Guys,
i wanna share a story and ask for some advice
last friday i did a gig on a small bar around 100 people max ( tecno cumbia band . aka selena quintanilla , elida reyna )
i own 4 LX18's (b52) that i did not used that gig cause i did not had help to move the boxes
anyway a friend have their kids ( on their mid 20's ) who help him with his speakers
so he offered to put the set the speakers for me,
i played that place before with the LX18's (i have 4 but used just 2 ) and 2 tops ( jbl MR925's)
i drive the 2 LX18's with a bridged crown XLS2500 and the jbls with a bridged XLS2000
with an old drive rack PA
so this was the thing, he lent me and move for me 2 yamahas CW218V's (dual 18 bass reflex ) and one carvin TRX215 as top
i adjusted the LP filter to 24db LR 30 HZ for the yammies and HP to 24db LR 100HZ
the yammies are rated at 30hz freq response and i can go lower on the LP setting but i wanted to play safe as those was not my speakers
( i tweaked the attenuation knobs on the amps so to have a balanced subs to tops balanced )
as i never played with that speaker setup before
anyway, after putting some reference tracks on the sound check i EQ'd the master bus on the board ( behringer X18 ) some BELL -6db on the 125 HZ range with a Q of 1
that taked off the boomines of the system/room sound and let the subs sound more punchy , i also attenuated BELL around 3-4k with -4db with a Q of 1 to take away the
harshines of the carvin top and boosted around 10k high shelf +4db
that made the tops to play more to my taste
ok so, the system was playing around 30-40 percent on the power amps lights
and i was impressed with the sub info coming out from the yammies, it felt more visceral, ( subs was next to me around 2 feet )
but people on the dance floor were more ecstatic if you can call it, as i can tell how they were dancing and compare to other times, indeed the smile on my face for how the sound was performing cant deny how i was enjoying the gig.
The workers and managers at the bars told me, hey we never heard that much bass coming from any system here ( i mean other bands own PA ) and not even my system
in fact the other guys do not have a sound guy and locally the knowledge in audio from local bands are close to none, there is a guy who plays with 4 QSC KS118's and 2 KLA12's
and not even sound half as good as the yammie system. ( told by one of the bartenders who also plays in other bands )
anyway, my point is that i was able to squezze the most i can get from the system even i was not playing to their limits but i mean that not with my own speakers i liked how it sound.
So do i switch to dual18's bass reflex that are easier to build as DIY or do i try the keystone or TH18 ( i know those cant compare to my rubish LX18's that i know not even were good designed like CV L36 )
If i go to double 18's what designs you recommend ( 18sound and b&c have recommended plans on their website also )
is there any bandpass design you guys recommend
and from from the horns and tapped horns what you guys recommend
I was truly impressed how i can feel the bass with 2 double 18's cabinets and i knows those yammies are not the best design
i want to start with 2 cabinets, 4 being ideal but will scale to 8 in the future
I just love the compliments if people that says that the band sound awesome and other that says
" your system rocks"
"never heard a system like it"
"this thing punch you in the chest"
" this make me to dance"
Phun intended !
thanks for making DIY one of the best places for advice and help
you guys ROCK!!!
Best.
Max.
i wanna share a story and ask for some advice
last friday i did a gig on a small bar around 100 people max ( tecno cumbia band . aka selena quintanilla , elida reyna )
i own 4 LX18's (b52) that i did not used that gig cause i did not had help to move the boxes
anyway a friend have their kids ( on their mid 20's ) who help him with his speakers
so he offered to put the set the speakers for me,
i played that place before with the LX18's (i have 4 but used just 2 ) and 2 tops ( jbl MR925's)
i drive the 2 LX18's with a bridged crown XLS2500 and the jbls with a bridged XLS2000
with an old drive rack PA
so this was the thing, he lent me and move for me 2 yamahas CW218V's (dual 18 bass reflex ) and one carvin TRX215 as top
i adjusted the LP filter to 24db LR 30 HZ for the yammies and HP to 24db LR 100HZ
the yammies are rated at 30hz freq response and i can go lower on the LP setting but i wanted to play safe as those was not my speakers
( i tweaked the attenuation knobs on the amps so to have a balanced subs to tops balanced )
as i never played with that speaker setup before
anyway, after putting some reference tracks on the sound check i EQ'd the master bus on the board ( behringer X18 ) some BELL -6db on the 125 HZ range with a Q of 1
that taked off the boomines of the system/room sound and let the subs sound more punchy , i also attenuated BELL around 3-4k with -4db with a Q of 1 to take away the
harshines of the carvin top and boosted around 10k high shelf +4db
that made the tops to play more to my taste
ok so, the system was playing around 30-40 percent on the power amps lights
and i was impressed with the sub info coming out from the yammies, it felt more visceral, ( subs was next to me around 2 feet )
but people on the dance floor were more ecstatic if you can call it, as i can tell how they were dancing and compare to other times, indeed the smile on my face for how the sound was performing cant deny how i was enjoying the gig.
