you beat me to it, with that 4"
I guess its a relatively new model
it even has a bit lower Fs than the 6"
I guess its a relatively new model
it even has a bit lower Fs than the 6"
These two drivers are looking so good.. The 6" is kind of pricey, if you think you need eight of them. And I would definitely go with four per side, the lower the distortions, the better, even in a home environment..
I guess that the 4" is not available through normal retail channels though..
I guess that the 4" is not available through normal retail channels though..
Pyle PDMR5 is quite a good choice, easy to get hold of and very cheap. I have not had a chance to compare it to the Misco 5" side by side, however they do seem to be reasonably comparable in sound.
The Celestion 4" requires a larger order and a group buy is a possibility. I feel the build quality is better than the Pyle and it will mount close enough to the throat to allow a higher crossover point. It does appear to sit in a nice sweet spot with good extension potential on both ends of the bandwidth. Anyone interested keep in mind that this driver may become a viable option soon at an attractive price.
I will be testing one on a Synergy soon and intend to use it soon. Also wanting to try some Tang bands.
Patrick, just wondering what Tang Bands you have tried and liked? You made a comment on my blog about an underhung 2" but I
The Celestion 4" requires a larger order and a group buy is a possibility. I feel the build quality is better than the Pyle and it will mount close enough to the throat to allow a higher crossover point. It does appear to sit in a nice sweet spot with good extension potential on both ends of the bandwidth. Anyone interested keep in mind that this driver may become a viable option soon at an attractive price.
I will be testing one on a Synergy soon and intend to use it soon. Also wanting to try some Tang bands.
Patrick, just wondering what Tang Bands you have tried and liked? You made a comment on my blog about an underhung 2" but I
I understand how a sealed back midrange speaker can simplify the construction of a Unity Horn.
I do not understand how a sealed back midrange speaker can provide the best sounding Unity Horn design solution.
I have learned from measurement and listening that the best midrange enclosure requires significant space directly next to the speaker as well as directly behind the speaker to avoid wall reflections reaching the back of the cone, which can be heard and measured. Significant stuffing behind the speaker and odd internal box shapes to break up resonances are also important. B&W and Impact speakers put a stuffed tapered tube behind the speaker to quietly absorb the rear wave.
Would one get a better sounding Unity Horn with open back midrange speakers using best practices design techniques on the rear enclosures?
I do not understand how a sealed back midrange speaker can provide the best sounding Unity Horn design solution.
I have learned from measurement and listening that the best midrange enclosure requires significant space directly next to the speaker as well as directly behind the speaker to avoid wall reflections reaching the back of the cone, which can be heard and measured. Significant stuffing behind the speaker and odd internal box shapes to break up resonances are also important. B&W and Impact speakers put a stuffed tapered tube behind the speaker to quietly absorb the rear wave.
Would one get a better sounding Unity Horn with open back midrange speakers using best practices design techniques on the rear enclosures?
I think the back chamber is so small it pushes the reflections above the drivers passband. I think Tom Danley has said something about this in this forum. I could be wrong though...
How in the hell did you get your hands on that Celestion 4" driver? I tried every way possible to get Celestion to sell those to me and they wouldn't do it. Those are the exact 4" that Danley uses in several of his Synergy horns.
I thought you might ask!
As they say, it's not what you know but who. I have a friend who can get them, but there is still a minimum order to fill. If it goes ahead it will be a good opportunity for those who've been itching to get hold of this driver.
As they say, it's not what you know but who. I have a friend who can get them, but there is still a minimum order to fill. If it goes ahead it will be a good opportunity for those who've been itching to get hold of this driver.
another 4" option ? but only EU available
looking at chassis, notice that it will be perfect fore 'back-mounting' 😉
MONACOR INTERNATIONAL : Produktdetailseite
looking at chassis, notice that it will be perfect fore 'back-mounting' 😉
MONACOR INTERNATIONAL : Produktdetailseite
Attachments
Since I couldn't get that Celestion 4", I went for the Misco RDC3T-A. It works damn well from what I've done with them so far. The best thing about them is that they were originally designed as a tweeter so once horn loaded they present a nearly resistive impedance. This makes it easier to use in a Synergy horn because you don't have to worry about its resonance screwing up the lower end frequency response. Its low end response is then purely controlled by the local area of expansion (i.e. local flare rate). I ordered a half case of them (30) and tested them all after breaking them in for 48 hours. Below are the overall average T/S parameters. The only way to come up with Vas was to use the sensitivity method with Smith & Larson Speaker Tester.
Fs = 1240Hz
Re = 7.76 ohms
Qes = 6.5631
Qms = 4.9345
Qts = 2.7557
Le = 0.4587 mH
Vas = 0.0559 L
Bl = 3.36
Cms = 3.36E-05
Rms = 0.77
Sd = 34.21 sq cm
Has anyone tried using a single mid driver? Is there any problem with the sharpness of the null with the mid ports located in only two of the four vertices?
I know this has been discussed but I can't find where it was. Is there a problem with mid ports not being located concentrically with the cone and causing pressure distribution problems?
I know this has been discussed but I can't find where it was. Is there a problem with mid ports not being located concentrically with the cone and causing pressure distribution problems?
These work well all the way down to 450Hz. Read what I wrote in Post #332. Once this driver is horn loaded it behaves as a resistive load and Fs have no effect on its frequency response limits.
No, not me anyway.
No, the null is controlled by the distance where the half wave reflection causes phase cancellation. It doesn't have anything to do with the number of mid ports. The diameter and length of the mid port along with the front chamber volume can further tailor the ending response edge before it drops off into the null.
Not an issue. By the time you have created any kind of pressure on the mid cone, you'd be well above 120dB SPL. The main reason to use at least two mids is to maintain symmetry. If you use a single mid, it could be possible to disrupt the polar response due to the mid frequencies not being symmetically loaded in the horn.
John, I'm certain I'm not the only one here that's dying to see what type of results you're going to come up with. Thanks for staying motivated!
Motivation has never been the problem. I'm just so short on time I get very little done on it. My company has cut back on people so much, I'm working overtime every week. I even had to go in for 4 hours on Christmas day to resolve some problems. I'm happy to have a job, but this stuff is getting old.
Sorry to hear that, I'm probably much younger than you, but I've lived the same experience for a couple of years..
Thank you for your clarifications earlier. I wasn't aware that having a flat impendance curve near the resonating frequency, actually lets you go down in the frequency, I somehow thought of impendance curve differently.
edit: I am not aware of any simulation of the midrange section of the Unity in Hornresp. Is this actually possible? Did any of you tried something like that, simulating in Horneresp, building and then confronting the sims? Thanks!
Could you please take a look below? I configured (I hope) hornresponse for offset driver placement, two groups in parallel, each group with two drivers in series.
Also, I believe I managed to simulate a 2cm slot, although not sure. The mouth of the horn should be around 90cm diameter. Is the input data correct?
Thanks!
Also, I believe I managed to simulate a 2cm slot, although not sure. The mouth of the horn should be around 90cm diameter. Is the input data correct?
Thanks!
An externally hosted image should be here but it was not working when we last tested it.
