Best 15 inch woofer for my system

Consider running the horns with the tube amp and using a solid-state for your woofers. Best of both worlds.
an idea of active low bass section(lower 70Hz) seems very nice...
I like warmth in lower voice, this is the main reason why i’m using tube amps
My crossover frequency is 600hz with 2 order, it is critical(very important) lower midrange and i’d like to left it for tube amp
 
Hello Andrew

my picks for your project:

1) Faital-Pro is a good choice, their published data will help you choosing drivers and designing crossovers.

2) absolutely follow @CousinBilly explanation, at resonance, the impedance is more than 100 Ohms

3) Pro-audio drivers are designed for high power handling. Your 15PR400 is rated 400W rms (for simplicity say AES=RMS). You need a big amp with a strong power supply.
Your 15W amp will produce no base, the cone will barely move and very likely it will go in clipping.
Imagine a big limusine with a 1 liter engine. Yes it will travel 100 km/h but it will sweat a lot. How about the acceleration?

Choose an amp 25% higher rms power than your speaker rating and it will run smooth. And for sure you will not play it at 500 W, probably at 10% volume. But you will have tons of headroom, dynamic range and transient response.

4) Pro-audio is designed around active crossovers, each driver with it's dedicated and matched amp. Way more flexible to work with than a passive crossover.

Cheers for 2019!
 
As later add:

5) Bad idea running speakers is series because of the electromotive force (emf)(Electromotive force - Wikipedia)

As no two drivers are identical, always one driver will move first to a impulse that will generate electricity (as a microphone ) that will be induced in the second driver. The effect is mote likely to be seen at Fs, where impedance raises may times causnf this back EMF.
(Speakers: Impedance (Z))
 
Hello Andrew

3) Pro-audio drivers are designed for high power handling. Your 15PR400 is rated 400W rms (for simplicity say AES=RMS). You need a big amp with a strong power supply.
Your 15W amp will produce no base, the cone will barely move and very likely it will go in clipping.
Imagine a big limusine with a 1 liter engine. Yes it will travel 100 km/h but it will sweat a lot. How about the acceleration?

This car analogy is not the best descriptor for a situation like that. IMHO.
The engine is still in your loudspeaker, the amp acts like the car's fuel delievery system (you cannot go with full throttle but the big engine has it's torque with 1/4 throttle too).
With a lower powered amp, a higher efficient speaker system can play loud enough for most home situation but you cannot exploit the full potential of a pro speaker with it obviously.

Anyway a larger car engine have lower efficiency compared to smaller car engines in general, but in loudspeakers, the larger cones (with larger motors) have higher efficiency.
 
Last edited:
  • Like
Reactions: 1 users
What LF speaker should i choose for using with tube amplifier?
Old altecs 515/416, tad 1601 works well with low power tube amps, AE are positioning like better alternative to this woofers
I had a conversation with AE support and they have told me that these woofers will work well with a few watt amp and i will have enough bass
It isn’t true?
 
Faital Pro 15XL1400
I chose these for my 3-way, and they are excellent.
My crossover is approx 275Hz to 8" midranges, but you could use them up to 400 or 500Hz okay.
AE drivers might sound nicer in upper bass / mids if you were doing a 2-way design crossed over at 1kHz or something, but if you crossover is fairly low anyway (200 - 300Hz) then it's less of a worry about transient response / sound quality and more a sheer comparison of acoustic sensitivity and output response to get the deepest bass extension in your cabinet, unless you have no size restrictions and are planning to build an enormous cabinet!!!
Likewise your limits of amplifier power available (if tube amps) will demand you search for the highest sensitivity (not at 1kHz or the peak sensitivity where manufacturers typically quote a figure, but down in the deep bass range where it matters.)

According to my computer graph simulations these Faitals delivered the strongest low freq output down through the 20Hz ~ 25Hz range, when loaded into my given design cabinet volume vented box, out of every available 15 inch woofer I was considering. I had rounded up all the published Theile-Small parameters of loads and loads of high-end and flagship 12 inch and 15 inch models from all the famous manufacturers, and Faital Pro 15XL1400 was the overall 1st place winner in for me - based on the computer graphs.

People will say you need to buy the actual driver and measure for yourself, not just rely on computer simulations, which is true, but you gotta start somewhere and you can't buy and personally test every model on the market.
 
  • Like
Reactions: 1 user
If you consider adding active bass extension to your tube amp I don't see any whole reason why not to use Faital driver from your first post while still keeping this discussion going. You can do what you want with that Faital with great results just using cheap DSP class-D amp.


Just do it and forget about other half-measures.
 
Last edited:
I just don't see 15 watts being enough for any sort of clean reproduction on peaks even with sensitive speakers. It will not match the capabilities of the horns in the least unless you plan on listening at low volumes all the time.

If you still insist on running on small tube amps for the woofers, I would recommend 2x15's each side. The Faitals will work just fine.
 
Last edited:
I was stuck with the same problem lately (845 SET amp. and 40m2). After a lot of searching I think that You won't find anything remotely close to 15PR400 looking at specs. This Audax PR330MO woofer is also quite fine looking unit but after specs alone Faital just looks way better. For mids at the moment I'm considering only Audax PR170MO < PHL 1120/1130 (You can also consider newer PHL's but I'd go for old school low mms mids).
 
  • Like
Reactions: 1 user
@Andrew, how much spl do you want at listening position. 100...125 dB?
You should target 115 for a sub!

SPL decreases 6dB for every time you double the distance.
Your driver has 99 dB/1W/1m but only 90 dB at 40 Hz.
At 2 m you loose 6db, at 4m you loose 12 db and so on.
For transient peaks you should add 6 to 25 dB headroom

Use this calculator:
Crown Audio - Professional Power Amplifiers

Say you want only 100 dBSPL at 2 m distance with only 6dB headroom for the 90db speaker sensitivity. The calculator indicates 159W required power from the amp!

So 15W tube amp on a sub will be nothing but quiet!
 
He is not looking for a sub but a woofer !
Maybe he can give us some numbers (room size, listening distance etc ) before we speculate whether his 15 watts are enough.
We can also look at it from a different perspective: If he definitley wants to use that amp for the given listening situation then he MUST optimize efficiency and that's where PA woofers can be very helpful.
I remember having listened to large Fostex studio monitors in the living room of a former workmate. They were driven by 2 W class A tube amps and I thought that it might have been too loud at times for the apartment building he was living in.

regards

Charles