The workers and managers at the bars told me, hey we never heard that much bass coming from any system here ( i mean other bands own PA ) and not even my system
in fact the other guys do not have a sound guy and locally the knowledge in audio from local bands are close to none, there is a guy who plays with 4 QSC KS118's and 2 KLA12's
and not even sound half as good as the yammie system. ( told by one of the bartenders who also plays in other bands )
anyway, my point is that i was able to squezze the most i can get from the system even i was not playing to their limits but i mean that not with my own speakers i liked how it sound.
So do i switch to dual18's bass reflex that are easier to build as DIY or do i try the keystone or TH18 ( i know those cant compare to my rubish LX18's that i know not even were good designed like CV L36 )
If i go to double 18's what designs you recommend ( 18sound and b&c have recommended plans on their website also )
is there any bandpass design you guys recommend
and from from the horns and tapped horns what you guys recommend
I was truly impressed how i can feel the bass with 2 double 18's cabinets and i knows those yammies are not the best design
i want to start with 2 cabinets, 4 being ideal but will scale to 8 in the future
I just love the compliments if people that says that the band sound awesome and other that says
" your system rocks"
"never heard a system like it"
"this thing punch you in the chest"
" this make me to dance"
Phun intended !
thanks for making DIY one of the best places for advice and help
you guys ROCK!!!
Best.
Max.
TS parameters that suite it show a TH (TPipe, as TL with benfits) as 'better than relfex if exposed where it counts. ART WELSYS can be a great quote for this to consider(i cant find the thread though, BR vs TH essentialy..
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Bass reflex in general has a wider useable bandwidth than Tapped horns.
Tapped horns also often have a more variable amount of group delay throughout the intented frequency range, whereas a bass reflex design has low delay in higher frequencies and it slowly peaks down towards FS.
TH's can give more output per driver, but this also requires more design volume, if you compare equal design volume per driver it will be more or less equal in performance to a BR.
Neither BR or TH are magical designs, both should serve well if you optimalize the integration to the rest of your system.
I do not think the Yamaha CW218V are a bad design, they know how to get good results from reasonably priced components.
You can probably DIY something better than those subs cheaper, but it's not a bad design.
I can generalize further if that will help you decide:
If you go for cheaper drivers I'd make some 2*18" BR subs to compensate the slightly lower xmax with membrane area, if you get more expensive drivers with more xmax I would make TH's.
My personal choice would probably lean towards BR because I like membrane area more than I like the "flapping about" of large xmax drivers, and there's a wider useable bandwidth especially up top so BR can in some cases be easier to integrate.
Good luck with your decision, you will probably be happy regardless of what you choose.
Tapped horns also often have a more variable amount of group delay throughout the intented frequency range, whereas a bass reflex design has low delay in higher frequencies and it slowly peaks down towards FS.
TH's can give more output per driver, but this also requires more design volume, if you compare equal design volume per driver it will be more or less equal in performance to a BR.
Neither BR or TH are magical designs, both should serve well if you optimalize the integration to the rest of your system.
I do not think the Yamaha CW218V are a bad design, they know how to get good results from reasonably priced components.
You can probably DIY something better than those subs cheaper, but it's not a bad design.
I can generalize further if that will help you decide:
If you go for cheaper drivers I'd make some 2*18" BR subs to compensate the slightly lower xmax with membrane area, if you get more expensive drivers with more xmax I would make TH's.
My personal choice would probably lean towards BR because I like membrane area more than I like the "flapping about" of large xmax drivers, and there's a wider useable bandwidth especially up top so BR can in some cases be easier to integrate.
Good luck with your decision, you will probably be happy regardless of what you choose.
Max,
Well braced BR are about the same as the Keystone in terms of "easy to build".
