DIY Speaker design?

Hi,

I want to build a 2x10 sealed cabinet for guitar speakers.

I've used BoxPlot for several 2 way speaker designs and enjoyed the results.

I bought a pair of old JBL K110 speakers that seem to be in dang near new looking condition.

I have some of these speakers in open cabinets and then can't take much power. I want to try a sealed box to see what they can do.

I have the data for the speakers.

So, here's where I am getting stumped. Boxplot and the other speaker box programs I am fooling with are doing all kinds of powerful things like designing ports and crossovers. The simple choices are intended for sub woofers.

I can't find a set of choices and results that seem to apply to a simple 2x10 full range sealed enclosure.

I used BoxPlot to predict a ideal volume of 2.32 cu ft but I am unsure if that result was really intended for my intended use. I used what it thinks is a sub woofer with no EQ pass filter or crossover and so got an ideal low extension for a sealed box (you can go lower at less power capacity with a tuned port) but I don't know if the results are also OK for a full range.


DIY speaker websites seem to be unfocused lately so I'm wondering if anyone here has some thoughts or might be able to run the the JBL k110 speaker specs through a design procedure using something hey are familiar with.

It's been a long time since I brok out a speaker design book... I've relied on BoxPlot. Maybe I should break out a book. :-)


thanks,
mike

Since no one else has responded, I'll give it a shot. I used to build hi-fi speakers, but haven't kept up with it in recent years, so take what I say with a grain of salt. As you mentioned, the box volume is one of the factors that determines the low frequency response of the speaker. But my understanding is that it would have no affect on frequencies above about 400 hz. What will have an affect on the frequencies above 400 hz is whether you use acoustic absorption material inside the box to dampen internal reflections of those frequencies. A lot of guitar speakers have little or no acoustic absorption material, which tends to result in a peaky, bright and perhaps harsh tone. Because it is so common, people are certainly used to this tone and some may even prefer it. Dampening the internal reflections will result in a more balanced, natural tone that should be truer to the actual sound the guitar/amp combo is putting out. It all depends on the sound you are trying to achieve.

I'm sure the sound of the sealed box will be significantly different than that of the open box. I haven't worked with open box designs, but wouldn't you expect the bass response of the open box to be quite a bit less than either a sealed or tuned port box?
 
Again, I'm probably not saying anything you don't already know, but the "higher power handling" of the sealed box is only due to the fact that it is less efficient at the lowest frequencies, compared to a tuned port box. The good things about the sealed box are that the bass response is smoother, with a more gradual rolloff, and the driver is less susceptible to over-excursion and distortion. This would make it more desirable as a multipurpose speaker, but possibly less so for a dedicated guitar speaker.