The Reproduction of Very Low Frequencies

[chrisbee]

Just in case you haven't come across this before:

www.pykett.org.uk/vlf_repro.htm

[autio]

I read through that article and it will never work that kind of design will just give Boomy sloppy bass uck!! (at least thats what the guy at a major car subwoofer manufacturer told me before I built my IB)

[ThomasW]

Fans of BIG bass have been using IB's since the 1950's. If I talk to some of the true 'old-timers', they all have stories of someone they knew with multiple wall mounted 15"s working in conjuction with Altec A7's or similar. Unfortunately no one seems to have any pictures of one of those set ups.

I thought about a similar setup using modern drivers but it just wasn't practical in my house. I don't really know who came up with the concept of a manifold. Nousaince's article was my first exposure to the idea. In late 1999 when I polled the bass-list members, 1800 pretty hardcore bassheads, no one had any idea as to how to go about designing a manifold.

[JeremyG]

I will no longer use the term "WAF" in my discussions of all things home audio. Now I will use my new favorite term "Domestically Objectionable." It may even make me sound more intellegent...

[dewardh]

Thomas:

I saw a number of "built in" bass units in the Berkeley area back in the 60's . . . it was a fairly common thing. They mostly used 15" drivers from JBL as I recall, although maybe there was the occasional ElectroVoice. Definitley not the high Xmax drivers of today, though . . . all underhung voice coils. Four 15s was sort of the "norm", but I believe that one local "HiFi" place (Thos Tenney, on College Ave.?) did a number of installations for customers using multiple 12" Bozak 199 drivers (for people who wanted a "built in" Concert Grand, which itself was almost big enough to qualify as an IB <g>). The prevailing wisdom back then was that there was no such thing as too big a box, especially for the B199. "Acoustic suspension" was new on the scene (AR1W/AR3 . . . pop off the grill and "wow, look how far it moves"), but except for DynaKits who could afford the giant amplifiers required <g> (I build a lot of DynaKits for books and tuition).

I seem to remember several articles about IB 'built ins" in "Audio" (which I subscribed to back then . . . why oh why did I throw away the back issues . . .) . . . you might find some old IB pictures there. Don't recall ever seeing a manifold, though, or anything like one, except maybe for paired compression drivers "Y'ed" into a horn throat . . . may have been, though . . . it's hard to find a truly "new" idea in audio.

dewardh

[ThomasW]

I started off building a Heathkit receiver and moved up to Dyna Kit separates as an impoverished undergrad. Dynaco 400's were the manly amp if one couldn't afford Phase (flame) Linear or Crown DC300/300A

I'll fire off a email to Greg Monfort he might have some pics of wall mounted JBL or Altec Lansing 15"s.

[autio]

Interesting stuff I asked my Dad if he ever seen anything like that in the sixties and said" how should I know I was just a kid !!!" ;D

[chrisbee]

Jeremy

I think I prefer "domestically challenged". ;D

Books and magazines of my youth in Europe suggested IBs as an alternative to giant reflex cabinets and boxes with resistive backs. Usually only one 10-12" driver was involved.

I fitted my (only) 10" driver in the over-door panel of my walk-in closet in my bedroom, mid 60s. But my next project: A 6'6" tall 18" diameter, cylindrical, 1/4 wave, folded horn gave more bass with the same unit.

I remember seeing the first sealed box speaker being demonstrated to a lucky customer at the local music shop. The box was standing on the floor. That driver really could wobble!

Another hifi magazine illustrated how a wealthy American was covering his vast listening room ceiling with dozens of large drivers. Not too sure about the date of that article, or the details now. But I am fairly sure DVD films were not involved.