hey Don - just felt like I was cluttering up things over at AA. Sounds like TH cone movement is under good contro although I'm not familiar with that cut of much of Fleck - - have your run DAFO's drop? - that seemed to center around 23Hz with a bunch of overtones and some sense of room ambiance
do you think the shock wave effect is partly psychoacoustic? Karlsons, although not going deep by sub standards can exhibit a quick wave. I'm using Klipschorn and those sound horrible & tubby on harpsichord recordings -ugh (K12 did more exciting bowed bass with Gary Karr's Koussevitzsky cd) If I can't get drum, cello and bowed bass semi-acceptable then am doomed from getgo.
hope your threshold offset comes back fast
lets get a coupler and tiny HF pipe going - not sure if would cover your room - how large?
Freddy
do you think the shock wave effect is partly psychoacoustic? Karlsons, although not going deep by sub standards can exhibit a quick wave. I'm using Klipschorn and those sound horrible & tubby on harpsichord recordings -ugh (K12 did more exciting bowed bass with Gary Karr's Koussevitzsky cd) If I can't get drum, cello and bowed bass semi-acceptable then am doomed from getgo.
hope your threshold offset comes back fast
lets get a coupler and tiny HF pipe going - not sure if would cover your room - how large?
Freddy
rick57 said:
Greets!
You're welcome!
No, that whole response was to one of Freddy's. Your 70 L/40 Hz Fb alignment actually has a very low GD, just no mid-bass 'slam'.
WRT 'fast' reflex alignments, the roll off slope and Fb will determine its GD and can be tailored to have the same GD as a Qtc = 0.5 sealed over the BW above Fb and if tuned low enough to decay away to ~15 ms/35 Hz, then due to our lack of hearing acuity down low the reflex will sound as 'tight' as the critically damped sealed alignment. If tuned higher, then a HP filter is required to damp the increasing GD below Fb.
?? You have to use something to optimize a reflex alignment. I mean if there's a reflex alignment that zeros in on the optimum GD alignment, I'm either not aware of it or it plum evades me at the moment as all I can envision are TLs and horns.
Linkwitz ~literally 'wrote the book' on OBs, filling in whatever Olson missed or glossed over, so no point in me re-hashing it.
GM
rick57 said:
Greets!
You're welcome!
It applies to passives also, but you'll need very 'deep pockets' to afford a 80 Hz 4th order passive.
They can be ~accurately simmed by any program that can do BLHs or DBRs. Most BLHs are basically big vent reflexes (BVR), so a half or 'hit' horn is just a truncated variant, ergo can have whatever expansion you want.
Not really, you want Fh to be beginning of the 'bump' BW, otherwise you get a deep notch between Fh and the 'bump' BW.
Pecking order WRT technically 'perfect' to acceptable transient response AFAIK is 'perfect' BLH, 0.5 Qtc 1/2 WL pipe, 0.5 Qp TL, 0.5 Qtc sealed, EBS reflex, 0.7 Qtb reflex. What sounds acceptable OTOH is room, frequency, alignment, personal sound perception dependent and why technically horrible systems such as the BIB pipe horn, Karlson, etc., can be very 'live'/'musical'/whatever, sounding to certain folks. As a general rule, we like plenty of harmonic distortion if its the right kind in the right BW, just like preferring 'rich' foods over 'healthy' (bland) ones or TVs tuned 'hot' Vs color balanced for most natural reproduction.
You're missing the point. If I have a driver with a Qts = 1 it will have an under-damped 'hump' in its response with the associated 'ringing', but if I put it on the correct size baffle that rolls it off so there's no 'hump', the system's effective Qt is lower, ergo no longer under-damped, improving its impulse response.
GM
freddi said:
Greets!
Once again, mass per se isn't the problem, it's the higher Qts due to not having a strong enough motor to compete with a lower Qts one.
?? What do you mean by 'side gapped vent' in a K?
At a glance, you'll need a lower Fs driver with the same ~230 Hz Fh that you say works well (Altec 421), so ~28 Hz Fs/0.227 Qts.
The K doesn't have a front 'pipe', none of the chambers have a high enough aspect ratio for TL action to occur in its passband.
'Lumped' front tuning? See my earlier explanation of how a K works. What are you calling a 'coupler'?
Don't know for sure, but it seems to me that baffle angle Vs cutout shape would mostly be a front volume Vs vent tuning thing just like any BP.
