Ricci

Currently I've got a ton of subs that need to move on to someone who will use them more than I do.

For sale

Sold...Qty (2) B&C 21ds115-4 drivers. 1 of the drivers has a slight kink in the flange of the frame in one area. Driver still functions 100%. Bend could be straightened out by front mounting it or the driver can be sealed using an extra thickness of gasket material. $490 shipped and insured / $440 for the driver with the frame flange issue. $900 takes both. Sold...

Qty (2) 18 Sound 21NLW9601 8 ohm drivers. $490 each shipped and insured. $950 takes both.

Qty (1) 18 Sound 21ID. $550 shipped and insured

Sold...Qty (2) Lavoce SAN214.50 drivers. $420 each shipped and insured. $800 takes both. Sold...

Time for me to start clearing out gear that has accumulated and is no longer needed. Funds from equipment sold is used to buy new sub's or gear or otherwise fund Data-Bass 

All gear is slightly used but in good working order unless otherwise noted. 

I will only ship to the 48 lower US states. I am willing to meet up for local sales in the Louisville KY area. 

I accept PayPal or cash for local sales.

There may be a tiny difference between the outer vents and the center ones due to oroximity to the side wall, but I'd have to measure it. Go with whatever works for you. It shouldn't made a difference. 

20 minutes ago, m_ms said:

That's very decent extension from a box of this (relatively) moderate size, housing a 21" driver, and sporting a sensitivity in the late 90's or around 100dB's? Impressive engineering/design, Mr. Ricci.

If blocking one of the 4 vents, would honest 20Hz or even slightly lower be achievable in-room? Continuing, will port noise with 3 open vents be a non issue below 120-125dB's (or even higher), with a pair of Skrams?

Any preference between drivers such as the B&C 21DS115, Lavoce SAN214.50 and RCF LF21N551? Here in Europe the B&C 21DS115 comes some 50 Euros cheaper compared to the other two alternatives, but overall performance seems comparable. Being even more expensive than either of those drivers, would there be any uptick in using the B&C 21SW152? The IPAL I'm sure will add a few dB's more output. 

If one were to compare a single Skram with a single MicroWrecker tapped horn (with a 15" B&C), how would that go about? The Skram I'm sure will have perhaps some 10dB's extra output from, say, 30 or 35Hz to 100Hz, but will it feel more visceral at the same SPL? A 21" driver has roughly twice the radiation area of a 15" unit, but the 15" driver in the MW is fully horn loaded (i.e.: as a tapped horn at least), whereas the 21" in the Skram isn't (it seems there's a slight horn-loading in the Skram?). That is to say: the force multiplier via the horn-loading of the 15" in the MW is bigger than any such of the 21" in the Skram. At least this would make a comparison on a driver-to-driver basis difficult, I'd say. Sorry for this speculative question - I'm just curious..

Skram has 4 vents. Each is equivalent to a 6" round port. With 1 vent blocked and 3 open you have the equivalent of three 6" vents still operating. Tuning drops to about 24.5Hz. There should still be a lot of headroom down to 20Hz in room. 2 vents open is 20Hz tuning, etc...

21DS115 is a good match if it is the cheapest option.

I can't really answer about the MW comparison. I've never heard one or modeled them so I'd rather not speculate.

20 hours ago, m_ms said:

I would expect that too. How low would you estimate they go, honestly - 25Hz?

In a home sized space they should do well to 25Hz with all vents open. Should only be roughly 6dB down outdoors at 25Hz. In room will probably boost it back up a little.

Double Skram should have a little bit extra on a single Skhorn at the limit, assuming both are using the same drivers.

22 minutes ago, Jesal said:

Would there be big gains by doing 1 or 2?

Or are both options pretty much 1/8 space corner loading?

Facing the corner should be a little bit smoother through the crossover region >80Hz. Other than that experimentation and measurements would give the best answers.

That escalated quickly!

Which Danleys are those?

Large aggressive thread screws. I like 1/4 x 20 lag screws for back mounting these 21" pro drivers.

The Behringer specs are optimistic. However you still cannot find amplifiers with more power for less $$$. The built in dsp is worth the extra $50 too. Most other amps with comparable DSP quality are 2 or 3x the price. If you have a receiver with XT32 and the processing is only needed for the sub by all means skip the minidsp and get the DSP equipped Behringer amp.

The fans are loud on these. A lot of guys have done fan mods on them to use quieter fans. There are plenty of threads covering it at AVS forum. I've not personally fan swapped one.

The dsp section in the amplifier has a limiter section that would be set in the amp if needed.

Hello Joselo. Welcome.

If you buy the 3000DSP you won't need to buy the minidsp. Personally I'd probably go that route. The less boxes, wiring and complication the better. I played around with a 3000dsp and it did pretty well, very well even considering the cost. DSP works well too. It does not sound good when it clips but a limiter set a bit below the clip limit will help with that.

1 hour ago, dsl1 said:

They've been done but haven't had a chance to run them. Failing over here. Life has been busy

I know how it is. Need a few more hours in the day. It's a shame we have to sleep.

