Froy Mk3 w/Dayton RS?

[MisterDuck]

I've been lurking about for a bit, trying to read up on speakers (great forum, btw!), and plan a project.

I was curious if I could take the Froy Mk3 ( http://www.seas.no/froy_mk3.htm ) and instead of using the Seas W15CY001 woofers, substitute the Dayton RS150--I'm sure the Seas is a good driver, but the Dayton is $110 for all four drivers, whereas the Seas are $130 a pop. The impetus for this question is purely economical.

According to the specs on PE, the dayton is like so:

*Frequency range: 45-3,500 Hz
*Fs: 48 Hz
*SPL: 88.0 dB 2.83V/1m
*Vas: .50 cu. ft. (14.15 liters)
*Qms: 2.10
*Qes: .50
*Qts: .40

...and according to madisound, the Seas is like so:

*Frequency range: 50-3,000 Hz
*SPL: 86 dB
*Vas: 13.5 liters
*Qms: 2.10
*Qes: .40
*Qts: .34


I'm guessing the cabinets and crossovers would have to be tweaked. The Froy page mentions something about the crossover suppressing a response peak on the Seas cone, so I'd imagine that alone would require some sort of modification...


Would this swap be relatively painless, or am I barking up the wrong tree? Any advice for a newb is much appreciated.
Ciao

 

[dtaylo3]

You could certainly build an MTM with the Daytons, but the Seas Froy cabinet tuning and cross over would not work very well.

The drivers have different frequency responses, cone break up modes, sound pressure levels, impedences, etc.

You would need a new design.

I would consult with darren at the parts express website's forum and he could get you going in the right direction

 

[MisterDuck]

Thanks for the reply! As I looked at things more, I pretty much came to the same conclusion. I'll check over at PE for their input.

Regarding the things that should be the same, how does the driver impedance and cone breakup influence the swapping?


After poking around on the net last night, I also decided an easy swap would be this:

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-362

...instead of this:

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-301

The SPL is more similar, the frequency response is in the ballpark, and a lot of the measured qualities are almost identical. I was thinking perhaps I could exchange the RS drivers in this project:

http://www.geocities.com/cc00541/Dayton_MTM_CC_FIN_TL.html



Anyways, thanks for your help.

 

[dtaylo3]

Driver Swaps

Very few drivers can just be used as drop in replacements.

The SEAS drivers in the Froy feature magnesium cones. These are great for sound reproduction, but that type of cone has severe frequency break ups and harshness at its upper frequency realm. These are corrected by using certain type of crossover elements specific to the breakup of that particular speaker. Go to the Seas website and look at the frequency plot of these drivers and you will see a smooth line that at the end before it dives is jutting up and down. this is the break up that has to be tamed by the crossover.

Aluminum drivers such as the new PE RS drivers also have severe break up, but it occurs at different frequency than the magnesium.

Also, all drivers have natural roll offs and these roll offs are affected by the type of crossovers used.

If you are a newbie, I would suggest you build one of the tons of proven kits on the net vs. trying to drop drivers into a specific design.

The PE $15 drivers in the MTM you point to are very good for the money. go to www.speakerbuilder.net and look at some of the PE designs there. very good for the $$$