Fertin project - calling all open baffle experts

[bcherry]

OK, Dice45 recommended making this an open discussion. I agree; here it is;

Fertin 20cm field coils installed in open baffles 120cm x 60cm x 5cm thick.

Voices are sublime, never heard anything like it. Midbass to treble has cracking dynamics. Very smooth response with none of the peakiness I've experienced with Lxxxxxxr.

But no bass below ~150hz. Any suggestions on open baffle placement/management/size? I'd be happy with 60-70hz with sound this clean.

BTW, speakers haven't been run in more than 2 hrs.

Cheers to all,
Brian

[Peter Daniel]

How did you get them?

[bcherry]

Originally posted by Peter Daniel
How did you get them?

TO, my old hometown! Any snow flying yet?

Got them from Fertin. Is that what you wanted to know?
Shipped by Airborne Express in a nice plywood box.

Brian

[Peter Daniel]

No snow yet and that what I wanted to know. I am seriously thinking about getting them too. How much were they?

And what exactly do you want to know?

[Steve Eddy]

Originally posted by bcherry
Midbass to treble has cracking dynamics.

Usually when I think of things cracking, it's not good. But it seems you're using "cracking" in a positive sense. Am I correct?

I've been eyeballing the Fertins for a while now but there's such scant discussion about them so I want to make sure that what little I'm reading I'm interpreting correctly.

But no bass below ~150hz. Any suggestions on open baffle placement/management/size? I'd be happy with 60-70hz with sound this clean.

Your baffle seems a bit small to expect much in the way of bass. Also, how much current are you running through the field coil? That directly effects the driver's Q and would also have rammifications as far as bass response goes.

se

[Peter Daniel]

The dimension is 17'x18'x10'. Woofer is Focal Audiom 15'. I'm using electronic crossover at 100Hz. In room freq.response is -3dB at 25 Hz. However, I'm also using another 12' woofer on top with slightly smaller enclosure. My point is that the size of a baffle doesn't really have to be big. No frequency correction was required.

[Steve Eddy]

Originally posted by Peter Daniel
The dimension is 17'x18'x10'. Woofer is Focal Audiom 15'. I'm using electronic crossover at 100Hz. In room freq.response is -3dB at 25 Hz. However, I'm also using another 12' woofer on top with slightly smaller enclosure. My point is that the size of a baffle doesn't really have to be big. No frequency correction was required.

The effective baffle size is larger than your dimensions would suggest seeing as it's a folded baffle. It's effective size is more akin to a flat baffle measuring 37" x 38". Hell, slap one more side on it and it's infinitely large.

se

[planet10]

Originally posted by bcherry
baffles 120cm x 60cm
....But no bass below ~150hz. Any suggestions on open baffle placement/management/size? I'd be happy with 60-70hz with sound this clean.

Actually i'm surprised you are getting that low with such a small baffle. If you are getting 150 Hz, doubling the dimensions of the baffle should give you 75 Hz. Keep in mind that the narrow dimensions is the dominant one in determining how low you go.

dave

[bcherry]

Originally posted by Steve Eddy


Usually when I think of things cracking, it's not good. But it seems you're using "cracking" in a positive sense. Am I correct?





Your baffle seems a bit small to expect much in the way of bass. Also, how much current are you running through the field coil? That directly effects the driver's Q and would also have rammifications as far as bass response goes.
se

'cracking', just like Wallace and Grommit. Yes, good, very good.

My mistake on baffle size: 80cm x 200cm

10V shows about 1.2A. Higher or lower doesn't make a whole lot of difference at this point.

Played another 4 hrs and the sound is getting even better.

Brian

[bcherry]

Originally posted by planet10


Actually i'm surprised you are getting that low with such a small baffle. If you are getting 150 Hz, doubling the dimensions of the baffle should give you 75 Hz. Keep in mind that the narrow dimensions is the dominant one in determining how low you go.

dave

Sorry, 'tis 80cm x 200cm
My mistake.

Brian