Best OB woofer up to 600 Hz?

[Studley]

For what frequency range?

Well it will depend how low the 4 x 12” woofers go, but I’ll be disappointed if the subs are needed above about 40hz. Very disappointed in fact.

 

[scottjoplin]

Right, understood. It does depend on the size of your room, but it could well be the case that OB subs would be of no benefit, have a look at this sub THOR - subwoofer If you are really serious about very low frequency then IB could be even better.

 

[Pano]

Do it right and you won't need a subwoofer. You might enjoy an extra sub, but you won't need it.

 

[Hydrogen Alex]

Great value Beyma 18 inch for open baffe

Well it will depend how low the 4 x 12” woofers go, but I’ll be disappointed if the subs are needed above about 40hz. Very disappointed in fact.

This driver looks really great for open baffle...
https://www.beyma.com/getpdf.php?pid=18PWB1000Fe

Looking at the spec and infinite baffle response a few good points come to mind:
(1) Very well extended and slow roll off below 120Hz all the way down to Fs (27Hz) - Approx 92dB / 1 watt at 60 Hz dropping to 85.5dB at 30Hz so very little Eq will be required to get a flat response from Fs up to 60Hz or even 80 Hz.
(2) Generally very well behaved all the way up to 1,000Hz suggests max crossover could be as high as 150Hz ish.... Large heavy coned drivers will all start to sound a bit thick and "cuppy" on male vocals if used above 150Hz.
(3) Mid range Qts of 0.38.
(4) Decent 4 inch voice coil will handle a good 500 watts without too much trouble ie Thermal compression. Ignore the 1,000 watts AES as Beyma regard 5db or 6dB thermal compression as acceptable.... Compare this to the state of the art Precision Devices PD1851 which has a 1.6dB Thermal compression limit at a true 1,000 watt AES rating. The PD is over double the weight and nearly triple the price!
(5) Not bad Mms / Bl ratio... Again not as good as the PD but still ok for open baffle subwoofer use.
(6) Generous 12mm Xmax.... Easily able to handle Eq down to mid 20Hz if you use an H baffle and two per side.... Solid accurate bass with high SPL and dynamic capability in domestic use.

 

[Studley]

Thanks for that, will keep it in mind!

 

[Studley]

So it looks like I’ve done a deal to buy 8 x 12” AE Dipole woofers

I may well start a new thread now on the design and build of the speakers as a whole.

 

[wcwc]

Cool. I was thinking of doing something more modest like 2 x 15" AE Dipoles. Hope it goes well.

 

[scottjoplin]

Have you heard OB speakers?

 

[wcwc]

Yes, but just briefly at a show.

 

[Pano]

You'll need help with your crossover. The low pass section for the woofers is not going to be like a box speaker crossover if you want a correct tonal balance. Different animals.

Don't hesitate to ask.

 

[gadut]

I've heard two of John Busch's OBs with 2x18" per side. Both were very, very good. One version used inexpensive high Q 18s, the other low Q pro sound 18s. Both work well as long as the crossover is done right.

I've only gone as big as 2x15 per side, or 1X21" per side.

ditto but i have given away 2x15" drivers and the panel. sometimes my mind telling me that maybe 21" OB is not enough, now i'm building 2x12" sealed push push subwoofer per side for extra Ompphh

 

[wcwc]

I am building Lx-minis and was planning to use the 15" dipoles in an H or U frame for bass support. I will be using DSP on the dipoles with it's own amplification. Lx-minis will be run with either ASP or DSP. I will see how that works out. Maybe if I want to go full OB later I could add another pair of 15" dipoles to go along with the full range driver or AMT for the upper end. Baby steps. Want to see if I like dipole bass. So many others seem to rave about it.

 

[puppet]

Dipole bass sounds the best to me with large driver(s) loaded in "U" frames and placed around the room (2-3) one mid height. Seems to blanket the room without the "in your face" feeling. Real natural sound.

 

[kazap]

So it looks like I’ve done a deal to buy 8 x 12” AE Dipole woofers

Well that's your drivers well sorted. Congrats. It just makes sense to use a woofer actually conceived and built for the job. I wonder why you went for eight 12" Dipole woofers when four 18" would move more air and save time and $?

I may well start a new thread now on the design and build of the speakers as a whole.

Yes please. Im looking forward to this.

 

[ErikdeBest]

I think Studley bought them from an Italian seller in the swap meet...

 

[Studley]

Latency

Well as I’ve now decided on the woofers let me take this slightly OT
If I did decide I needed some OB subs (I’m intrigued by the SLOB approach BTW) would I have a problem with latency if I used DSP to filter and EQ the subs but analogue active and passive crossovers for the mains?

 

[Studley]

Well that's your drivers well sorted. Congrats. It just makes sense to use a woofer actually conceived and built for the job. I wonder why you went for eight 12" Dipole woofers when four 18" would move more air and save time and $?


Yes please. Im looking forward to this.

I did think about using 2 x 18” per side but I need the woofers to go up to 600hz and I was advised against it. Also those nice AE woofers came along . . .

 

[scottjoplin]

My question earlier was to you actually Studley: have you heard OB speakers?

 

[Studley]

Yes several and also I have owned / own other dipole speakers. I’ve come to understand that I prefer the openness and airiness that you get with dipoles. This speaker though is going to be an OB / horn hybrid . . . . I’ll start that other thread and provide more details.

 

[scottjoplin]

Goodo, just checking Regards OB subs (below ~40Hz) I recommend you think carefully, what dimensions are your room? Latency for subs, not an issue, it takes a number of wavelengths to recognise the pitch by which time it will have bounced around your room a few times anyway