OB: Dark Star Shootout - Betsy vs. B200

[planet10]

Here is the average data from 4 i measured.

Fs 50.37
Re 4.75
Qms 9.99
Qes 1.08
Qts 0.97
Vas 71.38
Mms 9.75
Sd 221.67
dB 91.37
Vms 1.03E-06
BL 3.69

One must keep in mind that the measurements we take are scalars sucked from a curve, and the numbers you get depend where on the curve.

The attached are the measures i made for a pair of FE127eN and the measures made by Mark Fenlon using kit more often used by the big guys(along with factory for reference)

I made the statement at the time i 1st posted these, that i expected each set of measures to be perfectly valid. MJK didn't think this possible.

I recently got more support for my supposition. All of my measures for FE126e (n ~ 200) are equally far adrift from the factory as my FE127 measures, but i heard from Madisound that their measures using Audio Presicion pretty much coincide with factory.

What is becoming clearer is that a way of mesuring T/S curves and then modeling with the curves is necessary to take modeling to the next level.

dave

[Godzilla]

Here is my progress so far on the Betsy-Boomer. I need to cut bases so they will stand up with the drivers mounted. Easy build bc there is complete access to the front and rear of the baffle. I hope to have drivers mounted and everything hooked up for listening and tuning in the coming days. You can see my BIBs in the background along with H-frames and a super tweeter that i will incorporate into the build. I look forward to comparing the two setups.

Godzilla

[rjbond3rd]

Looking sharp there, Godzilla.

I have thrashed the B200's for a week. The B200 is an ambitious driver. There are lower low's (31.5 Hz is just barely audible) and higher high's, so off-axis listening is required and it takes a lot of tweaking. By comparison, the Betsy was a snap to setup but it wasn't trying to go as low.

The torture test I'm using is Bill Evans Trio's "Waltz for Debby". The Betsy's were plenty happy just 4 feet off the back wall, but it looks like the B200's need to be 5 or even 6 feet (!!) from the back wall to get more clarity in the bass.

Ultimately, I am going to use a spare PC as the source so I can EQ the mids and highs down, a la our thread-starter and guru Bob Brines. I just got the Music Streamer+ DAC and it's very nice. Pics to follow next week.

[human.bin]

Godzilla, wouldn't those wings at fullranger height interfere with the midband?

[Godzilla]

>>> Godzilla, wouldn't those wings at fullranger height interfere with the midband?

We shall see... but i don't expect them to.

My back went out yesterday (i was disarming someone with a gun during krav maga class... green belt test next thursday) and could not do much speaker building. But tonight i put together a pair of very cheap speakers from PE buyouts. Drilling, screwing lol, and wiring them up, not to mention listening to them thru a cheap sonic impact amp really loosened up my back for the better! Speaker building is good!

Godzilla

[pjanda1]

Originally Posted by human.bin

Godzilla, wouldn't those wings at fullranger height interfere with the midband?

I can't imagine they would. If those little wings were a problem, one would think a box would be a huge problem! I recall seeing some narrow OB's with really deep wings. I imagine that at some point, you develop a resonance strong enough to be an issue. I think Zilla's design is quite a bit shy of that.

Speaking of the SI, I need to get downstairs and try out my new Sure TA2024 board and Mean Well supply (not for me, part of the BetsyK TL setup for my brother in law). The Sure board makes the SI look pretty laughable, and its less than $20! The SI's lack of low bass is a plus in my book when used with a simple Betsy OB (prevents wasting excursion and thus creating more distortion by not pushing the driver where it isn't making sound anyway). But with helper woofers or a box, the Sure's extension will be welcome. The PCB also looks easier to mod. I'll be replacing the input caps and eliminating the low pass filter at the input (hopefully that doesn't create a noise problem when I shoehorn the amp and smps into the same box). I'm curious to compare the finished unit to my chip amp.

Don't think I'm bashing the SI. It is still a steal, and mine trounced some fancy gear (before I accidentally killed it). For those that don't want to solder, the finished amps with the Sure boards are the same price though (and better looking), which makes them a real contender.

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

[rjbond3rd]

My only camera is a cellphone. Here are the OB's in a temporary location, with the B200's, which demand that the wings be folded back.

The little amps are a Dared MP5 on the left, and the Bottlehead on the right. The Bottlehead is a lot sweeter but has just 2 watts to the Dared's 13 watts. (And behind the amps is our pride and joy, a wood stove that fits inside the previously useless fireplace -- winter is pretty cold at 7,000 feet.)

[planet10]

Originally Posted by rjbond3rd

Dared MP5 ... the Dared's 13 watts

Mine is labeled as the original HTS. Really need to try some cryoed ECC85s in it.

dave

[rjbond3rd]

Hi Dave, may I ask what HTS stands for?

Did yours come stock with the 6E2 ("magic eye" tube) and 6N1's? I have spare 6N1's and possibly a 6E2 if you ever need them (had to order in bulk from China). (Where oh where does one get cryo'ed ECC85s?!)

[human.bin]

very nice, and winter i bet will make them even nicer, it's sad to live in places where you never see the snow...