2" poly dome midrange alternative

[Marcel_D]

So for my shop class project I decided to build a simple pair of speakers following a proven design which is here. I'll also build the crossovers he designed for them.

The problem is that the 2" poly dome midrange he chose is no longer available on the site so I need to find an alternative between these ones. I don't really know what to look for so I need some help with this one.

[gtforme00]

Unless the midrange replacement has extremely similar impedance and frequency response curves, using the existing crossover for a different midrange will affect the integration of the speakers and will have an unpredictable result on the sound quality.

Don't let this intimidate you, but be mindful that some change will be necessary.

That said, the HiVi midrange is probably the best value, while still being fairly easy to integrate.

Good Luck,
David

[pjanda1]

You certainly have the correct idea sticking to a proven, well tought out design for your first project. Rather than substituting drivers on your first try, why not just find a design for which all the parts are available? Here is another 3-way that might suit you: http://www.speakerbuilder.net/web_fi...a/lyramain.htm Wayne is a fantastic designer (my first project was his D3's), and I wouldn't be surprised if he spent more time getting the crossovers right than Darren spent on the Jubilees. The tweeters would be better too. If you've already purchased parts, or cut wood, you're kind of stuck. Otherwise, there are plenty of speakers out there, many at least as good as the Jubilees.

The regular speakers forum is a better place for this. We're pretty dedicated to single drivers (one does it all, no woofer and tweeter) over here. If you head over there (or this gets moved, as I suspect it will), start out by thinking about your budget and musical tastes. A two way might be a nice first project, for simplicities sake.

pj

[Marcel_D]

Unfortunately I already cut the wood. Today I was going to cut the holes for the speakers as well but I waited. When I went home for the day I found out the mids weren't available...a pretty big oversight if you ask me.

Thanks for answering the questions. I thought that just maybe a different mid would work with out affecting anything but I guess not. If I had experience with building crossovers, then I wouldn't be worrying.

I suppose I'll just look for another site that stocks the mid ranges in the plans and order them separately. If I can't find them then I'll probably be back here.

Oh and if someone could move this to the Loudspeakers section that would be appreciated.

[Taterworks]

Typically I wait to begin building until all the parts have arrived.

[pjanda1]

If you've only cut the wood, and haven't purchased any parts, you might be able to find something else that works in the same enclosure. For example look at Noah's 8's: http://www.partsexpress.com/projects...oah8/index.cfm As its the same woofer, the same box will work. They'll be considerably cheaper, though they'll lack some midrange resolution in comparison. If you haven't had much experiance with real speakers, they'll still amaze you.

You might also ask over on the Parts Express tech talk board. They might have some other ideas for designs you can employ with the same woofer. Over here, one of us is soon to recommend that you buy something like a Fostex ff85k and cross it over first order to that Dayton woofer.

pj

[Jay_WJ]

Mahawk,

I just looked at the Jubalee crossover and compared the original midrange's frequency and impedance responses to those of possible alternatives.

You have to understand people's responses here. We don't usually recommend to swap drivers in an exsiting design.

But if you're not a perfectionist audiophile, I think there is a solution.

The frequency and impedance responses of the Dayton DC50F-8 2" dome midrange is the closest to those of the original Peerless dome mid. The Dayton is a bit more sensitive at the low end. Also it has a higher impedance rasonant peak but it is at relatively low, 370 Hz. Otherwise, they are very similar. Using a 12 uF capacitor instead of 15 uF in the midrange crossover network will make the Dayton midrange roughly work in the system. Also, order extra 9 and 10 ohm resistors to experiment with the series resistance in the migrange XO (currently 8 ohms). In case the midrange SPL feels a bit higher than you want, you can lower it by substituting one of these resistors for the 8 ohm one.

This is a low-cost design, anyway. I'm pretty sure this trick will work for you.

-Jay

[Marcel_D]

That sounds great to me, Jay. I was really hoping someone would tell me how to modify the crossover to work with a different driver because I have no idea how to design one myself. Not yet, anyways.

Also normally I wouldn't be in this situation because I tend to check things over and over until I'm sure it will work right but this time I was rushed and messed up a bit. I've learned a few things because of that so its all working out.

The reason I didn't buy my parts right away is because I'm buying a CRT projector near the end of the month which will drain my cash in a heart beat so I don't want to buy anything until I have it.