Hi Juergen
When you have two drivers doing the same frequencies, close on the baffle they are acoustic coupled, and the sum will be +6dB, not +3dB.
You will find much a better description here: http://audioheritage.org/vbulletin/s...ic+coupling%22
Hi Juergen
When you have two drivers doing the same frequencies, close on the baffle they are acoustic coupled, and the sum will be +6dB, not +3dB.
You will find much a better description here: http://audioheritage.org/vbulletin/s...ic+coupling%22
Johnny Haugen Sørgård
Well, if you want to get all technical and all... (sorry about MY poor English, but I hope you can see my slight "tongue in cheek" response.)
You are correct if you want to get into the actual efficiency of the woofer system based on 2.83 Vrms at 1 meter. However, as a system you do gain from mutual coupling and as in the case of the JBLs mentioned you also gain due to the lowering impedance. That's why I said that I doubted JK's claims of 106dB. I doubt you can gain anywhere close to that from mutual coupling and as you point out, if we limit the power input to 2.83Vrms, each woofer will only see 1/4 of that.
Widget
Edit: Johnny beat me to it by a few seconds.
I apologize Mr.Widget it would be very sad if I have annoyed them. I will post her by my friend translated so that I am sure that I have understood it correctly.
regards
juergen
No apologies needed... and your posts are quite welcomed and I am particularly impressed that you manage this well while struggling with the crazy English language.
Yep, that horn is none too pretty, but if it sounds great... well, it's certainly no worse looking that a 2370.
I don't know anything about the 1200FE. Work up a pair and let's find out.
Widget
Hello all, I have been reading here for a few years now, I never post because I don't have much to tell or show, but 2 weeks ago my dad and I got some TAD drivers and I'd like to share some pics and info with you guys...
Someone mentioned about AFAST on TAD horns earlier on this thread, my father and i got a pair of TH-2002 with TD-2002 drivers and I must say this combination is the best we've ever heard. Very clean and lots of detail, every instrument's texture is defined like listening to live music. We're comparing to systems we've had over the years (JBL olympus, wilson watt/puppy, tannoy super red monitor, tannoy westminster, westlake bbsm10 with SWP, Altec A5/A6 to name some of the bigger systems) IMHO they really are one of the best and worth every penny.
I don't know how much the AFAST is in effect here because we never tried the 2002 drivers with other horns, but I'll let you guys know as soon as I get some 1" horns. The other interesting thing is that the horn doesn't have an identical curve on top and bottom. I'm an art student so I can't give you much info from the engineering side of things, someone else here can probably explain why the curves are different.
Sorry about the pics, I used a cell phone...![]()
Keith
About the pictures Mr. Widget posted, those JK audio SL-10s (2002 + 1102) are over $20,000 USD!!! JK seems to just throw everything together and expect people to buy it because they're powered by TAD... I really don't see much engineering on their products. To top it off, check out these uglies by JK below...
The quad 15" SL-01s cost as much as Westlake's SM-1s... and the only way they can justify the 12.5 hz response is that they're talking about 12.5-45k (+/- 120db)
Alright, enough bashing on JK. I have a pair of 1102s that I'll be using to make the TAD 2251. My friend has the specs of the cab from TAD. I'll post some pics next month when they're done, they should look exactly like the little pic next to my name on the bottom![]()
Keith
Hello, do you have a pic showing the whole Urei horn? Is the helmholtz resonator placed on the top only? or both?Hmm, a helmholtz resonator placed in the mouth of a horn. Reminds me of a certain trick that Urei used on the 811A, 813A, 815A's back in the day.![]()
Keith
They are on both sides. There is an open cell material under the blue side walls to act as the cavity, and the blue disk is the "mouth".
Frederick
Thanks KCCT82 for sharing. ...and thanks for sharing the pics, though maybe a real camera is in order.I believe you when you say that the 2002 combo is about the best you have ever heard.
I have never heard the TAD 2251, but I have used the TL-1102 woofer and have played around a bit with the TD-2002 driver. The TH-2002 horn is a baby version of the TH-4003 that I have quite a bit of familiarity with. I have been making mineral filled cast resin clones of it (a material quite similar to JBL's sonoglas) and have played around with AFAST and non AFAST versions. I believe the AFAST tuning is to control resonance in the Maple for the larger TH-4003 horn and in the fiberglass of the smaller TH-2002 horn. In my massive cast clones, I ended up omitting the port as it actually added a resonance. My horns are ~65lbs. compared to the ~25lbs of the maple original.
I hope to build my own version of the 2251 in the future when time permits. Here is a review from the Feb. 2002 Absolute Sound magazine. I found it a few years ago online.
Widget
It is really hard to do since you never listen to just a compression driver. The TD-4003 is a 1.5" exit driver and the TD-4001 is a 2" exit, so they won't mount on the same horns without adapters. Below are plots of both drivers which may shed some light on the subject.
I am not sure what you mean. The TD-4001 doesn't have that sort of a peak on the JBL plot or on my own plot below.
The TD-4003 has a much lighter diaphragm due to directly bonding the VC to the diaphragm without the use of a former and a back cap chamber that was designed to reduce unwanted reflections and resonance. The TD-4003 also uses a neodymium magnet instead of an alnico.
Thank you Mr. Widget,
- So how is VC directly attach to the diaphragm without former?
- Is the surround of the TAD4003 also made of Beryllium, and it's all one piece as the dome part of the diaphragm too?
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