Nova - 5 speaker rebuild

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HI i am trying to rebuild or just replace the drivers in theses speakers i have. I was wondering what drivers to use along with what type of crossover to build or what one to buy. The speakers currently have a 8 in speaker along with a 3 inch tweeter. I listen to all types of music. I have a budget of around 150 per speaker thanks for the help.
 
Hey Mike the nova 5 speakers are in a ported enclosure. The port has a inside dia of 1.5 inches and is 4.5 inches long. Also the tweeter and and woofer are in the same enclosure, i had some concern with this. This internal volume of the box is 1202.5 inches cubed. Thanks Ryan
 
Tiny boxes! If I did the calculations right that is only about .7 cubic feet.

I ran a few quick sims on some likely candidates and these two would work OK giving response down to about 50Hz in a sealed cabinet (i.e. plug up the port) but are only really good up to about 2K so would need a tweeter that can operate to a bit below 2K. You would probably need a second order filter with these woofs.

Dayton Reference Series

Audax Sheilded 8

This Vifa could be used quite a bit higher giving you more flexibility in crossover (possible first order or higher xover) but it doesn't go quite as low. Again a sealed box is the only option at .7 cubic feet on this driver.

Now this HiVi is really nice (though not really all that efficient) as it will get near 40Hz with really nice response through most all of the midrange. This would be a great choice as you could plug the vent, put it in and use a very simple crossover with a lot of leeway for slope and crossover frequency. You might even get away running the woofer fullrange and using a simple blocking capacitor at about 8K on the tweeter. I would be sorely tempted to use this one with an inexpensive tweeter with blocking cap and Lpad to adjust tweeter volume and see how it sounded. If there were issues at that point one could twiddle with crossover design at leisure.

mike
 
Each order amounts to a six dB/8va roll off. So second order would be 12dB/8va while 4th would be double that at 24dB/8va. The simplest is the first order which has just one component in line with each driver (coil on woofer and capacitor on tweeter). The roll off is not very steep so there is a lot of overlap between the two drivers but the phase response is the nicest with first order. With careful planning you can take advantage of the natural response of the drivers to get a larger effective roll off but if the drivers get ugly outside their nominal range of operation higher order filters will be needed.

My philosophy is to use only as high an order as necessary. I am not very well versed in the phase issues with higher order filters so someone else will have to chime in if you want more detail.

I suspect on your project that you will be better off creating a new crossover to use with the new drivers and not try to use the old ones.

mike
 
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