of deliverables.

  3. Because the ‘call’ has better sound quality, the client can truly hear the nuances and inflections that a voice actor incorporates into their performance. This helps the client to better direct the talent if needed and makes it even easier to appreciate greatness in the voice actor’s read.

The main detractors of ISDN are:

  1. The service comes with an expensive monthly bill through your phone provider.
  2. To enable ISDN, you must also purchase a codec to connect the line into your recording system. Without going into the nitty-gritty, the codec is a piece of hardware that requires an initial investment in the thousands of dollars.
  3. Connecting with a phone company that can offer you ISDN is becoming more and more difficult to find.

Though ISDN has begun to experience a ‘phasing out’ over the last five to seven years, there are still handfuls of production houses and ad agencies in the USA specifically, that are happy using this older, yet reliable, technology.

However, that doesn’t mean that voice actors need to have ISDN in order to work with these agencies and production houses. There are now more cost-effective alternatives that allow connectivity to an ISDN line.

What is Source-Connect?

Now an industry standard, Source-Connect is an ISDN alternative that enables all of the above benefits without any of the above pitfalls, as it is a reasonably priced, monthly subscription software.

It allows its users to bridge into any ISDN line, making the need for an actual ISDN line obsolete. It also boasts audio quality on par with that of an ISDN line as well, enabling every user to achieve the connectivity required for smooth audio project management.

Available for Windows and Mac, Source-Connect makes remote recording sessions achievable from anywhere in the world with internet access. It even offers a plugin to connect directly to Pro Tools, the recording software, that allows users to directly pull audio files into Pro Tools for post-production work.

If the concept still isn’t quite clear yet, here’s a great video demonstrating how the Source-Connect software is able to bring together two parties from across the globe (as well as bring the audio into Pro Tools).

Using Source-Connect is a reliable, hassle-free way of being there with the client’s creative team, voice actor Brad Avenyou says.

“Much of our work as voice artists is (satisfyingly) solitary. Working with a director, producer and writers in a studio setting, however, is a golden opportunity to learn, contribute and grow. If you can’t be in the studio with the team – working remotely is the next best thing,” Brad says.

It’s critical to be able to offer clients a way to connect with you and record professional-grade recordings of your voice from their end. Especially with the growth in remote voice over jobs where clients and voice actors are working together from anywhere in the world. Source-Connect is certainly a more attainable and realistic option for voice actors who want to provide this level of service to potential clients.

What is a Phone Patch?

A phone patch is another way to enable the transfer of high-quality audio recordings to a client. Much like Source-Connect, a phone patch has the benefit of facilitating in-the-moment feedback and collaboration, with no delay of deliverables. A phone patch, in its proper form, requires the purchase of a telephone audio interface. This hardware allows you to connect your call to your recording booth, route the conversation through your headphones, and lets the client record only your voice over read.

This initial investment makes the phone patch option a bit more expensive up front than the monthly subscription of Source-Connect.

Sometimes, the term ‘phone patch’ is used synonymously with online calling services and conference lines like Skype or While these services definitely enable collaboration and have revolutionized how voice actors and clients can communicate, they differ from a true phone patch from an audio quality and reliability standard. Especially when relying on a wireless internet connection, online calling services can experience dropouts and cut-offs that cause hiccups and delays in the audio recording and project management process.

Imagine finally nailing a voice over read, just to experience a loss of signal at that exact moment. The recording isn’t captured, and your client is waiting for you to rejoin them. Of course, this problem can be solved by using a hardwired internet connection!

However, voice actor Ryan Sitzberger said Skype or any other conference call software has always done the trick for him.

“The client has heard the quality of the audition, so they understand what they will receive quality-wise,” Ryan says.

“In the cases of live sessions I’ve done for clients, they are simply looking to be able to direct my tone and pacing as I record. I think it’s easier on the client end as well as there’s no learning curve for them to figure out.”

Jason Wright, voice actor, says he also likes connecting on Skype because so many people use the platform.

“Anybody can use it. And if you both have a good internet connection, you can get a great quality signal with no further hardware or setup.”

What is ipDTL?

While ISDN has been the industry standard for more than 30 years, ipDTL has proven to be a solid, cost-effective alternative.

