I promised to take pics of the build and report on the performance of the cube. Sorry this has taken so long. Have had several gigs, lots of rain, and a honey do list. Need I say more...lol!
I finally got one knocked out and loaded with 3015lf. The 3015lf came out of a titan 48, so it was a broke-in driver. So far all the testing I have been able to do was to run thru 2-15's and horns for top speakers and 1 cube. I crossed over at 100hz. I pumped some bass guitar thru the PA for about 5 mins. The test was in my basement, with a drop ceiling. Not the best place to test... it was raining outside.
With only one cube built I thought it did very well. I did have to hold the tops back some. I bet with something like an O-top 12 and a cube, woud be a great light weight backline for bass. It really wasn't much of a test because the ceiling tiles were buzzing bad.
I can't wait to knock 3 more out and test them outside with some of the DJ music we play. I will report back when I get that done. Until then here are a few pics of the build.
Thank you to Jim and Don for the sharing this little jewel...
I finally got one knocked out and loaded with 3015lf. The 3015lf came out of a titan 48, so it was a broke-in driver. So far all the testing I have been able to do was to run thru 2-15's and horns for top speakers and 1 cube. I crossed over at 100hz. I pumped some bass guitar thru the PA for about 5 mins. The test was in my basement, with a drop ceiling. Not the best place to test... it was raining outside.
With only one cube built I thought it did very well. I did have to hold the tops back some. I bet with something like an O-top 12 and a cube, woud be a great light weight backline for bass. It really wasn't much of a test because the ceiling tiles were buzzing bad.
I can't wait to knock 3 more out and test them outside with some of the DJ music we play. I will report back when I get that done. Until then here are a few pics of the build.
Thank you to Jim and Don for the sharing this little jewel...
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Hi Mike,
Jim is doing all the heavy lifting. He does his designs using paper cut-outs and rough estimates, then builds and tests these
boxes. I come along and spend one lousy hour documenting the design with CAD and easy-to-follow sketches and dimensions,
and I get to share the glory.
While my drawings make it easier for folks to knock out a Tapped Horn, Jim’s rough folding and unintended deviations might
make a (slightly) better Horn. While my tapers are more uniform, Tom Danley has said that at least for the lowest octave,
taper is unimportant.
I hope my efforts have helped folks build Tapped Horns,
~Don
Jim is doing all the heavy lifting. He does his designs using paper cut-outs and rough estimates, then builds and tests these
boxes. I come along and spend one lousy hour documenting the design with CAD and easy-to-follow sketches and dimensions,
and I get to share the glory.
While my drawings make it easier for folks to knock out a Tapped Horn, Jim’s rough folding and unintended deviations might
make a (slightly) better Horn. While my tapers are more uniform, Tom Danley has said that at least for the lowest octave,
taper is unimportant.
I hope my efforts have helped folks build Tapped Horns,
~Don
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Yes Jim, thank you for all your hard work with the cube design and cut list. And thank you for sharing it with us. And thank you Don for taking the time to draw up the plan.
I will be sure to post more pics of the next 3 I build and report back. Can't wait to get them complete and test them outside with the Otop 12's. Jim, how many of these cubes do you think it will take to keep up with 4 Otop 12's?
I have this crazy idea running thru my head to build the cubes ultra light with foam core and fiberglass composite. I might just try to knock one out, it should be very do-able... I have a bad back so I try to make things as light as possible. Hmmm
I will be sure to post more pics of the next 3 I build and report back. Can't wait to get them complete and test them outside with the Otop 12's. Jim, how many of these cubes do you think it will take to keep up with 4 Otop 12's?
I have this crazy idea running thru my head to build the cubes ultra light with foam core and fiberglass composite. I might just try to knock one out, it should be very do-able... I have a bad back so I try to make things as light as possible. Hmmm
Scott runs 1:1 with his furybox with modified OT12's. (6 of each) Hornresp says the cube is not that far behind, so 1:1 would be a great place to start. (My last install was 1:1 with a beta12a2 top kinda like OT12) My brother is also running 1:1 furybox:beta12a2 tops at 4:4. A 6 cube, 4 top setup would be lots of fun however.
For weight savings, find your local fine wood supplier and get some poplar plywood. (40% weight savings) By the time you mat and fiberglass on both sides you are close enough to the poplar weight for it not to be that appealing. (my 2c)
And don, thanks again -- I still would love to see a sticky thread with drawings from you, oliver, flip and others documenting these TH's.
Hi Jim,
How should we do it? Some are just "sims", some have been built & some have been "tested." Should the "sticky" just be a
page of pointers to the posts where they were documented, or ...? So many people have contributed to the forum, it will
be impossible to credit everyones effort. I think nominal credit should go to the one who first makes sawdust on a design.
