wierd... I would think that bass would be a non-issue with BiBs and the hemp-8. My fostex 166e units have considerable bass (I play quite a bit of dub/bassy music). Interesting... Hemp-8s are lined up for my next large speaker project, so I'll stay tuned in to this thread to see what the experts suggest.
good luck
7/10
good luck
7/10
I guess I had better clarify my above Hemp BIB comments a little more. Don’t get me wrong the BIB design is able to produce bass. In fact, when the Hemp driver first arrived I built a small baffle for each driver and then mounted them and had a listen. There was no bass at all, and the overall sound was not that good (this was a very small baffle, about 12” square). The comparison between the BIB and small open baffle is like night and day.
Maybe we have unrealistic expectations. Most of our experience has been with the more traditional closed/ported speaker designs. One of the end goals is a stronger, transient, bass response. You know… the kind that hits you in the chest. Bass aside, the driver has a bunch of other aspects that we both really like and so the search for a new cabinet design.
Here is a photo of the BIB next to a Jordan MLTL. As you can see the Jordan is quite a bit smaller and less efficient, but at similar SPL levels is able to match the bass output of the Hemp BIB design.
In the end it really isn’t the bass that is pushing us to look for another design, but rather the cabinet colorations of the horn. Maybe we just don’t like horn speaker or maybe we still need to play around with stuffing. I don’t really know, this is my first attempt at a horn speaker. One thing for sure I don’t really want to climb inside this speaker again (yes that is right; the Hemp BIB is so big I am able to fit inside the cabinet).
I guess with any speaker design there are tradeoffs. As stated above, I may try a sealed box just to see what effect it has on the sound coming from the Hemp. If I am able to keep the dynamics of the BIB and lose the “echo”, then we will be getting somewhere.
Maybe we have unrealistic expectations. Most of our experience has been with the more traditional closed/ported speaker designs. One of the end goals is a stronger, transient, bass response. You know… the kind that hits you in the chest. Bass aside, the driver has a bunch of other aspects that we both really like and so the search for a new cabinet design.
Here is a photo of the BIB next to a Jordan MLTL. As you can see the Jordan is quite a bit smaller and less efficient, but at similar SPL levels is able to match the bass output of the Hemp BIB design.
In the end it really isn’t the bass that is pushing us to look for another design, but rather the cabinet colorations of the horn. Maybe we just don’t like horn speaker or maybe we still need to play around with stuffing. I don’t really know, this is my first attempt at a horn speaker. One thing for sure I don’t really want to climb inside this speaker again (yes that is right; the Hemp BIB is so big I am able to fit inside the cabinet).
I guess with any speaker design there are tradeoffs. As stated above, I may try a sealed box just to see what effect it has on the sound coming from the Hemp. If I am able to keep the dynamics of the BIB and lose the “echo”, then we will be getting somewhere.
Attachments
Hardman said:
For chest thumping bass, you really need to move some air... a couple CSS 12 or 15" Subductions would do the job. Scott & i have done a couple designs for the 12" that would make your BIBs look like your Jordans size wise
The bif 15" boxes should be even bigger.The ripple i heard in the BIBs was what inspired Karlson slot in the iBIBk -- some people are sensitive the ripple (me. you & your buddy it sounds like) and some aren't. In terms of horns, the BIB is pretty crude, so don't judge all horns by it.
dave
Well I've been banging my head againt a pair of FR8c on open baffle for over a week. It's a "Lampizator" style baffle. About 15" wide, 46" tall. Active bass on the bottom.
Yeah, the FR8 does beam less than I expected, but it does beam, just like any 8"FR is going to. But I'm comparing it to an Altec 811 horn, which is much wider.
On the 15x45" baffle, the FR8c has NO low end, none. A lot like the 12" square baffle that Hardman mentions. I had hoped for more, but it rolls off fast under 300 Hz, which leaves it sounding much too bright.
Been doing "Jedi mind tricks" on it to tilt the response down a bit. Simple inductors or an RL parallel shelving filter. So far it's good, but not great.
Maybe I'll have to try the JELabs baffle. On the tall, thin baffle I get no joy (yet).
Yeah, the FR8 does beam less than I expected, but it does beam, just like any 8"FR is going to. But I'm comparing it to an Altec 811 horn, which is much wider.
