Freddi - Reading on those MCM woofers, it seems the specs are off for many of them. That makes enclosure design a bit of a gamble.. though that's nice that some folks have posted their own measurements. Also, oddly yes it seems that many of these woofers in particular are more suited for OB than enclosures.. hmm.
You sent me down a rabbit hole there, Karlson->Exemplar->Jensen Imperial (not sure how) ... I had forgotten how much I liked those corner Imperials!
To feed the woofers, I'll have two channels, 85wpc @ 8 ohms, or something like 110wpc @ 4ohms. 1x 18"s would each get the 85w, or 110w each if I used 4 ohm speakers. The 2x 15"s (8ohm ea) would each get the full 110w then, but the quad 12"s (4 ohm ea, series-parallel) would only get 55w each. Yet another thing to factor in.
Jesse
You sent me down a rabbit hole there, Karlson->Exemplar->Jensen Imperial (not sure how) ... I had forgotten how much I liked those corner Imperials!
An externally hosted image should be here but it was not working when we last tested it.
In addition to ignoring Vd, I also neglected to mention wattage.
To feed the woofers, I'll have two channels, 85wpc @ 8 ohms, or something like 110wpc @ 4ohms. 1x 18"s would each get the 85w, or 110w each if I used 4 ohm speakers. The 2x 15"s (8ohm ea) would each get the full 110w then, but the quad 12"s (4 ohm ea, series-parallel) would only get 55w each. Yet another thing to factor in.
Jesse
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punch and slam can also be distortion.
My buddy made some speakers with dual 12's sub woofs, short x-max, sounded punchy.
When I replaced 2 x 15" sub with 4 x 12" push pull (all 8mm xmax), both crossed at 150hz, same amplifier, same location, I lost some slam, but rumbled better and was hard to locate.
Someone else also lost slam going to push pull 18's.
Hard to say really.
You can be really really loud yet not have slam.
A dj uses 2 x 12" full range drivers (in a single box) crossed at 150hz to subs.
That would be a FAST setup I guess.
Then again slam and bass is also volume related.
Maybe just massive midbass = slam, because 4 x 18's subs didn't slam as much crossed 100hz to a 15", but the double 15" per side slammed more. So it may also have to do with cone area and output. Under 100hz = rumble, I'm thinking slam may be as high as 200-300hz. And you need the leading edge of the harmonics of the bass note. Listen to a woofer by itself and tell me about slam.
Thunk and slam is also integration.
Some systems are more transient.
Usually 24db time aligned, or maybe even a 6db within volume constraints.
But the water is probably even more murky now.
Oh, and don't expect a driver to get much louder with 200watts on it versus 100watts, but that is a whole nother topic.
Overall, cone area is a definite plus, maybe it works as a better air lever.
I have a gut feeling I prefer 4 x 18" 4mm xmax versus 4 x 12" with 8mm xmax, eventhough both move the same air.
My buddy made some speakers with dual 12's sub woofs, short x-max, sounded punchy.
When I replaced 2 x 15" sub with 4 x 12" push pull (all 8mm xmax), both crossed at 150hz, same amplifier, same location, I lost some slam, but rumbled better and was hard to locate.
Someone else also lost slam going to push pull 18's.
Hard to say really.
You can be really really loud yet not have slam.
A dj uses 2 x 12" full range drivers (in a single box) crossed at 150hz to subs.
That would be a FAST setup I guess.
Then again slam and bass is also volume related.
Maybe just massive midbass = slam, because 4 x 18's subs didn't slam as much crossed 100hz to a 15", but the double 15" per side slammed more. So it may also have to do with cone area and output. Under 100hz = rumble, I'm thinking slam may be as high as 200-300hz. And you need the leading edge of the harmonics of the bass note. Listen to a woofer by itself and tell me about slam.
Thunk and slam is also integration.
Some systems are more transient.
Usually 24db time aligned, or maybe even a 6db within volume constraints.
But the water is probably even more murky now.
Oh, and don't expect a driver to get much louder with 200watts on it versus 100watts, but that is a whole nother topic.
Overall, cone area is a definite plus, maybe it works as a better air lever.
I have a gut feeling I prefer 4 x 18" 4mm xmax versus 4 x 12" with 8mm xmax, eventhough both move the same air.
