what is lower cutoff of tad 4001 sans horn?

[enochRoot]

http://www.deepaudio.net/html/product_info.htm

came across this website, and wondered how this could work? how low can the internal "horn" of the driver possibly load it? wouldn't it be in the thousands of hertz? is the driver just padded way down to flatten it out, and waste the sensitivity? thoughts?

 

[slowmotion]

Heheh, this is pure bull!
Who are this people?

cheers

 

[Magnetar]

http://www.deepaudio.net/html/product_info.htm

came across this website, and wondered how this could work? how low can the internal "horn" of the driver possibly load it? wouldn't it be in the thousands of hertz? is the driver just padded way down to flatten it out, and waste the sensitivity? thoughts?

Sure it will work with limited success with the driver below around 2K, I've done this before with the 4001's. I wide notch filter is needed. Better to load the driver in a good horn.

The 1601 woofers are really not that sensitive. I have some here right now that are only around 93 db with a watt.

They probably sound OK - I wonder what the author of that webpage would say if he heard my system? It would probably take 3*4 pages.

 

[enochRoot]

yeah...that's what i thought (about it "working", but with limited success). they do sound more like creative writers than audio designers

magnetar: is the 93db sensitivity for the 1601s an isolated issue? ie: are the unit to unit discrepencies to blame, or are these honestly that low across the board? i was looking to purchase some for a system i want to put together. also...what variant are they (a, b, or c)? finally...what type of aligment do you use them in? i was thinking about a horn loading for the 1601bs. not sure which way to take it though. rear or front horn. i almost thought that if i could build a 60hz or so front horn...i could live w/ that for the time being. i was a bit confused though about how "mass rolloff" comes into effect. is that just for folded horns? if not, it is like 175hz or so (if i remember correctly). does that mean i would only get loading from 60-175 that way? i was going to start a new thread about this, but might as well just use this one

 

[Magnetar]

I have a's and b's - they are both pretty weak chinned (low sensitivity) compared to say an EV 15L, Altec 921-LF, JBL 2220 --

That said they are not really a driver I'd use in a folded or straight horn. Best used in a bass reflex with multiple pairs if you want to keep up with a compression driver/horn. The mass roll off is caused by not enough motor to drive the horn - I used the 1601a's in a folded horn (unoptimized back chamber) and they peaked at around 180 in a 60 cycle horn - in the same horn a Klipsch K33 went out to 500 cycles without a problem. Overall (in a IB or reflex) they probably will still sound superior to most 'high end' drivers - just not as supreme as some of the others I mentioned.

Now the TAD 1201H - that's a KILLER horn driver - maybe the best ever in the midbass.

 

[DSP_Geek]

http://www.deepaudio.net/html/product_info.htm

came across this website, and wondered how this could work? how low can the internal "horn" of the driver possibly load it? wouldn't it be in the thousands of hertz? is the driver just padded way down to flatten it out, and waste the sensitivity? thoughts?

Oh dear. This is *remarkably* wrong-headed.

You're correct, the throat expansion inside the driver itself will load the diaphragm somewhat, but essentially it will be a very short horn with no decent transition at the mouth, in other words very close to an unflared tube. Timmy, what do we call that in speaker design? A resonant pipe? Very good.

I predict this thing will ring like mad at odd multiples of a quarter wavelength between diaphragm and mouth. Since it's 150 mm deep, a quarter wavelength is about 600 Hz (allowing for clearances), so expect resonances at 600, 1800, 3000, 4200, 5400, etc etc etc.

There's not a whole lot of space between the phase plug and diaphragm either, so they can't cross the thing very low; I expect many warranty returns unless the crossover is at least 1500 Hz. With the, ah, "designers" taking pride in no cabinet bracing or sound absorption behind the woofer, the decay characteristics will be *cough* interesting.


Francois.

