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[Mario Pollio]

SM 80 has a Butterworth 12db octave High pass set at 125Hz

TH 118 has a Bessel 24db octave low pass set at 130 Hz with reverse polarity and  1.25 ms of delay.

Wow that's pretty high for an 18 inch sub. How does it sound at those frequencies? And just out of curiosity, why reverse the polarity?

[Jonathan Betts]

The system was tuned by one of the best in the business. Danley supplied me with some numbers but they weren't specific to the ITech processing. While the tunings Danley gave me worked, the system performs much better with my current settings.

As far a reverse polarity, I am not qualified to answer this in detail.

[Scott Holtzman]

SM 80 has a Butterworth 12db octave High pass set at 125Hz

TH 118 has a Bessel 24db octave low pass set at 130 Hz with reverse polarity and  1.25 ms of delay.

I had never actually looked at the specs on the Danley's size.  The way people talked I thought these things were the size of a walk in fridge or something (again exaggerating for effect since Ivan takes me so literally).

Hell if those are halfway balanced I could load them in my pickup myself let alone in the trailer or the van.

Does Danley have the same 12 payments, no interest terms, doesn't show up on your credit report so the wife won't know terms as Sweetwater and American Musical ?

[Jonathan Betts]

They are only 63 pounds. You can pole mount them and get them way up in the air. They are really the answer to those looking for a compact, high output system, without killing your back.

[TJ (Tom) Cornish]

Wow that's pretty high for an 18 inch sub. How does it sound at those frequencies? And just out of curiosity, why reverse the polarity?

The TH118's peak output is around 150Hz. It has no problem being crossed at 120Hz. Reversing polarity is common - when aligning, you are looking for the shortest delay time. In some systems, that's with the same polarity, in others, reversing polarity of one band pass allows for a shorter delay time.

[Mario Pollio]

The TH118's peak output is around 150Hz. It has no problem being crossed at 120Hz. Reversing polarity is common - when aligning, you are looking for the shortest delay time. In some systems, that's with the same polarity, in others, reversing polarity of one band pass allows for a shorter delay time.

That's impressive,  I would of thought an 18" sub producing frequencies that high would be pretty stressful for the driver. How does the TH118 sound reproducing those upper frequencies?

[Tim McCulloch]

Meh, I'd make two comments to this:

1) When most people ask "how many people" they're generally talking about a relatively filled area. So for all intents and purposes area=people.

2) Bags of water (i.e., people) absorb sound. I can cover a lot more area with one person than I can with the area packed with 1 person/sq meter.

Cheers,
Randy Hyde

Okay, we'll pack 1000 humans in a 1000sf area.  My Peavey speaker on sticks will "cover" them.  Put those same humans in 10,000sf, with the same SPL expectations, and we'll need to butch up the rig significantly.

See the issue here?

Otherwise it's face-palm time...

And as to water bags absorbing... yes, they're soft and relatively fuzzy but that's not the point.  If you're outdoors you're mostly free of reflections anyway, and unless you directly cover the area the person is standing in, they won't get the full benefit of your work.  You still have to cover the AREA if people, no matter how many or how few, are in it.

The issue with crowds is the self-generated noise, not people "absorbing" the audio and sucking it out of the atmosphere.

It's time to cover the 200 people that will be in front of the stage on Thursday morning, and the 4000 that will be in the grandstand Friday night...  I'll send you a post card.

[Ivan Beaver]

Wow that's pretty high for an 18 inch sub. How does it sound at those frequencies? And just out of curiosity, why reverse the polarity?

The funny thing is that many sub manufacturers state there sensitivity and max output numbers at freq EVEN HIGHER than that!!!!!!!!!!!!!

The Danley horns put a lot of "control" over the driver movement-so for the same SPL the driver is not working as hard-so it sound cleaner/less distortion etc.

The proper polarity is the proper polarity-no matter that the speaker systems.

And proper DOES NOT mean IN polarity or OUT of polarity.

It varies with the particular system.

It is VERY VERY common in both active and passive speaker systems to have alternating passbands out of polarity with the adjacent bands.

One reason the "standard" polarity of the TH118 (and all other tapped horns) is because with a positive input, the driver moves away from you and presents a negative pressure.

We did this so as to create less confusion (although like this it creates confusion).

The + input is wired to the + speaker terminal.  So that if you every have to swap a driver or change the input plate-the wire colors will make sense.

We did not want put a "inverting color" block in the cabinet-as I felt this would also add confusion.

The PROPER polarity is the one that produces the best PHASE response around crossover-no matter what it is.

[Ivan Beaver]

2) Bags of water (i.e., people) absorb sound. I can cover a lot more area with one person than I can with the area packed with 1 person/sq meter.

Cheers,
Randy Hyde

People do not absorb sound-unless the speakers are sitting real low and you are trying to "push" the sound through them.

If the speakers are mounted above the peoples heads-the what the people "absorb" is the first reflection, which will simple make the sound better.

Now if you are relying on that first reflection to be part of the SPL goal-then that is a bad design.

Have you ever seen any of the prediction programs that have a "number of people" option?  NO.  It is ALL about the area (not people) that need to be covered.

The loudness does not change if you have 1 person or 1000 in attendance.

HOWEVER the EXPECTATIONS of loudness will change.  If you are trying to get 10dB about the sound of 1 person vs 10dB above the sound of 1000 people, then you will need a different system.

But the actual SPL over the area has not changed.

[Ivan Beaver]

Thank you again for the responses so far.  I appreciate the real world experiences shared in this thread.  They have helped me to understand that should my business advance, in the future, I will have to make investments in better speakers (Danley SM80/TH118 looks awesome for my applications).

The following is with different subs, but is a pair (1 per side) SM80s and recorded at 300'.  It was recorded on a small handheld recorder with NO post processing-simply dumping the file to facebook.  Use headphones to get the best sound.

The SPL (not at system max output) was around 95-98dBA at that distance.

You do not have to use this much sub-but it was here for some of the artists (that were bass heavy) that day.

https://www.facebook.com/video.php?v=726740944028708&set=vb.126113687424773&type=2&theater

[ProSoundWeb Community]