In the A/B comparison I did, the output of a single 18" Keystone sub equated to that of a dual 18 of slightly larger volume using the same drivers. Half the power requirements, half the driver costs.
https://www.diyaudio.com/community/threads/tapped-horn-vs-bass-reflex-case-study.184992/
Considering the limited power availability in many venues, the roughly 6dB advantage of TH can make a large difference in real-world output. Using half the power can also save a lot of AC power distribution costs, connection headaches and power-robbing peak "brownouts".
Art
Art,
so it is more efficient money and audio wise to go with an keystone with a 18sw115-4
the driver is around 750 and if i do a doubleb18 with budget driver...lets say 18tbx100 is around 320 so thats 640 (excluding tax) not to say that your comparison was same drivers so...i magine 2 18sw115's , around 1500 plus tax, 6db lower plus need double the power... mmmm i think there is nothing more to say.
are there any final plans with tips cause there is many mods on the thread of the KS , also i do not really need cone correction , do i?
Max.
so it is more efficient money and audio wise to go with an keystone with a 18sw115-4
the driver is around 750 and if i do a doubleb18 with budget driver...lets say 18tbx100 is around 320 so thats 640 (excluding tax) not to say that your comparison was same drivers so...i magine 2 18sw115's , around 1500 plus tax, 6db lower plus need double the power... mmmm i think there is nothing more to say.
are there any final plans with tips cause there is many mods on the thread of the KS , also i do not really need cone correction , do i?
Max.
Does not compute.
Yes, the keystone outputs more sound, but if I decided to use something other than the most commonly used dirt-cheap 18" drivers I could find, a double 18" box of similar size should be able to keep up.
The benefits of a double 18" BR would be:
1. Less power compression because each driver sees half the power.
2. More even response.
3. Lower group delay and fewer phase issues.
I also have a 377 liter sim with double 18" at 280€ per driver so 560€ total driver cost, that gives 130dB/2pi @ 30Hz, not sure what level you got the B-low version to but I expect the difference to be less than the 6dB advantage you claim.
I think the Keystone seems like a good design, but it seems to me those claims do not add up entirely.
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Hornresp sims are not capturing non-linear behavior like port compression. Most double 18" bass reflex designs have primitive ports that will limit output around tune with high xmax drivers. A benchmark pro sound 2*18 is the KS28:
a very different port design than most DIY efforts. The tapped horn has the advantage that as a series design all the ducts are large so such elaborate shapes are not required to to avoid compression. https://www.production-partner.de/test/l-acoustics-ks28-im-test/
a very different port design than most DIY efforts. The tapped horn has the advantage that as a series design all the ducts are large so such elaborate shapes are not required to to avoid compression. https://www.production-partner.de/test/l-acoustics-ks28-im-test/
That may be, but you do get some indication.
This is from that cheap double Thomann 18" sim running full-tilt. More expensive drivers running harder might benefit from using aero-ports.
Hey Kaffi,
what designs DIY BR do you recommend for double 18"s, since i am in the USA i have access to partsexpress for driver sourcing,
what would be some cheap USA sourced drivers. dayton , goldwood or maybe Lavoce if we stretch the budget.
18 sound and B&C have some double 18's plans on their website but idk if we can fit a cheaper driver other than the ones they made the BR box for.
there are like 2 guys on you tube who publish plans in 3d views from known commercial models, but i am not sure if they dimensions are real.
so are are BR drivers more easy to swap between BR boxes ? than on the TH designs that you must strict use the driver that was designed to SIM that cabinet.
what designs DIY BR do you recommend for double 18"s, since i am in the USA i have access to partsexpress for driver sourcing,
what would be some cheap USA sourced drivers. dayton , goldwood or maybe Lavoce if we stretch the budget.
18 sound and B&C have some double 18's plans on their website but idk if we can fit a cheaper driver other than the ones they made the BR box for.
there are like 2 guys on you tube who publish plans in 3d views from known commercial models, but i am not sure if they dimensions are real.
so are are BR drivers more easy to swap between BR boxes ? than on the TH designs that you must strict use the driver that was designed to SIM that cabinet.
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I am not advocating that you should use one design over the other, I merely wanted to make sure that you get a slightly more nuanced discussion of BR vs TH because that is what you asked for.
That said, tell me your budget for drivers and how big the boxes should be, and I will have a look at it.
I am a big fan of "bang per buck" designs.
I know many users here have a different focus, but for me personally I think the combination high xmax + high power is not "the way", I think it is a waste of electric power and money.
All glory to those that embrace the path of ultimate power and SPL, personally I am content with getting up to a small step or two down from the very peak.
