News & Media
Tech Talk With Big Tony
Sealed vs. Ported Enclosures
Are sealed or ported enclosures better for bass guitar? What are the differences between them? In this article, I will compare the two most common types of bass guitar enclosures and try to highlight the benefits and shortcomings of each. It took me a while to decide what details to cover, and I soon realized it might require a book to cover the concepts of cabinet design. It would take a couple of articles this size just to introduce the terminology. For the DIY guys and players interested in obtaining more knowledge, there is a wealth of information available online to learn more about cabinet design. There is also plenty of software available online to help you with calculations. Whether you find information about car audio, home hi-fi, pro audio or bass guitar, the principles are basically the same. This article will be used for the details I feel will help bass players the most.
Speaker Break-in
Speaker break-in is no myth and something significant really does happen. All speakers are built to meet certain specifications, and we work diligently through QC efforts during and after production to ensure that happens. Every component used in a speaker has tolerances, which can relate to small variances in initial performance. The mechanical properties of a speaker are slightly modified once a speaker is put into service, and the tone is affected by these changes. Speaker break-in is a natural process that is influenced by how much you use the speaker and how loud you play it. Think of a new pair of shoes. They are not most comfortable right out of the box. They feel best after you have worn them for a while, softened up, and formed to your feet. Much like your new pair of shoes, new speakers need time to “break in”, and will not sound best until they do.
High Frequency Driver Power Handling
You may need less power handling from your high frequency driver than you might expect! High frequency drivers will only see a small percentage of system power, if a proper crossover network is used. The woofer section sees the brunt of the power in a system, because lower frequencies are more abusive….
Providing the Proper Amount of Headroom
Here’s a question I get quite often: “How much amplifier do I need to properly power an Eminence pro audio woofer?”
This can be a rather ambiguous topic because there is really no “right” answer. You can damage speakers from over or under powering them.
How do I know if I have the 30W or 50W version of the Red Fang?
When Eminence released the 12” Red Fang in 2004, we were concerned the industry was not ready to accept a higher power Alnico speaker. The Eminence Red Fang is a very detailed and efficient speaker, so it’s a great compliment for lower power applications. There are a lot of misconceptions about power ratings, and we did not want anyone to overlook it for their lower wattage applications.
Cabinet Recommendations
Eminence is often asked to provide cabinet plans for our woofers. We do not provide drawings with specific cabinet dimensions and details, but we do offer cabinet recommendations in the form of specifications. The reason for doing it this way is because we do not know what size or shape cabinet you need or want to build. For example, if we specify a rectangular box of “A” width x “B” height x “C” depth, someone may not be able to fit the “B” height where the cabinet needs to be installed. Our approach allows the designer/builder the flexibility to build any shape. We provide multiple recommendations for all of our pro audio and bass woofers within their respective pdf files.
Can under-powering a Guitar speaker do damage?
Here’s a question I get often: “You recommend a 150 watt speaker for my 40 watt amp? Will my amp have enough power to push it? I have heard that under powering a speaker can do harm.”
Guitar speakers are typically very efficient (high in SPL) and therefore do not require an abundance of power to push them effectively or to make them loud. The SPL on most of our guitar speakers is 98-103dB at 1 watt, 1 meter from a microphone. A 3dB gain can be achieved by doubling the amp power. A 5 watt amplifier, for example, could potentially give you 109+dB of output on a 103dB speaker. Sure, some speakers sound “better” with more power, but adequate sound quality can be achieved at lower volumes as well.
Understanding SPL
SPL stands for sound pressure level and is also commonly referred to as efficiency and sensitivity. This parameter represents how loud a speaker is. A higher SPL equates to a louder speaker. SPL ratings are very useful and well represent speaker output when comparing one manufacturer’s speaker to another model of the same manufacturer. It can be misleading, however, when comparing two different manufacturer’s ratings.
Wiring Your Speaker Cabinet
It is crucial to match your speaker impedance (ohms) with your amplifier’s output impedance. Speaker impedance varies with frequency, so it is possible to approach dangerous conditions for your amplifier with an incorrect impedance load. A lot of amplifiers have multiple taps to accept various cabinet/speaker impedances. On a solid-state amplifier, you gain power by lower speaker impedance. On a tube amplifier, you can safely connect a variety of different cabinets or speaker configurations. Plus, the various taps on a tube amplifier may give you a subtle difference in sonic quality. We recommend that you never connect a different speaker or cabinet impedance than what is listed on your amplifier without checking with the manufacturer to determine if it is safe.
