Eton vs Vifa

[Seth Smith]

Hello all,

I decided to hold of on my clonus faber project, and can honestly say I am glad I did. The amount of knowledge I've accumulated here in the time since has drastically changed my direction. Although I have come to another difficult position, I have a general outline of what I would like to build over the summer break but I would appreciate some additional input.

The driver layout will be an exact match of the Veritas Elevation 3 seen here:

The cabinet is similar as well although I have exchanged curved sides for an angular hourglass shape, the lower woofer section will also have a modest angle to orient the driver a little more on axis with the listening position. If not to the aid of acoustics, aesthetics will surely benifit greatly.

My driver selection has led me to a vented Eton 8-800 in the 34 liter lower section tuned to 37Hz via 3" tubing to minimize compression. The bass section will be crossed to the sealed upper module at 200Hz via 4th order active filter. The upper half will house the mid and a Scan Speak 9500. Here is my problem, typical to say the least, what mid to use?

I have narrowed my candidates at the moment to the Eton 7-360 and the Vifa PL18, both 7" drivers. Both were chosen on their merit as very smooth performers out to 4-5Khz, a higher than normal crossover frequency is the ultimate goal here. Of course, polar patterns force my hand at 3K with these woofers. I was thinking 2nd order on the Eton for a predicted summed 4th order slope, then a 4th order on the tweeter and a reverse polarity wiring to bring the two back in phase. The Vifa would simplify matters to 4th order on both the mid and tweeter due to its extended response to 6K. The Eton's cone seems stiffer to me, which I would consider highly desireable, although it doesn't exhibit any ringing which throws me for a loop... is it really stiffer or just well damped? On the other side, the Vifa has a much flatter and extended response curve and is half the price of the Eton.

So ladies and gents, what would you choose? Just to recap, all crossover points will be active and the whole system triamped, 100 watts to each driver via an Anthem PVA-7. Room will be 12 x 14 with hard floors, goals are clarity and accurate image placement while retaining ability to reproduce sustained 110Db's full range with various program music.

[454Casull]

Why put the drivers so far away from each other?

[Seth Smith]

I am attempting to create an unusual shape along with a good speaker, so the long and short of it is that the visual dictated the distance.

If Dickason was correct though, at 200Hz, the distance shouldn't matter as it is significantly less than one wavelength at that frequency. My current drawing puts the center of the bass driver 32" from the center of the mid/tweet module. Shouldn't have problems until 400Hz, a full octave above XO. I'm hoping it will help to minimize any anomalies it is sure to introduce. I know I'm going to pay a price for the distance, but I just am not sure what that is going to be right now.

[Bill Fitzpatrick]

I'd drop the crossover frequency to 150Hz and use a 5" mid of greater than average efficiency - 92db or so - more if you can get it.

[Seth Smith]

Any recommendation for mids in that class? Seems most of the Danish entries fall short on the efficiency criterion. Also, the step down to 5" sizes, I am concerned that this will give way to nonlinearity problems later on when I ask this system to produce Dave Matthew's Band at 110 decibels for the entire Cd. I honestly do not believe they will handle the power, perhaps I am wrong on that. I have considered the smaller mids as a way of extending their usuable range but the displacement issue kept coming up and I am in a situation to say the least now in dealing with it.

[navin]

i think yours is a very nice design. between the Vifa PL and Eton 7 i prefer the Eton. from what i remember I think the Vifa PL has better bass, the Eton better mids and your application is for a mid more than a woofer. i have not heard eton drivers for a while (10 yrs +) now so i cant say how the current ones stack up esp since the vifa PL is a more recent line.

other obvious alternates are the SS, SEAS, Focal, and Audax Aerogel. I think the Audax Aerogel works well with the 9500 also for teh bass you might want to consider Peerless 8" CSX/HDS units.

[navin]

just re-read your post. u want the mid to work up to 4-5k? ouch. i think you should consider a smaller mid. if it is XOed above 200Hz dave mathews wont hurt it.

a larger mid will have more beaming and larger Mms.

[navin]

one alternate it so consider a dedicated midrange and not a mid woofer. since you are active you can XO the mid from 200-4k with higher order slopes.

[Bill Fitzpatrick]

Originally posted by Seth Smith
Any recommendation for mids in that class? Seems most of the Danish entries fall short on the efficiency criterion. Also, the step down to 5" sizes, I am concerned that this will give way to nonlinearity problems later on when I ask this system to produce Dave Matthew's Band at 110 decibels for the entire Cd. I honestly do not believe they will handle the power, perhaps I am wrong on that. I have considered the smaller mids as a way of extending their usuable range but the displacement issue kept coming up and I am in a situation to say the least now in dealing with it.

I can't make any specific recommendations as to which 5"(I'm looking myself) but with a 4th order crossover at 150-200Hz the excursion isn't going to be very much. I'd be more concerned about thermal compression at the levels you are looking at. Sadly, most of the 5" drivers seem to be designed for mid-bass use when it should be clear that there is room in the line for one which gives up some excursion in favor of efficiency for situations like this. Perhaps one of the PHL units with a passive notch to get rid of their ridiculous high frequency response. Of course most of the seemingly desireable drivers need a notch filter. At the prices they get for these things they ought to throw the notch filter in the package. Maybe Morel has something to offer.

[Bill Fitzpatrick]

I also just re-read your post and decided that the Eton 8-800 isn't going to cut the mustard.