Looking at your drawing a few posts up, I'd say sure...you can put it all in one box like that.
But I think there are things that keep it from working as well as might be expected.
In no particular order....
*whatever lows and mids are mounted on the unity horn, will need to have sealed chambers. No biggy for the mids; but sealing up the lows is gonna chew up internal box volume, and be tricky.
*if you add reflex ports for the lows through the horn walls, the cavities that let the ports work will have to be worked / added into the internal volume used, for their sealed up box..
*even with reflex ports added to the lows in near perfect fashion like Danley can do, a sub section will still be needed.
*if the sub drivers go into the main box you drew, I think after its all said and done, you just enclosed a MEH and and a sub in a big wrap around box
*if the sub drivers go onto the horn walls like in my syn11....I think the size of the direct ports needed gets too dang big, and messes with mids/lows. And it's still gonna need reflex ports to get below 40Hz. I now think a 15" is the largest driver I'd mount to a unity/syn.
*if you do decide to put it all in one big wrap around box (maybe for ease of rolling around or something) beware of longer internal box dimensions that make for standing wave problems...and make bracing needs really increase.
My bass reflex sub cart at 46"x40x29" D has this problem. Even after having a divided it two internally, where it's essentially two single subs in one box, internal spans are too long. Needs more bracing, but I'm gonna just scrap the sub carts I think, and build a new push-push slot subs.
Anyway, just trying to help with some bigger picture thoughts, before going minutia diving
But I think there are things that keep it from working as well as might be expected.
In no particular order....
*whatever lows and mids are mounted on the unity horn, will need to have sealed chambers. No biggy for the mids; but sealing up the lows is gonna chew up internal box volume, and be tricky.
*if you add reflex ports for the lows through the horn walls, the cavities that let the ports work will have to be worked / added into the internal volume used, for their sealed up box..
*even with reflex ports added to the lows in near perfect fashion like Danley can do, a sub section will still be needed.
*if the sub drivers go into the main box you drew, I think after its all said and done, you just enclosed a MEH and and a sub in a big wrap around box
*if the sub drivers go onto the horn walls like in my syn11....I think the size of the direct ports needed gets too dang big, and messes with mids/lows. And it's still gonna need reflex ports to get below 40Hz. I now think a 15" is the largest driver I'd mount to a unity/syn.
*if you do decide to put it all in one big wrap around box (maybe for ease of rolling around or something) beware of longer internal box dimensions that make for standing wave problems...and make bracing needs really increase.
My bass reflex sub cart at 46"x40x29" D has this problem. Even after having a divided it two internally, where it's essentially two single subs in one box, internal spans are too long. Needs more bracing, but I'm gonna just scrap the sub carts I think, and build a new push-push slot subs.
Anyway, just trying to help with some bigger picture thoughts, before going minutia diving
I think I get it, the trade offs don't justify it especially if one were to have separate subs which serve this purpose better. Also I may have ignored how low these are already able to go.
With the main issue being the size of the direct ports affecting the other drivers, along with standing waves.
I'm quite far away from having an adequate understanding of all of it even with these threads, and the Synergy Calc but I do hope to be able to make my own at some point.
With the main issue being the size of the direct ports affecting the other drivers, along with standing waves.
I'm quite far away from having an adequate understanding of all of it even with these threads, and the Synergy Calc but I do hope to be able to make my own at some point.
Sure it isn't practical, but it also isn't necessary. The reason you want to do this is valid, but if you understand the situation you can do it right using a separate source.
We aren't so sensitive to these issues at lower crossover frequencies (far enough below 1000Hz), but a separate source can create response and power challenges for you to solve, just like any crossover. These are the things we are sensitive to at these frequencies.
We aren't so sensitive to these issues at lower crossover frequencies (far enough below 1000Hz), but a separate source can create response and power challenges for you to solve, just like any crossover. These are the things we are sensitive to at these frequencies.
What do you guys think of these drivers for the lows and mids in a Syn 10 type MEH:
https://willys-hifi.com/products/sb-acoustics-sb29nrx75-6-norex-woofer.
https://willys-hifi.com/products/scanspeak-10f-4424g00-full-range?keyword=scanspeak 10f
https://willys-hifi.com/products/sb-acoustics-sb29nrx75-6-norex-woofer.
https://willys-hifi.com/products/scanspeak-10f-4424g00-full-range?keyword=scanspeak 10f
I'd sure try them if I already have them.
