Finally got around to further work with the ME464/DCX464 combo.
Biggest holdup was finding what works below it, and at what xover freq.
I wasn't pleased with any of my attempts to use two 18" sealed subs, where both were high-passed at 25Hz, and the bottom one low-passed at 120Hz, with the top one at 300Hz, mating to the CD/horn.
So I changed the top one for use as a low-mid only, 120Hz to 300Hz.
That helped me figure out the crossover point to the 464 combo, as it was simply cleaner sounding. (I keep coming to no sub should be asked to pull duty above low-to-mid 100Hz....but that's just me.)
Anyway, I tried xover steps between the CD/horn and 18" sealed, from 300Hz up to 500Hz.
Gotta give B&C credit, 300Hz works and is making for some happy listening.
As an aside, when I lost using two sealed subs for the very bottom end, deep down got weak.
So I had to trade the bottom sealed in for a vented sub (using the same driver....with cabinets i built some time ago for comparing sealed to vented...gotta love the 18n862 for happily going either way).
But back to the CD/horn. I'm finally pleased with the sound, and really want to stress it's been a matter of working out what goes with it.
I simply don't listen to, or compare CD/horns alone, unless they high pass identically.
And I have nothing besides the dcx464 that can drop to 300Hz, so no real comparisons have been possible other than via full systems.
Both horizontal and vertical polars are close to near-perfect for a 40 degree beamwidth.
And still decent to a 60 degree beamwidth, but past that response above 8kHz drops quickly.
I found I could get the same high quality polars inside the 40 degree beamwidth with any coax CD xover frequency from 3200Hz to 3800Hz. (Using linear phase 96dB/oct LR's.)
Listening has me settled in at 3.6k, like the B&C passive uses I think.
Also like that raising xover from the 3.2kHz that transfer functions had led me to previously, helps put more of the critical 2-4kHz range on the one section, so I don't constantly feel like i need to be adjusting both sections for tonal balance.
Biggest holdup was finding what works below it, and at what xover freq.
I wasn't pleased with any of my attempts to use two 18" sealed subs, where both were high-passed at 25Hz, and the bottom one low-passed at 120Hz, with the top one at 300Hz, mating to the CD/horn.
So I changed the top one for use as a low-mid only, 120Hz to 300Hz.
That helped me figure out the crossover point to the 464 combo, as it was simply cleaner sounding. (I keep coming to no sub should be asked to pull duty above low-to-mid 100Hz....but that's just me.)
Anyway, I tried xover steps between the CD/horn and 18" sealed, from 300Hz up to 500Hz.
Gotta give B&C credit, 300Hz works and is making for some happy listening.
As an aside, when I lost using two sealed subs for the very bottom end, deep down got weak.
So I had to trade the bottom sealed in for a vented sub (using the same driver....with cabinets i built some time ago for comparing sealed to vented...gotta love the 18n862 for happily going either way).
But back to the CD/horn. I'm finally pleased with the sound, and really want to stress it's been a matter of working out what goes with it.
I simply don't listen to, or compare CD/horns alone, unless they high pass identically.
And I have nothing besides the dcx464 that can drop to 300Hz, so no real comparisons have been possible other than via full systems.
Both horizontal and vertical polars are close to near-perfect for a 40 degree beamwidth.
And still decent to a 60 degree beamwidth, but past that response above 8kHz drops quickly.
I found I could get the same high quality polars inside the 40 degree beamwidth with any coax CD xover frequency from 3200Hz to 3800Hz. (Using linear phase 96dB/oct LR's.)
Listening has me settled in at 3.6k, like the B&C passive uses I think.
Also like that raising xover from the 3.2kHz that transfer functions had led me to previously, helps put more of the critical 2-4kHz range on the one section, so I don't constantly feel like i need to be adjusting both sections for tonal balance.
I really like your space .
The way the speakers are tucked away in the corners looks really nice , they almost appear to be small , or at least reasonable in size which they are not with almost 23" width of the horn .
would you mind sharing what woofers you use and how they work for you ?
thanks
Malcolm
Anyway, I tried xover steps between the CD/horn and 18" sealed, from 300Hz up to 500Hz.
Gotta give B&C credit, 300Hz works and is making for some happy listening.
.
that is really good news having it confirmed that the me 464 with dcx464 play down to 300hz . i just ordered the passive xover with better parts , dcx464 and me464. inspired by these great results . i will start out mating it with ae td15m sealed and subs . perhaps try open baffle from 80-300hz later .
