Peerless TC9 corner array build (low brow)

johnnycamp5

Member
Paid Member
2013-06-18 2:53 am
NJ
I thought I'd start a little build thread on a pair of corner arrays I'm going to build using the Peerless TC9FD18-08's.

By low brow, I mean to describe the lack of sophistication of this build.

That I am not a measurement and graph guru like most of the other line array builders appear to be on this forum.
Also the degree of craftsmanship and quality (both in labor and material) of most of the array builds Ive seen is a much higher level than I can achieve (or care to invest the time in).

Its more of an experiment, like some folks using foam-board, but ill use MDF.
Ive long wanted to try my ear at a full length (room height) array.

The decision to corner build is mostly because I have them.
I use corner horns now, and I love the lack of what I perceive (subjectively) as less early reflections, as compared to tower speakers out in the room.

This build is not a desire to replace my corner horns, its a desire to finally hear a full length array. I certainly do not expect them to play as loud or have near the dynamics. Just a different flavor (hopefully good).

Ive attached a pic of the room (basement) where they'll go, and pics of the 60 little TC9 drivers that just arrived.
The room is 14'.5 wide x 28' long x 8'8" high.

The entire ceiling is un-finished, with ultra touch (cotton) insulation showing, so I may have to install a triangle of sheathing above each array in the ceiling corner to get some of the benefits of a floor to ceiling array, but Ill try it without first.
 

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Halair

Member
2014-01-28 2:29 pm
Norway
Welcome to the "club" - I can appreciate the simple approach, which is very similar to what I did when I built my first pair :)
Kinda "backwards" to think introducing ceiling reflections isnt it?? :D

For a 28-29driver line-up you might need a dummy load to keep the impedance in check.

Wiring Series/Parallell:
(I currently run 4S5P for a nominal 6,3ohm load and mk2 will have two independent groups of 6ohm for each side.)
 

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johnnycamp5

Member
Paid Member
2013-06-18 2:53 am
NJ
What kind of EQ do you have in mind? Arrays do need EQ, even if the bottom end is supported by subs. I wish I had a room like that, I'd probably go completely bonkers thinking about the opportunities in a room like that :D.

I'm familiar with your build thread,
and I'll bet your arrays sound amazing... but i'll bet they might sound even better in the very room they were built in!

In my experience big listening rooms are like cheating lol...
 

johnnycamp5

Member
Paid Member
2013-06-18 2:53 am
NJ
I just checked the impedance of all 60 drivers with a multi meter, they all (but 3 or 4) measured right about 6.4Ohms.

I have a GW Instek frequency generator, so I could check each at 1Khz,
or I suppose I could sweep each (manually) but I wonder if this is absolutely necessary...

I hope to starting the baffles this weekend and Ill try and post some pics.
 

johnnycamp5

Member
Paid Member
2013-06-18 2:53 am
NJ
Hello.

I’m sorry…… I haven’t even started yet. Work got in the way, and I had to “make hay while the sun shines”.

It’s one of the reasons I was reluctant to start a build thread lol.
But the outdoor restoration/building season for my trade (masonry) is almost over,
and I will finally get to it!

It’s still the same plan with a pair of 8’ high corner towers, built as tightly into the corners as possible.
I believe 8’ allows 27 drivers per side, so I’ll likely have to create a dummy load to achieve (maintain) the nominal TC9 driver impedance.

I think I can do this by presenting a 30 driver per tower “load” using series/parallel wiring.

I have a wiring diagram/chart somewhere…but I have misplaced it lol.
 

johnnycamp5

Member
Paid Member
2013-06-18 2:53 am
NJ
Apologies for dropping out for so long.

Life got in the way and then I had some health issues starting in October that scared the hell outta me and Im actually still trying to recover.

I did finally get the rough version of these 30 driver arrays finished this weekend.
Just got them hooked up, now time for running some sweeps to see the response and then equalize/DSP and such.

Ill try and post some pics. I didn't take as many pics as Id like, as it was all I could do to even try to work on them.

Also who needs to see more front baffles with dozens of 3" hole saw cut outs lol.

More to come.

P.S. I did have a listen to them straight up as is (no EQ)...... as expected they did not sound so good!! :)
 

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Best wishes on your recovery. Health can be a fragile thing! Indeed, stay safe.

That's a lot of drivers in a row!
Are you going with that mini-DSP you mentioned? Try to get a feel of what's happening in the room by measuring at a few spots before deciding upon an EQ strategy.
As far as a room curve goes, I'd recommend the JBL trained listeners curve to get you close. Move on from there.

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I always end up close to that curve. You can vary it a bit from there to zoom in on something that sounds great. Just experiment a little.

What I meant by measuring at a few points is to determine the exact sweet spot by moving the mic equal distance to both arrays at the listening distance (playing a sweep on both arrays at the same time should show you a single peak by moving the mic around in just fractions of an inch).
Mark that spot! Get measurements of the left by itself and the right by itself etc. Now move the mic to the left and get measurements of each speaker again. Do this at a couple of spots of interest , both on the left and right of center (at the same distances from that center spot on each side!).
If you make an average of the left speaker results and it is close to what the left speaker does at the central position and the right speaker's average also mimics the central right measurement you stand a good chance to get great results just measuring at that sweet spot from now on.
If the results vary a lot, a vector average might be the better choice.
 

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johnnycamp5

Member
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2013-06-18 2:53 am
NJ
Well I finally got some EQ going with the Minidsp 2x4-HD.... using REW and a Dayton UMM-6 mic for measurements.

I recall running sweeps (only) on loudspeakers years ago, but I was really just an assistant.
This time I'm on my own, so there's quite a learning curve for me. Just getting my Mac laptop setup properly was troublesome for me as Im not tech savvy. The software setup for the dsp and REW was also time consuming, but I think Ive got things pretty well set now.

So far-
Ive only ran some frequency sweeps, with the mic front and center (approx 7.5' off front wall).
Sweeps from 20-20,000 (spl/phase category) all came out more or less the same, as did left only and right only sweeps....generally showing a peak from ~250 to1000Hz~ Then a more gradual down-slope from there up (1000-20,000).
As expected the response drops like a stone from about 175Hz and south...

As a quick test (in the PEQ output of the dsp) I pulled the hump down 10db, set at 521Hz.
It showed a much flatter response, and I was surprised at how much better it sounded with only that crude (single) adjustment.

I have not yet succeeded in is boosting the low end to where it improves (by ear). Honestly I did not expect any real bass out of these anyhow, especially in these tiny, sealed enclosures.
I have four subs in the center so its not something I am concerned with. I will do much more experimenting for certain.

Ive got the subs blended in pretty well now.... so for the rest of the night I'll just listen :)