RT-2 Horn sub, the result

[AKN]

Elbert,

Looks like your sim does not include the last "external fold", or does it?

[Elbert]

You reckon right, Elbert hasn't got a clue about what a tapped horn is, so he has some reading up to do!

If the new version of the gamma has a decreased performance over the older alnico version, that just proves that the ferrite magnet in the motor has not been beefed up properly to bring the gap flux density up to that of the old alnico.

But then again, considering how strong some of those more exotic magnets are, I guess it can take a rather substantial ferrite magnet to reach the same leve..

The horn was built out of "intense and long lingering" curiosity more than the result of an objective and rational approach to the ultimate sub solution, I'll admit to that!

On a subjective, and perhaps subtly emotional level, one tends to be drawn towards the more exotic and esoteric in the secret hope that some magic-like and physics defying result will materialize from all those carefully shaped curvatures and intricate carpentry, hehe..

Probably the same psychological convolutions that fuels a not insignificant part of the HiFi and "high-end" business!

But then again, that's probably human nature, to be curious, explore and expriment.
After all, a BR or closed box isn't all that exciting is it?

[Elbert]

You are correct Anders,

I just used the template that bjorno referred to in his link...

And if I want a housewrecker, I'll just down half a bottle of Whisky!

Or was that by acoustical means ?

[jbell]

Your problem with your bass, is that you aren't using any of these:
http://www.musicdirect.com/product/73452

It'll open a whole new world of odd-io-pile bliss....

(If you believe that... I sell......)


stick with math, it doesn't lie.

[Elbert]

jbell,

Once such a solutions presents it self, it all becomes so obvious!

HiFi, the alchemy of our time, hehe!

At the end of the day, I'd rather spend my money on a nice bottle of red wine, a source of long proven elevation if not of cables than at least of the mind! (within moderation of course)

You are right about the maths, but my problem (and I'm probably not alone here..) is that unless one can factor in everything (like room response, etc..) one is left to fill in some gaps with (sometimes speculative) theorization and experimentation...

Not to mention that there is a certain mastery required...

[tinitus]

A bit of luck is welcome too

btw, should you choose to buy other woofers, I think it would be good sense to have a second plan about how that certain driver would work perfectly, later on

Oh, the tapped horn suggestion was only a emergency options fore your box, fore music I dont think I would go that way

The most boring as you say, a closed box with the right woofer is the way, unless one is forced towards other more complicated option, due to SPL or whatever

[Elbert]

A very good comment tinitus!

It's actually something I'm trying to keep in the back of my mind as i consider alternative drivers. If not I'll end up with a heap of drivers (and a very empty wallet) that really won't lend themselves to any interesting use!

Ideally, a driver failing horn-service, should still be well suited to "conventional" application, preferably by converting the horn in to a closed or vented cabinet.

Looking at that visaton driver, if it fails, two of them in a BR conversion of the horn should yield a - 3 dB of 33Hz and a spl of 114 dB with the 90 W amp I'm planning to build.

Should be OK I guess..

[tinitus]

In the past I have actually seen some doing closed TL, a reversed horn closed at the end, and very similar to the B&W "snail" principle

It would be easy and kind of make sense to convert your "horn" into that
It wouldnt seem to have any sacrifices, other than maybe not being the right volume fore any woofer

[Elbert]

The thought has in deed crossed my mind!

Having said that, I would have no clue how to go about driver selection or any calculations for such an approach, so in the event that the horn project is canceled, a conventional BR is the more likely avenue of pursuit..

[tinitus]

Its true that there are many more woofers suited fore BR, and mostly the most attractive

Good woofers fore closed are more rare...you need low Fs, at least 25hz...and higher Qts, preferably at least 0.4, where as some sub drivers have even higher Qts, theres always a risk that it gets muddy and boringly "slow"
Not all people agree with that, and sometimes you may still need real world knowledge with the specific drivers to really succeed, or some luck could be needed

The 3 woofers mentioned, SBAcoustic, Dayton 10" and the GAMMA are actually fine examples of woofers that ought to work very well in closed, fore normal musical use and not house wrecking...if specs are true, which will always be an issue

People often say that a closed is much easier to get right, I dont think it is