Is it possible to cover the whole spectrum, high SPL, low distortion with a 2-way?

Camplo,

Push pull cancels even order distortion, and lessens 3rd i was told.

Search ppsl and "djk".

It can be sealed, ported, open baffle, whatever.
Just get drivers as close as you can.
I'd only do 2, as you do get a cavity resonance in the slot.
Hence the ppsl (push pull slot loaded).

Or search ppsl here or on subwoofer forum.
Unlike shorting ring working above 100hz (wayne parnham i think), push pull goes all the way down.
 
.....

Zvu, maybe if you made it make sense with some more information, I'd be interested in running a 12" mid. Like I stated, I believe that the larger the diaphragm the better the dynamic performance, (less compression of). When it comes to the attribute of dynamic contrast, horns seem to be the mainstay, or pinnical, so my goal is/was to get as much of the spectrum into a horn as possible. This "dynamic contrast" is the main focus for me, right now. I would love to be able to get 200hz on up, out of a horn (as I gander at the tractrix 100 on autotech lol). So any way, then I learned about the restraints of the upper register and landed in the middle at a 1.5" exit and a 350hz round horn.


Hey, this is our hobby, it's wonderful. We all pick our compromises or, to put it this way, what is a compromise for you may not be for me and vice versa.

Pros for 12" for me:
-12" midwoofer means that i can listen different set of waveguides on top 1", 1.4", 1.5" or 2" if i want
-i can cross it higher since i want to use 1" driver not to compromise the upper end and 15" is much harder to implement with a 1" driver
-there is a vast variety of reasonably priced/high quality 1"compression drivers from which you can choose, not so much with larger exit drivers
-it is a small cabinet (will be around 50 liters in my case) so maximum bracing will not be hard to do
-low Mms is easily achievable in 12" mid while there are only few good 15" that meet my criteria

Cons for 15" for me:
-high price
-high Mms
-demands low crossover point so, indirectly demands 1.4" or larger exit driver which are substantially more expensive in regard to 1" and they compromise high end (unless concentric which makes it a three way) - to what extent remains to be seen in measurements
-large cabinets so it is quite hard to deal with vibrations - learning from what Kef did with constrained layer damping (Gedlee too, but Kef gave an exploded view of how it looks in their cabinets) showed me that i can not do it effectively with materials i have available and i can't complicate the build even more with internal skeleton for bracing which would make the cabinet around 100kg or more

But these are my compromises, your set might be (and probably is) very different. You have very large room so you'll be using a bit more power from your amps, you decided on a very high budget for your speakers, don't care about beaming and resonances over 10kHz, you have a good carpenter and do not care how heavy or large cabinets will be, and so on and so forth...
 
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Hi,
The resonance is part of the design of slot loaded it can be minimised but will be present.
For those interested in ppsl ( :D ) you'll find info there:

A Thread for those interested in PPSL enclosures

Norman Bates if you fear lacking slam it may not be up to your preference as it is reported to minimise it as the 'slam' is in part produced by 2nd harmonic distortion. Outcome of ppsl is not dissimilar from servoed ( motion feedback amplifier again, Velodine) sub.

Mark100 build one some times ago and found that with good drivers ( Bms with 3 shorting rings) the gain was not audible to him. Reverted to Slot loaded and kept the sub if i understood correctly.
Djk ( RIP you are missed man!) once told that Slot Loaded ( without pp) was nice too and 'thick' sounding.

Papa (Nelson Pass) build a slot loaded open baffle and documented the build in an article you can find at Firstwatt's site.

Mark could give is point of view about that as he has experience with it.
 
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Camplo,
Whayne Payrham ( Pi speakers) have an interesting design philosophy that may be an inspiration to you.
Check the PI 7, from my understanding it is full/wideband 90* (horizontal covering) waveguide/horn loaded (there is some overlap with E. Geddes aproach in my view).
But it is corner loaded and if your room is big this may not be possible to implement it, worth a read though.
 
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Hey, this is our hobby, it's wonderful. We all pick our compromises or, to put it this way, what is a compromise for you may not be for me and vice versa.

Pros for 12" for me:
-12" midwoofer means that i can listen different set of waveguides on top 1", 1.4", 1.5" or 2" if i want
-i can cross it higher since i want to use 1" driver not to compromise the upper end and 15" is much harder to implement with a 1" driver
-there is a vast variety of reasonably priced/high quality 1"compression drivers from which you can choose, not so much with larger exit drivers
-it is a small cabinet (will be around 50 liters in my case) so maximum bracing will not be hard to do
-low Mms is easily achievable in 12" mid while there are only few good 15" that meet my criteria

Cons for 15" for me:
-high price
-high Mms
-demands low crossover point so, indirectly demands 1.4" or larger exit driver which are substantially more expensive in regard to 1" and they compromise high end (unless concentric which makes it a three way) - to what extent remains to be seen in measurements
-large cabinets so it is quite hard to deal with vibrations - learning from what Kef did with constrained layer damping (Gedlee too, but Kef gave an exploded view of how it looks in their cabinets) showed me that i can not do it effectively with materials i have available and i can't complicate the build even more with internal skeleton for bracing which would make the cabinet around 100kg or more

But these are my compromises, your set might be (and probably is) very different. You have very large room so you'll be using a bit more power from your amps, you decided on a very high budget for your speakers, don't care about beaming and resonances over 10kHz, you have a good carpenter and do not care how heavy or large cabinets will be, and so on and so forth...


