18Sound Eighteen vs Sundown Fifteen

[Karkov]

interesting read, thanks all

[Patrick Bateman]

22 hours ago, audiofanaticz said:

I disagree with the coil sizing. Just because 4 little ones maybe equivalent to 1 larger sized coil doesn't make them better.
The 3 inch sundown coil is made in the usa at precision econowind (which are some of the best coils you can get), the tiny type r coils are generic china coils that will unwind as soon as you give them close to their rms power it seems.
While the sundown sub will be laughing at a 5krms amp, those type rs will be blown on 3krms or less (that is unless they are doing something completely different from what they use to).

Purchasing based on coil diameter is just a rule of thumb. For instance, I have a pair of TC Sounds eights here ($149) and a pair of MCM eights here ($35). Though their T/S specs are close enough that they'd probably work equally well in the same box, I'll bet the TC woofers could handle twice as much power. Everything about them looks overengineered.

But there's some things you can do to keep the woofers from blowing up:

1) use a tapped horn and mount the woofer inverted. The air moving in and out of the horn will lower the temperatures 

2) The same trick can be used in a vented box, but not to the same effect. (In a TH, the sub is basically IN the port.)

3) Sometimes four cheap woofers can outperform one expensive woofer. For instance, I can get four of the MCM woofers for less than the cost of the TC woofer, mount them isobaric, and now I have four times as much surface area for my voice coil and a box with the same air volume. On the downside, the woofers take up a lot of space, and going isobaric can get expensive fast.

[audiofanaticz]

While everything looks fine and dandy on paper, or in a computer program it doesnt hold true in the real world, especially once things like cabin gain comes into play.

Since your goal is looking at SPL and possibly competition, there are people with single 15s and single 18s that are doing 156+db legal on single sub setups in db drag no wall classes with crazy amounts of power.

This is just one localish competitor that I loaned him one of my Digital Design subs to try in his car because he wanted to try it (he normally uses Cactus Sounds subs and amps).

156.2 db without going all the way up because he didnt want to damage my woofer. He had 2 5krms amps on that single sub (10,000 watts rms).
There are also people all over the world that compete in this class with single sub setups way louder than he was.
I would love to see 4 type r 10s on this kind of power..... LOL

No Type Rs are going to handle that kind of power or get that loud doing so. Just like four 2.6 inch voice coils add up to be larger than a single 3 inch coil is meaningless.

 

[audiofanaticz]

Single EMF Yolo 18 (which uses many stock Sundown parts) with a 3inch coil, 14000-15000 watts of power, 163.5 db
Using your logic, the Type Rs will be louder because the 4 smaller coils combined are equivalent to a 5.2inch voice coil, and the four 10s have more cone area than a single 18....

I will wait for proof of Four Type R 10s doing these kinds of numbers, or taking this kind of power.
 

 

[Patrick Bateman]

I'm just getting my feet wet, so to speak, and I still have a lot to learn. From what I can see, it looks like keeping the voice coil cool is basically the number one priority.

The reason for this is because the cone isn't moving at the tuning frequency.

Due to that, it appears that there are only three variables at work here. IE, if you want to win, you need to address these three things:

1) how much power compression is occurring due to heating of the voice coil?
2) how much compression is occurring due to losses in the port?
3) how much SPL are you losing due to destructive interference caused by the car flexing?

I'm not saying Alpine is the best, but for the money you get a lot of technology. They have FOUR patented technologies in the Type R woofers to address power compression, and due to those patents, you won't see those features in their competition. If anyone's curious, here are the patents:

https://patentimages.storage.googleapis.com/pdfs/59510fec9d17ea06c3de/US6678387.pdf

https://patents.google.com/patent/US7272238B2/

https://patents.google.com/patent/US7634101B2/

https://patents.google.com/patent/US20100142747A1/


One thing that I'm noticing, as I study and learn how to win at SPL, is that there's no free lunch. For instance, I really like TC Sounds, but I've noticed that the features that make their woofers sound good seem to yield a set of T/S parameters which aren't ideal for high SPL. For instance, their woofers have nearly four times as much XMAX as the JBL woofers that I have here. But the QES on all of their woofers is quite high. The JBL woofers have very high BL and low QES, which is good for a high power sub. But their XMAX isn't competitive with TC Sounds.

All of these hours spent poring over hornresp and spec sheets helps me understand why woofers like the 18Sound 18NLW9600 are so ubiquitous; they have parameters that feature the best of both worlds. The 18NLW9600 has nearly twice as much XMAX as the JBLs that I have here, but the QES is low and the BL is high. It's basically a 'sweet spot' between JBL and TC Sounds.

Too bad the damn woofer costs $700

[WalledSonic]

Just a word of caution: A patent on a concept doesnt mean its a good idea, it means it was the first-thought idea (or the first-claimed-thought).  I have reviewed patents related to my job that were awful ideas, but someone thought of it first and got a patent bonus (ie $$$ from his company).

Either way, I like where you're going, so keep it up!