It's not always about winning, for most of us it is about being able to take part in the experience.
That said, tell me your budget for drivers and how big the boxes should be, and I will have a look at it.
I am a big fan of "bang per buck" designs.
I know many users here have a different focus, but for me personally I think the combination high xmax + high power is not "the way", I think it is a waste of electric power and money.
All glory to those that embrace the path of ultimate power and SPL, personally I am content with getting up to a small step or two down from the very peak.
It's not always about winning, for most of us it is about being able to take part in the experience.
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As KaffiMan has shown, less expensive drivers with less excursion, and power handling have higher voltage sensitivity than a high mass, power and excursion driver like the B&C 18SW115-4 suitable for the Keystone TH, but can’t match the output.
No "cone correction" is needed with the B&C 18SW115-4 in the Keystone sub.
https://www.diyaudio.com/community/threads/keystone-sub-using-18-15-12-inch-speakers.185588/
Corrected plans are available in post # 487, with the exception that the bottom of part "F" is 89 degrees, the front of "G" is a 5 degree angle, the back of "G" is 3 degrees as shown in post #478.
Assembly instructions are in post #1525.
I might consider having a look at that, my example was one of performance per budget while taking into account power compression and budget for amplifiers.
I think that brute force is less effective than a lesser amount of correctly applied force.
Performance for equal budget and power would reduce the difference at least somewhat. Design volume should of course be compareable.
With dynamic music, power compression is not an issue with BC18SW115-4 with peaks well above 77volts.
No question that the Thomann 18" is great bang for the buck, but your sim was pushing them past Xmax, while the Keystone with the BC18SW115-4 was still well below Xmax- the (clean) output level difference between the cabinets would be more than 3dB in the low end, 6dB in the top.
Yes, i saw designs like CUBO, THAM, ROAR, PARAFLEX , i do not really dig the cyclops or W BIN. but most of my quest is between a Horn Type and BR.
Indeed, i heard the SRX728 and 828 , but they did not convince me much, maybe the FOH guy did not EQ them well, i dont know if the 900 series are better or not, from the standpoint of around 300 per driver 200 to 350 and boxes smaller than the 728 that is too large for my transportation , the 828 is ok and the yamahas CW218, size is ok, now what about singles 18's , easier to transport and build but i want that they stack em well to use in multiples of 2 ( still refering to BR designs) , somebody told me that the turbosound MILAN 18 sounded great., it was 500 now it is 999, the FB guy published the internals of it, but that suppose to be a 6th order bandpass ? , what would be some designs that can squeze the last drop of SPL from budget drivers between 200-350 bux, the amps already have , and i will want to get the 1 rack space sanway Pow,,,So.,. clones later one to have some compact and light rack.
(
I really dig what you are saying and i second your opinion, will all due respect to people who think otherwise, as some wise man once said, to each its own. 😀
is there a way to split the cost in half and the sum as you go ? i mean instead of using a 750 driver, use a 300 or 350 driver, then build another box and so on,
thanks for that info Art, i made my folder for the keystone and storing what you pointed.
Kaffi,
sanway is know for making clones of LA..GRU.. , but those i was not interested , till now they rolled our the 1U Rack Space Pow...Sof... clones
Those i like !!
😍😍
bass boss seem to be very loud, and do not seem to have the ks28 lips exit but a square exit.
https://www.guitarcenter.com/BASSBOSS/SSP218-Dual-18-Powered-Subwoofer-1500000223003.gc?
Allright, your concern is valid, let's have a look at that.
The 18SW115-4 has a 34mm VC and a 14mm magnetic gap depth, so you're left with 20mm after subtracting the numbers, if we follow the example B&C sets here we can take that 20mm and divide by 3 resulting in 6.66mm, double that number and we get 13.33mm which is not too far off the claimed 14mm xmax listed in the data sheets.
By the "Old World" logic of divide by 2 we should be left with 10mm, not 14mm.
The Thomann 18-500/8-A has a 21.8mm VC and a 11mm magnetic gap depth, resulting in 10.8mm after subtracting, use the same method of divide by 3 we saw with the B&C driver results in 3.6mm, double that and we get 7.2mm xmax.
By the "Old World" logic of divide by 2 we are left with 5.4mm instead of the 7.2mm I calculated.
You are perfectly correct that I used more than 1/2 of what is left after subtracting the magnetic gap depth, but I am not certain if there is any manufacturer left that still calculates numbers like that.
B&C and many others commonly list xmax as MORE than the VC-Mgd/3*2 number.