What do you think?
~Don
P.S. I did a "sticky" tracing the evolution of the tapped horn, and Tom validated it ... I don't know if anybody else read it.
How should we do it? Some are just "sims", some have been built & some have been "tested." Should the "sticky" just be a
page of pointers to the posts where they were documented, or ...? So many people have contributed to the forum, it will
be impossible to credit everyones effort. I think nominal credit should go to the one who first makes sawdust on a design.
What do you think?
~Don
P.S. I did a "sticky" tracing the evolution of the tapped horn, and Tom validated it ... I don't know if anybody else read it.
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New here by a few days on DIY and this thread is what attracted me. I've read through most all of the stadium system (wow!) and now looking at the 2' cube design... here's why I'm looking: I've had a pair of Altec 421-LF drivers on a shelf for ages and they either have to go away or become something. Is this perhaps the Something? Alongside them is a single Klipsch K-48E which handles a LOT more power than the old Altecs. I hate tossing stuff out but SO much here MUST go, or become useful...
thanks for the thread and forum and huge learning resource.
JV
thanks for the thread and forum and huge learning resource.
JV
Decades ago that was my thought, but while it's a fine-for-it's-day classic bass driver, very quickly the 421A-LF (unlike the regular 421A) showed itself to me to be simply horrid for guitar or bass as a single-driver choice as it's horridly honky and dull sounding and belongs in a multiway system rolled off above 1k or lower. My ignorant thought here has been that with limited excursion and power handling, getting the most out of them would be by using them in a horn system.
Only other thought was building a ported cabniet and availing myself of a pair of the big ElectroVoice Sentry mid-hi packages I know of, and making a DIY stereo pair of EV Sentry-III's.
All this just to keep from tossing a Nice Old Speaker.
Hard to tell Classic from Boat Anchor sometimes.
JV
OK, I'll be more specific then, the 1233 - 1236 which are about all they're good for IME with the 1236 making for a pretty good monitor/party speaker if a sub system is used: http://www.lansingheritage.org/images/altec/catalogs/1978-pro/page09.jpg
Of course a large FLH can be used or even a TH for that matter, but it just seems a waste of resources overall to me.
I know how you feel though, I've a NOS pair of 421-8Hs from the first palette load to Hotlanta and for one reason or another never got around to using them other than to break them in enough to measure, but don't really want to part with them. Every few years I drag them out of the closet and set them outside to let the Summer heat loosen them up/reposition the diaphragm.
GM
Of course a large FLH can be used or even a TH for that matter, but it just seems a waste of resources overall to me.
I know how you feel though, I've a NOS pair of 421-8Hs from the first palette load to Hotlanta and for one reason or another never got around to using them other than to break them in enough to measure, but don't really want to part with them. Every few years I drag them out of the closet and set them outside to let the Summer heat loosen them up/reposition the diaphragm.
GM
Thanks for the cogitation and advice. The 1233 is in the zone of the Model-19 slash EV Sentry-III idea. These initially came out of a pair of same era 1215 horns that either were just NOT what I thought they should be or I never set them up right (years back). My thought is that in those cabinets
1- I expected real bass and they really don;t go there, being too short.
2- They were running way up into 1kHz and they shouldn;t be up there, sounding hollow and resonant in the extreme.
and of course
3- the drivers cliff after 2k or so and they're thus awful, on their own, for musical instrument work, the full-range 421 makes sense there.
I have been for years occasionally re-trying the, admittedly romantic/nostalgic-based, search for a best-use cabinets and this time I discovered here the 2' cube which seems a triple-play of a fine size, affordability, and a reasonably simple build... but then with them might be the tendancy to push the 421's too hard a blow them up, rather than placeing them in a simple ported HiFi rig where they wouldn't be expected to shake people's vital organs. Selling prices are odd... my early 70's SRO 12's are apparently worth almost twice what the Altecs are! Go Figure.
Again, thanks for the consolation and guidance... no matter what I end up doing with these drivers, just finding DIY, and the enthusiastic and serious approach here, is worth the rambling! Learning is good.
John V
1- I expected real bass and they really don;t go there, being too short.
2- They were running way up into 1kHz and they shouldn;t be up there, sounding hollow and resonant in the extreme.
and of course
3- the drivers cliff after 2k or so and they're thus awful, on their own, for musical instrument work, the full-range 421 makes sense there.
