Richard, have a look at this - Conical mid horn with Alpha 6 with a flat response from 300 - 2k +/- 3db
http://www.geocities.com/adrian_mack/conical.html
Hence my interest in the Alpha 6 except for the fact it has 0mm xmax!
Re "midfi" according to some blind listening tests it was considered as good as Gradient speakers
http://www.geocities.com/adrian_mack/conical.html
An externally hosted image should be here but it was not working when we last tested it.
Hence my interest in the Alpha 6 except for the fact it has 0mm xmax!
Re "midfi" according to some blind listening tests it was considered as good as Gradient speakers
paulspencer said:
I hate to say this but the Alpha 6 sounds as bad as the graph indicates when horn loaded. There are many superior drivers out there to this if you are going to go through the labor to build a decent mid horn. For one - check out the Max Fidelity PR65Neo - It's like a PR170MO on steriods.
An externally hosted image should be here but it was not working when we last tested it.
http://www.solen.ca/
Magnetar do you really consider that a bad response? It's almost +/-2db and looks comparable to most typical hifi low eff speakers! The scale makes it look worse than it is. If you have managed to get flatter than that in a horn speaker, I'd be very interested to see how.
I'd like to hear your impressions on direct radiators vs mid horns. Is there a clear winner?
The 18 sound driver looks very impressive! I do wonder how you go about designing a horn for it as it needs some gain to get down low, hence I imagine u would need to get 10-12db of gain around 300 Hz to get it to be flat. The power compression numbers look very very good - only 1.6db at full rated power!
I'd like to hear your impressions on direct radiators vs mid horns. Is there a clear winner?
The 18 sound driver looks very impressive! I do wonder how you go about designing a horn for it as it needs some gain to get down low, hence I imagine u would need to get 10-12db of gain around 300 Hz to get it to be flat. The power compression numbers look very very good - only 1.6db at full rated power!
paulspencer said:
The dips are in the wrong places and it probably sounds that way. I have some alpha 6, IME you can do much better. There is major smoothing in the graph. It is more like +- 6 db with major midrange suckout and lack of power in the presence region. I've had far better response with my tractrix horns and many drivers measured with gated LMS. Try the TAD 1201H, Audax PR170, JBL 2123 or Adamson M-200.
The 18 driver with the right back chamber and horn appears to be just about as good as you will find for a mid orn if you don't eed too much output.. The bottom will come up and the top end will not load. Probably would be good for two and a half octaves.
The direct radiator will almost always have more bandwith and less ripple compared to a horn loaded driver. sometimes lower distortion, almost always more linear and if configured properly they can be controlled in directivity. I have know idea what you'd prefer.
paulspencer said:
Greets!
For 2 kHz, compression loaded requires a ~0.75" throat, so some old Altec 1.4" drivers coupled to either one of their 300 Hz horns or a custom CD design is the Hot Ticket.
For compression loaded DRs, the CR has to be low enough to keep cancellations out of the intended BW, so around 2:1 is what I recommend, and if we accept the horn as being 'done' by 2 kHz, then we need around a 2.16" diameter throat with a ~3.05" effective diameter driver, ergo we still need a huge horn since all we've done is trade some HF gain for a DR drive system. Factor in that its mass corner needs to be 2000/(2*pi) = 318 Hz, a 300 Hz Fc doesn't make much sense, but then a 4" driver doesn't make much sense for a much lower Fc either unless the horn is really, really huge or max peak SPL isn't a primary performance goal.
From this it becomes transparent that folks use DRs to foreshorten/reduce weight, cost, so the bigger the better up to the point where they beam too much for the app. A driver with well controlled break-up modes is your friend here.
You mean something similar to this?: http://www.users.bigpond.net.au/ggoodacre/centauri/diy/mh28450.html
GM
This doesn't say much for the midrange horn! Is there any reason to consider a mid horn loaded with a cone driver for hifi/home theatre use? (Yes for high SPL ~ 120 db)
GM, I had to read your response at least twice before understanding it ... lol
Yes, I did look at Centauri's dual 8" horns and was considering something like that but I have doubts that they are suitable for hifi use - thoughts anyone?
Slowmotion, why not use a conical horn?
paulspencer said:
Paul - depends on what your after. If you want the ultimate in dynamic realism and WOW factor and have the room to house it, a low compromise fully horn loaded (sub bass up) system is the way to go.