Yeah, the B&C is fairly well damped, but has a high Le, so I can see why it might not blend with a horn very well unless XO'd low/steep and its specs indicate tiny front/rear chambers in a K due to its exceptionally low Vas. The stiff suspension is probably the major cause for its 'thick'/'sluggish' sound.
Can't comment WRT the TH, though I'm curious how you 'kluge' it in Hornresp.
GM
Hi GM
> the roll off slope and Fb will determine its GD and can be tailored to have the same GD as a Qtc = 0.5 sealed over the BW above Fb
the indicator of GD being the (inverse of) the steepness of the roll off slope?
> the optimum GD alignment . . all I can envision are TLs and horns.
So TLs and horns have *better GD reflex or even sealed? Can GD be modeled for either of these?
> Linkwitz ~literally 'wrote the book' on OBs, filling in whatever Olson missed . .
I've read his material a few times, but don’t recall any discussion on OB GD/ Qt . .
Cheers
> the roll off slope and Fb will determine its GD and can be tailored to have the same GD as a Qtc = 0.5 sealed over the BW above Fb
the indicator of GD being the (inverse of) the steepness of the roll off slope?
> the optimum GD alignment . . all I can envision are TLs and horns.
So TLs and horns have *better GD reflex or even sealed? Can GD be modeled for either of these?
> Linkwitz ~literally 'wrote the book' on OBs, filling in whatever Olson missed . .
I've read his material a few times, but don’t recall any discussion on OB GD/ Qt . .
Cheers
Hi GM
> you'll need very 'deep pockets' to afford a 80 Hz 4th order passive.
mmm, yes
> They can be ~accurately simmed by any program that can do BLHs or DBRs.
What is a DBR?
> As a general rule, we like plenty of harmonic distortion if its the right kind in the right BW, just like preferring 'rich' foods over 'healthy' (bland) ones or TVs tuned 'hot' Vs color balanced for most natural reproduction.
Good analogies
> Pecking order WRT technically 'perfect' to acceptable transient response AFAIK is 'perfect' BLH . . .
I thought a large proportion of a BLHs' bass is out phase, compromising transient response.
> Your 70 L/ 40 Hz Fb alignment actually has a very low GD, just no mid-bass 'slam'.
If GD may not be easy to distinguish (room, frequency, alignment, perception dependent) and I certainly like slam, maybe my criteria would be better weighted towards slam . .
* What is your pecking order for midbass 70 – 350 Hz slam (including I hope an option for something able to be modeled and not as complex to build as a front horn, just yet)?
Cheers
> you'll need very 'deep pockets' to afford a 80 Hz 4th order passive.
mmm, yes
> They can be ~accurately simmed by any program that can do BLHs or DBRs.
What is a DBR?
> As a general rule, we like plenty of harmonic distortion if its the right kind in the right BW, just like preferring 'rich' foods over 'healthy' (bland) ones or TVs tuned 'hot' Vs color balanced for most natural reproduction.
Good analogies
> Pecking order WRT technically 'perfect' to acceptable transient response AFAIK is 'perfect' BLH . . .
I thought a large proportion of a BLHs' bass is out phase, compromising transient response.
> Your 70 L/ 40 Hz Fb alignment actually has a very low GD, just no mid-bass 'slam'.
If GD may not be easy to distinguish (room, frequency, alignment, perception dependent) and I certainly like slam, maybe my criteria would be better weighted towards slam . .
* What is your pecking order for midbass 70 – 350 Hz slam (including I hope an option for something able to be modeled and not as complex to build as a front horn, just yet)?
Cheers
hahaha GM - yeah - BIB, K's & whatnots = "technically horrible brigade" - even if stinks on ice can be a way to pass time (and money) - if that makes sense in a short and unsplendid life (?)
re:K - somehow CN puts significance upon taller aspect offering advantages but what can that really buy within a fixed bulk? - or worded differently, are there better layouts for K aspect-wise than what Mr. K used and if so what improvements might be possible?
what did KenL have back in the 1990's with a 20x20x70 or so tall K with transflex vent? Are tall K's moving away from coupled cavity and more towards t-line territory with less chance of coupled-cavity peaking? - - if so where might the transition occur? (might be difficult to define when the "pipe" leaks)
K-apertures are supposed to be set to leak energy in an even manner....