On the 15x45" baffle, the FR8c has NO low end, none. A lot like the 12" square baffle that Hardman mentions. I had hoped for more, but it rolls off fast under 300 Hz, which leaves it sounding much too bright.
Been doing "Jedi mind tricks" on it to tilt the response down a bit. Simple inductors or an RL parallel shelving filter. So far it's good, but not great.
Maybe I'll have to try the JELabs baffle. On the tall, thin baffle I get no joy (yet).
Dave - Thanks for the reply. Good to hear that not all horn speakers sound like the BIB. My faith in other designs has been restored. To be honest I didn’t really read much about the BIBs before building them. Most of the research was done by my friend. I mainly provide the shop and a second set of hands for assembly. I have always wanted to try something horn like so this was a good learning experience if nothing else. There were many plusses offered by the BIB design, but the above mentioned “extras” proved too much for our liking.
Do you think a sealed box is going to lose some of the dynamics offered by the BIB? If so what other type of a design do you propose? Above you suggested the Demetri, still leaning this direction?
What is an IBIBK? I assume it is an offshoot of a BIB?
I too have played around with the CSS subwoofers and really like them. I have both drivers currently. Just need to find some time to put them into a box. I know you are a fan of push-push enclosures, any designs for the SD12 or SDX15 (I guess if I weren’t so lazy I could just look on your site)?
Thanks,
Chris
Do you think a sealed box is going to lose some of the dynamics offered by the BIB? If so what other type of a design do you propose? Above you suggested the Demetri, still leaning this direction?
What is an IBIBK? I assume it is an offshoot of a BIB?
I too have played around with the CSS subwoofers and really like them. I have both drivers currently. Just need to find some time to put them into a box. I know you are a fan of push-push enclosures, any designs for the SD12 or SDX15 (I guess if I weren’t so lazy I could just look on your site)?
Thanks,
Chris
Hardman said:
Demetri might suit... it seems to want a big room. It was designed to be "compact and go againt a wall) Bruce (or a Chang variation) is where my mind goes 1st.
i for inverted, k for Karlson slot. This one was for FE127/126 so inverting it to floor load the mouth had some big advantages, and the Karlson slot was a shoy at smoothing out the ripple.
Besides the big BIB thread it has its own thread. A couple have been built. It hasn't got to the top of our queue yet.
I haven't posted any push-push designs yet. I just finished drawing up a set of sealed p-p SD12 (customer wants a stereo pair), and i have the data to do the small SDX15 push-push TL (~33 ft"3). I have a place to put a stereo pair of those. Have to rent a drywall lifter to get them up to the ceiling of my shop (which has a common wall with the hifi/living room space.
dave
Attachments
A Chang version? This should work. Chamber is basically the MLTL I did a week or so back for the FR8C, slightly shortened. Internal dims. Chamber 42in x 10.5in x 14in (HxWxD). Driver positioned in the middle of the front baffle. It'll need some bracing, & that useful triangle on the rear panel. Slot vents at the back of the top & bottom panels, 15mm deep, 102mm long, firing into two 15in tall flared vents. As far as I can tell from MathCad (keeping the software limitations in mind), it looks like it should do pretty well. Chamber needs lining -top, bottom, one sidewall & the back (keeping the vents clear).
Re the other boxes, Dimitri scores over the MLTLs if you like a wide baffle, & TQWT always sound subjectively a little different to a straight pipe, even though FR plots might look similar -seems to be mostly in the midbass where they seem to have a little more punch, at the price of a touch more ripple.
I'm surprised you didn't find the BIBs giving great LF -they should kill most cabinets in this respect. How did you damp them? Admittedly, they're not for everyone -some people are sensitive to the ripple, as Dave says.
Scott
This should work. Chamber is basically the MLTL I did a week or so back for the FR8C, slightly shortened. Internal dims. Chamber 42in x 10.5in x 14in (HxWxD). Driver positioned in the middle of the front baffle. It'll need some bracing, & that useful triangle on the rear panel. Slot vents at the back of the top & bottom panels, 15mm deep, 102mm long, firing into two 15in tall flared vents. As far as I can tell from MathCad (keeping the software limitations in mind), it looks like it should do pretty well. Chamber needs lining -top, bottom, one sidewall & the back (keeping the vents clear). Re the other boxes, Dimitri scores over the MLTLs if you like a wide baffle, & TQWT always sound subjectively a little different to a straight pipe, even though FR plots might look similar -seems to be mostly in the midbass where they seem to have a little more punch, at the price of a touch more ripple.
