15" OSWG & 15" OB 4 ME

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Yeah I do this with mine.

I have the 2x8,

With Digi-FP - for digital inputs, (3 in and 3 outs)

And Vol - FP, which controlling the volume with a knob, and has lights for the inputs, and lights for 4 different settings (seen people have one for movies, music, neighbours away etc)

the Vol-FP also has a remote sensor (an extra one i think) which works with sony remotes, so my old tv remote controls volume, input and settings.

I love mine, quite easy, cheap-ish. Have yet to implement room correction, but have their UMIK mic too, so you can measure and auto-correct.
 
Last edited:
Sonically I would not expect a huge effect. It would take some serious testing to determine this subjectively. But there are some small but significant improvement that can be had with active. I sell the active and passive for the same price, so its just the cost of another amp that matters. I don't recommend expensive amps so this is a rather small , but incremental, cost. The biggest factor for me (I still use passive) is that active is hard to do with a receiver.
 
Active with an AV reciever

Hi Earl,

I just recently had a great result using an 4 year old Yamaha AV receiver and an 8 year old Audiolab power amp ( worth approx. £150 for the pair) to actively power and DSP crossover a pair of Dynaudio Contour Mk2's.

I used the Yamahas DSP crossover at 200Hz ( 24dB slopes I think) and the pre outs to connect the customers Musical fidelity amp to power the BMR's, and the Audiolab powers the 6.5 inch Dynaudio drivers.

End result is really remarkably good.
Before the mod I couldn't get £300 for the Dynaudio speakers...After installing two BMR's and including the two amps I got £1,500....!
The customer is a top session musician and used to very high grade studio sound, he is blown away and has given me a great reference / introduction to some other guys.

Buying up classic passive speakers and older AV amps and power amps could be a great little add on your trade in business!

Cheers
Derek.
 

Attachments

  • 042.jpg
    042.jpg
    538.3 KB · Views: 316
  • 045.jpg
    045.jpg
    620.5 KB · Views: 326
Can the miniDSP be used as a pre-amp and act as a volume control for the system?

That's the basic idea, but using three elements is simply to allow a patent. two works just as well.

Interesting. When you first mentioned CLD bracing I assumed you were talking about what I call "Dodd braces," i.e. solid wooden braces connected to the relevant panels with a damping mastic. (I call them Dodd braces because I first saw them on Mark Dodd's old Tannoy DMT studio monitor cabinets, and they recently popped up again on his recent KEF LS50. (See [url=LS50 "White Paper", at 11, picture at 18.)

So your braces are now basically a composite of two dowels with a damping layer between them, and only one dowel touching each side of the cabinet?
 
An 18 " waveguide will just reach down to about 1 kHz. To go down to 500 Hz would require the mouth diameter to double (half the frequency double the radius). A 36" waveguide is going to be hard to make unless you are very well equipped. And then you will certainly need a second one as a waveguide this large will have trouble above about 8 kHz. To me, 18" is optimal because that is the only solution that allows for a single crossover point low enough to not be an issue.
"a waveguide this large will have trouble above about 8 kHz."
Can you please explain why is that and what means "trouble"? How does the increasing size of the waveguide affect its "troubleness" in the highs? (~ dependency of size to upper frequency).
 
Sure, but my question was, if the waveguide itself has such problems being that huge.
I am intending to build a wg as big as I can fit into the CNC machine, 2" throat. But before I waste several hours of milling time I just wanted to know if it is a complete nonsense to build such thing that is going down to 500 Hz or just an overkill...

And yes, I've read several times, that optimal size is 15-18" and bigger is not really needed, I just wanted to try it with BMS4590/4592 which I hope I can borrow for measuring :)
 
If I've understood correctly one of the reasons the Summa is so large is that Geddes has 110 + dB as his goal SPL. If you don't need that ( Your ears will thank you! :D ) then you could get away with an 8"-10" and a smaller waveguide. You could probably get a coaxial speaker to make the integration easier, make wavefront more uniform and save space.

This is entirely false.

The reason that the waveguide is big is to get good directivity control down to 700-800 Hz. Then the reason that the woofer is big is so that its directivity will match that of the waveguide at the crossover.

I use more efficient loudspeakers in order to minimize the thermal modulation (not to be confused with thermal compression) for good dynamics - even at lower listening levels.

The fact that they are extremely clean at 110 dB is nice, but was not really the goal (and almost never used.) Your suggestion - been there done that - will not result in performance anywhere near that of a NS15 or any of my speakers for that matter.

I have tried exactly what is being looked at here. I found the tradeoff to go dipole were not worth the advantages. And, as can be seen in my PolarMap software, the performance of coaxs never really live up to the theoretical advantages.
 
Last edited:
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.