Depends on what you define as 'full range'; the pioneers at Bell Labs decided that ~100 - 5 kHz was sufficient, so built a reactance annulled ~50 - 10 kHz expo horn driven with a 1.75" diaphragm/1" exit compression driver, so as you can imagine is huge and beams like a laser up high and quickly learned that it's impractical to mate super tweeters to it without the modern day electronics we take for granted and they probably couldn't even conceive of. Bass was typically the acoustic reciprocal of a horn, OB/IB.
Consequently, the industry went to dual compression horns [some back vented] XO'd at 300 Hz for PA and 500 Hz for everything else until the bass reflex was invented using a 'full range' 12" - 15" radio console driver and 1500-1600-2000/800 Hz horn for 'small' room apps, then about a decade later the Duplex came along, which of course all are still standard alignments to this day in one form or other.
In short, due to how we hear, we as a whole can tolerate simple 2nd order Butterworth filters up to at least 2000 Hz, though obviously there's going to be some folks who are OK with a higher point and those lower and of course there's always extremes, which this forum is dedicated to.
Anyway, even after ~400 posts we've still no real clue where you are on this curve, so all things considered, seems to me that until you do a bit of due diligence to finding out more about your hearing on this subject, we're [or at least I'm] mostly wasting time at this point; so recommend getting any inexpensive/dirt cheap enough, large [at least 12"] ~ high Qt 'FR' driver, small [<5.25"] high Qt driver [extends to at least 15 kHz] that it's no great loss if [accidently] blown [yard sale, pawn shop, Apex Jr., new on sale, etc., or new on sale as a last resort] along with as good a quality digital XO/EQ/TD [dbx is my price/performance ratio fave] within the budget will suffice and can later be used in some way. If you use a cheap/noisy one it will bias you to a [much] lower or higher acceptable XO point and/or higher slope orders. At least you don't have to do it the hard way with passive XOs, extremely minimal test gear like many of us did.
GM
It's an OK compromise, though like Freddi said, it takes multiple 15"/channel for high SQ punch/boom at the kind of elevated SPLs you seem to want, i.e. most of an unamplified drum kit's peak SPL. For all of it, dual 18"/channel. Horn loaded [ideally plus ear plugs] for amplified.
GM
I'd argue that we're not - I genuinely appreciate the information and opinions that have been passed on here, and like anything else I'm learning as I go. Ideally this thread passes that information on to others who are curious, and gives them ideas for what they'd like to do.
It is indeed difficult to know what I want, given what limited speakers I've heard... Though I've done my best to explain the sort of sound I'm after. I went into this quest more or less blind, and now have at least some idea of what I'm trying to do - so thank you for your help. It's a frustrating thing... I can't recall ever hearing speakers in a store that I was impressed with, though this refers only to big box store offerings.
As you may recall, this whole quest was actually started with wanting to build some sort of Khorn or Jubilee clone; this was actually initiated from listening to a set of vintage Klipsch heresy speakers that a friend owns. I like how those sound, though lacking in lower bass for my taste. The natural next step seemed to be the khorn or jubilee then. Somewhere along the way reading about them, I fell into reading about the afterburner and BIB FR projects, and the simplicity of construction (and lack of crossovers) + rave reviews made me reconsider and post here. It's all a fairly logical progression in my head anyway, with hours & hours of reading and consideration along the way.
Anyway, it's not like I'm planning on listening at 120 db (with or without ear plugs) every night/all the time. Just occasionally it's nice to crank up a good tune and not hear distortion or see smoke coming out of the cabinets (to more or less emulate a live concert experience). 🙂
Thanks,
Jesse
A proper bass horn is quite large. Horns typically have a range of 3-4 octaves only. Th e only FR solution that could suit would be a back loaded horn, where bass is horn loaded and it is a direct radiator above that. Vulcan might do you. It uses wall or corner loading to magnify the size of the mouth to get it to approach the size needed for full horn loading.