Kyle is right. Xmax is based off of either physical measurements of the coil and gap geometry, a distortion percentage (with a certain signal, at a certain frequency in a certain loading), or measurements of things such as BL, suspension compliance or inductance shifting at various positions of the coil in the gap. There are ways to measure the amount of driver excursion but you need one of these other methods to determine if it is within the limits set for xmax. It's a complicated subject. The "Myths" section on xmax covers some of it.

When I make note of excursion behaviors for driver tests. I am not rating the drivers xmax and I'm not measuring the distortion, or BL loss, etc. I am simply making a note of how the driver behaves in free-air, at what point it becomes obviously  distorted or loses it's composure, where it stops responding to power increases with more excursion, how loud the mechanical operational noise becomes, etc. It's a set of general observations about how the driver seems to respond to high excursion in a very basic sense.

What all of this means for your drivers and app is this. Don't worry about the xmax rating of the drivers. What matters to you is at what point the drivers start to sound bad or become in danger of damage. With some careful probing of their limits with measurements and test signals you can determine where they start to lose it and at what voltage that occurs.

On ‎5‎/‎2‎/‎2019 at 9:56 AM, dsl1 said:

Tried some white duratex. Kind of cool.

Two boxes are done. Driver fits! May put one more coat of duratex on. The white doesn't cover as well.

Hey Ti did you ever get a chance to put some voltage to these yet? Just wondering. Looked like you were about done a few weeks back.

11 hours ago, LSC said:

The first test session with both was so good, lots and lots of undistorted bass leaving the mighty box.. Effortless and natural as many said before about your hybrid designs! 

 

Outdoor measurements couldn't be taken yet due to rain but I can try to get some 1Watt/1m/nearfield indoor responses if wanted. 

Cheers, Nathan 

 

Thanks for giving us some feedback on the results. I think you may be the first to hear these. I'd say I'm surprised by your impression of them but I'm not. Ha!

Some close measurements would be great if you get a chance. If you do try a few inches away in between the 2 sets of vents and a very close response in the middle of one of each set of vents.

18 Sounds Xmax is based on coil overhang + 1/4 gap height. Same 14mm rating as their lower end drivers. It seems they only made the impedance lower and got more motor force out of it but otherwise it's no different from the MUCH less expensive 9601 drivers.  So far they seem to lose composure quicker when compared with some of the other drivers too. Definitely not directly on the level with the B&C Ipal units, which are beefier upgraded drivers from the lower range B&C drivers.

Thanks for linking to the JBL. New driver name is 2288H. I was unable to find much on it yet. My gut tells me it may have similar excursion as the 2269H but slightly improved power handling and higher efficiency. Looks like it is only used in the VTX B18 at this point. I really dig the port flaring on that cabinet. It wouldn't be too hard to do something similar on a 3D printer. I'm assuming they are using a quarter section of very large pipe for the ports.

Congrats on the 5000's I still plan to get ahold of one at some point.

Interesting. Got a model # or a link to the sub with the new JBL driver? I have not heard about this. 

Did you finally get those 5000's? We still have nothing over here.

Discussion of JBL's most powerful differential drive woofer should go here. 

This is an oldie but a goody. It's an expensive bugger like most of the woofers I test these days but it is still a cut above most of the 18" units on the market.  I always wanted to test one of these just to see how good it is. I don't expect many people to go out and buy these for a project at those prices but it is still a common driver to see in the industry in a lot of JBL's top Pro subs. I figure giving it a run through here should help give insight into the capabilities of the various JBL subs using the 2269H. It doesn't have the crazy efficiency and motor force of the drivers coming out in the last 5 years, but it does seem to offer quite a bit of power handling and raw displacement capability. It's too bad you never see these on the second hand market for a few hundred dollars like you can pick up other legacy JBL units for. It might be an option then. The retail price is a killer. It really doesn't seem like these would be that expensive to produce either with JBL's economy of scale and having been around for so long. 

https://data-bass.com/#/drivers/5cd9d5e8bd4b990004557d17

19 hours ago, radulescu_paul_mircea said:

Nice! Very good efficiency. I had mixed feelings with this driver and still have.

Care to elaborate? 

I've got some myself but I'm going to let the GP testing do the talking. 

13 hours ago, Kyle said:

Nice job Josh!

Another powersoft only driver... I honestly didn't think the IPAL was that popular, but it must be! 80 grams more moving mass has to be the lower wire gauge. Its clear because the inductance per ohm is higher and the BL^2/Re is higher, both point to a thicker coil cross section and hence 80 grams of copper.

 

 

 

I don't think it is that popular. It's not necessarily PS only. Anybody can buy the driver and it operates conventionally provided you have an amp that can drive the low impedance. Functionally this one is a 2 ohm driver which isn't so bad. I agree that it makes sense for the extra mass to be in the coil. 

Not yet...There are a few outfits with 12+ Othorns though.

6 Skhorns should be able to produce the levels and frequencies you are talking about at 50m outside. 8 for a bit of extra headroom. 16 sure would be more fun though.

An NX6000DSP should be capable on a pair of 4ohm Othorn subs. 1 per channel. There are better amps out there for sure but the costs go up rapidly. Testing shows about 1800-2000w into 4ohms.

Notes and measured specs for this driver are published now. It came in a little bit different from the factory specs but some break in should do it some good. Normalized motor force of 448...

NX6000 should be a good match for a pair of cabs really. 

What will you be powering them with?