re:GD - how is that figured for TH? will ARTA calculate properly? how does one confidently kluge TH simulations with Hornresp? - looks like there may be some patterns
which of these two aspect is - uh "better"?
re:K - somehow CN puts significance upon taller aspect offering advantages but what can that really buy within a fixed bulk? - or worded differently, are there better layouts for K aspect-wise than what Mr. K used and if so what improvements might be possible?
what did KenL have back in the 1990's with a 20x20x70 or so tall K with transflex vent? Are tall K's moving away from coupled cavity and more towards t-line territory with less chance of coupled-cavity peaking? - - if so where might the transition occur? (might be difficult to define when the "pipe" leaks)
K-apertures are supposed to be set to leak energy in an even manner....
re:GD - how is that figured for TH? will ARTA calculate properly? how does one confidently kluge TH simulations with Hornresp? - looks like there may be some patterns
which of these two aspect is - uh "better"?
An externally hosted image should be here but it was not working when we last tested it.
Would this work
I don't have a whole gob of money right now, but I do have a 12" KLH sub with a plate amp. How can I figure out if the driver for that sub would work in a Tapped sub? I don't have the money for an experiment, but I could swing for a couple sheets of MDF if I know it would work. Is this wishful thinking? Cheers.
I don't have a whole gob of money right now, but I do have a 12" KLH sub with a plate amp. How can I figure out if the driver for that sub would work in a Tapped sub? I don't have the money for an experiment, but I could swing for a couple sheets of MDF if I know it would work. Is this wishful thinking? Cheers.
k-slot might ruin the tapped horn--? - for experiment that would require a removable front panel
Danley's TH graphs look great!
If you build a 12" TH - as long as driver is accessible then can get right driver later.
on another note, I'm not familiar with Hornresp in BLH mode so not sure how to kluge-simulate TH nor do it with AJ-horn. AJ will go wild & way outta whack in some cases but may be good in certain constraints
here's Don's horn roughly simed as BLH in AJ
how does one kluge sim TH in AH?
BLH
http://img95.imageshack.us/img95/8360/quicksim1uo5.jpg
Power dip ~32Hz Lab 12 in BLH - would power handling dip to ~210 watts @ 32Hz with TH? Don's comments indicated very low cone excursion
http://img95.imageshack.us/img95/1451/pwrdip32sim1ff5.jpg
56 lliter reflex vs 243 liter BLH
http://img408.imageshack.us/img408/7507/brblhxz1.jpg
Danley's TH graphs look great!
If you build a 12" TH - as long as driver is accessible then can get right driver later.
on another note, I'm not familiar with Hornresp in BLH mode so not sure how to kluge-simulate TH nor do it with AJ-horn. AJ will go wild & way outta whack in some cases but may be good in certain constraints
here's Don's horn roughly simed as BLH in AJ
how does one kluge sim TH in AH?
BLH
http://img95.imageshack.us/img95/8360/quicksim1uo5.jpg
Power dip ~32Hz Lab 12 in BLH - would power handling dip to ~210 watts @ 32Hz with TH? Don's comments indicated very low cone excursion
http://img95.imageshack.us/img95/1451/pwrdip32sim1ff5.jpg
56 lliter reflex vs 243 liter BLH
http://img408.imageshack.us/img408/7507/brblhxz1.jpg
rick57 said:
Greets!
This only applies to sealed, vented is more complex since it's 4th order.
They can since the system's FR, phase, and GD are just different ways to view the same information, ergo can be modeled if you know the math, I don't. LspCad is the only program I have that models it, but can't do TLs or horns.
Probably because the pros who post on-line (and I imagine most others) don't use it per se as a 'marker' of system performance. I somehow managed to design a lot of well received speakers and didn't have a clue what GD was until I'd been on the old basslist for awhile. Now that I know about it, I still design them the same old way and folks claim to like how they perform, so please pardon me if I can't get too excited about GD per se.
WRT to OB and effective Qts, I admit I haven't read all his OB stuff, just assumed he addressed it in some form or other in all those design docs he published on his site. My bad.
GM
rick57 said:
Greets!
DBR = double bass reflex.