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can't prove it - but I think there can be coloration issues with large paper cones which still manifest even with an 80Hz xover (?) - I've never heard the Imperial - with proper coax, or components, it should be fun.
I'm confused about the Imperial's ad mentioning "reactance annulling" (is this one a FLH?)
maybe you could do a BLH for 12LTA and concentrate on punchy bass rather than LF extension
I'm confused about the Imperial's ad mentioning "reactance annulling" (is this one a FLH?)
maybe you could do a BLH for 12LTA and concentrate on punchy bass rather than LF extension
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A true reactance annulled horn is a hyperbolic BLH, though can get real close with an expo flare [early WE horns] and later Lansing, etc., folded bass horns; notice the vented driver covers on the rear of these W fold horns: http://www.lansingheritage.org/images/altec/catalogs/1942/page09.jpg
GM
GM
Thaniks GM. --- In sims with sealed rear chamber FLH, it seems good to try to keep back chamber volume as low as possible without affecting the passband reponse in order to reduce needless excursion below cutoff. (-I would have loved to hear an Imperial properly loaded)
Yes, murky water indeed.
Well, I'd classify punch, slam, and thunk as all sort of similar, and all of them good. Boomy on the other hand is of course bad. Is there a more technical description of all this? I sound like the lady who brings her car to the mechanic because it's making a "funny" noise. They grease an offending bushing, charge her for $100 worth of blinker fluid (or muffler bearings - they wear out!), and send her on her way...
I had read elsewhere that it took something like 4x 12" in boxes (not sure sealed or vented) to equal the output of a properly done BLH. But in terms of what, measurable volume at a certain frequency (range)? How would the "punch" or "slam" compare between the two?
Seems you're stuck with a large enclosure in either case, but hard to believe that the 4x 12" wouldn't outperform the single BLH 12" in some capacity at least...
Well, I'd classify punch, slam, and thunk as all sort of similar, and all of them good. Boomy on the other hand is of course bad. Is there a more technical description of all this? I sound like the lady who brings her car to the mechanic because it's making a "funny" noise. They grease an offending bushing, charge her for $100 worth of blinker fluid (or muffler bearings - they wear out!), and send her on her way...
I had read elsewhere that it took something like 4x 12" in boxes (not sure sealed or vented) to equal the output of a properly done BLH. But in terms of what, measurable volume at a certain frequency (range)? How would the "punch" or "slam" compare between the two?
Seems you're stuck with a large enclosure in either case, but hard to believe that the 4x 12" wouldn't outperform the single BLH 12" in some capacity at least...
wouldn't the simplest incarnation of that basically be the 12lta BiB, the BBBib?
🙂 Perhaps of interest: alegedly, Both Nelson Pass and his firm's ceo use Jensen Imperial Boxes fitted with 15" tannoys.
Fair to say either of those two people could choose to use ANY speaker setup on the planet .
Mebe they know something?
Fair to say either of those two people could choose to use ANY speaker setup on the planet .
Mebe they know something?
Probably the larger wall standing version though, rather than the corner horn... Decware has plans for an updated version. But, those are a bit large for even my wife to accept, haha. 🙂
You're welcome!
Correct; me too, I've only auditioned a scaled down one with a 1939 RCA field coil 12" 'full-range', AM radio guts I cobbled together back when I didn't have a clue about such things. Impressed everybody at the time though.
As fate would have it, once I had a bit of a clue, found out that overall it was an acceptable alignment that proved to be a big help in understanding all the info Dr. Leach exposed me during a chance visit and his later papers.
GM
Judge for yourself. Drawing does not show the base… with that it will be > 1.8m tall.
dave
Would this work with the Alpair 10.3?
The centre bit is a separate box. The A10.3 could be substituted for the A10p — it is an aperiodic midTL, or a smaller box for A7x/A6.2x/A5.2 could be used. Except that it is not really as suited as the A10p the A12p could be used. Or any suitable FR, it doesn’t need to be Mark Audio. A10p was choosen initially so as to get max output capability and to have as close a sonic signature between woofer & midTweeter to make XO easier and more seamless. n the lasr respect A6.2p would likely be the next choice. We do know that the A7.3eN and A7 MOAP work with the A12pw as well from our MTM:
We started with A7PeN in this box — it isn’t as good as the metal and takes a huge amount of break-in.
dave
We started with A7PeN in this box — it isn’t as good as the metal and takes a huge amount of break-in.
dave
I seem to recall reading that it may be an issue mixing a BLH (like a BiB, or the Imperial) with other horn speakers...? This may have been another strike against the BiB, but I can't recall.
