Hi vi 8a power tower

[xumbug]

Hi there,

My name is Stuart and would like some help in building a large and efficient HT system using 4 x m8a from Hi Vi in each cabinet, with a Eminence 2002 compression tweeter for the highs. This tweeter is realy efficient and sweet sounding above 1.8 - 2k. Klipsch have a loudspeaker, the RF83 and im sure it uses similar drivers to the m8a from hi vi. this klipsch sounds big and has good bottom end and realy dynamic. I would like to build something as good if not better using these drive units. Can any one help me!!! can you help me with box size and tuning as well as Xover

Regards,

Stuart

[Paul Ebert]

Well, Stuart, I hate to rain on your parade, but this is a very tall order and you're not likely to replicate the RF83 with the drivers you've selected. The 2002 is probably OK in an appropriate horn, but the M8a has a few obstacles.

First, 4 M8a's will only get you about 92-93 dB per watt, not including baffle step compensation (if needed). Let's say you position them against the wall and, hence, don't need baffle step compensation. You'll still need to pad the tweeter down 12 or 13 dB - and then you won't have the high efficiency system you seem to want (why, by the way?).

Second, the M8a has it's main breakup mode, including a significant impedance glitch at 2k - right where you're thinking of putting the crossover frequency. Personally, I wouldn't cross the M8a over any higher than 800 hz or so. And, I don't think you could use the 2002 that low.

Lastly, you would probably have to go with a 2.5 design, where the upper two woofers cover the full range up to the tweeter crossover, but the lower two are crossed over considerably lower - usually set at the point of baffle step compensation or below. This isn't a big deal, but something to be aware of.

This is just a hint of the complications involved. Speaker design is a very complicated endeavor. If you really want to tackle it, I'd suggest buying and reading this book as a good starting point:

Loudspeaker Design Cookbook

There are a number of completed designs that could probably suit your needs quite adequately, though not with 100 dB of sensitivity. I'd suggest you look at this one:

Dayton RS 3-way

I wouldn't be at all surprised if this design (or any of several others) sound considerably better than the RF83.

[xumbug]

Hi Vi m8a Power tower

Hi Paul,

Thank you for the help, I have now read the Dayton post from start to finish and what a read. Very interesting project. I am going to do some homework and get back to you.

Regards.


Stuart