Both of those drivers looked good to me, other than I'd also choose the lower cost 4NDF34 (and I use them already and know how they work)
One thing i would do when mounting the 4" you have, is figure out how I could remount the 4NF34 is you find you are short SPL at the low corner you want the mids to reach. Iow, just study the mounting holes, and if not the same, figure out how you can rotate one set out and another set in.
Well.....3 months later and I did it.....made new sub carts.
Not exactly a PPSL, but a hybrid as described here..https://www.diyaudio.com/community/threads/v-twin-double-18-bass-reflex-build.410229/#post-7627233
I've listened to syn11 and the older subcarts for long enough to know it is the clearest, most dynamic, sound I've achieved yet.
The only problem I've had with it, is the tonal balance varies more due to distance than any other syn version I've built. Sub bass is much stronger up close than only 10 ft further. I think the very large baffles of the older sub carts, and they way the interact with the room is the culprit. But dunno, cause it's been winter and no outdoor listening.
Anyway, now I have a syn11 on one of each type sub, and the birds are starting to sing....so I'm about to find out what the tonal shift with distance is about.
But all the other versions used my double 18" PPSL subs.
Only one of the new subs is built. Will listen outdoors, make syn11 measurements, while finishing two more subs.
Planning on revisiting syn10 in LCR mode when all 3 subs are finished.
The new sub was built to match up with syn10, blue horn on left below.
Hey, you know what was half scary just now....this 71 year old dude moving the big white 240 lb syn11 from the old subcart to the new.
One of these days I'm gonna really screw the pooch lol
When I thought to reuse my Eminence Kappa 12As instead of the 12" Danley uses - I looked at the T&S and thought, it's pretty close.. give it a go😀
(Only applicable to Danley clones)
Sounds like good advice. Troy is very impressed with the 10f’s so I figure they would be worth trying.
They look absolutely spot on. Love the finish too!
Can only imagine how incredible they sound!
Thx SpeedySteve, everyone...
@yys310, the syn11 has a pair of 12"s that reach down to 80Hz. It's the green trace below.
All my unity/syn build prior to syn11 have been design to cross to a sub somewhere around 100Hz.
But I've always wondered how it would sound to try to get the entire spectrum into one horn, and then use subs only for extra bass support.
So syn11 has a pair of 18"s in it, the red trace below.
The 18"s only reach down to 40Hz easily, so not what I was looking for. I tried adding reflex ports along with the primary ports, but the box volume was way to low for them to work.
I'd never put 18"s in one again... I think 15" is the limit, and I'd do some real modeling first.
@yys310, the syn11 has a pair of 12"s that reach down to 80Hz. It's the green trace below.
All my unity/syn build prior to syn11 have been design to cross to a sub somewhere around 100Hz.
But I've always wondered how it would sound to try to get the entire spectrum into one horn, and then use subs only for extra bass support.
So syn11 has a pair of 18"s in it, the red trace below.
The 18"s only reach down to 40Hz easily, so not what I was looking for. I tried adding reflex ports along with the primary ports, but the box volume was way to low for them to work.
I'd never put 18"s in one again... I think 15" is the limit, and I'd do some real modeling first.
I dunno....lot of trade-offs going on with that idea. Not something I'd try....I'd leave that to smarter horn folks like Mabat and gang
Hey all.....
SYN-11, rest in heaven.
I just put the last of the two big white horns, and sub-carts made for them...into the dump.
Stripped em clean and said bye-bye.
Wasn't easy...they really were the cleanest, most dynamic sound I've achieved/heard.....but they were just too damn big.
Sub bass was too directional.... big sub-carts needed additional bracing....
...and perhaps more than anything, I was really loving LCR with the smaller syn10s before the whole syn11 trip.
So, in a few days, I'll have three stacks of syn-10's with new subs running.
Cost of making 3 new double 18" subs has been relatively minimal. 9 sheets of 3/4 birch at $35 a sheet. And 3 gallons of Duratex paint at $84 a gallon.
So under $600,.... since already owning drivers and hardware, etc.
Damn lot of labor though