BillFitzmaurice.info

Hey guys I have a JBL SR4733a. One is loaded with x2 omega pro 15a and the other have the stock JBL 2226H. Im debating if I should be going back to the stock JBL 2226H. What can I do with these now? Or should I use the JBL 2226H for a project? The eminence sounds pretty good and small difference with the originals. I found some one selling a similar SR speaker with the exact woofers I need for cheap.

http://www.jblpro.com/pages/pub/components/2226.pdf

http://www.eminence.com/pdf/Omega_Pro_15A.pdf

I'd go with original JBL since that's what the boxes and crossovers were designed for.

The omega pro is down on Xmax and Vd compared to the 2226, so for the SRX's, good idea, find a pair of working 2226's and drop them in.
Then sell the SRX's. You're building a T48, and not long after you're done, you'll build another, so you won't need them.

I'm not sure what you can do with the Omega 15's then, sell them as well...

Grant Bunter wrote:The omega pro is down on Xmax and Vd compared to the 2226, so for the SRX's, good idea, find a pair of working 2226's and drop them in.
Then sell the SRX's. You're building a T48, and not long after you're done, you'll build another, so you won't need them.

I'm not sure what you can do with the Omega 15's then, sell them as well...

These are the old school sr II series. I doubt they are worth much and still play pretty great. These speakers won't be toured and are installed on a stage. I'm adding the t48 to enchance the system. Wonder what tops can compare to the sr4733a.

djoy62 wrote: I'm adding the t48 to enchance the system.

That isn't a good idea!

Horn subs and direct radiators don't play nicely together, you will introduce all sorts of phase issues that you can't possibly address, even with delay, due to differing path lengths.
I'm not even sure that running the T48 and the SR's on different outputs of your DSP (do you have one? You need it for Bill's subs) and aligning phase that way may work.

Bill suggests to not even mix his own sub designs.

The omnitops and the DR's are a world apart from most commercial offerings.
Either will likely have higher average SPL and sound clearer and cleaner than you can imagine.
And they will have more mids...

I was going to crossover the jbl from the sub. Is it a bad idea still?

djoy62 wrote:I was going to crossover the jbl from the sub. Is it a bad idea still?

Please clarify

I was going to setup the jbls as tops and pass all low end bass to the t48. I was thinking at around 200 hz. I have a dbx 166xs and a dbx 234 crossover. What would be the optimal setup with this equipment when I finish building the t48? Driverack pa might be added in the distant future. The jbls will run on a mpx 1200 and qsc rmx2450 for t48

Your crossover is insufficient, as it has no limiter.

Assuming you have a limiter, you'd cross over no higher than 100hz, and maybe as low as 80.

The dbx 166xs is a compressor and limiter.
http://www.dbxpro.com/en-US/products/166xs

djoy62 wrote:The dbx 166xs is a compressor and limiter.
http://www.dbxpro.com/en-US/products/166xs

Not sure that one's brickwall. If it lets through any transients at all, you have a problem.

Apologies,
I posted what I had said so far, thinking the 4733a's were subs, not full range boxes, as they happen to be.

I should myself, a pair of these are used as tops for an in house system in a venue I have been playing at once a month for the last 7 years.

Certainly, using a sub will help free up the 4733a's a lot. Even my POS single loaded 15"/piezo loaded cabs seem to have a new life once a sub was put under them and they weren't working as hard to produce bottom end.
And, used as top boxes, the phase issues I mentioned earlier will not be of significant consequence.

As far as the 166xs goes, nothing I could find in the literature/manual suggests it's a brick wall limiter, which is what is required to protect the drivers in Bills designs.
From what I can see, the 166xs is only a limiter when at a ratio of infinity:1.
At a ratio of 1:1 the unit is essentially off.
These sorts of compressor/limiters I more usually associate with use on vocals, drums etc, or to compress a whole mix.

When we discuss brick wall limiting, we usually mean a DSP, like the Driverack series, or the Behringer DCX2496.
Of course there are other brands that do the same thing, but these two seemed to be used by many people here, with great results.

In the case of the Driverack series, the brick wall limiter can be set to a 24dB slope, the DCX up to a 48dB slope, and the limiter set and engaged to get a specific maximum voltage (measured at the amp outputs), as listed in the plans for your driver choice.
Simply put, if you don't do this, you will blow the driver, maybe night one, maybe later, but it will go someday.
Both these DSP are also crossovers.

I agree with Brent, 100Hz could be good as a crossover point.
Since the Jaybees (supposedly) have response to 33Hz, you may even be able to reduce the crossover point down to 80 or 90Hz.

With one sub or multiples, 100Hz and below, bass is unidirectional, so it's won't localise bass content to a specific position (which it would if you set your cross to 200Hz).
I still think you'll want to build another T48 though, and then you should study the sub placement guidelines...

Sorry for the essay...