Or do you have any data to suggest I should reconsider my line of thought? Open to suggestions.
Edit:
I'm not trying to fight you, the Keystone seems like a great design.
It's just your too-bold-to-be-true statements seemingly presented as facts that do not seem to add up entirely:
And in your Case Study thread:
Of which one was an optimalized design for one particular driver versus a seemingly unoptimalized and slightly smaller design for that same driver.
It goes on and on, and in other threads claimed to be louder than similarly sized double driver BR boxes, admittedly with slightly higher distortion.
The Keystone is a great achievement for single driver designs, but please reconsider some of those claims.
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Just a quick recap of the dirt-cheap double Thomann driver vs the Keystone using a quite expensive single 18":
To be fair, the difference varies between nil to just under 6dB, I bet that 80-100Hz boost is the main reason you feel it has "significantly more output", I'll play nice and pretend like thermal and power compression does not exist for a small moment, and if we just roughly average out the difference it's around 3db.
How much power did you use again? 1700W? And the other one is using max 800W?
So the difference in power is roughly about 3dB, and the difference in SPL is roughly about 3dB.
You cannot possibly claim that the Keystone 18" has a 6dB advantage against similarly sized double 18" BR boxes.
It. Just. Does. Not. Add. up.
I can also adjust EQ to add more power in that particular passband to get that "party hump" for you if that's your thing, crossing over 133dB for the cheap design, so it's less than 2dB difference by your previously applied logic, without using significantly more power per driver, we are talking a whooping 50 watt increase per driver here. Should still be within the power budget.
Now... If we do add problems like thermal and power compression I am willing to bet hard earned cash that the difference between the Keystone running@1700W/driver vs the cheap double Thomann 18" BR would be negligible at best, except the indisputable fact that the cheap design needs smaller amplifiers as well.
I would recommend getting some other slightly more expensive drivers for pro use though, the 18-500/8-A was just chosen for being cheap and popular, and is a bit of an "unknown" in the quality department.
Still, should be very possible to make a better choice in drivers with more xmax for around 500€ or so.
To be fair, the difference varies between nil to just under 6dB, I bet that 80-100Hz boost is the main reason you feel it has "significantly more output", I'll play nice and pretend like thermal and power compression does not exist for a small moment, and if we just roughly average out the difference it's around 3db.
How much power did you use again? 1700W? And the other one is using max 800W?
So the difference in power is roughly about 3dB, and the difference in SPL is roughly about 3dB.
You cannot possibly claim that the Keystone 18" has a 6dB advantage against similarly sized double 18" BR boxes.
It. Just. Does. Not. Add. up.
I can also adjust EQ to add more power in that particular passband to get that "party hump" for you if that's your thing, crossing over 133dB for the cheap design, so it's less than 2dB difference by your previously applied logic, without using significantly more power per driver, we are talking a whooping 50 watt increase per driver here. Should still be within the power budget.
Now... If we do add problems like thermal and power compression I am willing to bet hard earned cash that the difference between the Keystone running@1700W/driver vs the cheap double Thomann 18" BR would be negligible at best, except the indisputable fact that the cheap design needs smaller amplifiers as well.
I would recommend getting some other slightly more expensive drivers for pro use though, the 18-500/8-A was just chosen for being cheap and popular, and is a bit of an "unknown" in the quality department.
Still, should be very possible to make a better choice in drivers with more xmax for around 500€ or so.
I'm not trying to wade in on whether BR or TH are better to me it depends on situation. I'm trying to make the point that Hornresp simulations are of limited use in directly comparing two boxes of similar predicted output capability. This box on databass illustrates port compression quite well (even though it has a relatively large port): https://data-bass.com/#/systems/5c2d2600d3a6a500040a808c?_k=w2d1gu
there is also some compression due to high excursion in the 40-60Hz range.
I have also compared a low end and a mid range driver in a bass reflex design and found while at some frequencies in the pass band the mid range driver offered +6dB more output at other frequencies maximum output was negligible: https://www.diyaudio.com/community/threads/isobaric-sub-based-on-pyle-plpw15d.345807/#post-7039398
there is also some compression due to high excursion in the 40-60Hz range.
I have also compared a low end and a mid range driver in a bass reflex design and found while at some frequencies in the pass band the mid range driver offered +6dB more output at other frequencies maximum output was negligible: https://www.diyaudio.com/community/threads/isobaric-sub-based-on-pyle-plpw15d.345807/#post-7039398