Tempest HORN LOADED (1 Viewer)

[Allen Ross]

Finally

Looks like adire has come up with a nice plan to horn load a tempest. from the site the box is going to be around 36X36X18 with extension from 35-200 at 97 SPL and max 125, THD is around 3%. Looks like those IB guys have some competition, build 4 of these in to a wall and i'd say you got one hell of a music room.

http://www.adireaudio.com/TextPages/...eFrameText.htm

 

[Scott Simonian]

Awesome!

One interesting this about it is that it is 97db efficient @ 2 meters. So figure at 1 meter that would be about 100db efficient. This is great news indeed. I knew a horn-loaded application would come from Adire sooner or later. Can't wait til the design is ready for our consumption.

 

[GrahamT]

Good idea, I would love a pair for a music system. Should be very clean bass.

 

[AlexKunec]

Its difficult to put an efficiency on a large horn in 1W/1m because it has such a large radiating horn. 1m/1W is accurate in measuring 12in drivers, not a readiating surface of 5 square feet, this is why they use 1W/2m sensitivity. For the labhorn, they measure sensitivity at 16 feet.

 

[Kyle Richardson]

And actually when room gain is added in it will extend fairly deep as well. Should be a nice design.

 

[James W. Johnson]

Sounds fun, does Adire have one of these set-up in their shop? I might have to shoot down for a listen.

 

[Jack Gilvey]

Well, when the horn-loading cuts off (30-35Hz?), you've got the response of a single sealed Tempest...so below that the IB guys may have a leg up since they usually use multiples and the "infinite" Vb allows the highest efficiency down low...short of a much larger horn than is even imaginable in most homes. Looks like lots of fun, though. I'd really like a smaller version adapted to the DPL-12...Dan???

 

[Greg Monfort]

With similar/same specs, smaller driver = longer horn for a given compression ratio (CR)/Fc, but it can be folded more efficiently, so for a given minimum mouth area most/all of the size reduction is due to the smaller driver and any reduction of the compression chamber Vb.

Another benefit of using a smaller driver is greater acoustic gain due to the longer/slower expansion, so for a given excursion will have a higher SPL if the driver's motor/suspension is 'stiff' enough, and for prosound apps, a higher peak SPL if the driver has enough suspension travel. Due to this, the specs that makes the DPL12 such a good IB driver makes it ill suited for efficient basshorn loading.

Doesn't mean you can't horn load it, just that it would be huge since the CR would have to be so low, i.e. large rear chamber and throat, ergo much larger mouth for a given Fc, though it would be much shorter.

For a smaller package horn, the AV8 sims well at relatively low compression (1.94:1) in a 25Hz flare/high gain 'M' factor (0.611), but not having any experience with this driver I don't know how much power it can handle before the motor/suspension goes non-linear. I'm guessing ~1/4 power based on its specs. Still, in-room we're talking ~125-127dB peaks above ~50Hz for a pair with

 

[AlexKunec]

I dont know if i agree with u about the DPL12 being ill suited for horn loading. The reason i say this is because the LAB basshorn can use either the eminence lab12 or the adire DPL12.

 

[DanWiggins]

James,

We have a pair of these for the warehouse. Along with a pair of Hurricanes. Makes a nice little system to bump out on the 'house... Come on down and we can bump the a bit for you. Just running off of 250W they get up and go!

Jack,

For the DPL12, just build a LAB horn. The drivers are so close to each other, it's a push. The LAB drivers can handle a bit more power, but other than that they're about identical. HOWEVER, having tried to assemble LABs before, I think I'll stick with this Tempest horn - it's smaller, MUCH easier to build, and if you want output from ~30 Hz and up it does a great job.

Greg,

Excellent comments as always! The AV8 can handle ~35W in a horn-type application, with linear stroke being limited to around 4mm one way. HOWEVER, we have a new 4 Ohm Koda 8 midbass driver with 12mm of linear throw that might be a good unit for horn applications...

Alex,

I see you got the DPL12/LAB12 thing taken care of...

Dan Wiggins
Adire Audio

 

[Allen Ross]

Dan, do you think this new 4 ohm Koda, will make it over and replace the AV 8 in the HT niche?

 

[DanWiggins]

If you want an 8" subwoofer, or an 8" woofer in your three ways, you bet. However, it's not as extended in frequency response as the AV8, so there's still a need for both drivers.

The Koda 8 is really a monster subwoofer that is clean to 1 kHz; it's got a real 12mm of one way linear stroke available, which is a lot for 12" driver, let alone an 8" unit.

Dan Wiggins
Adire Audio

 

[Hank Frankenberg]

Hmmm...well then, I MIGHT be impressed.

And BTW, where's that 6" baby?

 

[Greg Monfort]

Alex,

Well, what can I say, you can put any driver that will physically fit into a particular horn and it will load some BW, but for what I consider good performance (I did say efficient loading) the specs I have don't work well for the LABhorn, or any reasonable size compression horn due to its low Fs. It would make a killer sub backhorn though.

I've read a couple of comments on the HE forum WRT drivers blowing up in some LABhorn apps. I just assumed they were the LAB12, but now I wonder.......

DW,

I'm curious why you don't recommend the Shiva over the DPL12 since it's a better match spec wise for the LABhorn. Your comments make me wonder if there's been some changes to the LABhorn's design since I downloaded the initial dwgs.

Thanks for the AV8 info, seems I guesstimated a little high, though it should still do quite well. How far off is the Koda? BTW have you given any more thought to a HE15.1 kit?

Last, but not least, any comments WRT mass loading the Brahma?: http://www.hometheaterforum.com/htfo...hreadid=208702

TIA,

GM

 

[Cam McFarland]

What is meant by "horn loading"?

 

[Greg Monfort]

You attach a horn to a driver and sometimes enclose the back of the driver to make it a compression driven horn, but either one is horn loaded, i.e. the mass plug of air 'trapped' in the horn acoustically loads the driver, converting a high acoustic impedance load at the throat to a low impedance one at the mouth.

GM

 

[Cam McFarland]

Is there an English translation to this......:b

 

[Charlie C]

cam, the speaker just covers the small end of the horn. whether its mounted to a board and that board is mounted to the horn or the horn and speaker basket are made to go together.

 

[DanWiggins]

Hank,

Hey, don't tease me like that - impresssing you twice in one year will give me an overblown ego...

Greg,

The DPL12 works pretty well in LAB horns, but I haven't heard of anyone blowing them up yet. Only a few have been used that way. Below the cutoff of the horn, you have a simple sealed box, and the DPL12 really helps out in extension in that case, especially for the crazies who EQ the response down there, to gain flat extension down to the teens.

The Koda 8 exists and can be purchased today. There's a link to it on our home page.

As far as mass loading, that works fine, too. I'll go add comments in that thread later today.

Dan Wiggins
Adire Audio

 

[Cam McFarland]

I still cant envision this....anybody have a picture?