A 'perfect' BLH is so well damped that it has no output above the driver's mass corner and its sheer size so completely controls the driver that it physically delays its radiating output ('tail wagging the dog'). In a sim, its impulse response is so straight/sharp it makes a 0.5 Qtc sealed's look like a vented's, relatively speaking, but I don't have one to post. What I can say is that I built a truncated version of one using a 1" exit compression driver sans rear cover to keep the size semi-reasonable and it impressed me enough with its razor sharp attacks that it got me started on trying to reproduce it at lower frequencies in < room size cabs, winding up with low Fs, Qts EBS alignments as the most acceptable trade-off between size, performance, build complexity. It also convinced me that like most things there was a point of diminishing returns as to how 'fast' a design needed to be as my proof-of-concept was no where near long/large enough to be 'perfect', yet I couldn't imagine being able to hear anything 'faster'.
As time past and I learned more about human hearing perception I realized that while I couldn't hear it since the leading edge would be well above human hearing audibility, we can perceive ultrasonic frequencies up to ~40 kHz, so if the system can handle it and there's source info this high...........
I don't have any real 'pecking order' for typical 'slam' alignments since I prefer highly damped ones, which are all way too big for you.
GM
hey GM - WRT simulation of TH, AJ-horn allows movement of driver (not able to directly model mutal-loads)
would moving a driver half-way up the horn and overlaying that plot vs full BLH plot give any useful info? - (like estimation of fill-in of the upper dip?) - what makes sense in trying to kluge simulation via Hornresp and AJ?
http://img88.imageshack.us/img88/4855/2m4mnp8.jpg
Best, Freddy
would moving a driver half-way up the horn and overlaying that plot vs full BLH plot give any useful info? - (like estimation of fill-in of the upper dip?) - what makes sense in trying to kluge simulation via Hornresp and AJ?
http://img88.imageshack.us/img88/4855/2m4mnp8.jpg
Best, Freddy
freddi said:
Greets!
Yeah, we have to take our little pleasures when/where we can.
OK, now that I know what he's building, I agree that making the chambers such that TL action can occur to further load the vent (K-slot)/driver is desirable. His layout is more like a compression loaded pipe than a K, which is more along the lines of what I've periodically proposed, so the nod goes to the K-pipe IMO.
I don't have a clue how to calc GD plots.
GM
Mr. K's 1951 patent showed different aspect cabinets - guess we'll never know (?) what RCA/Olson had when they went up against K (and probably the Fulmer patent)
An externally hosted image should be here but it was not working when we last tested it.
Hi GM
> winding up with low Fs, Qts EBS alignments as the most acceptable trade-off between size, performance, build complexity.
I thought the only benefit of EBS was bass depth, and I have sealed subs that can be used, so didn’t consider that approach.
The 70 litres I referred to earlier, was simply struck as something able to give a response that could mate with the subs to give a flat response.
I like well damped alignments: if that means I need a much bigger box (but not a complex one), I’ll do it. The room could take 14 cubic feet (400 litre boxes) without drama.
If the size constraint is lifted, is EBS a good trade-off – even when extension isn’t needed?
Btw, rightly or wrongly I consider Onkens a variant of EBS, but they’re higher build complexity and I recall your points re comb filtering.
> I don't have any real 'pecking order' for typical 'slam' alignments since I prefer highly damped ones, which are all way too big for you.
Or are there some (big) 'slam' alignments more optimized to mid bass?
Cheers
> winding up with low Fs, Qts EBS alignments as the most acceptable trade-off between size, performance, build complexity.
I thought the only benefit of EBS was bass depth, and I have sealed subs that can be used, so didn’t consider that approach.
The 70 litres I referred to earlier, was simply struck as something able to give a response that could mate with the subs to give a flat response.
I like well damped alignments: if that means I need a much bigger box (but not a complex one), I’ll do it. The room could take 14 cubic feet (400 litre boxes) without drama.
If the size constraint is lifted, is EBS a good trade-off – even when extension isn’t needed?
Btw, rightly or wrongly I consider Onkens a variant of EBS, but they’re higher build complexity and I recall your points re comb filtering.
> I don't have any real 'pecking order' for typical 'slam' alignments since I prefer highly damped ones, which are all way too big for you.
Or are there some (big) 'slam' alignments more optimized to mid bass?
Cheers
GM
Searching on ‘slam’, I came across one of your posts from a while back where you said
“My definition of 'tighten' means to lower the sys Q, so tune it lower (longer vent).
Raising sys Q (shorter vent) would be more 'slam', or 'punch'. “
I think the same re 'tightening’ bass; however raising sys Q generates a mid bass hump, not what I’d first think of as slam, but certainly better than a mid bass slump
I think of slam more as uncompressed dynamics.
