pioneer b20 is on sale...

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Tonight I was about to order a set of pioneers as well as dayton Ndf20fa tweeter for either a half chang or full version. Since they are on sale, was just wondering if a bipole has ever been tried. Perhaps, sealed enclosure sucha as zilla used but as bipole. Or ml tl bipole? Any thoughts? Seriously tempted to order more.
 
Order more. Go surround in sealed floor standers :)

Or maybe go dipole in OB. I ran that way for a long time till I finally figured out what that niggling little issue with them was in the back of my mind. Being whizzered, the back wave isn't even remotely similar to the front wave, so their interaction is alot more rough and weird than say a nice, smooth woofer with inverted dustcap or even better, a planar driver. So, what I propose is 2 B20s (and possibly 2 tweeters) per speaker. Mount one as normal and mount the other reversed, beneath, that way you've got a front and a back wave launching from either side of the baffle. These are not ideal for OB, so you'll likely just be getting into the 70s with these without EQ. I used a pretty serious amount of EQ and was able to get good response into the 50s, as well as eliminating the need for tweeters.

Oh, and I prefer the 5/8" Dayton dome, personally.

Have fun.

Kensai
 

GM

Member
Joined 2003
Greets!

As already noted, these require big cabs to get the max gain BW out of them, so dual B20s require around 8 ft^3. They make fine MLTLs IMO, but they also work well in a prosound alignment (AKA max flat impedance AKA Wayne Parham's 'PiAlign') if you either don't need to get the bottom 1 - 1.5 octaves due to using a sub and/or you have the ability to pull them out away from walls/corners enough to get some LF gain without excessive mid-bass boost, which of course is desirable for a bipolar alignment. Since these alignments do a good job of protecting the driver down to Fb, they can typically be played at a higher average SPL and/or boosted or minimally compressed signals if you have plenty of clean power on tap, up to around 200 W for a bipole B20.

The downside from my POV is that its typically low tuning and reduced Vb means it doesn't yield what I consider an optimum MLTL alignment due to its excessively high aspect ratio the way I calc them, typically putting the driver too low when optimized without adding a short stand or lower ballast cavity. With the advent of MJK's software and how pleased folks are with aspect ratios Vs driver location that I've historically avoided from a theoretical POV, it may be much ado about nothing, so you may want to try this ~ear height variant if a small footprint is required, though of course it will require some form of wide stand to counter-balance its top heaviness:

L = 46.25"
WxD (CSA) = ~112.11"^2
zdriver = 9.25"
zport = 43.25"
dport = 3.5"
Lport = 3"

All dims inside (i.d.) and approximate, 0.2 lbs/ft^3 polyfil stuffing density simmed.

GM
 

Attachments

  • b20 (pe specs) dual max flat impedance (pialign) - ear height variant.gif
    b20 (pe specs) dual max flat impedance (pialign) - ear height variant.gif
    6.8 KB · Views: 860
http://www.zillaspeak.com/pioneerb20-3cubox.asp

The yellow line is the closed box. Looks like you can get more bass from the B20 but listening to the sealed box i do not feel it's lacking especially when compared to smaller boxes using Fostex or TB drivers. The B20s sound fuller. I always liked this driver and think it's worthwile to own. Some have been disappointed with it. But once a tweeter (pick your poison) is dialed in, it does sound very good. Plus, you don't worry much about the driver getting pushed in and destroyed since it's pretty cheap compared to similar Fostex. I feel the B20 offers its own set of pro's compared to some of the Fostex cons... but Fostex are better overall IMO. Certainly a different sound. If you want a relaxed, laid back sound go for the B20 (and miss some detail and speed). Fostex offers the detail and speed but their presentation is more forward. Enjoy!
 
Thank you guys for all of your responses, I will be ordering Pioneers tonight.
GM mltl you specified is for a bipole, correct? The foot print is not large, which is the way I would like it. Sorry, I've read it number of times but still get confused on terms. Thank you for your patience.
 
Probably the dimensions, if he's not used to them.

OK: short translation. Dims. will be internal.
L = 46.25" (cabinet height)
WxD (CSA) = ~112.11"^2 (cabinet cross sectional area, i.e. if you multiply width x depth, this is what you'll get.)
zdriver = 9.25" (distance of the driver centre from the internal top of the cabinet, or, more accurately, from the sealed end of the line)
zport = 43.25" (distance of the port centre from the top of the cabinet / sealed end of the line)
dport = 3.5" (circular port diameter)
Lport = 3" (length of port)
 
I liked much...............

I found them a little honky, part due to qtc.707 with no stuffing (6ft3 = qtc .577 no stuffing 1' deep x 2' wide x 3' tall, driver up against to of the box work much much better), and that tall whizzer.

Be sure to put loose cotton balls behind whizzer (It helps)

Run by themselves they sounded good to me with some help from a 10 band eq......... I trimmed off 1/4 to 1/3 of the whizzer....... I needed more eq (8khz and 16khz bands maxed on eq)..... Not the crispiest sound but nicer (less honky) than the full whizzer......... Then I cut the whizzer off, no honk, and zero highs even with equalizer help...............Learned my lesson there.

Some have luck with damar........

I've always wanted to try planet10 phase plugs but to me I'd pay $30 for a pair, no way in *ell I'd pay $50 for them.........

fostex would have better highs.
Tang band w3-871s blew it away for midrange clarity.
But the b20 has some bass that a 3-4" has trouble with.
And plays louder with less harmonic distortion.
My ears liked the bit of 2nd order harmonic distortion.
Made it sound like it had some punch.

Godzilla has luck with piezo.
My giant killer was an active crossover at 5khz/24db LR having a b20 and piezo (that rings at 4.5-5khz) ....even had the unmodified tall whizzer........

