ported sub using "pro sound" driver

[oddness]

This one was put together at home during a vacation from work about 2 years ago. I used a Dayton PF-460 18" "pro sound" woofer in a 10 cubic foot (net) enclosure with twin down firing 4" ports and an integral 250W plate amp in the back panel, eq centered at 22 Hz (3dB) and subsonic filter at 18Hz nominal. The cabinet is constructed with laminated 3/4" plywood (1-1/2") and heavily braced internally. The cabinet was made to resemble an old console stereo cabinet. f3 is about 23 Hz. The driver has a rated sensitivity of 97db/1w/1m, so it is quite efficient. After 2 years of serious abuse, this thing keeps coming back for more. The system weighs in at nearly 250 lbs. It is crossed over at 80 Hz. The best part is that the whole system cost under $400 to put together and does a great job on music and HT.
http://www.hometheatershack.com/foru...1&d=1200361657

[WillyD]

Neat build. I am looking at a certain pro 18" woofer for my bass guitar rig. Can't wait to get it and put it together.

[ISLAND1000]

Beautiful. How does it sound?

[oddness]

This sub gets used in a living room that is about 15 x 25 x 8 (about 3000 cu ft) and I have to say it does a fine job. It is very well controlled and very detailed. I listen to all kinds of music with it and it is never overbearing. On movies, when there is explosive bass, it handles it with ease. I have noticed though that the grille cloth is perhaps a little restrictive at the lower end and tends to flap somewhat at 30Hz and below at high spl (110+). Fortunately the ports are located in the bottom and aren't covered by the cloth and suffer no adverse effects from being partially blocked. I am planning on a second generation unit that will utilize two Peavey lowrider 18's along with an integral 1000 watt amp, again a sixth order ported system for use in a local church. I'll post as it comes together. Nearly thirty years ago, I had the good fortune to own a pair of EV Patrician IV's which were built in 1954. They were 4-way corner horns built under license from Klipsch, but they were about 30% larger and utilized 18" bass drivers. Those have always been my benchmark for truly effortless bass reproduction with extremely low distortion.

[ISLAND1000]

My buddy built one Patrician while I built Karlson enclosures and bass reflex filled with RCA theater electromagnetic drivers. We were both musicians and thought we were in Nirvana.
The Patrician WAS/IS a benchmark!

[Geoff St. Germain]

WillyD wrote:

Neat build. I am looking at a certain pro 18" woofer for my bass guitar rig. Can't wait to get it and put it together.

OT, but which one? I've been looking at a sub system for bass use along with a sort of mid/high cab for the 100 Hz and up range.

[WillyD]

Geoff St. Germain wrote:

OT, but which one? I've been looking at a sub system for bass use along with a sort of mid/high cab for the 100 Hz and up range.

A Ciare 18" Neo woofer. I actually intend on using mine up to about 250Hz. AssistanceAudio is selling them on ebay for $225+shipping. JonMarsh over at HTGuide has one and likes it quite a bit. Says its clean out to 500Hz at least, and really light. I'll probably put it in a ~170liter enclosure tuned to 30Hz, it looks good there.

[DS-21]

Generally, I think it's safe to say that big cone area and low inductance = musical sub.

[ISLAND1000]

I think it's a little more complex than that.

[DS-21]

ISLAND1000 wrote:

I think it's a little more complex than that.

The key phrase there being "a little." Partially at least because a woofer with very low inductance (e.g. Aura NST, JBL WGTi, many pro woofers) are also very good in terms of distortion and so on. Extension is an "issue," sure, but in the modern world just get sufficient volume displacement and use EQ to shape the frequency response.

The converse, high inductance = amusical, is a relationship that has held in every case I've personally experienced.

[ISLAND1000]

Your supposition seems to leave out any of the smaller woofer class speakers as being musical and also I guess you have to specify what is high and what is low Le before you can judge one driver to be musical and another not.

[DS-21]

ISLAND1000 wrote:

Your supposition seems to leave out any of the smaller woofer class speakers as being musical and also I guess you have to specify what is high and what is low Le before you can judge one driver to be musical and another not.

If by "smaller woofer class speakers" you mean distortion boxes such as the Sunfire "true subwoofer," that is exactly what I mean. Though I'm mostly talking about huge-Le long throw dedicated subwoofers such as the old TC Sounds 3HP, 4HP, and TC3000.

And yes, speakers with insufficient volume displacement will not produce any meaningful deep bass, musical or otherwise. You don't seriously think the bloated midbass from something like a BBC/KEF/Spendor LS3/5a is "musical" in any way, do you?

As for what I mean by low-Le (really Le/Re ratio), I think a useful rule of thumb would be to say that Le should be numerically be less than half of Re. And of course, one should presuppose intelligent design including use of Faraday rings in the woofer's motor.