18" woofers - which have high Qts (+low Fs)

[tinitus]

very low efficiency generally means heavy coned sub with very low Fs

but instead of aiming at the high Qts related bass peak in vented box, wouldnt it be easier just to use a smaller box ?

 

[OMNIFEX]

You need a heavy cone as the frequency decreases to propagate enough air to create an ample amount of SPL. There is no problem using a low QTS driver with a small box to attain very low frequencies. However, you will encounter a high degree of mechanical loss from the loudspeaker the further you move down in frequency, which will make you revert to an equaliser, trying to make up the gain lost by the driver.

As I focus primarily on 18 inch drivers, I have no idea where small drivers below 15 inches stand under such scenarios.

 

[Moonfly]

Because an 18-inch driver with a QTS of 0.5 or greater with an fs of 30 Hz can maintain its output gain as you move further down the frequencies without the aid of equalisation to make up the loss when compared to an 18-inch driver with a QTS of 0.3 offering an fs of 30 Hz.

Other than being a 4Ohm load, I'm finding it difficult to see why the Fi driver is no good for you. A 4 Ohm load can be solved easily enough by series wiring drivers in pairs (you would need to supply 1000 watts per pair @ 8Ohms though), and if your fine with large cabinets, and looking for more impact in the bass your getting, then the Fi looks ideal to me. What is it specifically about that driver that you see as making it unfit for your intended use.

 

[OMNIFEX]

Other than being a 4Ohm load

That is the main reason. I am not going to buy speakers and wire them series/parallel when I can buy the right speakers for the job. I thought you would have took the hint when I said...

I am into sound reinforcement not home audio. So the woofers I am seeking need to be aimed for the sound reinforcement market not for the home or car audio.

I am not interested in those speakers.

 

[Moonfly]

That is the main reason. I am not going to buy speakers and wire them series/parallel when I can buy the right speakers for the job. I thought you would have took the hint when I said...




I am not interested in those speakers.

I already asked if you could be more specific to your application but you havent been. I asked what it is about that driver that was contrary to your needs but you gave me almost nothing (BTW, its hardly uncommon to wire drivers in pairs). All your giving me is vague replies. If thats your attitude then I'll find a more productive use for my time, and you can find you own "right speakers for the job" if its that easy.

 

[OMNIFEX]

All your giving me is vague replies.

What is vague about saying...

I own twelve Double Eighteens (twenty-four Beyma 18 G 550s) reflex bins operating on six Crown MA 5000vz.

My avatar even shows the faceplate of a Crown 5000vz, yet you still don't understand when I say sound reinforcement. Anyone in pro audio would know what that means instantly. You are not into sound reinforcement, why you don't get it and, cannot comprehend why car speakers will not fit my requirements.

Tinitus understood what was my aim hence, suggesting the Beyma 18 LX 60v2 & the Fane Sovereign.

If thats your attitude then I'll find a more productive use for my time, and you can find you own "right speakers for the job" if its that easy.

Please do for I am not going to go into pro audio sound systems 101 just because you do not know the difference between a speaker designed for sound reinforcement applications & a speaker designed for the car.

As I said when I posted to Tinitus.

I had my eyes focused on the Beyma 18 LX 60v2 ever since Beyma brought the LX series back to the market. I own a few of the older 18 LX 60 so I know what they are capable of doing. However I wanted to keep my options open which is why I asked if anyone knows of an 18-inch driver offering a QTS of 0.5 (or greater) sporting an fs of 30 Hz (or lower) with an 8 ohm nominal load.

I am quite certain the Beyma 18 LX 60v2 will get the job done upon measuring the TS Parameters of my old 18 LX 60 which achieved a QTS of 0.7 and an fs of 28.75 in LIMP. Considering the Beyma 18 LX 60v2 TS Parameters indicates a high QMS (low mechanical loss), I found the driver that fits my requirements.