unity horn project

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   Tony's V4M is vented though, and designed to be vented, so the amount of SPL and headroom will be phenomenal. 
I would generally agree 4x12 is overkill but the brief was to get as much punch from 60Hz and up as possible in a single compact enclosure. The sealed is obviouly a fair few dB down by that point but would be crossed gently enough to the tapped horn to smooth the overall response, possibly with EQ if necessary.

We went over the comparisons between vented and closed box 12's and 15's (in varying multiples) in the other thread. dB for dB, the 4x12 sealed in the 60-125Hz passband gets the cones moving a lot further over a much wider frequency range. Even with the vd only coming from only one side of the cone, it worked out as being many times over - probably at least 6 or 7 times in real world conditions, as much total volume displacement as an equally sized and loaded vented enclosure playing to the same level, when the full range of frequencies that excited high levels of  cone movement were accounted for). 

I also think a v-baffle box is the most sensible way to do it (and would allow the build to start with less and build to more if found to be wanting)..said so about 10 times now already lol. But do speakers always have to be practical before any other consideration? People rarely complain of too much headroom, and I reckon there are ways of artfully using 4 12's in a compact system that wouldn't overpower the sound but would still get enough out of the drivers to justify using 4 of them.

If the brief is to keep the system as compact as 2 bass, two kicks, two tops, and no plans to expand, then there just aren't many routes you can go down to enhance that besides squeezing in more higher output drivers in lower efficiency enclosures. (lower efficiency in the band where they'll be working the hardest at least)

Not the most efficient use of drivers or enclosures, but side by side with a more efficient 2 or 1 driver alternative it would definitely have the edge at the levels one bass bin will allow it to play at. It's a shame it's become so huge as it does have the potential to be much less external volume in the split enclosure v-baffle format, but the conical nature of the space in front of baffle no doubt will give it some small acoustic edge for it's trouble.

Getting a 55kg+ box regularly up on top of a 1 metre high tapped horn isn't a prospect I would personally relish in the least but there we are.

Edited by Hemisphere - 29 August 2017 at 8:33pm

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Hemisphere Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 21 April 2008 Status: Offline Points: 2272	Post Options Post Reply Quote Hemisphere Report Post Thanks(0) Quote Reply Posted: 29 August 2017 at 8:27pm
	Tony's V4M is vented though, and designed to be vented, so the amount of SPL and headroom will be phenomenal. I would generally agree 4x12 is overkill but the brief was to get as much punch from 60Hz and up as possible in a single compact enclosure. The sealed is obviouly a fair few dB down by that point but would be crossed gently enough to the tapped horn to smooth the overall response, possibly with EQ if necessary. We went over the comparisons between vented and closed box 12's and 15's (in varying multiples) in the other thread. dB for dB, the 4x12 sealed in the 60-125Hz passband gets the cones moving a lot further over a much wider frequency range. Even with the vd only coming from only one side of the cone, it worked out as being many times over - probably at least 6 or 7 times in real world conditions, as much total volume displacement as an equally sized and loaded vented enclosure playing to the same level, when the full range of frequencies that excited high levels of cone movement were accounted for). I also think a v-baffle box is the most sensible way to do it (and would allow the build to start with less and build to more if found to be wanting)..said so about 10 times now already lol. But do speakers always have to be practical before any other consideration? People rarely complain of too much headroom, and I reckon there are ways of artfully using 4 12's in a compact system that wouldn't overpower the sound but would still get enough out of the drivers to justify using 4 of them. If the brief is to keep the system as compact as 2 bass, two kicks, two tops, and no plans to expand, then there just aren't many routes you can go down to enhance that besides squeezing in more higher output drivers in lower efficiency enclosures. (lower efficiency in the band where they'll be working the hardest at least) Not the most efficient use of drivers or enclosures, but side by side with a more efficient 2 or 1 driver alternative it would definitely have the edge at the levels one bass bin will allow it to play at. It's a shame it's become so huge as it does have the potential to be much less external volume in the split enclosure v-baffle format, but the conical nature of the space in front of baffle no doubt will give it some small acoustic edge for it's trouble. Getting a 55kg+ box regularly up on top of a 1 metre high tapped horn isn't a prospect I would personally relish in the least but there we are. Edited by Hemisphere - 29 August 2017 at 8:33pm
	Phase 1: Post on Speakerplans Phase 2: ????? Phase 3: Profit!

stalian87 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 16 March 2015 Location: United Kingdom Status: Offline Points: 110	Post Options Post Reply Quote stalian87 Report Post Thanks(0) Quote Reply Posted: 29 August 2017 at 8:39pm
	i appreciate all the ideas from everyone but as hemisphere pointed out, I've considered more than 1 design already. I've already got the pair of tapped horns and they're phenomenal no matter what anyone says. Adding a kick bin to each one, albeit slightly bigger than intended, and compromising on weight by having it look slightly different to conventional designs is what i've decided. unfortunately audiences don't tend to know or care about the difference between 1-2db at whatever hz but they do care much more about design and setup and that along with a great band will win business. Yes i'm a musician but i intend to make the most it. I have absolutely no doubt in the fidelity of the system i'm gonna build, i'm never on my own setting up either so i'm really not bothered about weight of things.

