small horn for 2inch comp. driver

[panduro]

Hi all,

complete newbee in the horn/waveguide department. read the first ten pages on geddes on waveguides, but to advanced for me...

im gonna build 3-way active ht speakers, using jbl drivers, 12", 6,5" and a 2" compression driver(jbl nd276). the horn that came with the driver is to wide(38cm) for my design. I need a horn within 20cm wide, 15cm tall.

I dont know much about horns yet, but figure(hope) i should not have a prob with crossin at 2000hz with a smaller horn.

so a well sounding small horn available in europe, any suggestions?

best regards

pandro

 

[whgeiger]

15" wide for horn vs. 12"+ for the woofer. Recommend +3" to enclosure width and leave tweeter as designed.
Regards,
WHG

 

[Defo]

Why not use a 1" compression driver instead when crossing that high? Better high end extension and dispersion then a 2" driver.

 

[panduro]

First thanks for the answer, i appriciate it!

Hmm sorry i dont really understand what you mean.

i am gonna build a 3-way, basreflex for 12", sealed 6,5 midrange and a horn loaded 2 inch compression driver for the hf.

You mean i should use the 15 inch wide horn that came with the tweeter to mate it well to a 12 inch bass? and that i should do a 18 inch wide enclosure?

The jbl compdriver, is close identical to the rest of the 2 inch jbl comp drivers (in mechanical build). which i suppose is ued with alot of different horn for different applications.

The horn was designed for very wide horizontal and little vertical dispersion applications. high spl long range wide soundpicture.

I would like my speakers to have a bit more vertical dispersion, as i dont need so much horizontal dispersion or as high spl at a long range distance, with seating position is only 6-8 feet away

hope you will take the time to reply and indlighten me as i need all the help i can get.

ps sorry fore the bad language!

BEST REGARDS

panduro

 

[panduro]

Hi Defo,

2 reasons and an oppinion..

first: I got a really good deal on 5 2inch drivers.

second: gonna do 3-way for the 3 front speakers, but 2-way on the rear(2" and 8" midbas).

oppinion: 16khz-20khz not really that important in a speaker only for ht, and the should do 18khz.

thanks for the reply, and please feel free to comment or give advice!

best regards

 

[Flaesh]

it would be understandable if you have named your drivers\horns.

 

[panduro]

cool, here it is!
bas Driver jbl le120h-1 12 inch
midrange jbl 726 gs 6,5 inch
compression driver jbl nd276 2 inch throat
horn:? 15inch wide/ mouth 3,5 inch tall and 6,3 inch deep

best regards

panduro

 

[moray james]

2" Vs 1" exit compression drivers...

Why not use a 1" compression driver instead when crossing that high? Better high end extension and dispersion then a 2" driver.

Defo: I recently spent some time looking into the possibility of upgrading the mid and high frequency compression drivers on a set of Klipsch Forte ll speakers. After a long hard look I decided to keep the stock drivers. During that time I found that the compression drivers which had the smoothest most extended range (ie.flat out to 20K) were two inch throat drivers. I don't think that I found a single one inch compression driver which was smooth and flat out to 20K. I did find a few tweeter combos, driver with horn which fit the bill but no comp drivers alone.
So I am wondering what you may have seen to prompt your comment? Further why would a one inch comp driver have better dispersion than a 2 inch unit assuming that both used design specific horns? Thanks Moray James.

 

[panduro]

Hi all,

I appriciate all the answers and help to guide me in the right direction!


I can only find small 1 inch horns, yes im am awere that its kind of logical: small driver small horn, high cross frequency, but none the less i got 2 inch drivers an want a smaller more domestic appeeling horn!

If somebody know of relativly compact horns for 2 inch drivers, round, square or some where in between please let me know!

best regards

panduro

 

[Pano]

Hi,
I think you are going to run into the problem that most 2" throat horns are meant for midrange duty and thus are large, just like your JBL. 40-46 cm is common.

But there are some smaller 2" horns made. Have a look at these, just as an example:

• Eighteen Sound XR2064
• BEYMA TD-460/N
• Eminence TI2000
• Selenium HL14-50

Look for a smooth inside curve. Some of these are diffraction horns with abrupt changes in the horn profile. Not the best choice for home use.

 

[doug20]

Defo: I recently spent some time looking into the possibility of upgrading the mid and high frequency compression drivers on a set of Klipsch Forte ll speakers. After a long hard look I decided to keep the stock drivers. During that time I found that the compression drivers which had the smoothest most extended range (ie.flat out to 20K) were two inch throat drivers. I don't think that I found a single one inch compression driver which was smooth and flat out to 20K. I did find a few tweeter combos, driver with horn which fit the bill but no comp drivers alone.
So I am wondering what you may have seen to prompt your comment? Further why would a one inch comp driver have better dispersion than a 2 inch unit assuming that both used design specific horns? Thanks Moray James.