Thanks, I kinda figured an 18" would probably be a better choice but I kept thinking about how good the speaker would look with the width of the waveguide and woofer being about the same . I'll take better sound over looks though.
I'm currently trying to decide between doing a trio of DIY JBL 4722's and the B&C ME464/DCX464. It's not a project I can start right away but some of the JBL components are getting harder to find so I feel like I need to make a decision.
. I'll take better sound over looks though.I'm currently trying to decide between doing a trio of DIY JBL 4722's and the B&C ME464/DCX464. It's not a project I can start right away but some of the JBL components are getting harder to find so I feel like I need to make a decision.
Thanks, I kinda figured an 18" would probably be a better choice but I kept thinking about how good the speaker would look with the width of the waveguide and woofer being about the same
The 464 horn going down to 300Hz does pose a dilemna how to use it.
I want to go straight to an 18" too, but a single 18 isn't high enough (i'm not a seated-type listener)
So right now it's stacked like this, on two 18s with the bottom being vented.
Still totally in the tuning/experimentation stage. I have no idea what I'll end up doing...maybe put the horn on a pair of 12"s...plain dunno.
It doesn't look like it in the pict, but the bottom sub is about 3/4" wider than the 464 horn.
I think you could make a nice size matchup with a vented 18..
(i really like 4 corner ports for vented. Ports double as bracing, and have a balanced loading around the driver.....they work imo/ime !!!)
I wish i could just put the 464 horn on top of my 4ft tall PPSL sub, but the sub isn't built for even close to 300Hz (due to the slot effects).
Hi Charles, yep! a MTM could be worth trying.
I keep thinking that horizontal pairs of 8"s or 10"s, both above and below the 464, might work very well.
With 10"s c2c would be under 16", which would be about 1/3WL at 300Hz.
Since i have four of the 10fe300's laying around from a former project...this will probably be a try.
(And would let me stack on top of PPSL)
I keep thinking that horizontal pairs of 8"s or 10"s, both above and below the 464, might work very well.
With 10"s c2c would be under 16", which would be about 1/3WL at 300Hz.
Since i have four of the 10fe300's laying around from a former project...this will probably be a try.
(And would let me stack on top of PPSL
)Vented in 7.5ft per driver. Not totally satisfied with them yet. They make a lot of noise but kind of sloppy sounding compared to the lightweight B&C 18's I had before in the same box. The B&C's were nice and tight at all listening levels.
One bridged PLD4.5 for two drivers gets them to xmax. I ran them in with pink noise for a day after trying them out. Haven't tried them again after that.
Might try connecting the boxes together in a push-push arrangement and running them under 80hz. There's a lot of moving mass.
Sorry to hear you don't like them more.
Did you try just one sub on the PLD4.5?
Which type bridging are you using, AB+CD, or all in parallel ABCD?
I ask because a 6 ohm nominal sub has always driven me nuts trying to figure out which PLD topology to use, given the large wattage variance by load per the charts.
I figure you are running the subs in parallel, yes?
If so, it could be the amp is running out of current at tuning freq, if using AB+CD.
ABCD might be needed to hold excursion control with such a heavy motor.
Maybe what looks like xmax, is overshoot ?????
Anyway, just spitballing having toyed with that amp and subs a bit....hope you don't mind...
Oh yeah, what's the f-3?
Did you try just one sub on the PLD4.5?
Which type bridging are you using, AB+CD, or all in parallel ABCD?
I ask because a 6 ohm nominal sub has always driven me nuts trying to figure out which PLD topology to use, given the large wattage variance by load per the charts.
I figure you are running the subs in parallel, yes?
If so, it could be the amp is running out of current at tuning freq, if using AB+CD.
ABCD might be needed to hold excursion control with such a heavy motor.
Maybe what looks like xmax, is overshoot ?????
Anyway, just spitballing having toyed with that amp and subs a bit....hope you don't mind...
Oh yeah, what's the f-3?
I only tried one box(two drivers in parallel) as the other box isn't ready yet. Each driver has its own air space.
I first tried two channels in parallel. Was a bit weak. Then I bridged two channels just for kicks. It went into limiting very quick.
Then I tried all parallel. Not much different than two channels.
AB+CD really got them pumping.
