QSC Horns (waveguides)

[Dennis H]

QSC is providing complete parts lists for some of their speakers and you can order the parts online. This horn looks really interesting and only costs $30. It takes a 1" bolt-on CD and a 6.5" mid. A guy over at AVS just ordered some. They don't have parts listed for the DCS SC-2150 in the pic but the HPR153i apparently uses the same horn and drivers.

http://www.qscaudio.com/support/resources/parts/HPR153i_parts_list.htm

[Ray Tremblay]

Im guessing that this $30 is for the lens only without the drivers?

[augerpro]

Great find Dennis. Here are a couple more that interest me. First is for use with a standard 1" dome tweeter: http://www.qscaudio.com/products/spe...s82/ad_s82.htm There is also an H version for 1" CD's. This looks pretty promising, considering the only other waveguide is the MCM one and that's not much of a waveguide. Here is another horn but for 1.4" CD: http://www.qscaudio.com/products/spe...pr/hpr122i.htm All of these are available from there store and are pretty cheap.

[ThomasW]

A couple years ago when looking for compression horn to XO below 1kHz I had a conversation with Jon. My thought was to use a larger diameter compression driver.

Although I can't remember the specifics, Jon said for high quality sound reproduction only 1" compression drivers were worth considering due to compromises in the designs of larger units. Perhaps at some point I can get him to post his thoughts around this...

For those that don't know Jon 'cut his teeth' with pro-sound gear starting in the late 1960's, so he knows this stuff inside and out...

[Dennis H]

Hey Brandon,

I was looking at a closeup of the one in the pic and also the parts-list pic. The CD mounting looks a bit weird. It looks like the driver they use has a plastic adapter on it and the adapter bolts to the horn from the back side. I guess, if nothing else, it wouldn't be that hard to build your own flat-plate adapter out of plastic or aluminum or whatever and mount about any driver.

I also noticed that the mid has a closed back and possibly a non-standard 2-bolt mount.

[Dennis H]

Here is another horn but for 1.4" CD

I think that's the diaphragm size. That's just how QSC describes them most of the time. The opening is 1" just like the one in the pic above. Okay, I just checked and it takes the same CD as in the pic. Looks like the plastic adapter is built into the CD and can't be ordered separately.

[Saurav]

I noticed the closed-back midrange too. I believe I've seen one from Eminence in the PE catalog (don't remember what size), not sure who else. Also I have no idea what makes a cone midrange driver suitable for horn loading. Any suggestions?

I hadn't noticed the CD mounting mechanism in the photos. Good catch.

[ThomasW]

I noticed the closed-back midrange too.

That's an unusual driver. The Unity horn uses a closed back mids, but they're the more readily available 5-1/4" units

[Dennis H]

I don't think you'd need a closed-back mid. They probably do it so they can use the whole box volume for the woofer in the HPR series. The QSC mid and tweet drivers are so cheap that you could order a set with a horn and see how they sound. Then decide if the horn has potential and if upgrading to better drivers might be worth it.

[AJINFLA]

A couple years ago when looking for compression horn to XO below 1kHz I had a conversation with Jon. My thought was to use a larger diameter compression driver.

Although I can't remember the specifics, Jon said for high quality sound reproduction only 1" compression drivers were worth considering due to compromises in the designs of larger units. Perhaps at some point I can get him to post his thoughts around this...

For those that don't know Jon 'cut his teeth' with pro-sound gear starting in the late 1960's, so he knows this stuff inside and out...

Hmmm. Are we talking exit or diaphragm size? If the latter, then I would have to disagree. The BMS is 1.5" and excellent, as are the 1.75" Radians. Times may have changed .

cheers,

AJ

[ThomasW]

Jon was talking about the exit size..

[JoshK]

Dennis, did you get delivery of these yet? I ordered a pair. Was wondering their width.

[Dennis H]

Josh, I ended up buying the ones from the 15" 2-way. See my comments in Brandon's driver testing thread. They need a little TLC in the throat area but I think they look promising. We'll see how Brandon's tests go as he has one too.

[JoshK]

I bought a pair of those for kicks too. Stuff to play with.

[JoshK]

Received all my QSC horns yesterday. I'll take pictures later and share. The round waveguide is indeed very close to the DDS-ENG 1-90. Not perfectly the same profile, but damned close. Superb bargain!

The 15" waveguide is indeed interesting looking. It will be neat to see how they test out.

The 6" driver + 1" CD waveguide (picture above) is interesting, but I am not sure the pattern control will be very low for the mid. I'd like to see how far it will controll dispersion. Anyone know what will happen if you use this above and below cutoff?

[Dennis H]

I think QSC is crossing around 5-600 Hz.

[penngray]

Received all my QSC horns yesterday. I'll take pictures later and share. The round waveguide is indeed very close to the DDS-ENG 1-90. Not perfectly the same profile, but damned close. Superb bargain!

The 15" waveguide is indeed interesting looking. It will be neat to see how they test out.

The 6" driver + 1" CD waveguide (picture above) is interesting, but I am not sure the pattern control will be very low for the mid. I'd like to see how far it will controll dispersion. Anyone know what will happen if you use this above and below cutoff?

Which QSC horn is close to the DDS-ENG 1-90?

I have the Hpr122 10" waveguide...is there a bigger one?

[JoshK]

yes, that one.

[EdL]

I've ordered some HPR152 HF Horn, part # PL-000446-GP that augerpro is using in his No Quarters.
I want to investigate altering the mouth termination by adding a LeCleac'h profile.
Can someone provide a formula or offer direction?

[Patrick Bateman]

Received all my QSC horns yesterday. I'll take pictures later and share. The round waveguide is indeed very close to the DDS-ENG 1-90. Not perfectly the same profile, but damned close. Superb bargain!

The 15" waveguide is indeed interesting looking. It will be neat to see how they test out.

The 6" driver + 1" CD waveguide (picture above) is interesting, but I am not sure the pattern control will be very low for the mid. I'd like to see how far it will controll dispersion. Anyone know what will happen if you use this above and below cutoff?

The waveguide that QSC is using is designed to match the directivity of the tweeter to the directivity of the wooofer... That's why the mouth is the same width.

The "typical" solution is to use a woofer which has the same diameter as the waveguide. For instance, my Summas have a 15" woofer and a 15" waveguide.

But there's nothing stopping you from putting a waveguide on the woofer. Another bonus is that it aligns the impulse response, by moving the diaphragm of the woofer backwards. That makes the crossover easier and improves the polar response.

Good engineering here.