Seeking advice on Theater speaker design SAM1HF,1200Fe,SUB1500 L C R

[JuniorJBL]

Hi everyone,

I have plans to build an L C R with SAM1HF's, 2X1200Fe's, and a SUB1500 per LCR.

I am wondering if active XO from sub to lo-mid to bottom of the sam would be the best choice or passive.

I would probably use an Ashly XR1001 for the XO's and a PQX 572 Parametric EQ for tweeking duties, 3 Proceed HPA-2's for the 12's and sam's, crown K2's for the sub1500's.

Also there are 3 other sub1500's for LFE

I am also looking for the best baffle layout. I notice that JBL Almost? never does a dual woofer in the top and bottom position but a side-by-side layout.

Would doing a woofer, horn, woofer in a horizontal fashion be of any benefit? 3.5 way?

Any and all input is welcoeme. Thank you.

[Robh3606]

I am wondering if active XO from sub to lo-mid to bottom of the sam would be the best choice or passive.

I would go active. Easier to set levels and setup than a passive at what 80Hz??

Two 12's??

Rob

[JuniorJBL]

I would go active. Easier to set levels and setup than a passive at what 80Hz??

Two 12's??

Rob

Subs at 50 or so and the band pass on the 12's out to 800 hz or there abouts, that of course will need to be tested.

I would maybe use the passive XO in the SAM's so HF/UHF would be on one channel of amplification.

So just for clarification, I have 2 sam1hf's and ready to buy 1 more, 6 1200Fe's and 3 SUB1500's for this L C R project.

[JuniorJBL]

Is there any reason to do one baffle layout over another?

[Mr. Widget]

Why use two woofers? You will be using a sub so you don't need the response below ~80Hz, and above that two drivers in parallel will cause comb filtering.

I would think a single woofer below would be best.


Widget

[Robh3606]

I would think a single woofer below would be best.

Yeah me too I was wondering why 2?? Unless you are going for power handling and efficiency.

Rob

[JuniorJBL]

Thanks for the reply Widget.

I thought it would be fun to use 2, but I see your point and never really thought about the comb filter affect.

I will do the single under the horn.

Robh3606

Sorry I did not understand that's what you were asking in your first post.

[edgewound]

Why use two woofers? You will be using a sub so you don't need the response below ~80Hz, and above that two drivers in parallel will cause comb filtering.

I would think a single woofer below would be best.


Widget

Are you going to do all towers or a horizontal D'Appolito config for the center? Or make them all match?

An extra 3dB thump/extension and quicker 12"s on the bottom end for stereo and a fabulously sexy tower.

Using the second woofer below 100Hz wouldn't cause any comb filtering, anyway. The 'ol Three and a Half Men....er, way.

I say DO IT!!!.

[JuniorJBL]

They will be behind a 2.35:1 perf screen so they will all be the same cab for L C R.

I imagined a very cool tower early on in a 3.5 way, I also thought of the name Array Pikes Peak would be cool since I am in Colorado!

I should probably try both. Thanks for the input Edge!

[pos]

If that is for HT then you will also have to deal with bass management: are you going to feed the subs with only the LFE channel, or are you also going to hipass your front speakers and send the lowpassed signal from the front to the subs toghether with the LFE?
With two 12" per front speaker you can go with the first option, and let the front speakers handle all their signal without any hipass, the subs doing only LFE (and thus not being used for music).

I would try this option, in a 3.5 tower configuration, with the lower 12" up to 150Hz or even 200Hz (up to the schroeder frequency it can be good to use spacially distant sources to smooth the modal response)

[JuniorJBL]

Hi POS

In the past I have run subs on the left and right and seperate LFE. I plan to do full frequency L C R this time as well.

My pre/pro is a PC with an MAudio profire2626 for input and output using Jriver media center. Jriver has great IO and DSP functions and the pc is eaiser to upgrade than a standalone pre/pro.

I can just swap in a new video card when I change formats. Audio is already 24/192.

I could just drop the LCR subs and use the 4 I have for LFE.

[pos]

Sorry I misread your first post and the fact that you would use one SUB1500 for each front speaker and additional ones dedicated for LFE duty (for a total of 6!).
I doubt it would be necessary though with two 12" per front speaker: they should handle the non-LFE signal without issue (if your room is not too big) and that would avoid a difficult crossover point.

Clearly you have too much drivers (and that's a good thing)

[edgewound]

I could just drop the LCR subs and use the 4 I have for LFE.

That sounds like the winner.

With the extra 12"s handling the full LF load with less effort, I bet your system will have considerably more headroom.

[JuniorJBL]

Clearly you have too much drivers (and that's a good thing)

It keeps me outa trouble!!

That sounds like the winner.

With the extra 12"s handling the full LF load with less effort, I bet your system will have considerably more headroom.

I'll build up a test box and see!!