Woden Design | Vulcan
There is a similar horn for the Alpair 12p. Woden Design | Avebury A10x as well.
dave
Woden Design | Vulcan
There is a similar horn for the Alpair 12p. Woden Design | Avebury A10x as well.
dave
lol, I've been trying to simulate the slamming bass from my 2 x 15" eminences crossed at 750hz for years.
Even 12" crossed 18db@150hz to the exact same 15's doesn't do it as well.
But it goes really really loud, not chest pounding, but you do feel the bass through the concrete 20' away. Crossing higher than that and you get funny phase wrap that affects what you hear.
Maybe you need serious cone area, like double 12's crossed at 150hz, I don't know.
Maybe 4 x 12's. The limited dispersion of a 12" may work well for not combing while moving serious air.
Even 12" crossed 18db@150hz to the exact same 15's doesn't do it as well.
But it goes really really loud, not chest pounding, but you do feel the bass through the concrete 20' away. Crossing higher than that and you get funny phase wrap that affects what you hear.
Maybe you need serious cone area, like double 12's crossed at 150hz, I don't know.
Maybe 4 x 12's. The limited dispersion of a 12" may work well for not combing while moving serious air.
for what little its worth you should "feel" K15 or K18 20 ft. away - but those are usually coax or K-tube based and not FR so don't apply. 18" are usually perceived as "slower" or more mellow than 15 when trying to xover very high. Mms should be kept reasonably low for K. "Speaker Enclosures" by Alexis Badmaieff and Don Davis discussed 15" as optimal size. EV claimed a 2.5" coil had best tradeoffs for 15" motor. In its range the old Karlson K15 (designed in 1951) can give articulate bass with ease - but it does not go "low"
Well I thought we had agreed previously a "FAST" setup would be required...?
I've already purchased the additional amp/electronic crossover to bi-amp the FR and helper woofers.
Even the 12lta BBBiB I have serious doubts is going to be impressive in the "punch" department... though since I've not heard a BIB, I don't know - you guys who've built one would know better. BLH acoustic coupling is apparently very good, so maybe that 12lta is moving a ton of air at the terminus and is providing more "punch" or "slam" than one might think. Or maybe it's just all boomy lows, I don't know. There's no room for a 12lta BIB AND a helper woofer.
I could build a prototype BIB for the 12lta and buy the driver, but then I'm stuck with the 12lta... not that that's awful, but the Alpair 10.3 and that less expensive TB W8 are also tempting and would go in a smaller enclosure that could sit on top of a sealed helper woofer box...
I guess GM is right, we've (I've) not made a whole lot of progress in sorting this out... :-\
I haven't agreed to anything 🙂 It was more of a general comment.....there comes a time.....I know and most here know you have to take a leap of faith....most I would guess have also had a difficult time making decisions without the extensive help you've had here, also too much information and opinion can be confusing and I would suggest we're not far from that point.
Meaning that the 2x 15" (I assume you mean 1 per side, 2 total.. or maybe you mean 2x per side?) Eminence woofers did better than the 12's? I was thinking single 18" per side helper woofers, though I could see that dual 15"s per side might be better since more cone area and possibly more motor behind that area with the two 15" combined...
I know, I'm getting close to jumping. At least it's a somewhat more educated leap. Unfortunately nothing trumps first hand experience, and making the mistakes yourself and learning, I know - I get that. Agreed we may be reaching the point of confusion... And I know my budget is limiting the selection of a lot of nicer (or at least more expensive) drivers. Everything's a compromise... sigh.
I have a set of fostex fe166en drivers in some 9.5ft3 BIB's. They were built with input from GM and others on the BIB thread. The way they load the room is impressive. Effortless. And musical. If you build them, they may not be exactly what you are looking for, but they can sound really good.
