Tad th4001/4001 + 1601 x 2

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That's an awesome job you're doing. Please post more pics!

Thank you. :)

I had to order a few things. I'll resume once they arrive.


Just curious how do you actually mount the horns to the cabinet.
Bolts from the inside on the cab ---> into the horn body.


I'm planning to get the horns from Thomas as well and building a 2402 clone cabinet. But looking at your pics now I'm really tempted to go with two 15's rather than one.
I think I could have been fine with a single 15 cab like Yuichi's classic E-170 enclosure. Put the horn on top and all done. A 2402 would probably be even better. These double 15 cabs sort of fell into my possession, so I had to give it a go.
 
Thanks for the compliments, guys- Much appreciated!!

I have the speakers up and running now. I doped the interior with acoustic sealant, lined it with non shedding fiberglass insulation panels, and loaded them up.

Unfortunately, this happened while my wife went on a little holiday and left me without the camera. I have no pictures of the process to share with you. Sorry. :eek:

I will take some pictures of the finished speakers soon, though.

As far as the sound---> Unbelievable. They are everything you'd expect from such legendary drivers. HUGE, dynamic, thundering things. Yet they play clean without any detectable distortion. This makes them particularly dangerous when you turn them up loud, because they do not offend even at higher SPL's. Amazing. Yet, they are delicate and sophisticated when called for.

I have some tweaking to do to get them right. My current active crossover (BSS FDS-310) will not allow me to do some of the things TAD did with their passive networks on the 2401 monitors. An asymmetric 2nd/5th would be more ideal, I think. I suppose TAD might have implemented such a steep slope on the low pass to help "slow down" the 15's in an attempt to time align them (the physical alignment of the voice coils is not good on the baffle). After some listening I think the steep low pass slope might have served a second purpose: The 4001's sound best (to me) at the lower levels near my chosen crossover point (~600Hz). The problem is, the sound of the 15 bleeding in to this area sounds awful and messes things up for the 4001. I have a passive schematic that I may try very soon.
 
After post# 14, the bass reflex ports were covered. Did you 'convert' it to sealed? Or did I miss something?


...

As far as the sound---> Unbelievable. They are everything you'd expect from such legendary drivers. HUGE, dynamic, thundering things. Yet they play clean without any detectable distortion. This makes them particularly dangerous when you turn them up loud, because they do not offend even at higher SPL's. Amazing. Yet, they are delicate and sophisticated when called for.
....

Ah! I remember that, and I'll never forget.

Quite some time ago, I had a chance to listen to a pair of (cloned) TSM-1, the version with 2 rectangular ports each cab.

Driven by (guess what) a JC Verdier 300B SE- what a glorious 6W amp - and a very close listening position, maybe nearer than 2m or so...

It was Rickie Kee Jones, Pop pop, "Dat Dere" playing. The plunks, body, weight, texture, depth... everything was visible and touchable. It totally blew me away, and grabbed me back.

That's THE VERY BEST acoustic bass I've ever heard, period.

Oh, uh, almost forgot. Congratulations! :D
 
After post# 14, the bass reflex ports were covered. Did you 'convert' it to sealed? Or did I miss something?

They're ported. The openings for the port were cut using a router template bit like the one pictured below. The bit bearing traced the circle of the port opening cut in the piece under it (hope that makes sense). Then the opening was hit with a roundover bit to make it flared. I'm still trying to dial in the tuning by ear. It's close, but it's not quite there yet.

42-0801.jpg






Ah! I remember that, and I'll never forget.

Quite some time ago, I had a chance to listen to a pair of (cloned) TSM-1, the version with 2 rectangular ports each cab.

Driven by (guess what) a JC Verdier 300B SE- what a glorious 6W amp - and a very close listening position, maybe nearer than 2m or so...

It was Rickie Kee Jones, Pop pop, "Dat Dere" playing. The plunks, body, weight, texture, depth... everything was visible and touchable. It totally blew me away, and grabbed me back.

That's THE VERY BEST acoustic bass I've ever heard, period.

