Hi all, looking to build some mid tops to go with my PA rig, 2 B&C sub15 mod kickers and a dual 15" ppsl sub - i have lying around a pair of PD.123C01 and B&Cde750 2" CD drivers so just need something to base a design on for some reflex tops. Had some yamaha club 12"s which i liked before and was thinking to more or less copy the design but without modelling and measurement knowledge not sure how to mod to best serve the PD drivers I have. Help appreciated!
Since those are going to be used as a mid driver in the two way box no porting is needed. A solid and braced box of convenient size for the components and portability will work.
The DE750 is a good driver, what horn are you looking at?
If you wanted to look at older horns the JBL 2300 flat front series are good ( I use 2385's) DDS, Renkus Heinz 3301's.
And of course B&C offerings,
The DE750 is a good driver, what horn are you looking at?
If you wanted to look at older horns the JBL 2300 flat front series are good ( I use 2385's) DDS, Renkus Heinz 3301's.
And of course B&C offerings,
Ah thanks Mike! Ok well in that case I’ll probably copy the Yamaha design more or less. I’m a joiner by trade and have a workshop so making the boxes is the easy bit it’s the science I’ve not wrapped my head around yet.
It would be nice perhaps to have the option of having them play low-ish for applications when they will cross straight to the sub or have no LF backup at all so if I do want to maximise their lower potential, or at least not limit it, would it be wise to vent or port the boxes in that case?
The horn was the next thing to figure out thanks for your suggestions I’ll take a look 🙂
Cheers
Fen
It would be nice perhaps to have the option of having them play low-ish for applications when they will cross straight to the sub or have no LF backup at all so if I do want to maximise their lower potential, or at least not limit it, would it be wise to vent or port the boxes in that case?
The horn was the next thing to figure out thanks for your suggestions I’ll take a look 🙂
Cheers
Fen
Too bad you don't have 4 of those 12's... that big CD is almost wasted on a single driver and you could probably use some more mid-high output given the rest of the system. Have you considered a horn loaded design like the PM60/90?
If your crossing into them in the 80hz to 100hz range sealed will work better. Now if you would ever want to run
them full range two way then ported would be better.
As just mentioned a double 12 two inch is a classic mid hi box just because that combination works well.
You'll just have a lot of headroom on the two inch driver.
them full range two way then ported would be better.
As just mentioned a double 12 two inch is a classic mid hi box just because that combination works well.
You'll just have a lot of headroom on the two inch driver.
I’ve had the PM90/60 suggested and it appeals but I’ve only got the 2 12” drivers and I’d need 4 wouldn’t I? And also it seemed to require a 1.4” or 1” CD and specific horn, and while I’d be fine building the box and I do have a decent enough DSP I think (JBL DSC280)... so it would involve selling lots of things and buying lots of new things and I’m sort of feeling impatient to get things rolling with what I’ve got.
That said, I’ve got a few precious sheets of 15mm birch ply I bought before prices went insane and I don’t want to waste them on a project that I wish I’d done better in a years time (don’t that before...) so I’ll definitely think on it
That said, I’ve got a few precious sheets of 15mm birch ply I bought before prices went insane and I don’t want to waste them on a project that I wish I’d done better in a years time (don’t that before...) so I’ll definitely think on it
The PM90 and 60 design use a very specific dual diaphragm driver the BMS4594 on a horn that can load the driver
to comfortably down to around 600hz.
The driver sells for around $1000 each.
It's a dual woofer design as well and the DSP he used was a higher end Lake with FIR processing.
A less powerful DSP would work but the true magic is the BMS driver.
to comfortably down to around 600hz.
The driver sells for around $1000 each.
It's a dual woofer design as well and the DSP he used was a higher end Lake with FIR processing.
A less powerful DSP would work but the true magic is the BMS driver.
Yeah so I think I’ll stick to using what I’ve got sadly! Maybe a future project when the current ones have earned their keep
I wonder what your guys’ thoughts would be on the paraflex 1x12” tops as an option...
I wonder what your guys’ thoughts would be on the paraflex 1x12” tops as an option...
Just a quick note that I'd always go ported for PA use. Ventilation is important for keeping the drivers cool.
Chris
The Paraflex 1x12 looks like a neat design but I don't think you will be able to mount the CD coaxially in front of the 12... you will have to stack it on top due to the size of horn needed to load the driver down to around 800hz. This pic from the SoundForums thread seems to suggest at least one person has done just that. Of course if the other option is going to be a reflex design then there is no real downside to this.
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Yes I’m happy to load the horn above, nice to gain a bit of extra height too and I’ve seen people tilt the recessed baton the horn fixes to to angle it slightly down as well which seemed smart. I also accidentally bought some 1" horn flares annoyingly, got a job lot of 3 pairs cheap and the larger pair were so large I assumed (n00b error) that theyd be for a large CD, but alas no. I have found a pair of JBL 2380A's that I will get for my de750's.
So im just now a little torn now what to do with the 12" section... but I suppose the Para 1x12" (assuming my drivers are appropriate - ive got the question pending on the FB group...) would get more SPL and keep up better with the horns. Bit more unwieldy in terms of size/shape/mounting but thats an ok trade off for better sound.
I guess I can let the deciding factor be whether or not the PD drivers work for the para design.
If not and I just go for a ported reflex box, tuned appropriately, are the ports just for ventilation or do I need to worry about size/length much...