(I'd like to hear something "effortless" - some of my speakers strain) - re:reflex - I'm pretty sure he means 2-15 per side. One 18 per side is "OK" One 15 is more toyish for 'slam' than 2-15-per side (unless 1-15 in a Karlson K15) K15 plus sub gets large so I hope sometime to hook up my K12 with sub). I'm playing with "compression horns" - here's a little midbass - 10" driver - should hit 100 - hope it can make it to 500 - might be a dud (?0 - foam pieces in the back chamber take back chamber volume down to about 10 liter http://i.imgur.com/uHt4u8k.jpg
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Yup, 1 loudspeaker having dual 15's crossing to 2' wide horn.
I'd wanted to try 2 x 12" full range a side, or even 4 x 12" in a vertical line array.
Maybe crossed 100-150hz, maybe not.
But, it didn't happen..........
I'd wanted to try 2 x 12" full range a side, or even 4 x 12" in a vertical line array.
Maybe crossed 100-150hz, maybe not.
But, it didn't happen..........
35 years ago I had little VMPS with 2- different polycone 12, downwards slot loaded PR with lots of Mortite , 5.25" polycone mid, soft dome, a couple of cone piezo - cabinet pretty much filled with fiberglass - no inductors in xover - just caps IIRC - funky blend but pretty solid in the bass 2 - decent 12 (woofer) per side would not be bad - dunno how 4-12FR would fare (like a Marshall cab?) 4-B102 or BP102 per side might be ok given sufficient power. (did you break down and order B102/Cat378?)
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The 12" has narrowing dispersion in the highs that i find helps.
Even 1 thiel i had threw an image away from the speaker when on the reflective side of the tv versus on the side with a couch sitting 90 degree angle from tv.
Using only 1 x 12" speaker, i find as the volume goes up, the reflected field is much better sounding than the highs going everywhere causing a giant blur.
I noticed this years ago but didn't put my finger on it till later.
Big vega 3 ways, i could only turn volume to 9:00.
Moved into a masonic temple, room was like 30 x 60.
I could turn volume up to 12:00 or more before the sound turned to mush.
So it seemed the louder i went, the more the room interfered with the direct sound.
Even 1 thiel i had threw an image away from the speaker when on the reflective side of the tv versus on the side with a couch sitting 90 degree angle from tv.
Using only 1 x 12" speaker, i find as the volume goes up, the reflected field is much better sounding than the highs going everywhere causing a giant blur.
I noticed this years ago but didn't put my finger on it till later.
Big vega 3 ways, i could only turn volume to 9:00.
Moved into a masonic temple, room was like 30 x 60.
I could turn volume up to 12:00 or more before the sound turned to mush.
So it seemed the louder i went, the more the room interfered with the direct sound.
Norman - So which had more "slam" or "punch", the 2x 12" or 2x 15"s? I know I need to just buy something and try it but hate to do this over and over in iterations...
Also I'm not clear on what we're talking about, FR or FAST helper woofer? I think you may be talking about the 12lta or fane full range... certainly regarding dispersion.
Todd - thank you for the input. The BIBs with those little Fostex drivers I'm sure sound good, subjectively... I just wonder how they could really fill the room with the lower frequencies. I could see some boom boom because of the excellent acuoustic coupling out the top of the boxes, but it's hard to believe there'd be much "punch" there... and at what volume? I was really hoping someone local to me would happen to have a pair and let me have a listen to make me a believer 🙂
Freddi - I'd like effortless too, but seems it would take a lot of driver to get there; this is essentially what I was hoping for in using a large 18" woofer to support the bottom end. Was just listening to some tunes on the cheesy Fisher 3ways + 12" sub cranked up in party mode, and while I don't notice any distortion it certainly isn't effortless. The fisher woofers are a movin' and the poor little sub is pounding for all it's worth. That's why it's hard to believe a typical BIB is going to provide satisfaction in this case.. Maybe with the 12lta, but then it's massive and still likely not going to have as much punch as I even do now (I'd prefer not to run this powered sub with the new speakers, rather let them stand on their own for music..)