Oh, uh, almost forgot. Congratulations! :D

It's the percussion that really gets me. I've always appreciated Art Blakey's work but felt it was never recorded particularly well. His stuff always sounded like slush and blur...until now. What I once thought was poor mic placement and terrible room acoustics has been brought to proper light by these speakers. I hear so much more. The TADs never lose pace, and easily keep up with Blakey's furious, primal thrashings. His rolls used to sound more like "roars", but now I hear his every move...his every hit like a true musical note...the textures...Exciting stuff, indeed!

Acoustic bass is also unbelievably well rendered, as you said. I'm a huge fan of Avishai Cohen (his "Gently Disturbed" album in particular). This sort of thing through these TADs conjures up so much stuff there is hardly enough time to discuss it here. I am smiling just typing about it! :D

I'm using modest amplification right now and plan to upgrade in the near future. Lows are currently handled by a Perreaux 2150B, and about the only thing I'd change here is getting a second 2150B so that I have bridged monos. It's proving to be a decent amp for low frequency duty. Highs are handled by a pair of amps I built based on the popular RH84SE (single ended eL84) with poly power supply caps, and James output iron. Sounds pretty good with the 4001's, but a cheap little solid state amp I have here (Nak' STASIS) has a few sonic advantages. I don't know if the 4001 is presenting a challenge to the amps or not, but they seem to like a bit of extra power.

This will take some time to dial in, and amps will probably be flying through here over the next several months until I find "the one"....and then the "other one"....you now how that goes. :)

Thank you! :cheers:
 
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Hi Shamrock,

They're ported. The openings for the port were cut using a router template bit like the one pictured below. The bit bearing traced the circle of the port opening cut in the piece under it (hope that makes sense). Then the opening was hit with a roundover bit to make it flared. I'm still trying to dial in the tuning by ear. It's close, but it's not quite there yet.
What a great project. Congrats! :up: Keep the updates coming.

It's the percussion that really gets me. I've always appreciated Art Blakey's work but felt it was never recorded particularly well. His stuff always sounded like slush and blur...until now. What I once thought was poor mic placement and terrible room acoustics has been brought to proper light by these speakers. I hear so much more. The TADs never lose pace, and easily keep up with Blakey's furious, primal thrashings. His rolls used to sound more like "roars", but now I hear his every move...his every hit like a true musical note...the textures...Exciting stuff, indeed!

Acoustic bass is also unbelievably well rendered, as you said. I'm a huge fan of Avishai Cohen (his "Gently Disturbed" album in particular). This sort of thing through these TADs conjures up so much stuff there is hardly enough time to discuss it here. I am smiling just typing about it! :D
Have you owned horn speakers in the past? Certainly the impact is the most stunning aspect of a good horn speaker because it is so shocking to hear for the first time. Nothing I've heard can give you that sense of being there like a good set of horns. You'll have to rediscover your whole music collection.

It would behove you however, to think seriously about that tweeter above 10kHz. There's is a whole new layer of air and detail that can only be had with a good super tweeter. I've used the JBL 077's on top of the 4001's and have been very pleased with their performance. I used a simple 1st order passive lo-pass and 2nd order passive high pass and a simple "L"-pad to match the levels.

I'm using modest amplification right now and plan to upgrade in the near future. Lows are currently handled by a Perreaux 2150B, and about the only thing I'd change here is getting a second 2150B so that I have bridged monos. It's proving to be a decent amp for low frequency duty. Highs are handled by a pair of amps I built based on the popular RH84SE (single ended eL84) with poly power supply caps, and James output iron. Sounds pretty good with the 4001's, but a cheap little solid state amp I have here (Nak' STASIS) has a few sonic advantages. I don't know if the 4001 is presenting a challenge to the amps or not, but they seem to like a bit of extra power.

This will take some time to dial in, and amps will probably be flying through here over the next several months until I find "the one"....and then the "other one"....you now how that goes. :)
One note of caution. You may want to put a passive hi-pass in between your amp and the 4001's. Those beryllium diaphragms don't take to kindly to being over driven, especially at the lower frequencies. All it takes is a loose connector when you're changing amps, and poof, $900+ per diaphragm (if you can find them) down the drain.
 
Hi Shamrock,

Can you share the measurements for the cleats?
Thanks!

