First Post Tc Sounds Tc7 15.1 Deep 15

If that woofer goes as low as they say it does in a normal sized enclosure its going to be terribly inefficient.

 

Actually Chris (Geolemon) and I were discussing some of the drivers that Ponte has been putting together over there on the phone just 2 days ago (about 5 minutes before I found out he has never seen Fast Times at Ridgemont High :blink: ) . Some specs would be nice, but Chris was mentioning the low extention, massive cones and low BL.

These appear to be very specifically designed drivers, and fugyaself is dead on... They are very inneficient. They like big boxes, and have low efficiency due to monsterous moving mass... all the makings for a LOW bottom dweller of a sub. I am sure the low frequency info will be stunning, but I fear a need for a mid-sub-woofer <_< . That's right, something that goes below midbass and yet covers the upper subbass frequencies nicely. Maybe an IDQ B) . They almost seem to me to be designed as audible tactile transducers... basicly earth movers.

For their purpose I am sure they are amazing drivers, but I really fail to see much usefulness in car applications.

 

What's up with TC and high Q drivers lately? First they had their 8, and now this. Also, I was expecting a lower Fs than that. 30 Hz seems a little high for this "ultra low" sub.

Steven Kephart
Adire Audio

 

Where did you see the TS?

High Q are great for Dipole. I am willing to bet that is what their design was intended for. It all adds up with the ultra low efficiency too.

 

If you follow the link above and click on that wierd picture on the page, you will find the t/s parameters. Here's a list:


Qts= 1.338
Qes= 1.568
Qms= 9.132
Fs= 30.347
Res =3.14
Vas= 64.5
Mms= 438 grams
Cms= 62.78
Bl= 12.93
Spl= 82.43

Steven Kephart
Adire Audio

 

Hmm is quite odd to have such a high Fs on such a low playing driver. Think they did it to save efficiency and possibly high end extension?

 

Super,

low efficiency and large boxes go hand in hand. The less efficient a driver is the smaller the enclosure as a general rule. If not, bottom end will suffer.

Fugyaself and Steven,

It appears to be designed for dipole use. In looking at the specs I think it is almost a sure bet. The high Q will add a nice spike at resonance, where dipole cancellation will occur. This reduces or eliminates electronic attenuation above or boosting signal at resonance frequency. These are really the 3 ways that we typically reduce that immenent cancellation, and what better way (and more natural way) to do that than through driver manipulation.

The Adire Dipole does it another way, by bringing resonance below most audible information. By doing that they eliminated the possibility of the cancellation being audible.

 

Then you are right. I really don't understand why the hell Steve would target the sale for car audio. I guess sealed box extension is desirable for some.

 

the first one looks nice, the low QTS offers a nice ported application availability, yet combined with the nice low FS it looks like it will also do very well sealed. I'd guess without modeling it, a mid sized sealed enclosure would yeild nice results.

The second seems geared a bit more toward ported apps. QTS and FS are both a bit too high for even thinking about sealed apps IMHO... Bring that Q up to .45 and I say it is an OK driver for sealed, but at .37 I say no way...

It seems like ported is not what you are looking for, so I suggest the first of the 2.

 

What kind of power and how much room are you really looking to use?


Looking at these drivers the tempest and shiva come tome mind. That is if you can supply the airspace for either.

 

Three 12"s would definatly be louder, but I dont think they can touch the SQ of a Brahma. A Brahma 15" with 1000 or so watts will be plenty loud and sound awesome doing it.

 

1 15 plently Loud???? :lmfao: :lmfao: :lmfao: :lmfao: neva

 

The TC drivers will not be able to keep up with the Brahma in terms of SPL and SQ. Please keep in mind that SQ is largely subjective, but from an objective standpoint, the XBL2 linearity and CMS linearity will provide for cleaner more accurate reproduction. Also, the short coils used in the Brahma motor bring Le (inductance) down low. What that entails is simply the lower the Le, the easier it becomes for the coil to be saturated with the signal. The more quickly the coil becomes saturated, the quicker and more agressively it can react. Couple that with XBL2's extremely linear BL (motor force) and you get an idea that it can react with more force when saturated. This equates to better transient responce as well. Here is a great tech paper that addresses woofer speed/transient responce in greater detail. Also, Xmax is simply 30% greater in the Brahma than the TC driver.

Enclosure size of the Brahma is tiny too, the 12 needing under a foot with 900 watts. to reach full capability.

The Brahma wins both contests hands down, but is it worth the extra money to you? The Brahma is what I consider 1 of only a tiny few drivers I would call supersubs... it is really almost without equal. But when you choose to buy something like this, you will pay dearly for the equipment, so be prepared. Without knowing much about you and you tastes/goals, I would hate to lead you in any direction.

 

Here's a critical quote from the selection:
"Don't let the efficiency # fool you - below 40Hz, you simply cannot TOUCH this woofer. The intentional low BL, and very high Mmd make this woofer a LOW bass MONSTER!"
I was mentioning to Seth that Stephen was doing some very interesting drivers, and it was a pleasure that someone of Stephen's caliber was actually listing them, because they could state things honestly, in keeping with the design goals...
And efficiency and small enclosure capability were intentionally traded away here.

Hoffman's Iron Law states the following three items are mutually exclusive:
1) small enclosure size
2) high efficiency
3) low frequency extension

He intentionally traded off #1 and #2 as much as possible, to maximize #3 as much as possible. B)

But...
For a mini-truck (which everyone around here knows I'm a fan of ), I'd say these subs would definitely not be a good choice...

They'll play low, but you've got so much cabin gain working for you in a minitruck, you really don't need a sub that extends that low- your cabin gain will boost it naturally.
Further, you don't have much space...
I don't know how much efficiency you are looking for - that's a big-ass amp, you don't need efficiency.
What it sounds like you need is simply a "small box sub"... priority #1.

 

Sounds like a plan.

Not sure if you've ever cut one - but when you cut your blow-through, be sure to cut from the bed side first, as the bed floor is generally higher than the cab floor, and you need matching cuts on the bed and cab to span with the accordion boot that keeps the weather out.