I'm surprised you didn't find the BIBs giving great LF -they should kill most cabinets in this respect. How did you damp them? Admittedly, they're not for everyone -some people are sensitive to the ripple, as Dave says.
Scott
Attachments
I, too, am surprised that you don't find the quantity of bass from the Hemp/BIB to your liking. I wish I could give a little of my bass away. Different rooms, different strokes. I still haven't gotten mine outside to finish.
Just a couple of days ago I was pondering hauling them out and cutting a K-slot in them for a change. Dave or Scott, am I right in thinking that a K-slot could diminish LF gain a bit and reduce ripple? I don't find the ripple that objectionable, but I am overloading my room. A K-slot would look cool too.
pj
Just a couple of days ago I was pondering hauling them out and cutting a K-slot in them for a change. Dave or Scott, am I right in thinking that a K-slot could diminish LF gain a bit and reduce ripple? I don't find the ripple that objectionable, but I am overloading my room. A K-slot would look cool too.
pj
Greets!
Well, this sucks! Apparently the pipe's 3rd harmonic dip is a bit much and combined with the driver's published broadband lead guitar 'shout', even a BIB's prodigious bass sounds weak, so at minimum some BSC is required, though a series notch filter to tame the ~1.5 - 15 kHz 'shout' would be my first choice and dial in a bit more damping as required to flatten the in-room response.
WRT the hollow sound, read mine and Lonnie's responses in the BIB thread about how he damped his: http://www.diyaudio.com/forums/search.php?s=&action=showresults&searchid=1163318712 If you can't make this work combined with the filter and/or some BSC, then regrettably a BIB system isn't going to work for ya'll.
FWIW, here's my take on a MLTL based on published specs, though it will need the notch filter and much more BSC than the BIB or it will sound like it has no bass at all based on your stated listening impressions:
L = 57.5"
CSA = ~113"^2 (recommend 13.5" W x 8.375" D)
zdriver = 20.875"
zport = 45"
vent = 4" dia. x 0.75"
density = 0.2 lbs/ft^3
GM
Well, this sucks! Apparently the pipe's 3rd harmonic dip is a bit much and combined with the driver's published broadband lead guitar 'shout', even a BIB's prodigious bass sounds weak, so at minimum some BSC is required, though a series notch filter to tame the ~1.5 - 15 kHz 'shout' would be my first choice and dial in a bit more damping as required to flatten the in-room response.
WRT the hollow sound, read mine and Lonnie's responses in the BIB thread about how he damped his: http://www.diyaudio.com/forums/search.php?s=&action=showresults&searchid=1163318712 If you can't make this work combined with the filter and/or some BSC, then regrettably a BIB system isn't going to work for ya'll.
FWIW, here's my take on a MLTL based on published specs, though it will need the notch filter and much more BSC than the BIB or it will sound like it has no bass at all based on your stated listening impressions:
L = 57.5"
CSA = ~113"^2 (recommend 13.5" W x 8.375" D)
zdriver = 20.875"
zport = 45"
vent = 4" dia. x 0.75"
density = 0.2 lbs/ft^3
GM
Attachments
Love that tickled up bass Greg.
I must be some kind of idiot! I'd clean forgotten the rising response of the hempster. Still, assuming there's some room-gain going on, you'd think that it'd balance out as that monster you came up with is ~flat (or as much as these things ever can be) down to 30Hz.
BTW -a Zdriver position of 0.2 line length rather than 0.217 seems to reduce the depth of the 3rd harmonic null somewhat.
I must be some kind of idiot! I'd clean forgotten the rising response of the hempster. Still, assuming there's some room-gain going on, you'd think that it'd balance out as that monster you came up with is ~flat (or as much as these things ever can be) down to 30Hz.
BTW -a Zdriver position of 0.2 line length rather than 0.217 seems to reduce the depth of the 3rd harmonic null somewhat.
Thanks!
As smoothed as the factory plot is, I'm betting it's got some spikes in our acute hearing BW that only a lead Heavy Metal guitarist would like and I assume Chris has way over-damped the BIBs trying to rid it of its major resonances judging by his perception of the little Jordan pipe being ~its equal WRT bass reproduction.