 

[enochRoot]

yeah...i don't really know much, but i knew enough to find this a bit off-base.

anyhow...i was going to start a separate thread about my current project to be, but i might as well just ask here. as i mentioned...the 1601b was a potential driver (making a simple 2-way w/ ported box, and 4001 or 2001 on top w/ horns). i was also thinking about the tl-1201h. so your post magnetar was interesting. what is the widest range i could run those? i want to cover as much w/ that as possible (if i were to go to a 3-way). tad lists crossovers at 200hz and 3000hz. is that in a sealed chamber? would horn-loading decrease that bandwidth? what type of front horn would work best. any input would be appreciated. not sure what i would use on the low-end. possibly just some vented or sealed enclosure. i thought that possibly 1601b sealed, 1201h sealed, and some sort of ribbon up top. i don't need insane low bass. would be nice, but if it goes down to 40-50 with authority...i would be happy.

 

[Magnetar]

what is the widest range i could run those? i want to cover as much w/ that as possible (if i were to go to a 3-way). tad lists crossovers at 200hz and 3000hz. is that in a sealed chamber? would horn-loading decrease that bandwidth? what type of front horn would work best. any input would be appreciated. not sure what i would use on the low-end. possibly just some vented or sealed enclosure. i thought that possibly 1601b sealed, 1201h sealed, and some sort of ribbon up top. i don't need insane low bass. would be nice, but if it goes down to 40-50 with authority...i would be happy.

Hello, in a straight 100 Hz tractrix horn (on the floor - not like this) they will cover 120-1200 extremely well. Horn loading will help the lower range but there will still be mass rolloff on the top.

I think a 60 Hz hypex straight horn would sound best. that should cover 60 to 1200. In a sealed box the 1201 won't do much below 250 cycles, the need a horn to help them down there. A 60 hz hypex would be quite large, and maybe even uglier than these beasts.

An externally hosted image should be here but it was not working when we last tested it.

They used TAD 4001 in a small 550 hz tractrix horn, 1201 in 100 hz tractrix and two 1601a's in a bass reflex - one front mounted one side firing, triamped - plus eight JBL 2235 15's in the corners for the deep bass. It sounded pretty darn good - could probably write 4-5 pages about these --

Here is another config with the 1201 - these had side firing 15's and 180 hz tractrix horn for the 4001 (250-10K) with electrostatic elements for the top end----- anothe 3-4 page speaker!

An externally hosted image should be here but it was not working when we last tested it.

 

[enochRoot]

wow!

just when i think i've seen all the variations you've used, you spring some more on me! hehehe. anyhow, what size are we talking for the 60hz hypex straight horn? i have a decent amount of room, and a very understading wife! WAF has never been an issue. also, once i decide on a design, would you possibly help me w/ the design? i'm not super lame, just on a mac, so i cannot run ANY of the horn response programs. i can use the online java-based contour calculators, but i wouldn't know when i have a good design. the 60hz horn sounds great, and i could just use a compression driver up top. and if worst came to worst...still start it off as a 2-way, and then add low bass, and supertweeter (if needed) later. thanks for all the info too...i appreciate it!!

 

[enochRoot]

forgot to ask. in a sealed box, the lower-end cutoff is 250 you mention. how is the top end effected? ie: is mass rolloff not an issue? would they play out to 2-3000? also, using a sealed box LOSES efficiency, right?

 

[Magnetar]

Re: wow!

just when i think i've seen all the variations you've used, you spring some more on me! hehehe. anyhow, what size are we talking for the 60hz hypex straight horn? i have a decent amount of room, and a very understading wife! WAF has never been an issue. also, once i decide on a design, would you possibly help me w/ the design? i'm not super lame, just on a mac, so i cannot run ANY of the horn response programs. i can use the online java-based contour calculators, but i wouldn't know when i have a good design. the 60hz horn sounds great, and i could just use a compression driver up top. and if worst came to worst...still start it off as a 2-way, and then add low bass, and supertweeter (if needed) later. thanks for all the info too...i appreciate it!!

The horn iiif designed to be on the ground, near the wall, would be around 28" x 30" at the mouth and 3' deep. I could run some simulations with the McBean program and the 1201's - It will predict a fairly accurate response - Edgar could build you a pair - I'm pretty busy with work and my own contraptions right now.

forgot to ask. in a sealed box, the lower-end cutoff is 250 you mention. how is the top end effected? ie: is mass rolloff not an issue? would they play out to 2-3000? also, using a sealed box LOSES efficiency, right?