Teunos Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 23 November 2008 Location: The Netherlands Status: Offline Points: 1799	Post Options Post Reply Quote Teunos Report Post Thanks(0) Quote Reply Posted: 29 August 2017 at 9:58pm
	Nvm Edited by Teunos - 29 August 2017 at 10:00pm
	Best regards, Teun.

stalian87 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 16 March 2015 Location: United Kingdom Status: Offline Points: 110	Post Options Post Reply Quote stalian87 Report Post Thanks(0) Quote Reply Posted: 29 August 2017 at 11:20pm
	nevermind?

Hemisphere Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 21 April 2008 Status: Offline Points: 2272	Post Options Post Reply Quote Hemisphere Report Post Thanks(0) Quote Reply Posted: 31 August 2017 at 9:43am
	Just spotted this picture of a coaxial centre channel speaker which has a lot of similarities in form to the top box in this design. It was suggested earlier that the coax would need as wide a baffle as possible for best results (suggesting the narrow baffle on the vertical axis currently specified was inadequate) - I'm not saying there would be no benefits from that, but you can probably get away with it as is.
	Phase 1: Post on Speakerplans Phase 2: ????? Phase 3: Profit!

stalian87 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 16 March 2015 Location: United Kingdom Status: Offline Points: 110	Post Options Post Reply Quote stalian87 Report Post Thanks(0) Quote Reply Posted: 31 August 2017 at 9:50am
	well the good thing about the coax box is that it's small and simple and if it doesn't work, it won't take too much £££ to redesign and try again.

smitske96 Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 16 February 2016 Location: The Netherlands Status: Offline Points: 1092	Post Options Post Reply Quote smitske96 Report Post Thanks(0) Quote Reply Posted: 24 February 2018 at 1:48pm
	Curious if you already build something.

stalian87 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 16 March 2015 Location: United Kingdom Status: Offline Points: 110	Post Options Post Reply Quote stalian87 Report Post Thanks(0) Quote Reply Posted: 27 February 2018 at 4:36pm
	yes I did. it was a very simple sealed box with the b&c 12cxn76 driver. Although it was very nice and clear, there wasn't much substance below 100hz. I've now designed a slightly different box which is now ported but also has a small line array of 3" drivers in front of a 12" woofer. very similar to the Bose F1 speaker. hoping to get this done within 6 month. got no cash at the mo!

Jo bg Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 08 March 2017 Status: Offline Points: 552	Post Options Post Reply Quote Jo bg Report Post Thanks(0) Quote Reply Posted: 27 February 2018 at 6:34pm
	hi what is the purpose of the 3 inch drivers? maybe you are considering super efficent drivers i don't know about, but the faital 3fe25, a good driver, has got 90 dBs sensitivity from the specs (91 declared but looks less from curves, i think 90 is still optimistic) and 20 watt power Handling, that is 13 dBs. This gives 90+13 103dBs max for one driver, 109for two 115 for 4 and around 118 for 6 drivers, max without accounting for power compression, real broadband efficency and the fact that they will only couple like that at lower frequencies... so maybe more like 115 dBs long term max? please someone correct me if it's all bullshit a 12 cxn 76, should do at least around 98 dBs with 1 watt, add a hundred watts or 20dBs and you get the same 118 theoretical, but with less power compression as you are feeding the driver less than 1/3 of the rated power instead of the full Handling, and with better, more consistent sound and less distortion as the driver is far from it's limits... and it could go at least 6db louder. furthermore, i think the 3 array would distrub the high frequencies of the 12cxn76, and it will make the speaker not go louder, higher or lower, and even if you are going to make it a three way cab and use the 3 inches to get the sought after paper sound in the mids, i see the damage on the hi freqs and the reduced output as far bigger cons. and with two way bass beneath it, why are you worried about the box not doing much under 100hz? do you plan to use it as a full range box too? i'm just a beginner too, so i am not bashing you, just expressing what comes to my mind, and just sincerely wondering wht's the reasoning behind this.

stalian87 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 16 March 2015 Location: United Kingdom Status: Offline Points: 110	Post Options Post Reply Quote stalian87 Report Post Thanks(0) Quote Reply Posted: 27 February 2018 at 6:46pm
	sorry i didn't mention that the 12" woofer will not be the 12cxn76. it will simply be a 12" sub...just not sure which one yet. I've had mini line arrays since the original bose L1 and they were fantastic at tonal clarity! the line array should also cover more of the floor from the front to the back due to the 16 degree curve on the baffle. this is, of, course, theoretical and i simply like building stuff and seeing which one best suites my needs. Although my primary use of these speakers will be on a 3 way system, i'll be using them on they're own for smaller gigs.

Jo bg Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 08 March 2017 Status: Offline Points: 552	Post Options Post Reply Quote Jo bg Report Post Thanks(0) Quote Reply Posted: 28 February 2018 at 4:04pm
	i see i like to have far more sub than tops too, but still 3 inch drivers on top of a three way system, will limit the total output to less than you could expect. it could make a nice fullrange box for lower levels, but i doubt it will keep up as tops on a bigger, groundstacked system. You usually don't push the tops to their limits as distortion is more noticeable than in subs there and rises when speakers are pushed. you want more headroom the higher you go in frequency... Did you choose your three inch driver allready? I suggest you do some simple calculations like the one i posted to verify if the level achievable could be satisfying for your needs, before committing to do woodwork and buy drivers. if you allready own the 12cxn76 and want a powerful midtop that could be used full range you could look at building something like the fulcrum fa22ac, a coaxial 12 + another 12 for the bass. if you keep it neo for the second 12" and maybe go with 15mm ply and bracing, it could still be reasonably light.