PHL 1220 enclosure recommendation

[Sjef]

I'm going to take over a pair of PHL1220 drivers from a friend and want to build some nice (monitor) speakers with them combined with a pair of the small ESS air motion transformers that I have.

When simulating the driver response in the recommended by PHL 16 l reflex enclosure tuned to 40 Hz the low end goes to about 50Hz but with a 6dB decrease in output from 60Hz to 150Hz or so. Has anyone tried this recommended enclosure and can tell something about the bass extension of it. (i.o.w. how does it sound?), or does anyone have better experience with them in another enclosure.

It's been a very long time since I have last build some basreflex speakers. last years was mainly closed boxes and open baffles, so any recommendation on reflex pipes and enclosure damping would be very appreciated.

Would be nice to get a decent 50Hz out of them, maybe with a ML TQWT design for them ? I wanted to do some simulation for a ML TQWT with them but for some reason the MathCad explorer doesn't seem to work on my PC.

[Magnetar]

The 1220 is best uses as a wide range midrange. Maybe get them and build a three way.

[Geenius]

Hi Sjef,

PHL advise for most of their (mid)woofers the Extended Bass Shelf alignment. More on that can be found here: EBS
I have worked with the 1240, 1280 and 1290 in various cabinets about the size PHL recommends, all with good results. Bass went down to about 60Hz, not as much as "hifi" midwoofers but still enough to give a balanced sound.

[Sjef]

I think I will just try the 16l/40Hz enclosure recommended by PHL and start from there. Seems like a petty dynamic speaker to me.

[Salas]

11 to 13 litres not more

[rick57]

Salas

What is the benefit of smaller?

[Salas]

Less distortion due to tighter travel. Better power handling if you gonna use a big amp is another benefit. The 1220 will not go better than -6dB @ 50 Hz including roomgain. Use 13lt net volume (calculate and add to that all extra volumes including drivers, xover, port and bracing but not the wadding!) and a 20cm2 by 14cm slot on its back. Not less than 2cm wide. Dont stuff the box, only felt inside, about 70% of the inside surfaces total area.

[rick57]

Salas

Why would tighter travel result from a smaller box, presumably just in bass ??

[Salas]

In my experience smaller boxes have better transient definition (talking smaller in the acceptable alignments box choice bracket).
This leads many people in being satisfied sooner in SPL for the reproduction's dynamic feel. Hence less distortion due to less travel from less power applied. But this can be argued to the 9th degree in diy audio. Just my practice I mention.

[Sjef]

Yes I can agree with that, but in this it would be a good candidate for a low/mid in a three way application. I could use them that way instead of my Phy-HP units in my main three-way system but I just want to build some nice, not to big speakers with them. Would they be a good candidate for a floorstandig TQWT. I am very curious about the sound of a (ML?) TQWT system because I never heard one but read a lot of good things about them. I consider this project a learning process, I would be very suprised if they actually sound better then my Phy-HP's but who knows, I'm open minded and audio can be very unpredictable some times.

Is there anyone who is willing to do a tqwt simulation for them in MathCad ? (since it doesn't work on my system, still don't know why), loudspeaker specs are as follows:

Fs = 35 Hz
Qe = 0.27
Qm = 3.1
Qt = 0.25
Vas = 30 l (1.06 cubic feet)
Sd = 143 cm2 (22.165 inch2)
Xmax = 3.5 mm (0.13755 inch)
Mmd = 12 gram
cms = 1
Rms = 1
Re = 6.1 ohm