Hi.

Sorry for the delay.

I started to type all the measurements, but realized it's a moot point. It will only serve to confuse and frustrate anyone trying to build a cabinet for these horns.

The amount you wish to "step" into each cleat will depend largely on the gauge and location of the gaskets used. This will greatly affect each successive measurement, and could mess up everything should you have a slightly different gasket material in a different location. I used a double set of gaskets, BTW.

This is further complicated by the "Taipei" horns not being very accurate from one to the other. I am told the components are CNC machined, but ultimately they must be hand assembled. This last stage makes for some variation from horn to horn. My horn will most certainly be a bit different from your horn. This should not be too shocking, as even the original almighty TAD TH4001 was a fairly "crude" object to behold. Beautiful in other ways, for sure, but it isn't as impressive (from a precise manufacturing point of view) as the clones. My opinion, of course.

Even on my pair, there was a bit of variation from the left to the right. It was subtle, but enough to make me cut one of the baffle cleats a second time, plus a bit of sanding and planing to get a snug fit. That's the most important thing- they must fit snug to prevent air leakage. It's a "hands on" experience requiring a bit of trial and error. It's best that you get a pair of horns in your hands to study them. You'll know what to do in no time at all.


Thanks for understanding.
 
Hi Shamrock,


What a great project. Congrats! :up: Keep the updates coming.


Have you owned horn speakers in the past? Certainly the impact is the most stunning aspect of a good horn speaker because it is so shocking to hear for the first time. Nothing I've heard can give you that sense of being there like a good set of horns. You'll have to rediscover your whole music collection.

It would behove you however, to think seriously about that tweeter above 10kHz. There's is a whole new layer of air and detail that can only be had with a good super tweeter. I've used the JBL 077's on top of the 4001's and have been very pleased with their performance. I used a simple 1st order passive lo-pass and 2nd order passive high pass and a simple "L"-pad to match the levels.


One note of caution. You may want to put a passive hi-pass in between your amp and the 4001's. Those beryllium diaphragms don't take to kindly to being over driven, especially at the lower frequencies. All it takes is a loose connector when you're changing amps, and poof, $900+ per diaphragm (if you can find them) down the drain.


Sure, I've had horns before. My top three before using the TAD were (in order) Tannoy dual concentrics, JBL "Smiths", and a well damped Altec 811b. A few others perhaps, but those are the ones that impressed me the most. I just feel like the TAD stuff is beyond the typical "horn" label, and is a completely different thing altogether. It's big boy stuff. A quad of 15's sure helps, too but that 4001 down low is astonishing. It really puts the meat on the bones if you know what I'm saying. The midbass is on par with some of the great JBL 10's (like the 2123) I've used in systems past. It's simply killer.

The 4001 is protected by an appropriate series fuse. I could use a cap here, but I had a fuse laying around and it doesn't really bother me to use it.

I'm looking at tweeters lately. I like the Pioneer ribbons. Mainly because I can't afford the ET703, but I'd like to try a pair. I'll probably get something in the next couple of months.

The system is now rocking with a big Plinius SA100 (Mk2) amplifier. It's wonderful. I tried using it on the HF, and a Perreaux 2150B on the LF. That was nice. I'm now using the SA100 on the LF, and a SET EL84 on the HF. Passive volume control (no active pre). Even better. I'm still set on building a passive crossover for this rig and run the Plinius full range. More on that later...

Thanks for the compliments. Much appreciated.
 
I should share a dirty secret- I have been running the Radian Al/mylar diaphragms this whole time because I couldn't justify the money for Be's without hearing them first. I realize many fans insist the Beryllium diaphragms are an essential element of a TAD compression driver, but I think it's less cut and dry.

To see if I was missing something worth paying a thousand dollars more for, I went to visit a friend who had two TAD based systems up and running. One used a TAD 4002/Be, and the other a 4001/Be. My fist impression was "wow"! They had that factor. There's certainly something to be said in favor of beryllium. Despite being able to identify the Be sound right away, the material is extremely good on the first part of a note (the initial transients). They have detail out the wazoo, so if you don't have an amp they like, they can quickly start sounding a little too "informative" if you know what I mean.

