Sub 1500 in 4625 Cabarets

[Zilch]

Plumbing complete:

[/nick "Wingnut"]

[Zilch]

Gotta move outta the 4 pi workshop, tho:

[mrbluster]

Please let us know how the sealed boxes are performing. I would also be very interested to know the results of adding equalization via the bx63a.

Thanks,

Mrbluster

[4313B]

Originally posted by mrbluster
I would also be very interested to know the results of adding equalization via the bx63a.

Ok, I'll check tonight then.

[4313B]

It actually doesn't look all that bad, give it a try.

[Zilch]

Originally posted by mrbluster
Please let us know how the sealed boxes are performing.

They sound fine. But they're still in the workshop, out from the wall, not in a listening room. They are smoother and less boomy than they were before I plugged the ports. They peaked up 6+ dB at 50 Hz with the original port tuning, apparently, so, much better now, though less "spectacular" in terms of rattlin' stuff in the room and blowin' back your hair, standard performance criteria here....

That's rebuilt (but not yet refinished) L222 Disco's behind them, there, and behind those, on the bottom shelves, B380's, the standard fare....

I would also be very interested to know the results of adding equalization via the bx63a.

Looks like the mighty Giskard's gonna produce some curves on these net 4.0 cu.ft. boxes for us here, maybe....

PLEEEEZE?

[4313B]

1500SUB in vented B380 enclosure and BX63

[4313B]

1500SUB in sealed B380 enclosure and BX63

[4313B]

1500SUB in 2.0 cubic foot sealed enclosure with 20 Hz high pass bump filter (Q = 2) and 50 Hz low pass filter

(Note - the BX63 is a 26 Hz high pass bump filter and a 63 Hz low pass filter.)

[Zilch]

From these paramaters:

Qts: 0.30 Qms: 4.91
Vas: 181.2 L Qes: 0.34
Fs: 21.47 Hz SPL: 92.00 dB
Re: 2.90 ohm Pe: 1500 W
Le: 1.55 BL: 20.70
Xmax: 18.00 mm dia: 330 mm
Z: 4 ohm Sd: 0.000 m^2

Let me know if any are erroneous.

WinISD gain plots for 4.0 cu.ft. box:

Blue = Stock 4625 ported
Green = Tuned to 27 Hz
Yellow = Plugged ports

Looks like closed box wants the BX63a, as suggested above by Giskard's more comprehensive analysis. As he also earlier recommended, room rise may make it perfect without assist....

[4313B]

Just remember that the BX63/BX63A is adding roughly 30ms to 40ms group delay. I posted that graph somewhere on the forum years ago. Running the 1500SUB vented and tuned low adds another 20ms to 30ms of group delay.

Here is what I am currently running and it is staggering.
Notice the hit in efficiency though - not good for people who like their ears to bleed.
4.0 cu ft sealed with B212 filter.

[4313B]

Originally posted by Zilch
Looks like closed box wants the BX63a, as suggested above by Giskard's more comprehensive analysis.

I would recommend building something along the lines of Ian's thread on variable frequency, variable Q active filters.

These can also be fun for subs - http://sound.westhost.com/projects-3.htm

Also remember that applying boost to a sealed enclosure is not like applying boost to a vented enclosure. The EQ'd sealed enclosure is all driver, the EQ'd vented enclosure is usually all vent. The 1500SUB is very robust and can usually take the abuse, a lesser driver run sealed with EQ would simply blow up (ripped spider and/or surround, snapped voice coil, etc.)

[Zilch]

Originally posted by Zilch
Plumbing complete:

[/nick "Wingnut"]

Of some apparent interest, the port blocks I used here are plumbers' test plugs for leak testing DWV systems in construction. Available from Home Depot, your local hardware store (where I got mine), and plumbers' supply houses, they come standard in nominal pipe sizes. These are 4" ones.

They're a resiliant rubber washer or bellows trapped between two metal plates which expands to grab the ID of the pipe (port) bore when you tighten the wingnut. Cheaper versions have just a screw in the center, probably a better choice where there's limited space behind the grille. Replace the screw with a hex bolt if you really want to torque them in.

You're grabbing the bore in the front panel, for the most part, so there's little likelihood of damaging the existing port. They make a tight, rattle-free seal with minimal cost or effort that is instantly reversible. Look at the several designs available to best suit your application....

Paint 'em to match your panel color (Bo Blue, even,) or let your "mystery" components shine through to puzzle your pals for as long as they keep bringing the brewskis in hopes of you disclosing your proprietary box tuning technology. Tweak the tuning for them occasionally to maintain the requisite interest level. It's all in their heads; mess with it, and enjoy windfall refreshing beverages for the duration....

[Zilch]

Look silly, sound GREAT!

[Haven't hooked in the BX63A yet, tho.]

Heh, heh....

[Tom Loizeaux]

I've been silently watching this thread. I'm very interested in this because, like other Forum members (I presume), I have a Sub 1500 waiting for a decision on a custom cabinet. After following the older thread on the Sub 1500, I was leaning toward a vented 5 cu. ft. cabinet, tuned to 30Hz, driven by a plate amp without EQ.
Now I'm wondering if I should consider a smaller (3 cu.ft.?) sealed cabinet with an EQ'd plate amp.

See, some of us are watching these posts and just trying to learn something.
Thanks for sharing your project!

Tom