I have been for years occasionally re-trying the, admittedly romantic/nostalgic-based, search for a best-use cabinets and this time I discovered here the 2' cube which seems a triple-play of a fine size, affordability, and a reasonably simple build... but then with them might be the tendancy to push the 421's too hard a blow them up, rather than placeing them in a simple ported HiFi rig where they wouldn't be expected to shake people's vital organs. Selling prices are odd... my early 70's SRO 12's are apparently worth almost twice what the Altecs are! Go Figure.
Again, thanks for the consolation and guidance... no matter what I end up doing with these drivers, just finding DIY, and the enthusiastic and serious approach here, is worth the rambling! Learning is good.
John V
The furybox is compressed. The driver exits through a smaller hole creating a "shock absorber" and compression. Helps keep the driver from slamming into xmax among other benefits. I wouldn't be comfortable exceeding the xmax spec or even getting too close to it with a uncompressed box.
I don't run the cabs all the time that hot but it's there if I do by accident.
Most real pro speaker companies underrate their cabs slightly for the same reason.... end user protection.
Tapped horns do need a good cutoff filter.
Damaged 3015 LF driver in the Stadium Horn
One stadium horn is still going strong, doing a great job.
The other has a driver that has been making funny sounds.
I have removed the driver from the cabinet.
It looks immaculate, clean, perfect from a visual point of view. No tears in the dustcap, surround or anything else I can see.
It moves smoothly. No rubbing when pushed in and out.
It still produces a fair bit of sound when connected to an amp.
But it makes additional noise, like wires (tinsel leads, maybe?) are banging against the nside of the dust cap - but I just don't know.
The driver stops making the funny noise when I control it by placing my hand gently against the cone or dustcap while it is working.
Has anyone has a similar experience, or can anyone give a diagnosis? I would be very grateful to learn from you!
Regards, Ben
One stadium horn is still going strong, doing a great job.
The other has a driver that has been making funny sounds.
I have removed the driver from the cabinet.
It looks immaculate, clean, perfect from a visual point of view. No tears in the dustcap, surround or anything else I can see.
It moves smoothly. No rubbing when pushed in and out.
It still produces a fair bit of sound when connected to an amp.
But it makes additional noise, like wires (tinsel leads, maybe?) are banging against the nside of the dust cap - but I just don't know.
The driver stops making the funny noise when I control it by placing my hand gently against the cone or dustcap while it is working.
Has anyone has a similar experience, or can anyone give a diagnosis? I would be very grateful to learn from you!
Regards, Ben
It is blown!
That speaker is done... blown... blasted....fried....and must be pulled out of your system....NOW.
A buzzy tinsel sound is usually the bottom of the voice coil flapping around. This is due to overpowering the unit such that the Glue burns off and the copper coils start coming loose off the former. This can result in a dead short or turning your amp into an arc welder. Pull the speaker for recone as it is finished.
That speaker is done... blown... blasted....fried....and must be pulled out of your system....NOW.
A buzzy tinsel sound is usually the bottom of the voice coil flapping around. This is due to overpowering the unit such that the Glue burns off and the copper coils start coming loose off the former. This can result in a dead short or turning your amp into an arc welder. Pull the speaker for recone as it is finished.
screamer is probably right.
the only ting you can check to see if dustcap is on 100%,a tiny tair in the suround,or the litse wire rattling agains the cone.
i had a lose duscap on a rcf and one tair in a beyma surround.these probs were hard to locate
Have removed the driver
and sacrificed one of my T36 for a transplant. Yes, I removed its still beating heart!
I just noticed the surround on the old 3015LF is more elastic / all foam, and the newer drivers are part cardboard. The older seems to provide a better seal.
Also, the back of the old driver look slightly corroded, like aluminium that has been around for a while. It's working fine, so should this concern me?
screamersusa - Thank you for the advice!
epa - Thank you too! Unfortunately, the driver looks perfect, absolutely no signs of damage, so it will have to go (or be reconed?)
and sacrificed one of my T36 for a transplant. Yes, I removed its still beating heart!
I just noticed the surround on the old 3015LF is more elastic / all foam, and the newer drivers are part cardboard. The older seems to provide a better seal.
Also, the back of the old driver look slightly corroded, like aluminium that has been around for a while. It's working fine, so should this concern me?
screamersusa - Thank you for the advice!
epa - Thank you too! Unfortunately, the driver looks perfect, absolutely no signs of damage, so it will have to go (or be reconed?)
Happy - good results at an event. But wondering how much more is possible...
Had to improvise a little - the cabinets are standing up, and split, with a pair of Peavey PR 12 sitting on top of each.
Next time there'll be a modified OmniTop 215 on each side.
(However, I am not sure what platform to use to keep the tall new tops stable when I have them ready.)
Also, I will try putting the subwoofers flat on the floor next to each other.