In contrast, the Radians are a bit more forgiving. To the praise of the Radians, they are much better at adding weight and body to the notes, and have a much more pleasing voice to these ears. I actually prefer them to the Be's. They simply do not play nearly as high as a Beryllium though, so a tweeter is essential. The Be's didn't sound *quite* as natural (IMO). Neither sound all that natural, really. I think it all comes down to personal preference. What I'm saying is that if anyone out there has the chance to get their hands on some TAD drivers that need replacement diaphragms, don't get so caught up on the cost of Beryllium. The radians may or may not be to your liking, but they are certainly worth trying. You'll need a tweeter. No ifs ands or buts about it.
 
I wanted to give the above information (posted only moments ago), because it will be one of the last things I share about this build. The reason? I've already moved on. In my time in this hobby no speaker has ever come and gone so quickly nor has any speaker before it astounded me as much or left a more profound impression. These speakers challenged me to think about why I listen to music. I quickly realized, through the aid of the TAD's, that I'm not willing to sacrifice certain criteria in favor of others. In short, my musical priorities were put into proper order right away. The TAD's will never do what I need a speaker to do above all other things, and for that reason, they must go. No hard feelings whatsoever. It was an invaluable learning experience for me.
 
Why?

I got a couple of PM's asking me why on earth I would dismiss such 'great speakers'. To simplify my response(s)- I'll post my impressions here for all to read. They are MY impressions, and like opinions...well you know what they say about opinions. Take this with a grain of salt. This stuff is about personal preferneces. It's likely some of you will strongly disagree with me, and that's perfectly fine. It's a good sign we have developed tastes.

Sometimes you listen to gear that is so detailed and revealing, it (to borrow a popular expression) misses the forest for the trees. The TAD stuff lets you see a tree close up with great clarity, and it is truly marvelous at doing so. However, it is so zoomed in and hyper focused on those details, I could barely tell it was a tree! For me to understand what I'm looking at (hearing), I need to have some perspective. Distancing myself away from an object lets the light come into play to appreciate it's shape, and I need to see something it in it's environment to gain a sense of scale. These factors are very important to me, because only then am I officially looking at a tree. Too close, and I'm looking at the parts of a tree (bark, branches, et al).

Before I go on, I must say that I heard three TAD based systems while making these assessments, and all three were a bit different but they shared these common traits. It didn't matter what sort of amp was driving them either (DHT, PP, SS, etc). It was proven to be a factor of the TAD's, or my interpretation of them. Mind you, these traits may be the very thing you seek when choosing a speaker. They were not my credentials, however.

When I first heard the Be's, I was not satisfied with the body of the notes. The aluminum diaphragms had far more weight and reminded me of the Altec romances I once held dear years ago, but the Be's seemed to put all of their effort on the initial transient of the notes and more or less "spelled out" what the body of the note should sound like without actually producing it in a convincing way. I assumed the aluminum Radian diaphragms were the hot ticket. Believe me, if I would have thought Be was worth it- I would have shelled out for them instantly. I didn't...but it was more than this gripe. Much more.

Even with the smoother, weightier Radian's the speakers didn't prove to hold my attention for more than 1 hour sessions. After these sessions with the TAD's, I felt exhausted and energized at the same time. "Fried" is probably more accurate. It was as if I had been analyzing the living end out of every track, and indeed I had- determining where the mics had been placed, how it was mixed, and so on. It's hard work on the mind! It was after only a few short days I realized something profound: I was listening to the best speakers I had ever owned..but there was one fundamental problem. I didn't want to listen to speakers. I wanted to listen to music.

