# A peek inside a hiquphon tweeter



## Whiterabbit (May 26, 2006)

Was sitting on one. Tried to take one apart before on a small scroll saw but it was too shallow to cut through the tweeter. Now that I have a band saw, it was time to open one up.

For those who do not know, Hiquphon makes IMO the best tweeter for the budget range. for a large format tweeter they are smaller than all others. Smack in between a small and large format tweeter, they also sport a smaller dome for improved off-axis response. They are wonderful drivers for both car and home, and integrate easily into any system design. Many models are available for any stage type all of which have the same form factor, so one kick panel design is interchangeable for any stage design.










Because the dome is recessed behind the mounting plate, it is easy for an installer to place a sticker over the dome and buzz off the mounting plate on a table router for an improved mounting diameter. The plastic casing fits snugly inside schedule 40 3" PVC.

But the casing is not a necessary part of the tweeter, and despite the sealed nature of the driver, can be peeled away.

The back of the casing slices right off, revealing the nature of the chamber inside:


























We see the use of an absorptive material behind the pole vent as well as the large copper pads that make up the terminal. so far so good.

Next, note the lock ring used to hold the business end of the tweeter into place:










FYI anyone wanting to take apart their hiquphons should cut BELOW this ring to get the backplate off. cutting the serial number in half on the label will yield a cut just below this lock ring. as for me, the job was a little tougher to get that piece out.

Note how the backplate is slightly slightly larger than the motor slug ID. More on that later.

Tweeter pops right out at this point. a triple layer of cardboard, felt, and foam keep the body of the tweeter from rattling against the mounting plate:


























Resoldering the leads, adding homebrew stress relief, and padding the rear will result in a brand new hiquphon tweeter at a FRACTION of the size of a standard hiquphon tweeter. This particular piece can be mounted inside doorpanels in cars with door mounted tweeters, or in cars that have especially large A pillars.

The form factor is significantly smaller, from mounting depth to overall diameter:


























The foam easily peels away for those who do not need it.

The final picture shows the tweeter on 3" pvc. The original Hiquphon comes with a mounting plate slightly larger than the 3" PVC OD, and the body is slightly smaller than the ID. Now, the motor body is 2 3/8" in diameter, just a fraction of the previous size and perfectly suited to holes fabricated via hole saw.

mounting depth is minimal.

One can also get creative with mounting options. For example, one can thread that vent pole and use a vented screw to mount from the rear. Or one can mount inside a 2 3/8" socket. Many possibilities exist.

the plastic is approx. 1/8th inch thick and will not require a band saw to penetrate. Likely greater than a utility knife will be required to punch through.

I hope everyone enjoys this little blurb showing the inside of a sealed and previously mysterious tweeter.

-Steve


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## braves6117 (Feb 13, 2008)

Man, you have balls!!

I had a hard time just painting the flange, worried me sick that I would do something wrong, but you da man!


And also, a brief observation from my experience...I mounted my OW1's on axis and they sound paticulary amazing! But I do have a wacky car enviorment as well....


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## rekd0514 (Sep 24, 2006)

Kinda like the people de bucking Scanspeak drivers way back. SCARY!


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## DT053 (Mar 23, 2007)

Hey,

just adding my 2cents.... probably not worth much more

That area where the arrow is pointing is pretty critical to the response of the tweeter; the radius just over the roll edge and the distance to the roll.

like I said before....what it's worth.


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## Whiterabbit (May 26, 2006)

easily removed via router and reinstalled 

Would actually be very smart to do as it would protect the dome as much as the standard hiquphon.


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## cvjoint (Mar 10, 2006)

Awesome job! This would have been my first pick for a driver if it weren't for the ribbons. I always thought the case was used as a chamber. I'm intrigued.


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## Whiterabbit (May 26, 2006)

Ill bet you can heat a razor blade with a lighter and cut just above the serial number on the hiquphon (only through the plastic) an dissassemble the unit that way.


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## Rudeboy (Oct 16, 2005)

Saw more stuff.


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## shinjohn (Feb 8, 2006)

Dude, Steve, I told you to route off the flange, not cut the thing open! 
Nice job, but I do think the removing the casing will have some negative impacts. That felt at the back seems to indicate that the plastic is used as part of the rear chamber. And of course the front faceplate has been mentioned....
So I must ask: what do you have planned for these now that you've miniaturized them?


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## less (Nov 30, 2006)

I'm sure I am not the only to ask Mr. Wrondring directly to make a small format version for us mobile SQ lovers... although he's helped me resolve a few things in the past (first class gentleman), he never specifically addressed the small format in a reply... yet!

I must say, from his responses to me, I was under the impression that both the front plate and the rear chamber were essential to achieving the sound he wanted from the tweeters - and that was why he only offers the 2mm removal from the factory.

On another note, he did send a picture of something that we may see in the future. Someone has been asking him about including a grill over the dome for protective reasons. The person apparently supplied OW with a fine screen looking affair that was cut into a small circle. They used a Hiquphon lathe to remove a small amount of material directly around the edge of the hole in the faceplate and placed the very lightly countersunk screen in place. 

Less


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## sdl2112 (Feb 15, 2008)

Thanks for taking the plunge. I'm looking for tweeters to put in my A-pillars but have limited space. I have a pair of OW1s I could use. I was curious if you routed the faceplate flange but kept, for lack of a better term, the horn loading part what would be the overall depth. I was thinking I could just stuff the cavity in the A-pillar to simulate the chamber. I have Soundeasy so if it looks like it would fit I could measure the before and after response, impedance and distortion.

Thanks,

Scott


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## Whiterabbit (May 26, 2006)

raw tweeter is 1 1/16 inches from back to top of the dome. the faceplate adds another 16th of an inch on top extending past the dome tip.

Keep in mind what less stated about this dimension not allowing ANY space behind the motor for padding. It may be critical for the OW low frequency extension.


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## jets88 (May 12, 2008)

Hi, I was wondering how the OW1's sound now. I have a set and while I'm not about to do what you did I'm thinking about removing part of the flange. You think this would be a bad idea?


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