Best Enclosure for Pioneer B20

[tripathdude]

I have already built the half chang for the Pioneer B20s. I want to try something new for these speakers. They are already modified with phase plugs and puzzle coated. What enclosure would give the most bass output from these drivers? Would BIBs be the best way to go? Thanks

[norman bates]

I know my qtc .577 (6ft3 sealed, no fill) huge box (3' tall x 2' wide x 1' deep driver on top middle edge) sounded much better than my qtc .707 sealed (1.7ft3 with a little fill, dual walls with sand). Baffle step and lack of back pressure on the cone doing midrange are my thoughts..................

The big box run by itself or with a 24db LR crossover to a piezo was very good.

Most bass ?

Well, a ported will lower driver excursion (always a good thing) but can unload below tuning frequency as well. Maybe a tranmission line would work well. I think it was duke that said a ported always blind tested better compared to his more favorite sealed when designing a speaker.

Norman

[PJN]

Consider a MLTL, I built one several years ago for my B20's, not too huge, but nice bass. Can get down into the 30's no problem. To estimate the size from memory I guess it at 48" high x 10" wide x 15" deep.

PJN

[tripathdude]

I heard a corner loaded enclosure will get the best bass response especially if you have thick corner walls. My house was made with 1" thick plaster walls so vibration won't be an issue. I love the B20 drivers so much that I am completely satisfied with them. I am not tempted to go with fostex or Tang Band since I heard the B20s give the best bass response out of any 8 incher. They have more bass and sound less muddy then my 12" hammer dynamics speakers in a half chang cabinet! This is still hard for me to believe sometimes. Thanks for your responses.

[GM]

Originally Posted by tripathdude

What enclosure would give the most bass output from these drivers? Would BIBs be the best way to go? Thanks

Simple pipe horns such as the BIB is a step in the right direction, but the answer will always be a freaking huge BLH with a cut-off based on the driver's specs (~8-10 Hz for the B20) that will completely overpower the driver's mids/HF output and potentially reduce your plaster walls to dust, but I seriously doubt this is what you really want. The maximum practical bass output then is based on how large a BLH can be tolerated and what the room's gain curve is.

GM

[Godzilla]

>>> The maximum practical bass output then is based on how large a BLH can be tolerated...

Tolerate is a good word here bc i actually like the B20 best in a small sealed box sitting behind me at the office with a rear firing tweeter. It's all i could tolerate in the room. The Half Chang may be the best compromise there is for this driver but i never heard it... but it looks great and i bet it performs great too. Nelson's transmission line may be best too... or a BIB tucked in corners may be best if you can tolerate the size... and the bass it will produce. It may not take any more floorspace than the Half Chang or the transmission line. I even liked it very much on Open Baffle with bass and treble support.

[freddi]

I can't imagine a large pipehorn for B20 having a lot of clean power - here's a direct comparison of B20 vs the earlier version of Eminence B102 in a "Druid" sized pipe with floor vent each at the same drive level, each with mic and speaker in the same spots - look at the levels at 50Hz for the same input drive - a MLTL might be a good compromise - or go OB with 15 or 18 - -maybe I'll buy a fresh B20 to try

[Godzilla]

Thanks Freddi, i wonder if that downward trend from 1 - 3khz is the main reason for them sounding so mellow? Thanks for posting the chart.
Godzilla

[GM]

Originally Posted by Godzilla

Tolerate is a good word here bc i actually like the B20 best in a small sealed box sitting behind me at the office with a rear firing tweeter.

I even liked it very much on Open Baffle with bass and treble support.

Yeah, my experience with a much earlier version of the driver was in a ~2 ft^3 reflex tuned to ~40 Hz. Backed up to wall and driven with a PP amp it handled most of the vinyl, tapes of the day. Rick Wakeman's The Six Wives of Henry VIII and DSOTM did them in at a party though.

Agreed, the cobbled together OB I posted about on the other FR forum back when these were (re)discovered showed a lot of 'el cheapo' potential coupled to a mass loaded B20 woofer + piezo horn nestled between them. Still have the drivers and hope to revisit/optimize this system one of these days.

GM

[nuconz]

try the B20 in the Hedlund cabs with an inverted dome tweeter and your Shadow SW. wow on some ok program music and on some good program music - really wow.

but the Hedlunds are 78" tall!

wonder what a pair of these would sound like with a flared exponential horn?