You've mentioned this before, so have you actually compared the two in-room? I must admit I'm skeptical since this is a ~zero throat area pipe that I've found require gross driver position changes to notice any obvious difference one way or another, at least in the large mass loaded variants I've experimented with where Av = ~Sd regardless of Sm used.
As smoothed as the factory plot is, I'm betting it's got some spikes in our acute hearing BW that only a lead Heavy Metal guitarist would like and I assume Chris has way over-damped the BIBs trying to rid it of its major resonances judging by his perception of the little Jordan pipe being ~its equal WRT bass reproduction.
You've mentioned this before, so have you actually compared the two in-room? I must admit I'm skeptical since this is a ~zero throat area pipe that I've found require gross driver position changes to notice any obvious difference one way or another, at least in the large mass loaded variants I've experimented with where Av = ~Sd regardless of Sm used.
Dave, Scott GM,
Don't you think these huge panels would create resonances also?
I made the "hand clap test" in the driver opening when they were undamped. Of course you get echo when undamped. But this got me thinking of my spare room that was unfurbished for a while. Hand clap effect prominent here. Now there's shelves for the childrens toys on one wall. Guess what, echo is gone, despite not much of soft material in the room.
In my naivity I ask, would it work in a BIB without change of other physical properties of the horn. Of course I'm talking of smaller sections of different lengths of shelves in the horn path.
Cheers
Don't you think these huge panels would create resonances also?
I made the "hand clap test" in the driver opening when they were undamped. Of course you get echo when undamped. But this got me thinking of my spare room that was unfurbished for a while. Hand clap effect prominent here. Now there's shelves for the childrens toys on one wall. Guess what, echo is gone, despite not much of soft material in the room.
In my naivity I ask, would it work in a BIB without change of other physical properties of the horn. Of course I'm talking of smaller sections of different lengths of shelves in the horn path.
Cheers
I guess I had better chime in while the chiming's good and since i'm the other half of Hardman's posts. Let me 1st put you into my frame of ear.
Almost 2 years ago I approached Hardman about building some speakers. He asked if i'd be willing to guinea pig a design he'd read much about and was interested in. I consented and we built Jim Girffin's Bipole ML-TL (based on GM ML-TL) for the CSS FR125S. I can't explain the euphoria I felt when we hooked those puppies up. The bass that came from blew me away regardless of driver / cab size. Not only was it there, but it was there in spades...and not the muddy bass I had heard all my life from Circuit City (and the ilk) listening rooms but clean, full, rich, warm, and...flowing bass. To my ears, they were the best speakers I had ever heard. Some complain about the top end being a bit lackasidasical. I've always been overly sensitive to high frequencies so I didin't mind (or notice much for that matter). What they lacked in frequency response was more than compensated for with what they offered. I loved them with one caveat. They didn't play loud enough. Fast forward to now.
I chose the Hemps for the fact that since I found out about them I had often read how great they were supposed to be with rock (probably what I listen to most), boogy-ing with an unprecedented "organic" sound...I just had to try them. As for the enclosure the BIB seemed like the perfect fit. I chose it with the hopes of acheiving the same (or very near) bass of the FR125S set but with much higher SPLs available at my disposal plus a peerless natural sound. Here's what I told a friend what I thought about the sound once we built them...
"Hardman and I first put the hemps in an open baffle setup...they sounded pretty terrible. Once the BIBs were together we were surprised at how frickin awesome they sound...with a couple of caveats. The lf extension, while there and also loud at times, is anemic compared to the other freqs being produced. Certain higher freqs are harsh, Hardman and I chalk that up to 2 things, the driver itself and also probably reflections from the direct backside of the speaker. The final thing is there is an echo-y-ness about them that is hard to describe. Colorations (we think) inherently produced by the cabinet. Without spending countless hours getting the stuffing exact I don't think that problem is going to go away. If even then. On the plus side, certain mids sound better than I think I've ever heard. There is an open and natural sound to these drivers that is unmatched."
That's the best way I can describe the bass...there but anemic. Add to that the colorations and I'm afraid these cabinets are going to have to go. I'm glad we built the BIBs but like Hardman said...expensive endeavor that we were disappointed in.
