Ricci

On ‎5‎/‎29‎/‎2018 at 12:56 PM, deepthoughts said:

Pennynike1 took a first step of stacking the Othorns in the double stacks (I wasn't there).  Of course any stack over 6' warrants a picture:

 

After some tinkering he currently spun 2 of the Terraform D18s around to slide into the outer cavities firing toward the front wall.  Remember this all has a screen hung in front of it.  Here was the last in process picture I got:
 

I'll be curious to see how things are measuring when I visit next and see if we might be able to use the 2 remaining Othorns to good effect at the sides or rear of the room.

I was reading this and was going to ask if other Terraform placement options were being considered. I look at all those cabs and I am glad that's not my room. I'd probably spend 2 to 3 days measuring/listening and changing cab configurations like having the worlds largest Jenga set.

Also...And I cannot believe I'm about to say this, but...I think he should probably sell off or repurpose a few of those Othorns and get a bit of space and placement flexibility back. I can't see how anyone could really uncork 8 Othorns in a space like that. He could go down to "just 4" LOL and it is still going to be headroom well beyond what will be used. He probably has 115dB sensitivity or higher over much of the bass range. 100W total spread across the 8 cabs is probably well into house wrecking levels already.

Ughh...Dang. I might have to pick up HH just to give that a listen. Has anyone seen it? The reviews aren't good but if it has some big demo worthy moments I might give it a go anyway.

External dimensions?

Agreed on the ID 18sound drivers vs the IPAL B&C's. I have the 21nlw9601 and a 21ID and they are identical outwardly. Only the sticker visually indicates a difference. I believe the 18Sounds simply use a heavier 4 layer coil to get more force on theirs vs the 9601 series, whereas the B&C drivers seem to have entirely different and beefier motors and coils.

On 5/16/2018 at 1:17 PM, deepthoughts said:

 

He had everything set in place before he got around to covering the walls, where this picture shows a lot more of the craziness going on here:

 

I also want to point out the pink rigid foam wedged into the window well openings on the front wall...  Those were added after he literally BROKE the windows.

After visiting and seeing what was roughly going on, but not yet breaking out my microphone and just going on what he has measured, it would appear things would be much happier if we change the 2x2 stacks deep, to 3 units set on their side for a 6' tall stack, with the mouth against the front foundation wall.  As the front center location did measure rather well in his room, I'm thinking to put the 2 stacks of 3 firing at each other against the front wall.  This brings me to the question... for this thread.

I've done some creative horn extensions with some of Tom Danley's past designs, with very useful results.  With the 2 stacks firing at each other, lets assume for a moment we confined the height to the 6' tall stack.  This would provide a much tighter spacial load, along with extending the horn length by most of the 36" height of the cabinet.  We can vary the distance between the two stacks to adjust the area of the added segment, and I'm wondering if anyone has a model already in Hornresp who could check what range/type of effect an extension might have?

I'm thinking I would start with about 36" between the two, which gives an extension area for each of about 18" x the 24" height of each for about 36" figuring the 90 deg turn and mouth/end effects.  If anyone had time to model a 12" x 24" (1860 cm2), 18" x 24" (2790 cm2), and 24" x 24" (3720 cm2) extension that is 36" long, it would be appreciated and interesting.

-Mark

This looks like a fairly small room, with cinder block walls and a cement floor? Yeesh that room probably has an extraordinary amount of gain to begin with. Blowing out windows??? No wonder. What's the dimensions on that space? I'd bet there is some weird effects going on due to that connection to the other space. It'd be a good data point to see the before and after effects of closing that connection off. 

Looks like if he stacks 6 of the Othorns on the 36x36 side he would have the same height overall but save 12" of depth out into the room. What he does with the other 2 Othorns I'm not sure...Good luck with the endeavor. I'll be interested to see what you find. The 36" extension sounds like it may work and he definitely has headroom to spare so a loss of a few dB midband shouldn't be noticed. 

1 hour ago, StainlessSteve said:

Oh, my apologies Mark. I didn't realize you were so knowledgeable in the area of the tapped horn.

Fun fact... Mark and Jeff from JTR both used to work with Tom D. back in the day. They've both been around the block so to speak. Definitely have high level horn design and all around audio kungfu. 

Good luck with whatever you end up deciding to do Paul. Share a bit when you can. 

17 hours ago, radulescu_paul_mircea said:

I've just ordered 2 21Id drivers, so I'll probably build these. They'll have 2 21Ipal on the front in series and one 21ID on the back . I'll use a Powersoft K10 on the front drivers and a FP14K clone on the ones on the back, one on each channel . Processing will be a DBX driverack. 

It will be very helpful to get some direct comparisons between the 18Sound and B&C drivers, I'll also get to play with some mammoths, because they'll get very large

 I'd probably just design a separate cabinet module or an identical 3rd Skhorn sub to be placed in the arrays to keep weight and size down. If the situation lends itself to it and you don't need a cardoid pattern so much, you can leave the extra size and weight at home. I don't like it all being built into the same cab even though it can greatly simplify the setup. YMMV

On ‎5‎/‎10‎/‎2018 at 3:33 PM, awlambert said:

Thanks! I found a guy who is doing exactly that now. I'm happy to post the files here once its all done if that's cool...