Thinking aloud, once you get over ~ 100-150 Hz, if the driver and amp are good enough (eg low distortion, faraday ring(s)/ HE) is the alignment that important?
If the alignment still matters, now that I know your terms better . .
I’m not after maximum gain or extension at either end, which should make a decision easier:
I’ve probably had not enough opportunity to compare to be *certain what level Q I prefer, so I should do my own comparison . . which raises the question of the “best” options of either type
~ Midbass optimized for transient response
> A 'perfect' BLH is so well damped that it has no output above the driver's mass corner and its sheer size so completely controls the driver that it physically delays its radiating output ('tail wagging the dog').
While the room is not small at 17* 22* 12 feet (5.3 * 6.7 * 3.8 m) peaks of a modest 105 dB will do me, I just want minimal constraint up to that level: what midbass BLH driver(s) would you suggest, any alignment tips?
And optimized for slam – with 105 dB being enough, ~ 98 dB drivers achieve 107 dB with a modest ~16 watts.
Maybe for that modest dB need there’s zero benefit in adding gain(?).
Would you agree that a bass hump perceived as good for drums/ rock/ fun/ uncompressed dynamics, would be centred between 70 – 120 hz?
based on some snips from http://stereophile.com/reference/26/index2.html:
“Fender Bass: most energy is at the 2nd harmonic, 82 Hz.
Timpani (kettle): Energy centred between 75 – 200 Hz.
Kick drum: a broad span of frequencies with very high energy between 30 and 80 Hz”
. . maybe best to tune for a peak somewhere around 80 Hz
how many dB is a nice peak to aim for, say 1.5 dB?
I just tried a lot of sims on the JBLs, and as the vented box became bigger, eg increased from 60 to 120 litres, was surprised to see that the roll off became *steeper.
A 100 litre box tuned to 58 Hz, sims an F3 of 55 Hz, and a 1.6 dB peak centred at 81 Hz – is that what would likely be perceived as slam, still with reasonable GD?
Thanks Again
Searching on ‘slam’, I came across one of your posts from a while back where you said
“My definition of 'tighten' means to lower the sys Q, so tune it lower (longer vent).
Raising sys Q (shorter vent) would be more 'slam', or 'punch'. “
I think the same re 'tightening’ bass; however raising sys Q generates a mid bass hump, not what I’d first think of as slam, but certainly better than a mid bass slump
I think of slam more as uncompressed dynamics.
Thinking aloud, once you get over ~ 100-150 Hz, if the driver and amp are good enough (eg low distortion, faraday ring(s)/ HE) is the alignment that important?
If the alignment still matters, now that I know your terms better . .
I’m not after maximum gain or extension at either end, which should make a decision easier:
I’ve probably had not enough opportunity to compare to be *certain what level Q I prefer, so I should do my own comparison . . which raises the question of the “best” options of either type
~ Midbass optimized for transient response
> A 'perfect' BLH is so well damped that it has no output above the driver's mass corner and its sheer size so completely controls the driver that it physically delays its radiating output ('tail wagging the dog').
While the room is not small at 17* 22* 12 feet (5.3 * 6.7 * 3.8 m) peaks of a modest 105 dB will do me, I just want minimal constraint up to that level: what midbass BLH driver(s) would you suggest, any alignment tips?
And optimized for slam – with 105 dB being enough, ~ 98 dB drivers achieve 107 dB with a modest ~16 watts.
Maybe for that modest dB need there’s zero benefit in adding gain(?).
Would you agree that a bass hump perceived as good for drums/ rock/ fun/ uncompressed dynamics, would be centred between 70 – 120 hz?
based on some snips from http://stereophile.com/reference/26/index2.html:
“Fender Bass: most energy is at the 2nd harmonic, 82 Hz.
Timpani (kettle): Energy centred between 75 – 200 Hz.
Kick drum: a broad span of frequencies with very high energy between 30 and 80 Hz”
. . maybe best to tune for a peak somewhere around 80 Hz
how many dB is a nice peak to aim for, say 1.5 dB?
I just tried a lot of sims on the JBLs, and as the vented box became bigger, eg increased from 60 to 120 litres, was surprised to see that the roll off became *steeper.
A 100 litre box tuned to 58 Hz, sims an F3 of 55 Hz, and a 1.6 dB peak centred at 81 Hz – is that what would likely be perceived as slam, still with reasonable GD?
Thanks Again