BillFitzmaurice.info

The first thing I need to be clear on is that I will be multi-amping with an active crossover to multiple cabinets functioning in different frequency ranges. Please no lectures about not buying crossovers from the Speakermax or whatever it is website.

Note: Bill is an engineer, he inherently understands that when I mention compromises in speakers that I am aware ALL speakers must have some compromises. I am searching for the best situation that suits my needs with that fact in mind.

I do have the plans and have for sometime studied info in the plans, on the website and on the forum.

As a result of that study, I think I know what I should do, but I believe some quality discussion here could be beneficial to the final decision and success of my goal!

Essentially what I am trying to duplicate is the output of a pair of Peavey Project 2's with a pair of 118s folded horn subs....but without as much weight. That is where BFM cabs come into play.

I currently have a pair of 118s FH subs, so I am not looking to build subs at this time.
In fact I need to purchase one more NU4-6000 power amp before I can build speakers.

Electronics to the mains (mains is really all I am looking at at the moment) post mixer will include a stereo 31 band eq, a processor, and a 3 way stereo- 4 way mono crossover.

I am looking to in this process replace my Audio Centron 15-10-CD horn tops.

My current debate is between O-Tops and Jack Lites.

To clarify more above the tops I will have a horn loaded mid bass cabinet and a separate top above on each stack.

All respectful input will be greatly appreciated! Even if you do not agree with me please respect me and I will certainly return the same.

bjm362 wrote:
To clarify more above the tops I will have a horn loaded mid bass cabinet and a separate top above on each stack.

Not sure I understand what you mean here......

You'll have a BFM OT12 or Jack in addition to a mid-bass box and a sub? Or do you mean that you are building the high frequency section as a separate enclosure from the OT12 or Jack?

You haven't stated the purpose of your goal.

Given you are talking about using your present 1 x 18" loaded FLH's, I'm guessing either DJing or live music. Please correct me if I'm incorrect.

One thing, regardless of purpose, is that you would be better off with a rack DSP unit with at least 4 outputs rather than a 3 way stereo/4way mono crossover.

The DSP can cross, and also limit and, even with a DCX 2496, PEQ.
No, that's not GEQ, but at least gives flat response if you add a 31 band to tweak venue to venue.

Get a DBX branded product and you can limit, cross and have the 28 band EQ + RTA capability in one x 1RU box.

Unsure of your branding on the 2 x 1 x 18" FLH subs, but they will also benefit from limiting capability.

If, after building whatever it is designed by Bill for tops, you decide to convert to all BFM, then your DSP is already on hand...

Thank you Bruce and Grant for your replies. I was really hoping you two were both still around here! You both asked good questions that help me see where I need to be more clear to help us all create better communication and understanding.
Bruce's reply:

You'll have a BFM OT12 or Jack in addition to a mid-bass box and a sub? Or do you mean that you are building the high frequency section as a separate enclosure from the OT12 or Jack?

Yes I should have been more clear with that. I have 118s folded horn subs. I am looking to put a 15" horn loaded cab AND a 12" horn loaded top both above that. A lot of the info I have been looking at lately has been the BFM SPL charts. Those currently make the option of An Otop 15 woofer only for mid bass and an Otop 12 top attractive. I can find SPL charts for Jacks, but not for Jack Lites. Jack Lites look to me like they should be better overall than regular Jacks and may be worth the extra effort in building them.
Grant's reply:

You haven't stated the purpose of your goal.

Given you are talking about using your present 1 x 18" loaded FLH's, I'm guessing either DJing or live music. Please correct me if I'm incorrect.

One thing, regardless of purpose, is that you would be better off with a rack DSP unit with at least 4 outputs rather than a 3 way stereo/4way mono crossover.

The DSP can cross, and also limit and, even with a DCX 2496, PEQ.
No, that's not GEQ, but at least gives flat response if you add a 31 band to tweak venue to venue.

Get a DBX branded product and you can limit, cross and have the 28 band EQ + RTA capability in one x 1RU box.

Unsure of your branding on the 2 x 1 x 18" FLH subs, but they will also benefit from limiting capability.

If, after building whatever it is designed by Bill for tops, you decide to convert to all BFM, then your DSP is already on hand...

I did completely forget to say WHY I am this complicated.
I need to be able to make components mix or match and add together well for a variety of live sound and/or DJ situations. For really small situations I do have some BR stuff that will work where horns are just too much projection. However there are some large rooms as well as outdoor gigs I do not want to be out of my reach...

My rack DSP only does have 4 outputs. I also still need my crossover as I am using more crossover points than available otherwise, and it adds an additional CLEAN gain stage. A big part of the purpose of this thread was to compare a stacked multi-amped Otops to the same in Jack lites.

If you are using subs, then there is no need for Jacks as their claim to fame over the OTop is the lower response, but it gives up some output to do that. So, that makes OTops the clear winner in that category.

I often thought of the idea of some lo-mid boxes - my concern has always been the stress of the lower frequencies on the OTops.....that's why I high-pass 'em at 125hz. However, even though I sometimes cringe when a bass player starts slapping notes.....I've yet to blow a 2512 in the OTops. I run six T39s and four OTops total.

I would suggest that you start with just the OTops w/ your current subs. You could then go three way if it isn't what you want.