Norman
 
The phase plugs are worthwhile, and with the drivers down to $20, they only make the whole package $45 per driver. My B20s have had the full P10 modification done to them (the only pair of the kind in existence as far as I know). I'd don't the phase plug mod with plugs from P10 quite awhile before getting the puzzle coat and EnABL mods done, and that was after having used them daily for almost a year stock.

The phase plugs were the cheapest, easiest and most bang for buck part of the whole modding epic, and easily recommend that part if you've got a bit more money to burn on drivers. Even at full price ($50/driver) they compare favorably against TB and Fostex drivers of similar price (they have alot more bass and are alot more forgiving of enclosure or the lack thereof), and you can't get another 8" full ranger for anywhere near the price (excluding, of course, the 8" Goldwood).

Being as that may, the cheapest part is just ordering them on sale right now. A stock B20 sounds way better than no B20 ;) When I received my pair as a present for christmas '06, I spent the first couple weeks kicking myself over having stuck with my similarly priced though locally available 6"x9" bicone Kenwood drivers, that at the time I had thought sounded pretty good. My reluctance to order drivers had wasted nearly two years of quality yet inexpensive DIY time. Advice to everybody that isn't already firmly entrenched in this hobby -- grab at least a pair of these now while the getting's good. They'll probably beat everything you have on hand now, they'll provide you with a very wide array of DIY experimentation opportunities (just think of the cabinets and driver mods that could be done), and over time, after your DIY budget has long pulled away from these drivers, you may find yourself coming back to them. At the very least they make great units for secondary system, surround speakers playing second fiddle to more expensive efforts, systems for the kids' bedrooms, gifts for family and friends, hand-me-downs, etc.

Enjoy!

Kensai
 
kensai,

you are right...........I have found myself coming back to them.........after a few years..... but active with piezo...... I don't like the way they honk..........bad whizzer...........

and I've been following most words you've typed.

I guess I just have a hard time with the price of the phase plugs.....

and I do like more bass than a 3" can beliver but detest most circuitry.

Norman
 
Norman,

Yeah, the price of the plugs is a bit offputting since it doubles the price of the driver. I totally get that. I spent months trying to finds a way to fashion my own or repurpose something else to do it for me, but that was a total waste of time and patience. When Dave said he had plugs, meant for a Fostex driver but fit for the B20s as well, I just broke down and did it.

After I stopped kicking myself about not buying B20s earlier than I'd gotten them, I started learning to live with them, and yeah, they honked and they rasped along at the top end in a way that I could never quite make sound pleasant using the considerable EQ abilities of my Emu 0404 sound card. I just had to keep reminding myself what I had been living with before, but every once in awhile I'd be listening to a piece and really digging in when they would throw me a curve and then I'd be back to "how can we mod these things to fix them". Researching and asking questions around the boards basically got me down to a few thing, mainly, damar or puzzle coat for the whizzer and then phase plugs. Coating the things was basically irreversible, so it would suck it that damaged things. The only problem with plugging was the initial dustcapectomy. I'm handy with a knife so so that was the way I was leaning.

Anyway, the phase plugs really fixed the honk. In effect they push that honking distortion up an octave, effectively rendering it inaudible. Seemed to smooth just about everything out, not to mention giving me a solid 2-3Hz extra at the bottom, mostly due, it seems, to removing the resistive pocket of air under the dust cap. It also turned out that the dust caps on these are easy to remove and don't really put the voice coil or leads in danger. It seems like another no brainer in retrospect, but you know annoyingly clear hindsight is.

Just my $.02

Kensai
 
Kensai "Anyway, the phase plugs really fixed the honk"

good to hear..........that honk made sax's sound more real, adding bite, but bothersome on voice to me otherwise.........never bothered me b4.......then i heard it...then i always heard it.......grr.........

I'm sure the honk is due to the extermely tall whizzer making the highs off the dustcap bouncing around in there untill they tumble out. But the driver also honked more in a smaller box than qtc.577 I'm thinking the box reflections just added with the whizzer honk so now we have a boxy-honky sound.

The resonance under dust cap, common problem. Seen a tweek of the .89 wonders where they poked a hole in the dust cap with a soldering iron, graphs too. Some drivers are worse off with this tweak tho.

In the b20's defence, it taught me how bad my electronic crossover actually was. I crossed the b20 at 200hz (24db LR) to double 15's.... The highs were awfull, gritty, plain horrible compared to no active crossover, just dvd player into amplifier (with volume controls) into pioneer b20. And it allowed me to hear echos coming from a great pa horn I was borrowing (bless my friend). Later I tried running it full range but had huge basement and couldn't tolerate bass modulation to voices sitting 7' away.......

Unsure on the puzzlecoat but have read the enable stuff.....
maybe another day.

Have to think if I want to order a couple with phase plugs.
Currently I want to make a "time alignment demonstrator" to bring to local diy show. Using 2 full range drivers (seperate boxes, peerless v-line) put cap on one and inductor on the other, move back and forth, and let people hear what a time aligned/phase aligned system sounds like. Tweeter would work better but need to trap out resonance and get tweeter exact in level. Using 2 full rangers with benign impedence curve makes for easy network

I realize time is money, as is the frustration and intellectual work it takes for design, tweaking, knowledge, and experience.

Since I'd cross them at 5khz, I'd trim 1/4 of the whizzer off, worked for me.

Seeing the recent price hikes (falling US dollar, gas increase, materials increase) may push more diy and used than ever b4.

Norman
 
Kensai,

Please forgive my confusion.

beyond he dustcapectomy, and the Phase plugs, did you also give your drivers a " whizzerectomy " ?

I am trying to put an HT system together without spending too much, would you think that B-20 BIB's with phase plugs, and puzzlecoat, satisfactory for front mains?

John
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.