Shortening the speaker cable from 12ft of 14 gauge to 1.5ft of 12 guage actually made a noticeable difference. (Internally 3ft to each driver) One I've never noticed before with other drivers.
I might try running them in series. Lots of mental gymnastics with all the different possible combos.
Overshoot is what it sounds like in theory but I have no way to quantify it.
Tuning came out to 29hz. F3 in the low 30's. Seems close to the sims. Will need to do more testing as the ports weren't permanently mounted.
I first tried two channels in parallel. Was a bit weak. Then I bridged two channels just for kicks. It went into limiting very quick.
Then I tried all parallel. Not much different than two channels.
AB+CD really got them pumping.
Shortening the speaker cable from 12ft of 14 gauge to 1.5ft of 12 guage actually made a noticeable difference. (Internally 3ft to each driver) One I've never noticed before with other drivers.
I might try running them in series. Lots of mental gymnastics with all the different possible combos.
Overshoot is what it sounds like in theory but I have no way to quantify it.
Tuning came out to 29hz. F3 in the low 30's. Seems close to the sims. Will need to do more testing as the ports weren't permanently mounted.
Gotcha. Really sounds like current limiting might be in play.
Especially given that the shorter heavier speaker cable helped...cause yeah, that's a pretty rare experience.
How low does impedance get, for how wide a freq range?
Since each driver has it's own airspace, could you drive one (and short out the other).
Because I think I'd drive one full AB+CD just to make sure it's not an amp-balls issue.
What size & length ports are you using?
Especially given that the shorter heavier speaker cable helped...cause yeah, that's a pretty rare experience.
How low does impedance get, for how wide a freq range?
Since each driver has it's own airspace, could you drive one (and short out the other).
Because I think I'd drive one full AB+CD just to make sure it's not an amp-balls issue.
What size & length ports are you using?
I'll need to see if I saved the measurements. I'll make new ones if I didn't. I don't think it went below 3 ohms.
Yeah I just thought about running one to rule that out. It's strange how all that surface area with those motors didn't have more effortless impact in the 60-120hz range.
Ports are two 6" diameter x 20" pipes. Not enough area for max output but I was planning on running them conservatively 95% of the time.
Strange experience so far. Never maxed out a prosound amp with four drivers in free air before. I'll update this when I try them out again.
Yeah I just thought about running one to rule that out. It's strange how all that surface area with those motors didn't have more effortless impact in the 60-120hz range.
Ports are two 6" diameter x 20" pipes. Not enough area for max output but I was planning on running them conservatively 95% of the time.
Strange experience so far. Never maxed out a prosound amp with four drivers in free air before. I'll update this when I try them out again.
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I figure you're familiar with all the below, but curiosity has me researching with you ..
Hornresp with 7.5 cu ft volume and two 6" pipes 20" L.
Those 2 ports are for single driver with it's own sectioned off box, right?
Looks more like an 8 ohm nominal to me; so it makes sense AB+CD made it come alive, especially with the tall peak spanning 35-75Hz.
But I can definitely see the PLD4.5 being too small for 4 of those monster 21" drivers.
It's been too small for four of the bms 18n862 @1500W AES each, under every configuration I've tried.
(The four 8 ohm drivers come alive with two in parallel, on each channel of a PL380.)
Amp might even be too small for just two of the 21"s, given the need for both massive current and high voltage.
Power chart comes from https://www.qsc.com/resource-files/whitepapers/q_wp_sys_amp_flexibleamplifiersummingtech.pdf
Plain dunno if the PLD's were really made for heavy sub duty...
Hornresp with 7.5 cu ft volume and two 6" pipes 20" L.
Those 2 ports are for single driver with it's own sectioned off box, right?
Looks more like an 8 ohm nominal to me; so it makes sense AB+CD made it come alive, especially with the tall peak spanning 35-75Hz.
But I can definitely see the PLD4.5 being too small for 4 of those monster 21" drivers.
It's been too small for four of the bms 18n862 @1500W AES each, under every configuration I've tried.
(The four 8 ohm drivers come alive with two in parallel, on each channel of a PL380.)
Amp might even be too small for just two of the 21"s, given the need for both massive current and high voltage.
Power chart comes from https://www.qsc.com/resource-files/whitepapers/q_wp_sys_amp_flexibleamplifiersummingtech.pdf
Plain dunno if the PLD's were really made for heavy sub duty...