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[Mark ☻Bass Pig☻ Weiss]

I've read that the reasons can range from tumours to muscle damage. Although mine is related to a automobile impact from 2007. It's a recurring problem, and hits me mostly after long winter of sedentary inactivity. I put my YMCA membership on hold for 3 months, as we couldn't get out of here and none of our household wanted to go out in -19°F weather with 3'-7' of snow piled around us. We still had snow on the ground last week. The rains we had this week finally melted it away, and I restarted my Y membership. But I have been backlogged with work and tax filing up to the 15th so only went once so far this month. I hope to get more pool time in this week and gradually easy my way back to weight training. Thanks for those book links. I will looking into those and gather as much information as possible into treating my condition and the types of exercise that are more efficient at doing so.




I've never heard an MP3 that didn't have good bass. Well, maybe in 1995 or so, there were exceptions, especially Real Audio when it first came out, sounded like gurgling instead of music. I'd imagine that affected the bass, too. But MP3 really gives itself away with the 'swizzling' sound in the highs. Breathy vocals and certain synth sounds aggravate artifacts. But analog tape where the phase integrity between L+R channels is not solid REALLY degrades badly, even at 320kbps, as I found out years ago when dubbing some cassette tapes to MP3. The most outstanding losses are in the highs, mainly the impact of cymbal crashes gets mashed into a swizzling sound. Since it takes very few bits to encode low frequencies, the majority of the compression artifacts are at the higher frequencies. This reminds me I should do some tests to see if I can measure any effect on low frequencies. Null testing is tricky because MP3 adds header and padding to the file, so the lengths are a few hundred samples off from the masters, thus difficult to line up in time for a null.

[Mark ☻Bass Pig☻ Weiss]

I'm back from my testing of the Radian 2218 Neo, and I can say that the laws of physics remain intact, and the world is not turned on its ear.


In a nutshell, it's a well-built driver and a generally solid performer. However, it doesn't revolutionize any aspect of bass reproduction.


The gentleman who originally spoke with me about the driver and made some outrageous claims, is no longer with the company, so I've been told by another person following up on my sample request.


My findings show that the peak to peak excursion before bottoming out is about 1.1", little more than half that of the E-V driver. While it does have some very strong output around 24-28Hz, it's upper mid-bass efficiency is rather low. Overall dB per watt of input is about 3dB below that of the E-V driver.


In listening tests, all across the board, head to head with the E-V driver, there was a 3dB advantage to the E-V, over a wide range of bass frequencies. Despite all that neo (5lbs or so), the design of the magnet system probably loses most of the flux to the surroundings, rather than focusing it in the gap like Bassmaxx/CGN drivers.


The Radian driver is very durable, and if you don't bottom it out, it does okay. It might actually work well in a horn-loaded situation, where excursion is more limited. The voice coil seems to withstand a lot of power without smoking, indicating advanced materials used in the coil assembly. But that Xlim is a real show stopper for me. The driver clips like a transistor amp. Very clean until it suddenly get real ugly. Watch the drive levels, maybe horn load it, and it could make a decent lightweight sub.


Bottom line: I'm going to stick with the EVX-180Bs.

[Jeff Bankston]

i still like the FaitalPro 18XL1600 and mine are flat to 40hz in a 7 cuft ported box. I use mine as woofers not subs and cross them at 130hz into Caire 12" mids also crossed at 130hz. i dont use subs and dont need them. the 18XL1600 is an awsome woofer and rattles things apart when an open e bass string is lit up. FaitalPro is coming out with a 18XL1800 that models -2.5db at 26.9hz and will handle 1600 watts at 26.9hz. its -0.8db at 30hz. it needs an 11 cuft box to get that.

http://www.faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=201070150

[Mark ☻Bass Pig☻ Weiss]

I have also been keeping an eye on Faital Pro, though I've not been impressed with the quality of foreign-made speakers so far. There is one model that has decent specs and the suspension looks like it will provide long travel. Sensitivity is a bit down though.


The thing is to try them out. It was fortunate that Radian Engineering was willing to let me try one of theirs.


There is on Faital Pro that has like 12mm Xmax and 29mmXlim, and a neo magnet design similar to the Bassmaxx drivers I now use for sub-30Hz bass. It looks well-engineered, not thrown together by guesswork. It may be a good option.

[Art Welter]

I have also been keeping an eye on Faital Pro, though I've not been impressed with the quality of foreign-made speakers so far. There is one model that has decent specs and the suspension looks like it will provide long travel. Sensitivity is a bit down though.


The thing is to try them out. It was fortunate that Radian Engineering was willing to let me try one of theirs.


There is on Faital Pro that has like 12mm Xmax and 29mmXlim, and a neo magnet design similar to the Bassmaxx drivers I now use for sub-30Hz bass. It looks well-engineered, not thrown together by guesswork. It may be a good option.

Mark,

Having used the EVX 180 (and tons of the EVX 150) and having also used the B&C 18SW115-4, for
30-130Hz the B&C simply is a class ahead as far as output.