Thanks for your helps everyone
So im just now a little torn now what to do with the 12" section... but I suppose the Para 1x12" (assuming my drivers are appropriate - ive got the question pending on the FB group...) would get more SPL and keep up better with the horns. Bit more unwieldy in terms of size/shape/mounting but thats an ok trade off for better sound.
I guess I can let the deciding factor be whether or not the PD drivers work for the para design.
If not and I just go for a ported reflex box, tuned appropriately, are the ports just for ventilation or do I need to worry about size/length much...
Thanks for your helps everyone
The port is an integral part of tuning so they have to be correctly sized, but with a relatively high tuning(~60-70hz) they won't be very long and as Chris suggested you should consider a non conventional location for the ports to encourage some convection cooling... heat rises so one port up high and one down low.
My double 12 mid hi boxes are not ported, never any issues.
The first ones I built were ported and when starting to build more I did some testing with
the ports plugged, they sound and measured a little better.
I sealed those and went with no ports on the rest.
I cross into them at 100hz.
The first ones I built were ported and when starting to build more I did some testing with
the ports plugged, they sound and measured a little better.
I sealed those and went with no ports on the rest.
I cross into them at 100hz.
Im now thinking to go reflex, I found some horns (JBL 2380a) for the 2" drivers but they are enormous and overkill so I think i might get some 1" CD drivers to go with the horns I have already and make BR boxes for these drivers. And then i have a long term plan for a larger rig for which I will build some paraflex mid tops and get those big horns involved where they will better suit the output
One thing I dont really know is whether a 1" such as the P-Audio BM2-D450 would be a good fit for those 12"s...
One thing I dont really know is whether a 1" such as the P-Audio BM2-D450 would be a good fit for those 12"s...
It's as good a fit as any other good quality 1" exit CD would be... which is to say you can certainly build a good sounding system with them. What you give up is a narrowed polar response in the 1-2khz range where the CD hasn't fully taken over yet and a bit better performance on live vocals, but if this is primarally a recorded music playback system nobody will notice..
As mentioned if you start using them for live sound the DE750 would be the best choice by far, you can't beat a large format CD for live sound. You can cross it over a little lower and get better pattern control, it's more efficient so you don't need to drive it as hard and will sound cleaner.
Thanks very much for the insights!
It will most likely be used for recorded music playback the majority of the time, but it would be nice to have a good option for live sound which will certainly come around sometimes. Ive found and bought those large 2380a horns for the DE750s and was planning to use them for the larger future build just because i cant picture a well proportioned 1 x 12" reflex box with an integral horn that big and the paraflex tops just seem a bit unwieldy and large for my little PA but now I am torn again!
And i just googled that driver the PM90 uses and I can get it for about £500/each here in the UK. I almost definitely shouldnt spend even more money on bits, but it did get me thinking... every time i think ive settled on a direction theres a reason to reconsider all the options ha, I will continue to stew on it all. PM90s do sound great but Id have to sell a kidney to buy all the drivers, im keen to use what I gots
It will most likely be used for recorded music playback the majority of the time, but it would be nice to have a good option for live sound which will certainly come around sometimes. Ive found and bought those large 2380a horns for the DE750s and was planning to use them for the larger future build just because i cant picture a well proportioned 1 x 12" reflex box with an integral horn that big and the paraflex tops just seem a bit unwieldy and large for my little PA but now I am torn again!
And i just googled that driver the PM90 uses and I can get it for about £500/each here in the UK. I almost definitely shouldnt spend even more money on bits, but it did get me thinking... every time i think ive settled on a direction theres a reason to reconsider all the options ha, I will continue to stew on it all. PM90s do sound great but Id have to sell a kidney to buy all the drivers, im keen to use what I gots
Ok peeps sorry to be the boring guy reviving his own thread but i need one more round of help please...
Settled on going BR for these cabs and using the stated woofers in thread title but some 1" horns (as i already have them) and CDs (will save the DE750s for bigger future project) - Was thinking to use these B&C 1.8khz crossovers as the PD drivers response gets a bit wobbly around there
Im probably going to make a 70l enclosure with ports, as sometimes these will be used as full range monitors or in other configurations but probably more often as main mid tops over kicks/sub, so would like to keep them versatile.
My only issue is not knowing how to design the ports. Assuming a sensible tuning freq for when they are to be used for full range, perhaps 60hz.
I was thinking to more or less copy my old yamaha S112iv's but they just have two holes in the front face so no port length to speak of, can I just do that....?
Have learnt lots about sub design over the last year but less about this sort of thing and still no modelling skills to speak of sadly!
Settled on going BR for these cabs and using the stated woofers in thread title but some 1" horns (as i already have them) and CDs (will save the DE750s for bigger future project) - Was thinking to use these B&C 1.8khz crossovers as the PD drivers response gets a bit wobbly around there
Im probably going to make a 70l enclosure with ports, as sometimes these will be used as full range monitors or in other configurations but probably more often as main mid tops over kicks/sub, so would like to keep them versatile.
My only issue is not knowing how to design the ports. Assuming a sensible tuning freq for when they are to be used for full range, perhaps 60hz.
I was thinking to more or less copy my old yamaha S112iv's but they just have two holes in the front face so no port length to speak of, can I just do that....?
Have learnt lots about sub design over the last year but less about this sort of thing and still no modelling skills to speak of sadly!