Any 15 with 96db for a f3 of 50 hz in a sealed box

RE: Any 15 with 96db for a f3 of 50 hz in a sealed box , posted on August 4, 2023 at 09:08:59
Bill Fitzmaurice Industry Professional Posts: 5390 Location: New England Joined: October 20, 2002	I'm confident the answer is no. You can get that ported, but not sealed.

maybe (???) with a really, REALLY big sealed box (infinite baffle) , posted on August 4, 2023 at 11:08:56
mhardy6647 Audiophile Posts: 16140 Location: New England Joined: October 12, 1999 Contributor Since: October 23, 2016	Maybe. Get someone to put an Altec 515B in a 20 or more ft^3 box and measure it, or do some sims. all the best, mrh

Altec 515B , posted on August 4, 2023 at 11:37:17
Bill Fitzmaurice Industry Professional Posts: 5390 Location: New England Joined: October 20, 2002	No matter what size sealed box you put it in an Altec 515B f3 will never go lower than 115Hz. With a Qes of 0.18 you couldn't find a driver less suited to a sealed box or IB than the 515B if you tried. It would suit the OPs needs in a 5 cu ft net ported cab tuned to 50Hz, though a modern driver like the Eminence 3015LF would work even better in 4 cu ft net box, also tuned to 50Hz.

How about a 12?, posted on August 4, 2023 at 16:37:56
Paul Joppa Industry Professional Posts: 7318 Location: Seattle, WA Joined: April 23, 2001	Fostex FW305 should do 95dB in 3 cubic feet, with QT=0.5 at 50Hz, but a zero-feedback SET will bring the QT up to around 0.7.

RE: How about a 12?, posted on August 4, 2023 at 18:05:36
Bill Fitzmaurice Industry Professional Posts: 5390 Location: New England Joined: October 20, 2002	The best f3 you'll get with the FW305 in a sealed box is 75Hz, with broadband sensitivity of 93dB.

RE: How about a 12?, posted on August 4, 2023 at 21:20:29

Paul Joppa
Industry Professional

Posts: 7318
Location: Seattle, WA
Joined: April 23, 2001

That's perfectly true, if you use an amp with a high damping factor and/or a lot of wall absorption. My interest is in SETs, which usually run a DF around 2 to 3, so I added that calculation.

And you're right about the efficiency too - I mistakenly applied a 20xlog efficiency calculation instead of 10xlog to the claimed 1.4% 2-pi efficiency. So yeah, 93.5dB/m/W. The spec sheet claims 95dB, which seems to be in the 800-2000Hz range, well above piston behavior and only on axis.

I stand corrected.

RE: Any 15 with 96db for a f3 of 50 hz in a sealed box , posted on August 4, 2023 at 23:16:33

freddyi
Audiophile

Posts: 3852
Joined: December 6, 2001

same answer I gave at DIY = ASSUMING a solid state amplifier with low output impedance

maybe try a 3rd order box - you ran run the numbers for this woofer using hornresp -play with stuffing density

Karlson Evangelist

RE: Any 15 with 96db for a f3 of 50 hz in a sealed box , posted on August 5, 2023 at 04:57:20
Bill Fitzmaurice Industry Professional Posts: 5390 Location: New England Joined: October 20, 2002	That's pretty good, Fred. I wouldn't have thought of it, as it needs a 35 cu ft box for maximally flat response.

That is very clever but I have a few questions , posted on August 6, 2023 at 11:28:30
merdy Audiophile Posts: 1674 Location: New paltz,ny Joined: July 25, 2001	After adding the cap to the woofer and now and then a simple 6 db crossover for the tweeter does the phase remain the same What happens when I then use a inductor at the crossover knee? Not a big fan of the logo Nice to see you post and hopefully your health is holding up Silence is golden duct tape is silver

I have added a 1 ohm resistor to the drivers and it helps with some set amps , posted on August 6, 2023 at 11:34:13
merdy Audiophile Posts: 1674 Location: New paltz,ny Joined: July 25, 2001	I did model the foster 12 and 15 but they drop around 60 hz So plan b P.s the vsac show in 2001 was the best thing ever Silence is golden duct tape is silver

RE: Any 15 with 96db for a f3 of 50 hz in a sealed box , posted on August 12, 2023 at 22:19:37
KanedaK Audiophile Posts: 2519 Location: Brussels Joined: April 27, 2010	Ahhh, PRV! :-) I'm using their D2200PH midrange driver on their WG45-50 horn in my main system: it costs close to nothing, sounds fantastic and measures great! Glad to see they have other interesting products

RE: That is very clever but I have a few questions , posted on August 13, 2023 at 02:07:42

freddyi
Audiophile

Posts: 3852
Joined: December 6, 2001

where does the "tweeter roll in" ?

2mH just flattens it more

Karlson Evangelist

RE: Any 15 with 96db for a f3 of 50 hz in a sealed box , posted on August 15, 2023 at 01:42:10

freddyi
Audiophile

Posts: 3852
Joined: December 6, 2001

That's great on the waveguide - I'll assume it works better than the ones sold by "XYPC". What's your crossover F and slope? Would the combo work comfortably in a La Scala type situation with just a cap roll-on?

The prices even pre-hyper-inflation for K55 diaphragms was crazy - I'm surprised a Chinese vendor didn't step in with aftermarket Klipsch midrange diaphragms.

I'd like to see those measurements !
Karlson Evangelist

RE: Any 15 with 96db for a f3 of 50 hz in a sealed box , posted on June 3, 2024 at 06:19:42
imagon Audiophile Posts: 13 Joined: July 21, 2002	The new Faital Pro 15PR300 should be perfect

High Efficiency Speaker Asylum

Any 15 with 96db for a f3 of 50 hz in a sealed box

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