Perhaps a new thread for the Helper Woofer is needed, to separate it from the FR part of the build. I know this thread is long and confusing enough as is.
....
Briefly, for the helper woofers (which will have their own cabinets under the full range boxes), I'm trying to make sure I'm going the best route given my budget and want for "Punch" and frequency response down to at least 40 hz (35 would be nice).
1x 18" woofer
2x 15" woofers
4x 12" woofers
Given that my budgetary build has about 200 in it for the woofers all told... A pair of decent entry level 18" could be had (goldwood, dayton, prv), or there's also some mystery house brand woofers over at MCM that are even cheaper. A quad set of 15's means they can only be 50 bucks each or so, and that might limit things to MCM house brand or similar, or something like that one Freddi had found for me previously. A set of eight 12 inchers and we're talking 25 bucks a woofer, so again bargain basement stuff like the MCM house brand.
Ignoring t/s specs for a moment and just comparing cone areas to get a sense of how they compare just moving air (nominal dia used, not actual cones):
1x 18" per side -> 254 in^2 per cabinet, 508 in^2 total cone area (stereo)
2x 15" per side -> 353 in^2 per cabinet, 707 in^2 total cone area (stereo)
4x 12" per side -> 452 in^2 per cabinet, 904 in^2 total cone area (stereo)
Thus the 4x12" has nearly double the area of the 1x18"... which is surprising, or was to me anyway. This topic has to have been beat to death before, but I haven't come across anything really conclusive yet regarding what's best. I'll allow that any comparisons are moot without knowing the drivers... but still, would a name brand 18" like the Dayton PA460
https://www.parts-express.com/dayton-audio-pa460-8-18-pro-woofer--295-036
be outperformed by 4x 12" like these MCM 55-2962?
MCM Audio Select 12'' Die Cast Woofer with Paper Cone and Cloth Surround - 175W RMS 8ohm | 55-2962 (552962) | MCM Audio Select
Outperformed meaning in "punch". I'm guessing either option would go as loud as I liked...
https://www.parts-express.com/dayton-audio-pa460-8-18-pro-woofer--295-036
Also I'm not clear on what we're talking about, FR or FAST helper woofer? I think you may be talking about the 12lta or fane full range... certainly regarding dispersion.
Todd - thank you for the input. The BIBs with those little Fostex drivers I'm sure sound good, subjectively... I just wonder how they could really fill the room with the lower frequencies. I could see some boom boom because of the excellent acuoustic coupling out the top of the boxes, but it's hard to believe there'd be much "punch" there... and at what volume? I was really hoping someone local to me would happen to have a pair and let me have a listen to make me a believer 🙂
Freddi - I'd like effortless too, but seems it would take a lot of driver to get there; this is essentially what I was hoping for in using a large 18" woofer to support the bottom end. Was just listening to some tunes on the cheesy Fisher 3ways + 12" sub cranked up in party mode, and while I don't notice any distortion it certainly isn't effortless. The fisher woofers are a movin' and the poor little sub is pounding for all it's worth. That's why it's hard to believe a typical BIB is going to provide satisfaction in this case.. Maybe with the 12lta, but then it's massive and still likely not going to have as much punch as I even do now (I'd prefer not to run this powered sub with the new speakers, rather let them stand on their own for music..)
Perhaps a new thread for the Helper Woofer is needed, to separate it from the FR part of the build. I know this thread is long and confusing enough as is.
....
Briefly, for the helper woofers (which will have their own cabinets under the full range boxes), I'm trying to make sure I'm going the best route given my budget and want for "Punch" and frequency response down to at least 40 hz (35 would be nice).