The top end will begin beaming at around 600 cycles but they sound great on axis well above that. The carbon fiber cone and huge magnet makes for beyond 'electrostatic' midrange - on par with field coils and in some way better in my opinion. Bass reflex will have very little benefit with the 1201. Maybe a bit more efficient below 250 but it will ring more than sealed system.

 

[enochRoot]

great...thanks for all the info! that size is totally manageable for me. and i will be building them. i LOVE woodworking, the only problem is the design part, as i'm on a mac. until i can get virtual pc up and running, and install the mcBean program (amongst others) i'm kinda stuck. will these be 100% straight (ie: a truncated pyramid), or will there be one angular bend somewhere along the horn (as i have seen in others)? just curious. they sound like just what i am looking for!! now...do you have any for sale? tried to find some used, but only found them at one place. and OF COURSE there is a minimum purchase of 4. even at that...you can get 4 for the price of 2 new, so i might do it anyhow. there is one on ebay, but that is 8 ohm (and i wanted the 16 ohm versions).

also....i have 2 corners to use if that will help the situation out any.

 

[Huss]

I recently came across this thread...obviously ancient history now. I am the designer of the Model 16 system. I enjoyed the discussion.

 

[Huss]

http://www.deepaudio.net/html/product_info.htm

came across this website, and wondered how this could work? how low can the internal "horn" of the driver possibly load it? wouldn't it be in the thousands of hertz? is the driver just padded way down to flatten it out, and waste the sensitivity? thoughts?

Hello...I am the designer of the M16 system.

The answer to your question is that the whole point was to get it to work WITHOUT any horn.

There is no compulsion technically (or emotionally...or any other reason) to require horn-loading if the driver sounds good without a horn and it is not being used in an application requiring maximum safe power handling. Yes the low-frequency sensitivity and efficiency of the driver are improved with horn loading, but this trades-off against other things...take your pick.

Without a horn it still can be considered a very wide-band, beautiful sounding HF driver. And, it measures very nicely as well. I am not chasing ultimate power-handling. This is not a PA system. It is for moderate SPL levels in the near field, in the quiet environment of a domestic room. At these levels the sonic virtues of using the driver horn-free outweigh the down-sides. It's no big deal...no one will throw you in jail if you try it (except possibly some of the acoustic-theory police on this forum...)
Sure, on-paper the short throat theoretically has some resonances, but this is more of a theoretical problem than a musically-objectional one. The 4001, in the near field, sounds fantastic without a horn...this is simply a fact. Try and find a HF driver from Scan, Dynaudio, Peerless, Morel or anyone else which combines so many virtues. It's not a cheap driver though...

 

[Magnetar]

Re: Re: what is lower cutoff of tad 4001 sans horn?

Hello...I am the designer of the M16 system.

The answer to your question is that the whole point was to get it to work WITHOUT any horn.

There is no compulsion technically (or emotionally...or any other reason) to require horn-loading if the driver sounds good without a horn and it is not being used in an application requiring maximum safe power handling. Yes the low-frequency sensitivity and efficiency of the driver are improved with horn loading, but this trades-off against other things...take your pick.

Without a horn it still can be considered a very wide-band, beautiful sounding HF driver. And, it measures very nicely as well. I am not chasing ultimate power-handling. This is not a PA system. It is for moderate SPL levels in the near field, in the quiet environment of a domestic room. At these levels the sonic virtues of using the driver horn-free outweigh the down-sides. It's no big deal...no one will throw you in jail if you try it (except possibly some of the acoustic-theory police on this forum...)
Sure, on-paper the short throat theoretically has some resonances, but this is more of a theoretical problem than a musically-objectional one. The 4001, in the near field, sounds fantastic without a horn...this is simply a fact. Try and find a HF driver from Scan, Dynaudio, Peerless, Morel or anyone else which combines so many virtues. It's not a cheap driver though...

If you remove the back cap and listen to the diaphragm directly it sounds a lot better - It's also very linear down to 800 cycles. A 'super dome'

 

[pinkmouse]

I like the TADs a lot for PA use, but they do have issues. The motor is held together purely by magnetism, so the pole piece or front plate can shift if they are treated roughly or dropped. The magnets also tend to lose power over time, and at a variable rate, so two old, (10+ years or so), drivers side by side can sound completely different.