Double 15” and Horn Drum Fill

[Joris Wijgerde]

Joris,
Great to see how quickly you have put these together. You indicate that you havent used the BMS2236. From the foto i can see that you used the xt1464. Is that right? In adation i would like to ask where yo got the dcx464. BlueAran is soldout as is TLHP
The passive crossover they offer looks great. The reason i'm asking is that i am building a pair of pm60/90 and also want to use this driver horn combination. I could use a little help. I 'm using xilica xd processing an if you had a startingpoint for setting that would help.
Greeting Frank

Hi Frank,

The first prototype I built was with the BMS 2236 horn (I only redid the front baffle when I went with the DCX). I still have a BMS 4592 + horn and passive xo laying about if you're interested. I did like the sound but as I was planning to build 4 cabinets the B&C + XT1464 was just cheaper. I ended up ordering the XT1464 horns from thomann, the DCX464 from TLHP (it is currently in backorder both at TLHP and at the german distributor, but with the corona virus everything is on hold since the drivers have to come from Italy).

I also got the passive crossovers from BlueAran and they sound great. It wasn't difficult to cross the driver actively but being able to use a single amp channel / cable & connection panel just makes this a great option for me. I currently cross over between the XT1464 and PD158 at 600Hz, but found that anywhere between 500 and 650 works well enough. The PD158 doesn't lack clarity in this region at all, so I don't feel a need to go any lower.

Let me know if there's any more info you need. I can always upload some measurements or more pictures.

 

[Paul Smith]

... I think 3 of the new NX series with a passive crossover on the HF driver would be a cost effective way of powering the PM60 / PM90 or my double 10".

Hi Peter,

I'm in the process of building the PM90 and have been debating the passive crossover on my DCX464s for a while now. Eventually I will be fully active but I just had a baby so every penny counts right now. You say 3 of the new NX amps with a passive crossover...wouldn't you only need two or am I misunderstanding? I ask because with subs and fully active I would need four amp channels per side and most of the reasonably priced processors only have 3 outputs per side. I have been going back and forth between doing the passive crossover route and therefor using one processor and 3 amps or going all out and using one processor per side and 4 amps.

 

[Max Warasila]

I also ordered me some passive crossovers designed specifically for the DCX464 by Convair Electronics (through Blue Aran) and I was very pleasantly surprised. The FR with the passive XO is a great starting point (had to reduce some of the 1-2kHz midrange with a low Q filter and flip the polarity of the Hi membrane) and saves me an extra amp channel.

Taking a look at the design, this is to be expected. When I simulate the x-over, I get the same peak. If you're planning on doing any sort of aggressive FIR processing it doesn't really matter. This is my simulated filter to help fix it:

 

[Joris Wijgerde]

Taking a look at the design, this is to be expected. When I simulate the x-over, I get the same peak. If you're planning on doing any sort of aggressive FIR processing it doesn't really matter. This is my simulated filter to help fix it:
View attachment 209121

Thanks for the feedback Max. I use either Armonia (Powersoft) or my trusty XTA 4-series processor (IIR, they can do FIR but only very limited taps) depending on the system so I won't be doing any aggressive FIR filtering. However there isn't any abnormalities in the response which require any crazy corrections in the first place so I'm pretty happy with the result.

 

[Joris Wijgerde]

Finally had a chance to do some decent measurements outside (even though it was a bit windy). Measurements were performed using a UMIK1 taped to a broomstick on a ladder, speaker facing upwards. The mic was placed at about 1m right between the upper woofer and horn) Pretty happy with the result so far, the speaker sounds great. EQ & crossover is all armonia on a Powersoft M50Q, LR24 slopes. (90Hz highpass, crossover between woofers and horn at 550Hz)

I'm pretty new to interpreting waterfall (or spectrogram) plots, but as far as I understand the spike around 115Hz illustrates something I was expecting. The cabinet lacks proper bracing on the side panels, hopefully stiffening up the cabinet will reduce decay times and tighten up the lower end of the response.

Any tips on how to improve this further are more than welcome! Also, Peter, if you prefer I can move this to a new thread but because it's been rather quiet here I was hoping the discussion can help others.

 

[Peter van Gils]

Finally had a chance to do some decent measurements outside (even though it was a bit windy). Measurements were performed using a UMIK1 taped to a broomstick on a ladder, speaker facing upwards. The mic was placed at about 1m right between the upper woofer and horn) Pretty happy with the result so far, the speaker sounds great. EQ & crossover is all armonia on a Powersoft M50Q, LR24 slopes. (90Hz highpass, crossover between woofers and horn at 550Hz)

I'm pretty new to interpreting waterfall (or spectrogram) plots, but as far as I understand the spike around 115Hz illustrates something I was expecting. The cabinet lacks proper bracing on the side panels, hopefully stiffening up the cabinet will reduce decay times and tighten up the lower end of the response.

Any tips on how to improve this further are more than welcome! Also, Peter, if you prefer I can move this to a new thread but because it's been rather quiet here I was hoping the discussion can help others.

Also try a half space measurement (with mic and speaker on the ground) to verify the result (there might be some back reflections in the low mid in your measurement).
BTW: What is your ‘achternaam’?

 

[Joris Wijgerde]

Also try a half space measurement (with mic and speaker on the ground) to verify the result (there might be some back reflections in the low mid in your measurement).
BTW: What is your ‘achternaam’?

Tried changing it after registration but didn't find the option, probably should contact a moderator to get it sorted.

Thanks for the advice about the half space measurement. I'll try to get some done tomorrow if the weather's good. Today I got distracted by listening to tracks from my soundcheck playlist.

 

[Joris Wijgerde]

Did a sound check of the top cabinet stacked on top of one of our bass horns today. Really happy with the overall sound. If anyone's curious here's a video recording I made:

 

[Chris Baines]

I have been around a while and have gone through the passive pub rock of the late eighties and 90s now all active. But during the transition I used my old Peavey SP4 as a drumfill. Worked great powered with a CS3000. As it is a quasi three way the two 15s worked really well. Just ran it full range