Anyway, the planned overkill HT subwoofer to accompany these mains is a Tapped Horn or Front Loaded Horn - so that may be a valid concern...
Anyway, the planned overkill HT subwoofer to accompany these mains is a Tapped Horn or Front Loaded Horn - so that may be a valid concern...
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Only in that the lengths of the horns can cause significant time issues… a place with a DSP XO and their ability to offset the signal in time is your friend.
dave
Hmm... Okay - thanks, I thought it was more a case of constructive/destructive interference or some other reaction peculiar to horns.
Just another tangent, not meaning to continually derail my own thread.. just this is (unfortunately) how my brain works.
Any opinions on the multi-woofer type setup (note we are talking about the FAST or WWW assist woofer here...)?
multi-woofer vs. horn? I also seem to recall reading that a suitable 12" in a horn (might have been a BLH.. don't recall) was the equal of at least 4x 12" woofers direct radiating (and presumably sealed boxes). I wonder how the type of sound compares... I'd expect the horn to have more "rumble" (I know, more technical terms), vs the multi-woofers to have more "punch". The horn may still go louder with better coupling to the air.
It bears repeating that there's much more to this business than I had originally assumed - my hat is off to the experts who work/play in this field...
Edit: I thought the time issues were minimal, since they were only the low frequencies coming out of the horn terminus, and as such we aren't sensitive enough to pick up on them? <250-400 hz I saw somewhere
Just another tangent, not meaning to continually derail my own thread.. just this is (unfortunately) how my brain works.
Any opinions on the multi-woofer type setup (note we are talking about the FAST or WWW assist woofer here...)?
multi-woofer vs. horn? I also seem to recall reading that a suitable 12" in a horn (might have been a BLH.. don't recall) was the equal of at least 4x 12" woofers direct radiating (and presumably sealed boxes). I wonder how the type of sound compares... I'd expect the horn to have more "rumble" (I know, more technical terms), vs the multi-woofers to have more "punch". The horn may still go louder with better coupling to the air.
It bears repeating that there's much more to this business than I had originally assumed - my hat is off to the experts who work/play in this field...
Edit: I thought the time issues were minimal, since they were only the low frequencies coming out of the horn terminus, and as such we aren't sensitive enough to pick up on them? <250-400 hz I saw somewhere
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So if I understand this correctly, a A7 or smaller would work better as an MTM with the 12pw since there is less overlap in the drivers and the A7 or smaller will have a better top end than the A10 and there is more overlap between the A10 and the A12pw at the bottom end. With the A10 you could get louder than with the A7. The MTM that you show the picture of has a combined volume?
How different would it sound like with separate volumes for each driver? I could run it actively. 🙂
Wouldn't really need a sub to supplement the low end it seems.
Hahaha 🙂 @ Scott
Played around with the fisher 3 ways and 12" powered sub a bit tonight. Cranked the adj. crossover on the sub all the way up to 150 hz (not sure what the slope is though) to simulate a helper woofer for the fishers (normally I have it turned down around 60-70hz).
To my surprise, the sound was not any more "punchy" with the sub turned on.. just more "thumpy" or boomy" (no end to these technical terms), which that part isn't a surprise given the subwoofer***. This bears out what GM had been saying prior about the "punch" freq being rather higher than I had thought, though all the way down to 30 hz still carries some component of the punch - or maybe "slam" is better term there. With the mains off and only the sub, there's really no punch.. just boom boom thump thump. So even with the sub on, those weak little 12"s in the fishers are making most of the punch (they go from~45 - 1600 hz til they cross to the mids). The other Yamaha 3 way speakers I have with 8" woofers have almost no punch at all.
***A few caveats - the sub is a subwoofer driver not a woofer, its a ported box so fairly boomy and not terribly representative of the type of sound I want.
