Receiver's can be complicated devices, and it's easy to lose track of what specs and ports you need. One feature some receivers have--a Pre-Out--can be especially confusing. If you’re looking into buying an A/V receiver, you may be wondering what a pre-out is and how to use it.
A pre-out allows you to connect an external power amplifier instead of using the amp that’s built into the receiver. It allows a signal to pass through the receiver without amplification, and to instead be amplified by another power source.
When you first buy a receiver, you won’t have to worry too much about the pre-outs, but they can add valuable flexibility later. Some of the picks on our top ten list of best A/V receivers have a pre-out for every speaker and two connections for the subwoofer. There are various reasons why someone would use pre-outs on their A/V receiver, and there are both pros and cons to using them.
A common usage of the pre-out is with a subwoofer. Subwoofers have their own internal amplifier, and it is often beneficial to use a pre-out connection in this scenario. However, they can also be used to add all kinds of channels to your home theater.
And even some of the most expensive A/V receivers are often lacking adequate power for more complex home theater systems, even if they do technically offer enough speaker ports. Separate power amplifiers open up new possibilities for your setup that weren’t attainable before due to power limitations.
When you have a massive sub or special speaker channels, using an external amplifier with these added speakers can increase the sound quality and also lessen the load on your receiver’s built-in amplifier.
Many subwoofers and other speakers will include their own amplifier. Known as Active Speakers, these should use a pre-out connection. Doing this properly will lessen the load on your receiver and allow your speakers to operate at their highest capacity.
Another common use is when you have Zone 2 or Zone 3 outputs, which allow you to play audio in another room. Additionally, when the room your speakers are in is particularly large, they allow your system to use more power. In all of these examples, pre-outs will open up your home theater to serious upgrade options.
By now I'm sure you understand some of the benefits a pre-out can offer you, but let's look at some specific benefits.
Using pre-outs with an external power source has many benefits. The most obvious is that your receiver now has to use less power. It is important to take care of your A/V receiver, and we recommend purchasing a more expensive model so you never have to operate at full capacity and push it too hard.
Our highly recommended Onkyo TX-RZ820 THX-Certified 4K Receiver (on Amazon), for instance, has pre-outs for 7.1 channels of sound. So you can scale up this unit in a way that will always give you the option of expanding to a pre-out while preserving the receiver's capacity.
The receiver’s built-in amplifier has a limited power supply and your speakers will benefit from sharing the power among fewer channels. By utilizing pre-outs connected to external amplifiers, your receiver will work better, and for longer.
Another benefit is the ability to increase the capabilities of your surround sound system. Pre-outs make complex setups like Dolby Atmos possible and are necessary when many different channels are involved.
If your pre-out section has connections for speakers like “Front Wide” or “Height 2”, these are unique added channels that should be used with an external power source. There are endless possibilities with your home theater system, and understanding when to use each connection is important.
When using pre-outs, both Passive Speakers connected to the receiver’s amplifier and the Active Speakers with their own amplifiers will benefit. The overall sonic character of your system will be improved. While they aren’t totally necessary for a basic speaker system, knowledge of pre-outs is essential for more advanced and expensive setups.
There are no free lunches when it comes to high quality audio equipment though. Pre-outs can have their drawbacks.
The first disadvantage of using pre-outs is the price. If you’re looking to have a high-end home theater system, a more expensive A/V receiver will be necessary for your experience. Buying a powerful A/V receiver with plenty of options in the pre-out section is not cheap, but you get what you pay for.
This can be a little discouraging when your shopping for a new receiver, since units like the Denon AVR-S540BT 5.2 channel 4K Receiver (on Amazon) can seem like a real deal until you go to expand them later, only to find there are actually no pre-outs.
Another thing to think about when using pre-outs is the power consumption involved. More powerful A/V receivers will use more energy, and pre-out connections like your subwoofer will also need to be plugged into an outlet. Home theaters can be expensive and having a more advanced system that utilizes additional power will cost more in the long run.
If you’re using most of the pre-out connections on your receiver, plenty of cables will be involved and things can get confusing. It’s always important to keep your cables organized and safe. If you need to plug in multiple items, check out our top ten list of the best surge protectors.
It’s possible that when using several different amps, slight inconsistencies may occur within your sound. However, these flaws would be so minor that virtually nobody will notice. But for a true audiophile, it’s possible that these sonic inconsistencies could be a disadvantage.
Pre-outs have become quite common on A/V receivers, especially with higher-priced models. Each individual receiver will have different connections, so be sure to research your options before buying.
More expensive receivers will commonly have more connections than less powerful models. Some won’t include any pre-outs at all, but this is usually only with the cheaper models. Most A/V receivers on the market today include pre-outs.
Previously, we looked at how to connect a preamp to an AV receiver. Using the pre-outs on your receiver is a similarly simple process. First, identify if your speakers will be using the receiver’s amp or an external amp. For the speakers with an external amplifier, locate the corresponding pre-out connection on the receiver.
For example, when connecting your subwoofer via a pre-out, there are a few different connection options. A single tip RCA cable can be used, while you may also use an RCA cable and Y-Splitter if there are multiple sub inputs. Some companies even offer a dedicated subwoofer cable.
Once your receiver and speaker are plugged in and connected, you should be ready to play audio. If you’re not getting any sound, double-check the connection you used on the receiver - it can be easy to accidentally insert your cable into the wrong connection.
Setting up pre-outs is an easy task, and learning about them will allow you to improve your home theater considerably. If you’re looking for creative ways to add to your speaker setup, utilizing pre-outs is a great option.