Flat out to 20KHz isnt important (you win a prize if you can hear it at all )

What is really important is that the 2" CD drops like a rock off axis really early compared to the 1" CD.

Lets not worry so mcuh about flat on axis response. Polar response is far more important when it comes to using CDs. Of course everyone has to pick what is important to them and I have heard some very nice JBL designs with 2" CDs so meausrement specifics are not everything.

 

[EarlK]

Here's where JBL used the 276ND .

It's found in the older Synthesis 2 line , in the model ; S-2M L/R .

For those of us familar with JBLs' product offerings, it's obvious that this driver is a (Nd) variant of the 2426/7 . ( The replacement diaphragm is the giveaway .)

FYI; the 2427 was made by adding a screw-on 1"-2" adapter onto a standard 2426.

Your 276ND seems to have it's own ( bolt-on ), 1" to 2" adapter .

Your adapter might be removable / leaving a standard 1" exit, 3 bolt
driver ( ND ) . Then you can use a 1" entry, bolt-on, waveguide/horn .

How about a picture of your driver ? ( I've never seen one of these drivers )

<> cheers

PS : a search for 276nd , over LHF , returns quite a few references to this driver / though with little actual information .

 

[Pano]

That's very interesting info, Earl!

If the driver is indeed a 1" exit with adapter, that could make things a lot easier - open up a lot of horn choices.

 

[whgeiger]

JBL 276ND ?

cool, here it is!
bas Driver jbl le120h-1 12 inch
midrange jbl 726 gs 6,5 inch
compression driver jbl nd276 2 inch throat
horn:? 15inch wide/ mouth 3,5 inch tall and 6,3 inch deep

best regards

panduro

This compression driver has a 1" dia. throat.
Horn mounting is via 1-3/8"-18 male thread.

Regards,

WHG

 

[Pano]

Great photo, thanks.

So no 2"' horn needed. Problem solved!

 

[EarlK]

Metric Mix-Up !

Thanks for the pic ! That cleared things up .

<> cheers

PS : Looks like we barely escaped having another Gimli Glider" on our hands !

 

[moray james]

hello Doug...

Flat out to 20KHz isn't important (you win a prize if you can hear it at all )

What is really important is that the 2" CD drops like a rock off axis really early compared to the 1" CD.

Lets not worry so much about flat on axis response. Polar response is far more important when it comes to using CD's. Of course everyone has to pick what is important to them and I have heard some very nice JBL designs with 2" CD's so measurement specifics are not everything.

Doug: thanks for your reply. I agree I won't be winning the "I can hear 20K prize" When I was looking at possible comp drivers for the Klipsch Forte ll horns I was looking for smooth extended response both on and off axis along with a well behaved impedance curve. Off axis response should probably look as much like the on axis as possible but rolled off. My rational was that a driver with a smooth response that has no irregularities was probably going to be a good sounding one with no weird response issues. Many of the one inch units I saw were anything but smooth and well extended. The pro industry seems to think that 20K response simply means that the driver gets there even if it is 8-10 db down (or more) when compared to its average.
I was looking for drivers in which the off axis response tracked the on axis response in a smooth and similar fashion (similar looking curve). This would seem to me to be an indication of a well executed design and would result in even power response throughout a room. From what I saw two inch drivers were not only better extended in both directions but they were for the most part smoother in overall response. I am not suggesting that all were like this but in a comparison of the best I found the two inch were the clear winners. as far as smooth extended response goes.
I did not see a lot of polar response graphs for the comp drivers I looked at of if there were they may have been on different pages so I did not notice them. Would you describe what features of a polar response graph are of importance to note? I would imagine smooth uniform with minimal lobe patterns? Thanks Moray James.
PS: most companies do not seem to provide the throat exit angle of their comp drivers. I would have thought that this was critical to insure a good match to possible horns that may be used with a driver to minimize reflections. I suppose that companies want you to think that you have all the horn options in the world when you buy their compression driver as long as it fits on.

 

[panduro]

Hi again,

hmmm im embarresed now, that shows how little i know about comp. drivers and horns.

SORRY

the picture is the same driver as mine, mine is still in the box.
Seller said it was a 2 inch, but apparently he didnt mean 2 inch throat.

Thanks alot guys, that widens my options alot i suppose.

Just to besure, I should have been looking for a 1 - 3/8" throats?

Best regards

panduro

 

[Pano]

No worries! We all learned something. And I got to see some small 2" throat horns that I had never noticed.

 

[panduro]

still confused,

that means that im am looking for a 1,4" throat horn or a 1" throat horn?

best regards

panduro