If you have patience, time to search the net for bargains and a little luck, you don't need to spend big money. I paid less than €300 for 2 big horns, 2x 15" (new) and 2x B&C 2" including ME60 horns, also as good as new. My BD designed cabs were for free, but these are only 62kgs each without driver ;)

When I wake up after a looong sleep, I'll post my subjective impressions of the Danley J1, 16x TH118, SH96HO and some smaller subs/in-fill stuff.
 
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It was more like dub-techno, with an occasional semi-acoustic track mixed in.
Luckily, it wasn't too crowded, but the people were very nice and the atmosphere was great, before, at and after the party.
As a result I've been awake for more than 48 hours.
Time to get some sleep.
 
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Dub techno! Yeah much more to my liking that mainstream 'electro' edm of the moment.
Makes nostalgia memory about 69DB ( Sebastian @Spiral23) and Arzach ( 69Db + Cristal Distortion-Simon) live acts circa 2000...

I'm waiting review of my next headphone's: Jericho J1! LOL.
 
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I agree about the art!
I don't think Sebastian's name is Mullaert but maybe...In the free party movement they were known by their firstname or alias ( 69db, Cristal Distortion, R-Zach,...) and everybody known who they was at that time as they lead the movement.
Most of the Spiral Tribe guys and girls ( Ixy in the mix) where from UK. They relocated in France around 1995 after being chased from UK by law which made freepartyes illegal there. From the latest news i have some are now in Berlin... others who knows?! They were travelers after all! ( living and producing music in trucks!!! Going from partys to partys).

Here is a link to a 1995 mixtape which was one side of what they produced at that time... oh man i feel old! I played this K7 to death... oldies but goodies low tempo dub techno (with live violin) from my youth!:

69DB Live set Dub meet the Man with the Eastern Violin.(1st jam) 1995 by Electronics-Archives | Mixcloud

Perfect sound for your case: afterparty chill out! ;)
 
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Yeah i've got it! 20 years ago i was like you. ;)
You too got it, they were the underground avantgarde. Analog maybe more probably romplayers ( mc 303 or Rm1x) with a bunch of guitar effects and a space echo. Vst didn't even exist at that time ( my first sequencer was atari's mega4 with cubase midi only, i still have it somewhere...)!

Please don't push me into making the thread go off topic! Adrian Sherwood is one of my favorite mixer/ producer ( i come from industrial music background and more or less followed same path that this guy except i ended in D&B rather than dub).

Lots of nice chillout music from this time: Chain Reaction, Plastickman's 'consumed', Pole 1/2/3, some Tangerine dreams tracks, Autechre 'tri repetae' and electronica's stuff, Bill Laswell's productions ( equation of eternity, Miles Davis & Bob Marley dub's version), Scorn, Zion's train... time flyes!

Back to nice loudspeakers!
 
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Hi Krivium, good memory regarding the PPSL sub.

Camplo, remember me posting earlier in this thread that I used the same driver (18n862) in a sealed and a ported sub? Well, the next step was to use 2 of them in a PPSL. I used the ported sub design for the PPSL build.

The biggest reason for building the PPSL was to get opposed driver force cancellation....the sealed and ported single 18"s would walk around when really cranked up.
I was of course hoping for better sonics too....from the reduction in 2nd order harmonics a PPSL is supposed to give. But I didn't hear such...maybe because the driver is a very low distortion unit to begin with. I dunno, but i do know the driver vent cooling holes made more noise than I liked. So I put the drivers in push-push (clamshell), where both cones face into the slot, and have been using the subs that way since. Check out #758 in the thread Krivium linked if you want more info.

The cabinet vibration reduction is remarkable...almost hard to get the sub to toss a beer set on it :D
And as big as it is, it easier to move around than two single 18" boxes. I set up outdoors alot.

As Norman said, there is a cavity resonance to contend with. My slot is 11", which is as tight as would work getting the two 18"s in and out. This gave a real wide peak at about 170Hz, which is easy enough to eliminate if you use active processing.

Oh btw, the plans for the PPSL were very recently posted on a prosound forum Push pull double 18
 
You wouldn't be the first to try it:

779873d1567841464-cover-spectrum-spl-low-distortion-2-a-bd-20design-201-jpg

I really like the look of this but how effective are large curved guides on efficiency, whats the design philosophy surrounding them.
 
A wave guide of that size could be constructed of a wooden frame, cloth, and then resin, or fiber glass. Whats the point of cropping the woofer cone surface area though? I'm guess the curves are based off of tractrix/jmlc etc?

I'm envisioning this on the project I'm working on.
 
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