for the overload: what watts are necessary to do so? does this happen when using real big amplifiers, or also with 10 Watt amps and slightly clipping ?
for the DC: a series cap should prevend, but what would be the largest value for series cap here without danger for the diaphragm?
This pop, its gone, is it dead, silent, or does THD increase? i imagine if one plays a diaphram with small cracks and does not recognize some time, small berillium dust will come out of the horn and kill you.
till said:
I don't think that will happen, Till. The diaphragm wont vaporize into dust even though it breaks.. It's a metal.. it will come off in pieces, due to the floating electron structure of metals.. If this was a possible scenario I would expect these drivers to come with a small warning sticker..
In case they would be made by a european company .... they would not have beryllium diaphragms. As far as i know the material is forbidden for any products (except for military use) in EU countries. If pioneer would declare there is berillium in the driver, they would not be able to import them from japan to europe. In germany i was told they do not import, it took me more than 9 month to get TD2001 here. I found a MAK value for Be, 2ug / m^3 - that is not really much...
I hope it never will happen. As i plan to active crossover in a lower order some day i ask for safe series cap value.
I made a couple of mistakes with these drivers. First I did not put a series cap on them and second I unknowingly used my DVD as a transport for my CD's. In the second case, when I put in a DVD without switching the pre off the DAC I would get the decoded DVD output at the speakers, which I assume is a series of high level square waves of various periods. The combination of the two mistakes was all it took.till said:
The failure mode was for the surround to separate from the dome right at the voice coil attachment point (look very closely at the photo below). The sound was to become increasingly distorted and compressed over a period of a couple days until one stopped working altogether.
Attachments
Till,
As far as I know the 2001 has a beryllium dome with a "special high-polymer"
surround, ( what ever that means
)
"which prevents fatigue and rupture caused by an exsessive input level"
according to TAD .
TAD also states that the 2001 has a wider frquency range than the 4001,
but can take only half the input power.
Anyway, that's what the TAD paper say, in real life I don't know .
cheers
As far as I know the 2001 has a beryllium dome with a "special high-polymer"
surround, ( what ever that means
)"which prevents fatigue and rupture caused by an exsessive input level"
according to TAD .
TAD also states that the 2001 has a wider frquency range than the 4001,
but can take only half the input power.
Anyway, that's what the TAD paper say, in real life I don't know .
cheers
Just thought I should add that there's another 10 left of the TAD 4001 going for the same price.. $150, no diaphragms.. Mine are on their way with FedEx as we speak, so I guess I'll report if they live up to expectations when they arrive (I won't be able to test them right away though, will have to wait for diaphragms too...)
If they turn up in good condition i suspect some others on this forum would be interrested as well
If they turn up in good condition i suspect some others on this forum would be interrested as well
Midbass
Slomotion, all
Regarding the horn-loaded midbass, I like the idea, from recent posts at AA and success of others, of keeping the vocal range unmolested from crossovers. Magnetar and other people I know have done this and seem to prefer it.
So, with that in mind, crossovers in the 100 - 250 Hz region with a passband spanning up to 1200 Hz seem like a good plan.
Potential candidates would be any good 10" or 12" like the JBL D123, 2123 10", 2205, 2206, the EV 12", the TAD 12", etc. Whatever looks good in the horn programs like McBean.
I really don't think the flare rate matters too much, either, although the simple, straight conical has some very nice qualities.
The fast initial expansion seems to allow clean reproduction with fewer throat related distortons.
Tim
Slomotion, all
Regarding the horn-loaded midbass, I like the idea, from recent posts at AA and success of others, of keeping the vocal range unmolested from crossovers. Magnetar and other people I know have done this and seem to prefer it.
So, with that in mind, crossovers in the 100 - 250 Hz region with a passband spanning up to 1200 Hz seem like a good plan.
Potential candidates would be any good 10" or 12" like the JBL D123, 2123 10", 2205, 2206, the EV 12", the TAD 12", etc. Whatever looks good in the horn programs like McBean.
I really don't think the flare rate matters too much, either, although the simple, straight conical has some very nice qualities.
The fast initial expansion seems to allow clean reproduction with fewer throat related distortons.