Hopefully this will improve response and coupling further.
The DJ and audience were happy, but I felt that more was possible!
So I'll be playing and experimenting a little. (Floor, wall and corner loading, aux fed.)
I don't have space for more subs in my van, so I may need to upgrade another way for more demanding events - maybe put 18 inchers in, as JBell has suggested in the past.
If so, should I get the EIGHTEENSOUND 18NLW9600 or something else?
THIELE SMALL PARAMETERS (5)
Fs
34 Hz
Re 4.7 Ohm
Sd
0.1134 sq. mt. (189.88 sq.in.) Qms 8.7
Qes
0.29
Qts
0.28
Vas
149 lt. (5.1 cuft) Mms
261 gr. (0.58 lb) BL
30 Tm
Linear Mathematical Xmax (6)
± 14 mm (± 0.55 in) Le (1kHz)
2.11 mH
Ref. Efficiency 1W@1m (half space)
95.1 dB
Jim - Thanks for the Design!
And all the other DIY guys out there, Thank you!
A special thank you to Syd who suggested I take a look at this forum!
Had to improvise a little - the cabinets are standing up, and split, with a pair of Peavey PR 12 sitting on top of each.
Next time there'll be a modified OmniTop 215 on each side.
(However, I am not sure what platform to use to keep the tall new tops stable when I have them ready.)
Also, I will try putting the subwoofers flat on the floor next to each other.
Hopefully this will improve response and coupling further.
The DJ and audience were happy, but I felt that more was possible!
So I'll be playing and experimenting a little. (Floor, wall and corner loading, aux fed.)
I don't have space for more subs in my van, so I may need to upgrade another way for more demanding events - maybe put 18 inchers in, as JBell has suggested in the past.
If so, should I get the EIGHTEENSOUND 18NLW9600 or something else?
THIELE SMALL PARAMETERS (5)
Fs
34 Hz
Re 4.7 Ohm
Sd
0.1134 sq. mt. (189.88 sq.in.) Qms 8.7
Qes
0.29
Qts
0.28
Vas
149 lt. (5.1 cuft) Mms
261 gr. (0.58 lb) BL
30 Tm
Linear Mathematical Xmax (6)
± 14 mm (± 0.55 in) Le (1kHz)
2.11 mH
Ref. Efficiency 1W@1m (half space)
95.1 dB
Jim - Thanks for the Design!
And all the other DIY guys out there, Thank you!
A special thank you to Syd who suggested I take a look at this forum!
Had to improvise a little - the cabinets are standing up, and split, with a pair of Peavey PR 12 sitting on top of each.
Next time there'll be a modified OmniTop 215 on each side.
(However, I am not sure what platform to use to keep the tall new tops stable when I have them ready.)
Also, I will try putting the subwoofers flat on the floor next to each other.
Hopefully this will improve response and coupling further.
The DJ and audience were happy, but I felt that more was possible!
So I'll be playing and experimenting a little. (Floor, wall and corner loading, aux fed.)
I don't have space for more subs in my van, so I may need to upgrade another way for more demanding events - maybe put 18 inchers in, as JBell has suggested in the past.
If so, should I get the EIGHTEENSOUND 18NLW9600 or something else?
THIELE SMALL PARAMETERS (5)
Fs
34 Hz
Re 4.7 Ohm
Sd
0.1134 sq. mt. (189.88 sq.in.) Qms 8.7
Qes
0.29
Qts
0.28
Vas
149 lt. (5.1 cuft) Mms
261 gr. (0.58 lb) BL
30 Tm
Linear Mathematical Xmax (6)
± 14 mm (± 0.55 in) Le (1kHz)
2.11 mH
Ref. Efficiency 1W@1m (half space)
95.1 dB
Jim - Thanks for the Design!
And all the other DIY guys out there, Thank you!
A special thank you to Syd who suggested I take a look at this forum!
In general on their side works better than standing up. (maybe add a pole socket in the side?) And yes together works better than apart.
Hate to tell you this, but the best upgrade for the big cabinet. (if you don't need mid 30's response) is to put your current drivers in the smaller ss15, and buy a couple more 3015lf's, and have a fleet of 4 ss15's. They will fit in your van...
The big cab is about 102db from 60hz on up, the ss15 is 105db from 60hz on up. So a pair of ss15's vs a pair of big cab's is +6db in that range. It's in the 38-42hz range that the big cabinet really shines, so depending on the music you play, depends on which cabinet is best.
So, a pack of 4 ss15's vs a pair of big cabinets should get you +12db, and be flat to 40 doing it. (and the ss15 is only 50lbs a cabinet... that's the part I really love)
thanks for sharing your pics !!
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