1x 18" woofer
2x 15" woofers
4x 12" woofers
Given that my budgetary build has about 200 in it for the woofers all told... A pair of decent entry level 18" could be had (goldwood, dayton, prv), or there's also some mystery house brand woofers over at MCM that are even cheaper. A quad set of 15's means they can only be 50 bucks each or so, and that might limit things to MCM house brand or similar, or something like that one Freddi had found for me previously. A set of eight 12 inchers and we're talking 25 bucks a woofer, so again bargain basement stuff like the MCM house brand.
Ignoring t/s specs for a moment and just comparing cone areas to get a sense of how they compare just moving air (nominal dia used, not actual cones):
1x 18" per side -> 254 in^2 per cabinet, 508 in^2 total cone area (stereo)
2x 15" per side -> 353 in^2 per cabinet, 707 in^2 total cone area (stereo)
4x 12" per side -> 452 in^2 per cabinet, 904 in^2 total cone area (stereo)
Thus the 4x12" has nearly double the area of the 1x18"... which is surprising, or was to me anyway. This topic has to have been beat to death before, but I haven't come across anything really conclusive yet regarding what's best. I'll allow that any comparisons are moot without knowing the drivers... but still, would a name brand 18" like the Dayton PA460
https://www.parts-express.com/dayton-audio-pa460-8-18-pro-woofer--295-036
be outperformed by 4x 12" like these MCM 55-2962?
MCM Audio Select 12'' Die Cast Woofer with Paper Cone and Cloth Surround - 175W RMS 8ohm | 55-2962 (552962) | MCM Audio Select
Outperformed meaning in "punch". I'm guessing either option would go as loud as I liked...
https://www.parts-express.com/dayton-audio-pa460-8-18-pro-woofer--295-036
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These numbers are useless, they need to be actual effective piston area Sd*Xmax = Vd to compare.
Note too that excessive 'punch' can really mess with male vocals unless a very low XO point, high slope order is used..........
GM
Note too that excessive 'punch' can really mess with male vocals unless a very low XO point, high slope order is used..........
GM
Agreed, its only meant to be a generic comparison.
Is my planned 150 hz xo point low enough? 24 db/octave slope, LR4 on that electronic xo.
Is my planned 150 hz xo point low enough? 24 db/octave slope, LR4 on that electronic xo.
re: those MCM 12 - pay attention to the reviewer who made measurements - they are good (for OB - assuming relatively linear) "FS - 47hz Qts - 1.18 Qes - 1.518 Qms - 5.31 Le - 1.88 Re - 7.51"
the Karlson 15 gets loud without hardly any visible cone motion - but does not go "low" (unless used per Exemplar re-tuned with 2-3" right angle pvc ports and boosted ~6dB at 20Hz) - so a sub would be in order for classical organ music - its cutoff is sufficient for modern bass and synth bass drops to sound robust. Someone will eventually get those 15CXA
you could use 1 re-tuned-K15 with Altec 416 (or low fs 515) as a helper sub for a 2.1-way system with ~80Hz xover - I got good results with a 25 watt receiver - 1 channel for K15 - 1 for a K12 with pathetically weak Allied-Kinight-Jensen 12cx (it had pretty mids) = very nice on theatre organ - the ambiance really opens up when
the bottom octave is available
this is the Exemplar system
the Karlson 15 gets loud without hardly any visible cone motion - but does not go "low" (unless used per Exemplar re-tuned with 2-3" right angle pvc ports and boosted ~6dB at 20Hz) - so a sub would be in order for classical organ music - its cutoff is sufficient for modern bass and synth bass drops to sound robust. Someone will eventually get those 15CXA
you could use 1 re-tuned-K15 with Altec 416 (or low fs 515) as a helper sub for a 2.1-way system with ~80Hz xover - I got good results with a 25 watt receiver - 1 channel for K15 - 1 for a K12 with pathetically weak Allied-Kinight-Jensen 12cx (it had pretty mids) = very nice on theatre organ - the ambiance really opens up when
the bottom octave is available
this is the Exemplar system
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