I thought maybe the voicing of the big woofers was to blame. I mean, anyone who has spent some time playing around with speakers eventually realizes a smaller cone (like a 10 or 8 inch) produces a more palpable sound over a big 15 (16) inch in the midrange. This is especially true with vocals. For all the praise I can give the EL403's (1601a) it was still a big woofer and I understood it's limitations from the onset. I thought about crossing the 4001's into smaller drivers like 12's. My friend has such a system with 8 (count 'em!) 12" drivers-> Four 12's on each side coupled to a TAD driver/horn. It was better in some regards, but still had no magic to speak of. It also could have benefited from a LF helper on some passages, and well there is the sensation that the uppermost HF is lacking in authority. Thinking out loud: "....why would you want to take away from what makes a 4001 great- its range (?). The fact it can play so low and so high is part of what earned its legendary status. It was idealized as the star centerpiece in a two way; that's how TAD saw it. And rightfully so. To start thinking it might be better idealized in a four way is downright heresy to some. Yet the fact a tweeter helps up top, and crossing over to a midbass/midrange in the middle would be sweet, with a LF driver on the bottom end and....and.... sure enough your dream system starts to become a 4way in a hurry."
I didn't want to go there...IME 4ways are difficult to balance out to say the least. I'm not that skilled, nor do I have that kind of time/patience. The "value" of the 4001's range started to diminish in my mind.

This assessment would not be complete without addressing the horn itself. A beautiful thing to behold and hear, the TH4001 types are about the best I've heard. Surprisingly clear and open. Compared in a direct A/B comparison with a george augspurger horn (both had TAD 4002's with Be drivers in them and crossed actively), the GA took the medal in terms of accuracy. The TAD horns had more romance and better overall dispersion. Things sounded bigger and slightly warmer out of the TAD horns, but vocals were also a bit pinched and nasal on them. The GA's had none of those traits. They had a much more straight up direct projection. Probably doe to the lack of compression in the vanes, and the shorter (physical) size/throw. Choosing a winner was hard to do, and would depend on your tastes and (more importantly) the application. Getting the TAd horn to time align with a transducer is more of a challege due to the physical length of it, and the loading itself. I suppose that's why TAD opted for a 2nd/5th asymmetric crossover slope in their monitors- to "slow down" the 15 in hopes of letting the horn "catch up". Call it quasi-time alignment. But neither horn was free from annoyance with the Be's as the driver....

All in all the TAD type monitors I heard let you hear into what was happening better than ever. If you are the kind of guy who appreciates all the details and techniques in a recording- these will do it for you. Also, you won't do much better for dynamics, either. Lots of that stuff.
Ultimately they came sounding devoid of life, but my 'devoid of life' might be your "distortion free". My "lack of magic" might be your "lack of coloration". My "giant boom box of sterility" might be your "accurate and authoritative". My....you get the idea. To each their own.



Me? I'm going in the opposite direction. I'll be heading to a Spendor dealer for the third visit to try and understand why those things are so bewitching and disarming to me. I'm looking for a speaker that let's me listen to the music, because I am far more passionate about music than speakers.
 
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Good points. Excellent writing.

A friend had been using TAD large format system for years, and guess what, eventually he gave up, too (and turned to vintage K-horn). I myself don't have a chance to use them for long enough. Brief sessions always impress very much, but somehow it makes me think this way - what I need is something I live with, not a star in a show.

:)
 
Update-->

After a rather lively discussion about TAD's last night, it was decided I wasn't being totally "fair" regarding my assessments. My good friend (an avid TAD lover who's speaker ego is easily bruised) says I should have qualified something: None of the TAD's I heard had factory networks save for one which used the TN4. The TN4 is a sort of "one size fits all", and was in no way the optimum network for the drivers being used (TAD 4002's with ATC 12's). Even with this "less than optimum" set up, a notable improvement over the active (BBS FDS310) was heard. My TAD loving friend is wrapping up his latest project- a complete 2402 with a proper network. I am very exited to hear it. If yet another level of performance is gained, I may very well peruse TAD's again in the near future (especially now that the right crossover is at hand). It is an extremely important element, and cannot be understated. Now that I have cleared the air, I still stand by everything I said earlier.

For now, I am currently enjoying a pair of classic SP1 (broadcast) monitors. They reproduce vocals far better than anything I have heard thus far. Midrange is exceptional, and timbre, etc is all there like it should be. They make magic. All of it comes at a dear cost, though. No dynamic punch is to be had anywhere. Conclusion? There is no perfect speaker. If the TAD's can get this level of midrange magic even HALF as right as these Spendors, I'd consider them as close to a 'perfect speaker' as I could hope for.

To be continued....;)
 
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