Aligning the horn with the tweeter (for 1kHz) will put the mouth out in front, regardless of whether it is folded (will you be using a digital delay?) The benefit of folding is only to reduce the size of the mouth and not have it in the middle of the room. Both of these are questionable if the horn isn't designed to be a good match for the corner. This goes beyond it simply fitting in a corner.
A shorter horn is a compromise though it has been done. You may have to deal with cutoff problems at a higher frequency and less horn loading below this. There comes a point where it can be better to do the design more thoroughly based on a higher cutoff.
A shorter horn is a compromise though it has been done. You may have to deal with cutoff problems at a higher frequency and less horn loading below this. There comes a point where it can be better to do the design more thoroughly based on a higher cutoff.
Some page's back we discussed the Monacor KU 516 and it's distortion, wondering if it could perform well below 500Hz. Quoting a measurement in this horn:
I concluded the KU 516 it would distort below 500 Hz. And could not be used below.
That distortion is probably the driver / horn combo loosing hornloading which leads to a lot of excursion for the KU 516. Can anyone point me out to some distortion measurements for a given driver on several horns? From small to bigger? I understand there is a lower limit for a 2 inch phenolic 🙂 But a bigger horn might help it.
(I was wrong concluding this driver could not be used below 500Hz, learning curve, my apologies)
I concluded the KU 516 it would distort below 500 Hz. And could not be used below.
That distortion is probably the driver / horn combo loosing hornloading which leads to a lot of excursion for the KU 516. Can anyone point me out to some distortion measurements for a given driver on several horns? From small to bigger? I understand there is a lower limit for a 2 inch phenolic 🙂 But a bigger horn might help it.
(I was wrong concluding this driver could not be used below 500Hz, learning curve, my apologies)
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Recombining the horn paths may improve off axis response, but still will result in two apparent sources, I'd still expect more ragged response than a single source straight or folded horn.
My preference in the $160 range for low mid in the 100-1000 Hz range would be a pair of Alpha 8" and HF drivers of choice on a Synergy type horn.
That solution would provide a single coherent mid/high point source, impossible with large separate horns.
Art
I like your optimism 😀
might help it below the 1khz
Thanks Tinitus 🙂
Halfway this page i found the above measurement. No distortion measurement included, but at least some more info what happens if you use the Monacor KU 516 on a really big horn.
Bigger horn = more excursion control & more dB's for the given range at equal wattage, compared with a smaller horn.
Halfway this page i found the above measurement. No distortion measurement included, but at least some more info what happens if you use the Monacor KU 516 on a really big horn.
Bigger horn = more excursion control & more dB's for the given range at equal wattage, compared with a smaller horn.
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That makes sense. I'd imagine you'd have to ensure perfect symmetry between the paths to reduce the amount of phase problems. It didn't seem like a practical idea anyway 🙂
I've used the Alpha 8 speakers before, and they're quite nice, and I've been reading a few of the threads related to the synergy horns. While it solves the problems you've stated, I know a lot of experimentation has to be done to get it right, and you also need a lot of drivers 🙂
I'm going to make use of one of my computers and its soundcard, so that I can effectively work on a bi or tri-amped system, applying individual EQ and delay (if necessary) to each system individually.
Yes, i wouldn't personally want to risk it, especially when the graphs show so much distortion below 500Hz. It's a shame that the compression drivers I'd need for this frequency range are beyond my budget at the moment, but maybe I'll have a chance to replace the cone horn in the future.
However, I wonder if anyone has tried those compression drivers on a Sato horn...
The Alpha 8 has gone up from when I last bought it, but four go for around $200, not too far from your $160 budget.
I have used a number of expensive drivers (JBL 2441, 2482, 2445, EV DH1A, N/Dym1, Community M4) down to 500 Hz (250 Hz with the M4) and prefer the sound and additional mid output capability of cone drivers in each case.
As far as the Monacor KU 516 horn, the 98mm vertical height would only provide uniform dispersion to around 3400 Hz, it will start to "go omni" below that frequency.
Wow, 3400Hz is a pretty high frequency to 'go omni'!
I noticed that the Qts and Qes are around 0.6 on the Alpha 8 - from the other discussions on this thread, would that be too high? I was thinking of getting two, and then using them in that Pi Midrange horn...eventually 'upgrading' to the dual-driver Jubilee horn. Would that work, or would I be better off sticking with getting two of the Delta Pro 10a (or b?) speakers?
I noticed that the Qts and Qes are around 0.6 on the Alpha 8 - from the other discussions on this thread, would that be too high? I was thinking of getting two, and then using them in that Pi Midrange horn...eventually 'upgrading' to the dual-driver Jubilee horn. Would that work, or would I be better off sticking with getting two of the Delta Pro 10a (or b?) speakers?