Tim
slowmotion said:Been thinking a lot about low midrange / upper bass lately
Well, it's a lot to think about -
Seems to me that this is the heart of the matter and where you have to get your compromises rignt.
It's the place that it's the easiest to get it wrong, and the hardest to get it right.
_grin_
regards
Ken L
Lower midrange, upper bass
The system I am working on is my very first using front loaded horns. The only decent sensitivity speakers I posess at the moment are a set of small Fostex back-loaded horns, and they don't do much more than 93-94dB.
Since I will bi-amp the upper horns (TAD 4001+tweet) from the midrange, I am thinking I could get away with less sensitivity in the midrange 100Hz-600Hz, and I am thinking of a small PHL coax, the 1520, a 6.5'' driver with 97dB sensitivity/8 ohms, to cover this area. No horn loading here in the first round. What is the biggest sacrifices I will make by using such a relatively small driver? And how can I expect the sound of the PHL compare to the TAD4001 ?
The area below 100Hz is not of concern at the moment, as my active subwoofer system will take care of it.
The system I am working on is my very first using front loaded horns. The only decent sensitivity speakers I posess at the moment are a set of small Fostex back-loaded horns, and they don't do much more than 93-94dB.
Since I will bi-amp the upper horns (TAD 4001+tweet) from the midrange, I am thinking I could get away with less sensitivity in the midrange 100Hz-600Hz, and I am thinking of a small PHL coax, the 1520, a 6.5'' driver with 97dB sensitivity/8 ohms, to cover this area. No horn loading here in the first round. What is the biggest sacrifices I will make by using such a relatively small driver? And how can I expect the sound of the PHL compare to the TAD4001 ?
The area below 100Hz is not of concern at the moment, as my active subwoofer system will take care of it.
It will be interesting to see what Tim and others think of your proposed system
Some general suggestions here conceptually
As I understand your post, with the subs you will be triamping. If that is the case you probably ought to consider using a high quality digital crossover _grin_ which by rights should be a different thread _bigger grin_
the biggest sacrifice here is no horn loading _grin_
Make this an area of concern and integrate it into your overall game plan now - how and where you crossover and to what will be critical - to the overall sound.
Design the whole system from top to bottom with the realization that you will get around to actual changes there last - and that it is not a _construction_ concern at this time but it is a _design_ consideration.
This is something I overlooked because my horns load down to 135 or so. It appears that this will work out well in my case. However, having been looking at this a great deal recently, I have become aware how important it is and how hard it is to achieve well - which prompted my post _smile_
I will leave comments and suggestions pertaining to your specific driver questions to others more qualified than I _big grin_
Regards
Ken L
Some general suggestions here conceptually
Rocky said:
As I understand your post, with the subs you will be triamping. If that is the case you probably ought to consider using a high quality digital crossover _grin_ which by rights should be a different thread _bigger grin_
Rocky said:
the biggest sacrifice here is no horn loading _grin_
Rocky said:
Make this an area of concern and integrate it into your overall game plan now - how and where you crossover and to what will be critical - to the overall sound.
Design the whole system from top to bottom with the realization that you will get around to actual changes there last - and that it is not a _construction_ concern at this time but it is a _design_ consideration.
This is something I overlooked because my horns load down to 135 or so. It appears that this will work out well in my case. However, having been looking at this a great deal recently, I have become aware how important it is and how hard it is to achieve well - which prompted my post _smile_
I will leave comments and suggestions pertaining to your specific driver questions to others more qualified than I _big grin_
Regards
Ken L
Actually, I think I just might wait, and audition some different midbass setups once I have my TAD4001 horns ready.. Using active XO, it should be an easy task to look for amp/driver combinations that will fill the lower end according to my musical taste... At least to get an idea of what I really want for my lower end.. But thanks for all the help so far folks!
Rod: I'll make sure to try your 4.7uF trick and do some measurements, before i'll concider active equalization..
...and if anyone has impedance plots of the radian diaphragms, let me know!
Rod: I'll make sure to try your 4.7uF trick and do some measurements, before i'll concider active equalization..
...and if anyone has impedance plots of the radian diaphragms, let me know!
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.