If you don't want to pay the neo price premium, the B&C 18TBW100 would also be an excellent choice, with  Xmax of 12mm and Xvar of 14mm you are insured of 6 dB more output potential than the EV 180B which has only 6.4 mm Xmax. Both the 18SW115 and the 18TBW100 are available in 4 or 8 ohms.

Of course, to achieve the 6 dB output potential will also require a bit more than 6 dB more power, but the B&C can take that level of power with far less power compression than the EVX. I have (accidentally) hit the B&C 18SW115-4 with 120 volts of sine wave (multiple times) with no problems.

The graph below show the B&C 18SW115-4 response with no smoothing, the box is undersized for the 28 Hz tuning(purple trace), resulting in the bass rolloff. Some port resonances are visible in the 37 Hz Fb box (green trace), but would be above your passband.

To take advantage of the extra excursion you may have to increase port size (and length) to avoid port compression and turbulence at the higher drive levels.

Art

[Mark ☻Bass Pig☻ Weiss]

The B&C looks like an interesting contender, and real world experiential data is helpful.


On paper, it looks pretty good, albeit a bit low on sensitivity and rather high Le, which would slow down the transient response. It's nearly twice the 180B's Le, and since this would be in a mid-bass usage, that concerns me.


The 180B will go almost 2" peak to peak before really ugly noises happen (tested this in free air with 750W sine tones between 10 and 40Hz), but with six of them driven by one QSC PL 6.0 PFC there's only a kw available per driver. Loosing 2dB or more sensitivity would make for a pretty big hit in SPL capabilities, if all six drivers were replaced. I would need more amplifier power, but we're already stretched to the limit with 200A service now and the power line sag is almost 18% when the system is being driven hard.


When I had the 2218 Neo in there, comparing cabinet to cabinet with a 180B, the 'slam' was greatly reduced with the Radian driver and when pushed, made ugly noises as it bottomed out. Even though the 180B has less Xmax, it has a lot more Xlim, and gracefully saturates, making it the analogy of tube vs. transistor sound.


I was contemplating one of JBL's Differential Drive units, but I hear they are not sold outside of their systems.


Now the B&C driver, being 2/3 the price of the 180B makes it enticing just to try it out. Parts Express has one left in stock.

[Art Welter]

1)On paper, it looks pretty good, albeit a bit low on sensitivity and rather high Le, which would slow down the transient response. It's nearly twice the 180B's Le, and since this would be in a mid-bass usage, that concerns me.

2) Loosing 2dB or more sensitivity would make for a pretty big hit in SPL capabilities, if all six drivers were replaced. I would need more amplifier power, but we're already stretched to the limit with 200A service now and the power line sag is almost 18% when the system is being driven hard.

3) I was contemplating one of JBL's Differential Drive units, but I hear they are not sold outside of their systems.

1) The 18 TBW100-8 has a Bl of 26.4 compared to only 22.5 of the EVX-180 B, the extra magnetic force more than compensates for the higher Le (2.45 compared to 1.6mH, though at sub  frequencies both would be a fraction of the rated figures) and there is certainly no lack of "slam" or "punch", transient response is as good as anything I have heard with similar LF response.

2) Unfortunately, doubling excursion does not come without a price, to be clean at high drive levels does require more mms, which reduces sensitivity. By going to a tapped horn, you can increase sensitivity by 6 dB, this would give you a 2/4 dB more sensitivity than the 180B. Tapped horns would require the upper and lower speakers to be delayed to compensate for the horn path length difference to properly align phase response in the crossover regions.

3) Because of the additional Xmax and reduced power compression, one BC18SW115-4 in a Keystone tapped horn
http://www.diyaudio.com/forums/subwoofers/185588-keystone-sub-using-18-15-12-inch-speakers.html
can easily outrun differential drive dual 18" JBLSRX 728, and has the almost exactly the same sensitivity.

Art

[Mark ☻Bass Pig☻ Weiss]

What I'm working with is 8 cu ft boxes for these drivers. I've no plans to go horn-loaded again (been there, didn't like the boxy sound), just looking to see if there is a drop in replacement that will give me more with the same input power. Seems that for this configuration, the 180B is still the best option.

[David Morison]

What I'm working with is 8 cu ft boxes for these drivers. I've no plans to go horn-loaded again (been there, didn't like the boxy sound), just looking to see if there is a drop in replacement that will give me more with the same input power. Seems that for this configuration, the 180B is still the best option.

Surely if Vb stays the same but you get more output for the same input (ie higher efficiency) then LF extension will have to be curtailed (Hoffman's Iron Law)?
Sorry if I am missing something here,
David.

[Mark ☻Bass Pig☻ Weiss]

I am trying to optimize the installation. But I may already have the optimal driver for this configuration. I thought maybe more magnet power might improve the efficiency a tad, but perhaps not.

[ProSoundWeb Community]