If you use a compression driver with direct radiator cones the system is going to be choked down. Like a top fuel dragster running on 87 octane. You will be driving resistors instead of the air. IMO the most difficult system to build is fully horn loaded, not only should you match the sensitivity and dynamic compression between the elements you need to try and match the radiation at the crossover frequencies plus try and get it to all blend at your listening position plus fit it in your room where it will perform properly. It's a challenge most people won't take. If the steps are taken a system like this will be like a monster you have keep under lock and key. If you let it get out of hand it can be fatal.
What if it is actively run?
Say you have a 3 way with an MTM with a pair of pro 15" drivers and CD down to 80 Hz then a massive bass horn loaded down to 20 Hz or so?
Are you running this kind of fully horn loaded low compromise system? If so I'd be very interested to hear about and see pictures if you have any.
Suppose we are talking about a 3.9 x 4.2m room ...
Say you have a 3 way with an MTM with a pair of pro 15" drivers and CD down to 80 Hz then a massive bass horn loaded down to 20 Hz or so?
Are you running this kind of fully horn loaded low compromise system? If so I'd be very interested to hear about and see pictures if you have any.
Suppose we are talking about a 3.9 x 4.2m room ...
Magnetar said:
IMO the most difficult system to build is fully horn loaded, not only should you match the sensitivity and dynamic compression between the elements you need to try and match the radiation at the crossover frequencies plus try and get it to all blend at your listening position plus fit it in your room where it will perform properly.
Will be a bit more easy with BMS coaxial compression drivers.
http://www.bmspro.info
Here is an American supplier:
http://www.woodhorn.com
el`Ol said:
I've used a 15" Beyma coaxial (and smaller Tannoy) with both front and back horn loading and have to say the main problems (as well as what you'll find with the BMS) is 1) mass rolloff of the cone not meeting the lowend of the compression driver. 2) interference of the response with the coaxial compression driver from the coaxial cone's front horn. 3) obtaining the correct back chamber for both the front and back horn with little compromise. 4) getting proper bass loading down to the point where it meets the horn subwoofers.
It is actually very difficult to get right. Lot's of trial and error and time intense juggling of different configurations- it can take month's of fiddling.
paulspencer said:
The MTM direct radiator 15's will still be the weak link.
I have built a few of these systems. I am not listening to them now though. I'm listening to a quad amped ipen baffle system with 21" woofers and horn loaded bass below 40 cycles.
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
paulspencer said:
Greets!
Well, a WG to control directivitiy, though for high SPL, a CD horn is required if there's not enough space for a WG.
Sorry about that, I apparently don't have a Tom Danley's ability to describe acoustics without at least some basic physics of the situation.
His are a bit long throw with too large a c-t-c for a typical HIFI/HT app, so was just using it as an example. Since his is a commercial app, he can't legally use the Unity concept as you can though.
GM
paulspencer said:
Greets!
Hmm, 120 dB in this size room is a waste of resources except for some classical CDs that have clipped +30 dB transients centered around 300 Hz, so the rest of the system can be considerably lower until you get down into the room's gain curve to help handle pipe organ symphonies. For DD/DTS reference HT, only 105 dB/listening position is required, which any HE system worth mentioning can meet at low power in such an acoustically tiny room.
GM
el`Ol said:
That wouild be easier. Much like the TAD 4001/4002's that don't need a tweeter and used in some of the above systems . In some I loaded in 180 Hx horns for 250-20K bandwith. It eliminated one horn out of the array. You might get by with a two way (horn) with the BMS if you don't need low bass or subs. I had the smaller BMS driver and the larger format BMS and they were OK - not overally impressed with the large format driver but the little Neo driver was nice and not too expensive.
Hi ,
Yeah, I know I probably shouldn't have said that,
since conical horns are very popular now...
But I am afraid one of the reasons is that they are so very easy to make.
Anyone can knock a pair together in an afternoon,
and get a taste of horns.
For a horn system in the home I think there are better alternatives.
cheers
paulspencer said:
Yeah, I know I probably shouldn't have said that,
since conical horns are very popular now...
But I am afraid one of the reasons is that they are so very easy to make.
Anyone can knock a pair together in an afternoon,
and get a taste of horns.
For a horn system in the home I think there are better alternatives.
cheers
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