As far as crossovers, if you are using a passive crossover in your tops, then a driverack would take care of your system even if you decide to add the extra boxes. If you are planning to bi-amp the tops, then you'll need to step up to a 4 way obviously.

bjm362 wrote: I need to be able to make components mix or match and add together well for a variety of live sound and/or DJ situations.

You're going about it the wrong way. The right way is to pick a DR or OTop model, based purely on how low you need them to go, and stack as many as are required for the size of the gig. We often have to tell newcomers to forget everything they thought they knew about sound system design when choosing which of our cabs will best fit their needs. That's definitely the case here.

bjm362 wrote: I did completely forget to say WHY I am this complicated.
I need to be able to make components mix or match and add together well for a variety of live sound and/or DJ situations. For really small situations I do have some BR stuff that will work where horns are just too much projection. However there are some large rooms as well as outdoor gigs I do not want to be out of my reach...

My rack DSP only does have 4 outputs. I also still need my crossover as I am using more crossover points than available otherwise, and it adds an additional CLEAN gain stage. A big part of the purpose of this thread was to compare a stacked multi-amped Otops to the same in Jack lites.

None of the following is critical or judgemental!

By and large it seems that the only DJers who want kick bins are the EDM genre players.

When it comes to sound, the strength of bass drum thump is in the subs region, somewhere between 50 to 80Hz (depends on source, ie tuning of the bass drum and bass drum size when either recorded or live).
In live music, you also want to find the "click" from the bass drum pedal hitting the batter head. It's usually in the 2-3K region and provides definition of the bass drum.
Metal drummers, with their super fast bass drum pedal/double pedal techniques, like over compressed bass drum sounds with lots of click dialled in for this reason (just as an example).

You have to remember that kick bins are only providing harmonics, not the core thump frequency.
My opinion is that, unless you're playing EDM and demand it for that reason alone, dinosaur rigs like double 3 and 4 way systems have disappeared, for good reason. They require additional amps and cabling for each and every set of cabs, and, if your going to venture into live sound with the same rig, additional amps for each bandpass, in case one stops working mid gig.
Sure, with such systems built on designs from Bill, there is some weight savings, but ultimately, you have to ask yourself is it really necessary to have a double 3 or 4 way system when you can get the same fidelity out of one of Bill's 2 way systems?

Why do you need more crossover points?
Subs, kicks, mids, highs is 4 outputs (in mono, and that's all you need unless you absolutely demand panning effects in DJing).

You don't need more clean gain by adding something else. My system can't handle the amount of available gain from mixer to DEQ to DCX to amps now, with no redlining or clipping.

For me, it would also come back to cost.
For me, I would forsake kick bins and the costs and associated build time, for the other things I would need to purchase to step into live sound if I were in your position, such as mikes, stands, multicores (digital or analogue), mike and signal cables, DI's, and so on.

And, no disrespect to the Jacks, but they are the Jack of all trades (so master of none).
I would look at something with the highest efficiency possible if I was going to consider kick bins.
That, without having to even look at SPL charts, would suggest to me bass only Otop 15's. Maybe even better would be T39's.

I think you need to get a good listen to a full 2 way BFM designed rig, run by someone who has a very clear idea about running them, and lots of sound reinforcement experience.
It would give you quite a different perspective.

Simple is good. Especially when it comes to problem solving on the fly mid gig...

I appreciate everyone's efforts and replies. I have read through them and believe I should go back over them before I respond further or ask anyone else to respond further. I hope we are able to continue this more in a few days.

A large part of the delay is personal time constraints, the other large part is taking into account Bill's reply. He is right that some of my experience may need to be reconsidered on my part.

After much more studying, it currently looks to me like O-Top 12 J-Arrays are going to be hard to beat for multi purpose usefulness......

BJM- you should fill out your location your profile, then you could find someone in your area with a BFM system to check out.

Rich4349 wrote:BJM- you should fill out your location your profile, then you could find someone in your area with a BFM system to check out.

Updated...Location is Oklahoma City, Oklahoma. If anyone has BFM systems near me, I would love to check them out.

bjm362 wrote:After much more studying, it currently looks to me like O-Top 12 J-Arrays are going to be hard to beat for multi purpose usefulness......

That would certainly be a good option.
How many cabs a side were you thinking, and have you thought ahead as to how you are going to utilize that option?
ie, mini scaffolding rig each side, or stands (max 2 cabs per side) to hold the cabs up?

Grant Bunter wrote:
That would certainly be a good option.
How many cabs a side were you thinking, and have you thought ahead as to how you are going to utilize that option?
ie, mini scaffolding rig each side, or stands (max 2 cabs per side) to hold the cabs up?

I am thinking I want to build the stand in the plans with lower brackets and and base and countersink a top hat in the bottom of that instead of in a cabinet.
That way the base stand can hold cabinets stacked in the manner in the sketchup, or it can hold up to two per side on speaker stands. Always maintaining ideal angle!
My speaker stands are air cushion 130lbs support each so 60 lbs a side in cabinets plus the base stands and brackets with the correct angle should not be a problem.
That would leave open the option to stack 3 cabs per side on the mini scaffolds as they are in the plans...
I am also thinking it may take me still a bit longer, and some more gear wrangling to raise cash, but I would really like to build them with 3012 HO's...