A little help with PA purchase decision Please

[soundinmotiondj]

You're right. CA subs aren't at all optimized for PA applications because they are high-excursion, low-efficiency drivers. This does not, however, mean that they necessarily make poor drivers given enough power.

That would depend on your definition of a "poor driver". If it takes 2x or 4x or 10x the power of a "good driver" to achieve "the same" results...that might qualify for someone as a "poor driver."

YMMV.

[sss18734]

That would depend on your definition of a "poor driver". If it takes 2x or 4x or 10x the power of a "good driver" to achieve "the same" results...that might qualify for someone as a "poor driver."

YMMV.

If efficiency is the #1 goal, then obviously it's the wrong choice. But if you have plenty of power on tap, as I did, the increased power handling and excursion more than makes up for that weakness. And saved me a ton of money in the process.

Basically, I've once again started a discussion on topic too in depth for this forum. My main objection was to your post that said "car subs are only useful if your venues are as small as a car." That is simply not true.

[soundinmotiondj]

Basically, I've once again started a discussion on topic too in depth for this forum. My main objection was to your post that said "car subs are only useful if your venues are as small as a car." That is simply not true.

Close. My exact statement is this:

And, car audio speakers are fine...as long as the venue is no larger than the interior of a car.

I maintain that. CA drivers are the best choice for CA applications.

And I added this:

That would depend on your definition of a "poor driver". If it takes 2x or 4x or 10x the power of a "good driver" to achieve "the same" results...that might qualify for someone as a "poor driver."

To that (and other things) you replied:

You're right. CA subs aren't at all optimized for PA applications because they are high-excursion, low-efficiency drivers. This does not, however, mean that they necessarily make poor drivers given enough power.

OK...so what is your definition of a "poor driver"? Maybe we are just dis-agreeing on the semantics.

Yes, the combined subs had more cone area, larger combined enclosures, and more power - so they were certainly not optimized like the LS801P was. But they did exactly what they were supposed to due to the box design. I actually threw them in my truck to test them out and they actually fared quite poorly inside the car environment.

Emphasis mine.

Doubling the cabinet count adds about +6dB to the output.
Doubling the power adds another +3dB to the output. (But, you didn't mention how much additional power was applied...so this is just a number for conversation.)

That roughly translates into a single box advantage for the LS801P compared to the DIY cabinet in sensitivity of 6-9dB.

So the DIY solution takes up more pack space, (likely) weights more, requires additional cabling, and in the end is providing "the same" volume level....measured with your ears. This is balanced against the fun of building speakers, and the savings in $$$. Overall, I think that is a bad trade off.

There is no SPL trace that shows output across the frequency range (this alone is enough to get me to walk away from a purchase...no graph, no sale). Based on past experience, in general, CA drivers tend to be "one note wonders" centered on 60Hz. 60Hz is one of the frequencies tested in CA competitions....and tends to be a strong design point for CA drivers. Also, cabin gain is about +6dB/oct below 100Hz...and that tends to make up for an overall lack of low end extension in CA drivers & enclosures.

All I'm saying is that anyone who has basic knowledge with design software can build a pair of subs that easily outperforms anything in its manufacturer alternative price range - even using CA drivers.

How is your specific example illustrating "easily outperforms"? Is this strictly a dB/$ proposition?

After all this, I still maintain my original recommendation (even if not explicitly stated): When building speakers, use pro-audio drivers for pro-audio applications, and car-audio drivers for car-audio applications. My time spent building the enclosure is typically worth more to me than any $$$ difference between two drivers....so I tend to pick the one that offers the best performance.

[rotebass]

If efficiency is the #1 goal, then obviously it's the wrong choice. But if you have plenty of power on tap, as I did, the increased power handling and excursion more than makes up for that weakness. And saved me a ton of money in the process.

Basically, I've once again started a discussion on topic too in depth for this forum. My main objection was to your post that said "car subs are only useful if your venues are as small as a car." That is simply not true.

Do not listen to this guy...