So here is a simulated group delay for the same driver in two enclosures. One vented and one horn loaded.
Initial impressions will be that the group delay is much worse. Upon a bit of thinking it will be a little different. The difference is about 40 thousands of a second worst case. Second thing the delay on the horn is more even over frequency. Not just a peak that could potentially become annoying.
Third thing is that this level of group delay in reality is next to inaudible in normal conditions. Under very controlled conditions it could be discerned, but not guaranteed to bother you.
In short if you can hear the difference your pretty special.
Will delay on your receiver help? Nope. Play with it but I'd be willing to bet that you will never hear a difference one way or the other.
Horn path is only 23 feet LOL! Sound travels at 340 meters/second. So about 8 meters in length 0.023 seconds of travel worst case scenario. Group delay through the vented box where the port is doing most of the work is actually very close.
The difference is striking when you consider what is actually going on inside the horn.
Matching output to output a Trio12 horn loaded will be eight times more efficient than the vented version. That means one eighth the excursion so a start and a stop is actually quicker in the horn than in the vented cabinet. It also means that there is considerably less distortion on the horns output compared to the vented boxes output. Usually 4 times less. Sometimes even greater reduction in distortion. It really depends on the bass content of what you are listening to. Some of the spookiest stuff is comes from the few pipeorgan recordings that actually plumb the true low end. With this horn you can follow notes being played as low as the instrument will play in real life. I have never been able to do that with normal subwoofers. One twelve will not do that under any circumstance I have ever heard. You need to move four liters of air to hear 16 hertz in a normal size living room.
It gets more awesome the more I learn. And...I'm a half deaf carpenter so I don't think I'll hear the delay, if you can even call it that. I'll be ordering the CSS kit soon, and because corner placement is good I'll be able to build it according to those plans. Construction will probably not start until the new year. One concern I have, if it's even a concern is that this deep clean punchy bass will not suit the movie LFE that is 90% of what I'll be using the sub for. And I only think that because of the lack of, in my opinion, discussion on these horns in the DIY forum. It's way more common to build a ported sono sub. And I'm not sure why that is.
I demonstrated this sub at the first DIY Ottawa show. I put iion some music for test purposes. But there's a gentleman who was there by the name of Adam. (Binary) He threw on some music (I mean rapp) that he thought would be a good test. I'll see if he will make a comment.
I technical terms it is this simple. The sub reproduces what ever you send it's way very loud with very low levels of distortion. There really is no such thing as a rock speaker or a home theater speaker. There are accurate speakers and not no accurate speakers.
One concern I have, if it's even a concern is that this deep clean punchy bass will not suit the movie LFE that is 90% of what I'll be using the sub for. And I only think that because of the lack of, in my opinion, discussion on these horns in the DIY forum. It's way more common to build a ported sono sub. And I'm not sure why that is.
You'll be fine. My little 6.5" driver horn fills my garage with sound nicely, and it wasn't optimized for output like Mark's Trio horn. Just be sure to use a high pass filter so you can drive it to potential. The LLT sonosubs are very light in weight, for a large 15" or 18" driver cab, and the footprint is very small for the displacement and low end achieved.
The horn concept is just now getting attention here mostly because designs are limited by the available ones by Mark and Mike (and BFM, that I know of). The cabinet design is critical, unlike typical ported designs which are quite forgiving. The other potential limiter is cabinet shape is limited to the original dimensions (without elaborate redesign), and I think many members have specific needs in that regard.
The trio12 Front loaded horn was, to put this simply, a showstopper. Litterally. I put on a single track, and it took less than 30 seconds to clear the old fuddy duddys from the room. They actually came back a within the next few minutes to ask me to turn it down or stop. We only had 65 watts...
Side note: I think if you think its too loud, You're too old.
The sub wanted more, but the building was complaining. (wooden floors were oscillating just a tiny bit and the windows were creaking slightly. lol) We did have a bigger amp, but concluded that with 65w, we were more than happy. (my bets are on the fact that the older guys couldn't handle it being any louder. lol)
For comparisons sake, I have a rather large subwoofer at home. A ~14 Cubic foot internal cabinet tuned for ~15-16hz with an SDX 15 in it. The Trio12 was getting similar output to my SDX15, but with less than 1/10th the power. I run a QSC RMX2450 In bridged mono on the 4 ohm load of the sdx 15, 2400W and i have clipped the amp while listening to the subwoofer.
Something has to be said about the CSS Drivers, The Build quality on them is AMAZING.
I am trading up from my SDX 15 in LLT, to two horn loaded dual 8" enclosures using some Trio8 Drivers.
I expect to gain 6db at 25hz as compared to my SDX 15. There really is something to horn loading.
If this doesn't say it all, then i don't know what does.
The only downside to a horn is that they don't overexaggerate their presence unless called upon by the music/movies, Unless you want to purposely run them hot, they blend into the background quite seamlessly. Most people would consider this a plus, but some people are bass-heads like myself.
I've been lurking on this site for years. Watching and waiting for a HT/music sub build that perfectly matched my goals. When I saw the TRIO12 Horn, it looked perfect. After a brief discussion with Bob at CSS, I ordered the kit, built it, and recently got it installed. I've now put a few hours on it and it's exceeding my expectations.
I'm not an audiophile, don't have any microphone/tuning equipment, and don't have anything else to compare this sub with. (My existing sub was a 10" NHT.) That's why a pre-designed 'kit' was so appealing to me. I bought a 300W O-audio Bash to drive it. Any boy does it!
As I mentioned, I don't have much to compare this with. But everyone who hears it gets a big grin on their face and says something like, "I've never heard anything like that." As others have mentioned, it's not like a car with a pair of 12's and 1000 watts that booms. It shakes and moves you. Very low, very clear.
The 'kit' is very nicely put together; it has excellent detail and great pictures and lot's of tips and suggestions. I'll try to get some pictures up soon.
Hi Mose, thanks for your comments. I would love to see some pictures. Maybe you could start a thread documenting your build and installation...I can't wait to start my build of this unit! My wife even gave me the "I think you should do it" comment the other day, so it's just a matter of timing and time. It's great that the sub is performing like or better than you expected too. You'd hate to do all that work and end up with questionable results.
I was a little hesitant about the OSB as well. The plan is designed around 1/2". I looked into different materials and settled on 5/8" OSB (actually 15mm). With the excessive bracing in the plan, I think this is overkill and the 1/2" OSB would have been fine. I think it's a great compromise if you are hesitant.
But I didn't care about weight (or so I thought). I also didn't care how it looked since I put it in the attic. And since it was in the attic, OSB seemed like a better choice since it uses exterior glue. MDF would be too succeptible to moisture in the Pacific Northwest. Saved me painting it. And OSB was about half the cost.
It was also kinda nice to work with the OSB since MDF creates such terrible dust.