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most of the Monacor horns are for 'home disco' (in lack of better words)
and one or two might be a bit better than that
but some of their more expencive compression drivers I believe are Visaton
and there may be a Celestion also, maybe
if you cannot afford good drivers, better forget it, and listen to what weltersys say, and use cone drivers
I remember some tried the big BMS compression mid driver crossed very low around 300hz, and thought it was a bit too difficult to get right
and crossing it higher, and you might end in the middle of nowhereland, and have problems at two ends, instead of one
and one or two might be a bit better than that
but some of their more expencive compression drivers I believe are Visaton
and there may be a Celestion also, maybe
if you cannot afford good drivers, better forget it, and listen to what weltersys say, and use cone drivers
I remember some tried the big BMS compression mid driver crossed very low around 300hz, and thought it was a bit too difficult to get right
and crossing it higher, and you might end in the middle of nowhereland, and have problems at two ends, instead of one
1. I thought that the values for Qts and Qes were very important, and earlier in the thread had been advised to be less than 0.3. Going from your response though Art, that's not the case 🙂 What do you look for in a cone-based horn system (driver + horn) personally?
2. You did 🙂 In this case, I'm considering the Alpha 8 speakers with the Pi mid horn (as mentioned in post #3) just for now, and then when I can afford another pair I can make your Jubilee, as my budget is able to go down, but not up! 🙄
I look for a horn/driver combination that can cover the required frequency response at the required SPL levels without exceeding Xmax or size restraints in a given budget.
I also am not adverse to using EQ to correct amplitude variations, though avoid drivers with ragged response.
I am not a "horn purist", using a combination FLH/BR would be preferable to me in most domestic situations to a huge horn, and using two less expensive drivers may outperform one more expensive "better" driver.
Art
Not to derail this thread in any way, but my goals are somewhat similar to yours. My target response is ~80hz (not as critical but lower is better) up to 500hz (more critical). Length of horn is my enemy more than size of mouth (to a point). However, I'd rather not make too many shortcuts in proper designing.
Thus the solution I have been tinkering with is 2 12pe32's mounted on either side of the "throat" rather than the apex so that I can atleast avoid the additional length of the backchamber. The wasted space behind the shadow of the mouth fits the backchamber. I just need to figure out how to use hornresp for this, or akabak and play around and see what size I can live with.
Thus the solution I have been tinkering with is 2 12pe32's mounted on either side of the "throat" rather than the apex so that I can atleast avoid the additional length of the backchamber. The wasted space behind the shadow of the mouth fits the backchamber. I just need to figure out how to use hornresp for this, or akabak and play around and see what size I can live with.
That type of horn is modeled as an "offset horn" in Hornresp.
80 Hz response will require around 3.5 feet (just over a meter) horn length, going with a combination ported/horn you could cut that length in half and still get plenty of 80 Hz response.
Josh,
The drivers need to be as close as can be to the beginning of the horn in such a design. Maybe fig 11. can help you out getting there. http://patentimages.storage.googleapis.com/US7506721B2/US07506721-20090324-D00004.png
The drivers need to be as close as can be to the beginning of the horn in such a design. Maybe fig 11. can help you out getting there. http://patentimages.storage.googleapis.com/US7506721B2/US07506721-20090324-D00004.png
Ok, here's my first guess with an Alpha 8:
I didn't mask the horn and throat resonances, so I'm sure that contributes to the waviness of the response.
So, I used a conical horn, with a length equal to 150Hz, and a mouth 'diameter' of 18 inches. I suppose it could be curved, and the SPL response looks OK. Would an exponential or tractrix shape be better?
I didn't mask the horn and throat resonances, so I'm sure that contributes to the waviness of the response.
So, I used a conical horn, with a length equal to 150Hz, and a mouth 'diameter' of 18 inches. I suppose it could be curved, and the SPL response looks OK. Would an exponential or tractrix shape be better?
After fiddling a little, I've found that the Tractrix and Le Cleac'h shapes are the smoothest, but they exhibit a 'crest' in the 200-400Hz range. That could be EQ'd down, but all of the horn shapes seem to drop down at least 10dB from that 'peak' by the time it gets to 1kHz.
Still, it's encouraging. Should the throat of the horn be smaller than Sd? I did experiment by making it half or a quarter of it, and it didn't seem to make much difference...even though they helped a little.
Still, it's encouraging. Should the throat of the horn be smaller than Sd? I did experiment by making it half or a quarter of it, and it didn't seem to make much difference...even though they helped a little.
Two 12PE32 woofers per horn is a lot of output. A pair of Eminence Delta-Pro 8B will give you more than enough output and can be wired in parallel for a nominal 8 ohm load. I don't recommend an offset driver arrangement over the bandwidth you're looking for. A standard front loaded horn will have smoother frequency response and fewer phase issues. If you are looking to shorten the horn, then I would fold it like the attached graphic. I would not fold the horn like the linked image in Post #155. It leads to rougher frequency response.
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