Great. Sounds like it'll work out for you.

On ‎5‎/‎12‎/‎2018 at 2:08 PM, Shredhead said:

The clipping was pick attack so yeah, it sounded less harsh when de-clipped and played by itself but once the bass was put in the mix and EQ'd, it's pretty hard to tell a difference. 

 

You still playing these days?  Any new recordings or vids? 

Yep still playing. Practicing 3 total days a week with 2 groups. Shows peppered in there as well. Wrapping up an EP recording etc...

PM me your email and I'll try to send you a few tracks.

My advice would be to pay the operator to setup a cut program off of the print. It's not hard. He should no how to do that. Barring that perhaps someone will help you out. 

I'd do xmech rating +2mm or something. You'd never ever hit that but you don't want to take that chance either. 

Wobbles could be reflections from surfaces and vibration/resonances. I put about 150lbs on my speaker stand to drop the vibration resonance of the top section down below 5Hz. Otherwise it shows up in the impedance measurements. You'd be surprised what adding some weight and turning the cab just 15 degrees might do sometimes. I bet that desk isn't as stable as you'd think. I usually put my cabs on a bar stool if measuring in my garage and angle them towards the far corner then add a couple 50lb dumb bells and some sandbags on top. Larger cabs like Skhorns, MAULS, etc. get done outdoors.  

Not having the driver bolted in will probably make the system a bit lossy too. I'd expect that standing the cab up and properly bolting in the driver and sealing it will probably sharpen the lower peak a little and perhaps lower it a bit more. 

Im not real sure. Never tried it. Id guess at 3 or 4 inches minimum if driving it hard. If you try let us know how it works out.

Cheers Mike for helping Samps out. 

Looks good. Yes I would expect your port to act a bit longer than what you have calculated for the length plus 90deg turn since it is close to the back wall. I'd guess it acts a good 3" longer than expected. Impedance measurement should show where it lands.

Interesting comparison of the declipper function Shred. Could you hear a difference? I know it might be difficult on some very short transient peaks but just wondering. 

If you use something like the PZB100 drivers you will probably lose around 10-12dB in maximum output when compared to the version I have with the 21Ipal's.

The WW cab is a good data point and just about the Goldilocks size for this driver for HT. Honestly I wouldn't go any bigger for this driver for a vented cab tuned near 18-20Hz. It just doesn't need it. 10-12ft seems about perfect. Any bigger would hit the point of diminishing returns. Don't forget that you'll likely get some lift below 30Hz in room. 3 to 6dB in the 16-20Hz range is a good general guess.

20ft would be great for 2 drivers though. 

I've got one of those and a 21ID for testing that they sent me by mistake. Was supposed to be 2 9601's. No measurements yet or for awhile probably. However I wouldn't hesitate to buy em and trust the factory specs. They have a good rep and VC mag has tested the 18" and a bunch of other 18S drivers. I expect that the 21SW152 might be just a bit "more" but a 21" like these for $400 is a killer deal. Should match up with the Skhorn and Othorn cabs well. Should be great vented too. 

EDIT: They dropped another $20 to 374...

Another deal...$394

18Sound 21NLW9601

Buy em now people!

Most of the time direct vibration transmission from the sub enclosure, into the floor and structure, is probably negligible, or of much less concern than the vibration caused by acoustic transmission. However we can't make a blanket statement and say it is never an issue. A worst case scenario might be something like: A suspended floor,  hard surface, down firing driver/s or PR's which are not mirrored, very high mms, lightweight enclosure, sub being driven very hard. In this hypothetically bad scenario or something similar it may indeed be an issue. For most typical sub designs in a carpeted space it's unlikely to be worth addressing IMHO. 

On 3/27/2018 at 9:53 PM, EndersShadow said:

I agree.  Its quite cool!  I also like the anti poke factor 

Thanks Ricci!  

My buddy in Evansville is going to help me with the builds.  He's the fella who bought those two Chase subs off you about a year ago.  When we get these built, I'd hazard a guess you'd be welcome to come see em in person before I take em back to Indy to install them (although you'd be welcome to a demo at my house once they are dialed in, but its a lot farther of a drive)

We've already spitballed a bit and potentially adjusted the build a bit in a good way.  

A struggle I knew I would have would be driver removal.  The JBLs are 12.25" including the basket.  Since the cutout in the cabinet is only 24" it would make it a PITA to remove drivers if one got blown.

We are thinking we just remove the bottom of the cabinet and configure the "shell" to slip over the top of the "new" sub.  Then add some furniture inserts to the sides and maybe front so that we can secure the two boxes together.  That also would give me more space for the box so we can make sure to brace it well and still get to 6cf so it closely matches the existing sub I've got.

Then if I need to get into the box to service a driver its as easy as separating the two boxes.

For now the box is in my house in its final resting place so my wife can get a feel for it.  It will make its way down to Evansville here in the next month or so to begin its new life...

That's right. I almost forgot about that. 

Actually Indy and Evansville are about the same distance for me. I'm in Floyd County down by Louisville. 

I like this idea. Old school looks with updated performance. Holy crap that's a lot of 12's...Projects for years.