New cab build with Eminence CB15-8

[RodK]

Originally Posted by bgavin

Eminence offers a 500 Hz passive crossover, with an 18dB/octave slope that works well with this driver.
The downside is the woofer operating up to 500 Hz.
This might sound boxy, and the woofer is somewhat directional at 500 Hz.

I was surprised to see this as I was recommended to use the 800 hz crossover.

[bgavin]

The resonant frequency of the driver is 514 Hz.
By the book, you should cross over a full octave higher than Fs, or 1028 Hz.

The tradeoff with the lower crossover is less directional problems (beaming) with the woofer.
The ideal crossover would be active, 24dB/octave or higher at 500 Hz.

It all depends on how hard you pound it.

[RodK]

is there such a crossover available. I know nothing about building crossovers

[bgavin]

My advice is buy a crossover.
Eminence can manufacture them much cheaper than you could build one.
FWIW: 800 Hz is safer for the mid-range if you pound it hard.
Contact Leland at www.speakerhardware.com or order online.

He is one of the big 5 eminence distributors and stocks most everything.
Even though he is a personal friend, he is an absolute 100% standup guy.
Leland is the sort of vendor you want to keep doing business with.

[RodK]

If I build this with just the cb15-8 in a 3.5 - 4 cu ft cab ported to 40 or 45 hz, will it sound better than a cheap store bought 15" ? Trying to keep it simple and on budget.

[nick98338]

Sound better than a cheap...? I can't say. I've never played a cheap store bought 15". Mine sounds good, to me. That's all I care about. Better...? Worse...? All opinion. Simple? A single driver, no crossover, rectangular wooden box. Can't get much more simple. Budget? My build cost me $313 dollars US. Counting all parts and materials. Not counting incidentals like sand paper, and rubber gloves, and the like. YMMV.

[RodK]

Would it sound better than a Peavey headliner 210 or 115 ?

[BogeyBass]

Seems to me Eminence kinda fudged the Le Rating on the
"new" legend. Mechanical Quality and few others have changed as well so it is a different driver. But yah the model shows glorious highend because the gave a very low number for Le and this will have a big effect in the model.

A Le of .33mH is a little ridiculous for a 15. Model the legend with a Le of 1.1 mH then the model will kinda show more whats happening in the real world.

For the most part it still sounds like any legend I have heard.
Which is really just average for alot of 15's with a roll off around 2k
Which is the biggest difference between looking at pretty graphs
and actually hearing the driver.

anyhoo look at the Response chart of the Legend CB158

then look at the response chart of the Delta Pro 15a

Sensitivity advertised at 101 dB much much more highend.
handles about 40 watt less than a legend in bass applications.
But for a single 15 rig not much of a issue and the sensitivity is much better.

no im not talking about the standard series delta its the pro series Delta pro 15a

If your worried about the lowend response of the 15. Just remember how many dudes just do fine with weezy 10's

throw a legend 10" or some other eminence 10" in a standard volume of say 1.3 cubic feet, and then compare a 15" in 5cubic feet and right away you will see the difference in lowend.

The volume and tune you chose for the legend is a great choice.
5 cubic around 40hz. that driver sounds best in bigger boxes.

The Delta pro can drop in the same large box.
if you really concerned about power handling the Delta sounds fine in smaller boxes so take it down to 4 cubic and tune at 40hz.

[will33]

Better than a cheap store-bought cab....at least as good as a good one.

I'd probably do the 800hz crossover and la6cbmr as an add on if you want, although the Legend is pretty good on it's own for most stuff outside of bright grindy or bright slappy tones. It's on the warmer side of things but has enough going on for old school thump, strong lowmid sound. Sound more ampeggy and less gk-ish, if that makes any sense.

[will33]

Caveat: I'm probably basing my impressions off the older CB-15, though I didn't think the newer ones had changed all that much.

[will33]

Hmm.....the current one looks like it may not have quite as much of an upper peak as the old? Could be a good thing. I call it about -3db @ 2500hz. -10db @ 3khz or so. Falling off pretty quick by then. Still works good in smaller enclosures. I'd probably put it in something between eminences large and medium vented designs. Say 3.5 cu.ft. net with a ballpark tuning almost anywhere in the 40's....could just tune it by ear.

That should leave enough room in the baffle for a closedback mid add-on, though I'd try it by itself first.

[Downunderwonder]

It should perform similarly to the old Trace Elliot 1153, no budget cab in its day.