So. Going back to what do I want to build... thoughts of the moment:
- bigger mids/mid-bass is better for punch, so likely bigger full range is better for punch as well with the downside that as the cone gets bigger some detail is lost and some coloration may be present.
- crossing at 150 hz is probably fine, as long as the full range driver is large enough to punch; otherwise xo freq could be raised experimentally up to the woofer's top limit to see how it sounds. Likely this would improve "punch" at the expense of messing up other things, anything that crosses over the xo like male vocals as noted by GM.
- helper woofer needs to be punchy not boomy... are sealed cabinets the way to go? Or horns can be punchy as well?
Played around with the fisher 3 ways and 12" powered sub a bit tonight. Cranked the adj. crossover on the sub all the way up to 150 hz (not sure what the slope is though) to simulate a helper woofer for the fishers (normally I have it turned down around 60-70hz).
To my surprise, the sound was not any more "punchy" with the sub turned on.. just more "thumpy" or boomy" (no end to these technical terms), which that part isn't a surprise given the subwoofer***. This bears out what GM had been saying prior about the "punch" freq being rather higher than I had thought, though all the way down to 30 hz still carries some component of the punch - or maybe "slam" is better term there. With the mains off and only the sub, there's really no punch.. just boom boom thump thump. So even with the sub on, those weak little 12"s in the fishers are making most of the punch (they go from~45 - 1600 hz til they cross to the mids). The other Yamaha 3 way speakers I have with 8" woofers have almost no punch at all.
***A few caveats - the sub is a subwoofer driver not a woofer, its a ported box so fairly boomy and not terribly representative of the type of sound I want.
So. Going back to what do I want to build... thoughts of the moment:
- bigger mids/mid-bass is better for punch, so likely bigger full range is better for punch as well with the downside that as the cone gets bigger some detail is lost and some coloration may be present.
- crossing at 150 hz is probably fine, as long as the full range driver is large enough to punch; otherwise xo freq could be raised experimentally up to the woofer's top limit to see how it sounds. Likely this would improve "punch" at the expense of messing up other things, anything that crosses over the xo like male vocals as noted by GM.
- helper woofer needs to be punchy not boomy... are sealed cabinets the way to go? Or horns can be punchy as well?
Yes, A10 gets you greater loudness potential. A7 sounds better — but not by a lot, the latest generation of A10 really closed the gap. And there is nothing short of the A6.2p that has the same vintage voicing as the A10p. The smaller cabinets for the smaller cabinets brings the A12pw closer together which means thw 1/4 wavelength difference allows for a higher XO. But any of the mentioned Alpairs will give you a very good speaker.
The MTM has a separate havily tapered midTL inside. The 2 A12pw are in the same ML-TL.
That would depend on your bass needs. They have anecoic F10 of below 25 Hz, so they reach into subwoofer territory. Whether 2 6.5” drivers can move the air you need is a different question.
dave
sbcrx007, seems about right.
Remember, using 24db Linkwitz Riley active crossover, running double 15" (ported to 30hz) crossed at 750hz to a 2' wide horn has way more slam than running same double 15" crossed at 150hz to a 12" full range driver. That I have and know.
So, on that knowledge, running double 15" crossing at 150hz to double 12" full range should slam way better than a single 12" full range (crossed at 150hz).
Don't get me wrong, 12" full range crossed at 150hz to double 15's will go waaaayyyyy loud, just doesn't beat you up like 2 x 15" run from dc up to 750hz. The bass feeling from double 15's crossed at 750hz seems there even at lower volumes. Maybe I'm just imagining it.
Remember, using 24db Linkwitz Riley active crossover, running double 15" (ported to 30hz) crossed at 750hz to a 2' wide horn has way more slam than running same double 15" crossed at 150hz to a 12" full range driver. That I have and know.
So, on that knowledge, running double 15" crossing at 150hz to double 12" full range should slam way better than a single 12" full range (crossed at 150hz).
Don't get me wrong, 12" full range crossed at 150hz to double 15's will go waaaayyyyy loud, just doesn't beat you up like 2 x 15" run from dc up to 750hz. The bass feeling from double 15's crossed at 750hz seems there even at lower volumes. Maybe I'm just imagining it.
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