The system was created by former BBC sound engineer Kevin Leach, after he discovered that Google Chrome’s web browser came with an open-source codec. ipDTL is a peer-to-peer format just like ISDN. However, it uses a high-speed internet connection instead of an ISDN line to connect your computer to the client with ipDTL on their computer.

ipDTL offers audio quality from 72 kbit per second mono for voice actors, 320 kbit per second stereo for outside broadcasts and 3 mbit per second video link at 1080p for high-quality video.

At the time of publishing this article, prices for ipDTL are listed at $80 per year for a starter mono subscription, $160 for the high-end stereo audio and $250 for the video subscription. 

While the price point for ipDTL is reasonable, the main setback is the current lack of clients using it as a form of connecting to voice actors for a live recording.

Relying on Local Studios’ Tech

If your yearly budget is tight and you’re not able to invest in an ISDN line, Source-Connect, or a phone patch, you can try to find a local recording studio who offers one of the three options.

This option may also make sense for voice actors who seldom come across clients asking for live-directed sessions and live recordings. Rather than investing in any of the three options for your home studio, it may be more affordable to book a recording studio for these far and few between jobs.

Food for thought: The downfall of this option is that it can create a delay in recording as you and the client wait for a time slot to be booked at the studio. If another voice actor is able to meet the demands of the client quicker because they are equipped with one of the above, this delay may cause the client to choose the other voice actor.  

How Do Voice Actors Prefer to Connect with Clients?

So now you’ve read up on the options. But what are most voice actors actually using to connect with clients?

In a recent internal survey of 174 voice actors, found the five most popular options for voice actors to connect with clients for a live recording were:

  1. Phone patch (31.6%)
  2. Skype (24.7%)
  3. Source-Connect (23.5%)
  4. Using local recording studio’s tech (9.2%)
  5. ipDTL (5.7%)

Of those who chose phone patch, 80% said they prefer it because it’s easy to use.

ipDTL ranked the highest in terms of reliability at 90%. While 62.8% of those who chose Skype said it was because of affordability (it’s free anywhere in the world if you’re calling someone else who also has Skype).

The most surprising piece of data was that only 5 of the 174 (2.8%) voice actors surveyed said they use the former go-to industry standard ISDN.

The top three regarded as the industry standards were Source-Connect, local recording studios and ipDTL.

However, voice actor David Brewer says while he does use Source-Connect, Skype and phone patch, sometimes just a cell phone will do fine.

“…Even a simple iPhone with earbuds works well every time for me. There is rarely a technology breakdown through a speakerphone, earbuds or patch and the session can commence with little downtime,” David says.

Add Connectivity Options to Your Services

No matter what you choose to use – ISDN, Source-Connect, phone patch, ipDTL, online calling services or a local studio, be sure to weigh out which option makes the most business sense for you, and go from there.

Have you already committed to one of these options? How is it working out? Let us know in the comments below if you’re loving the decision you made, or, if you’re beginning to look at other audio connection options.

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  • SomeAudioGuy
    February 11, 2008, 10:28 am

    Those looking for the cheapo version should check out tubeplug:

    And it’s been mentioned before, but if all you need is phone patch (meaning you’ll record locally and send the audio some other way), then Skype will be your best friend.

  • Janet
    December 4, 2009, 1:25 pm

    I’ve found that ISDN was totally worth the money spent on it. I think that it opens your variety of business. Clients don’t always have recording studios to work in, some don’t mind when you work from your own studio and some even prefer if you go in and work with their people. Either way, it allows you to adjust your rates for you being your own recording engineer and eventually could lead to more money in your pocket.

  • Keaver Brenai
    March 19, 2019, 1:10 pm

    Thank you for the bog article, Niki! I use both ipDTL and Source Connect Standard and find them easy to use as standalone or syncing to ProTools.

  • Keaver Brenai
    March 19, 2019, 1:11 pm

    Thank you for the blog article, Niki! I use both ipDTL and Source Connect Standard and find them easy to use as standalone or syncing to ProTools.

  • Lizet Vásquez
    April 10, 2019, 3:09 pm

    That is very useful information. Thanks! It’d terrific if you could expand some information about Source Connect, since it has three different versions. I’d like to know which one is the most requested by studios and clients. Regards, Lizet.