Sorry for my drawn out post but I wanted to give those in the know an idea of where I was coming from, what it is I'm looking for and where I'm at right now. So my question is...with the hemps (because i do believe i'm sold on their sound sans the colorations these BIBs are producing) how do I achieve that bass I'm looking for? Ultimatley I'll probably try the OB design but I can't afford a sub right now (space or money) so how do i milk these dudes for all their LF worth? I'm rather drawn to the Demitri as opposed to a simple BR design simply based on the success of the previous MLTL we tried but like Hardman said (and as demsonstrated by simply building the hemp BIBs) I'm open to suggestions.
Almost 2 years ago I approached Hardman about building some speakers. He asked if i'd be willing to guinea pig a design he'd read much about and was interested in. I consented and we built Jim Girffin's Bipole ML-TL (based on GM ML-TL) for the CSS FR125S. I can't explain the euphoria I felt when we hooked those puppies up. The bass that came from blew me away regardless of driver / cab size. Not only was it there, but it was there in spades...and not the muddy bass I had heard all my life from Circuit City (and the ilk) listening rooms but clean, full, rich, warm, and...flowing bass. To my ears, they were the best speakers I had ever heard. Some complain about the top end being a bit lackasidasical. I've always been overly sensitive to high frequencies so I didin't mind (or notice much for that matter). What they lacked in frequency response was more than compensated for with what they offered. I loved them with one caveat. They didn't play loud enough. Fast forward to now.
I chose the Hemps for the fact that since I found out about them I had often read how great they were supposed to be with rock (probably what I listen to most), boogy-ing with an unprecedented "organic" sound...I just had to try them. As for the enclosure the BIB seemed like the perfect fit. I chose it with the hopes of acheiving the same (or very near) bass of the FR125S set but with much higher SPLs available at my disposal plus a peerless natural sound. Here's what I told a friend what I thought about the sound once we built them...
"Hardman and I first put the hemps in an open baffle setup...they sounded pretty terrible. Once the BIBs were together we were surprised at how frickin awesome they sound...with a couple of caveats. The lf extension, while there and also loud at times, is anemic compared to the other freqs being produced. Certain higher freqs are harsh, Hardman and I chalk that up to 2 things, the driver itself and also probably reflections from the direct backside of the speaker. The final thing is there is an echo-y-ness about them that is hard to describe. Colorations (we think) inherently produced by the cabinet. Without spending countless hours getting the stuffing exact I don't think that problem is going to go away. If even then. On the plus side, certain mids sound better than I think I've ever heard. There is an open and natural sound to these drivers that is unmatched."
That's the best way I can describe the bass...there but anemic. Add to that the colorations and I'm afraid these cabinets are going to have to go. I'm glad we built the BIBs but like Hardman said...expensive endeavor that we were disappointed in.
Sorry for my drawn out post but I wanted to give those in the know an idea of where I was coming from, what it is I'm looking for and where I'm at right now. So my question is...with the hemps (because i do believe i'm sold on their sound sans the colorations these BIBs are producing) how do I achieve that bass I'm looking for? Ultimatley I'll probably try the OB design but I can't afford a sub right now (space or money) so how do i milk these dudes for all their LF worth? I'm rather drawn to the Demitri as opposed to a simple BR design simply based on the success of the previous MLTL we tried but like Hardman said (and as demsonstrated by simply building the hemp BIBs) I'm open to suggestions.
Greets!
Nothing you've said changes my opinions/suggested solutions and the perceived harshness, etc. just confirms to my satisfaction that the driver needs some form of serious EQing regardless of box alignment, though multiple drivers and/or true BLH loading would somewhat reduce the amount required.
Bottom line, like most FR drivers it's basically a wide BW mids driver that needs a sub and super tweeter system for the type of max performance you desire from it.
GM
Nothing you've said changes my opinions/suggested solutions and the perceived harshness, etc. just confirms to my satisfaction that the driver needs some form of serious EQing regardless of box alignment, though multiple drivers and/or true BLH loading would somewhat reduce the amount required.
Bottom line, like most FR drivers it's basically a wide BW mids driver that needs a sub and super tweeter system for the type of max performance you desire from it.
GM
GM said:
Yeah, that makes sense about the plots. Be interesting to see some unsmoothed measurements. I'm betting these things must be crammed with material if the Jordan's are apparantly matching them for extension.
Nothing that I'd call a proper test. I knocked together a couple of MDF test boxes last year to try a few things out & this was one of them. There seemed to be a small difference. They were only in the garage though, rather than properly sited in the house. It's more an observation based on the 1/2 space sims that the nulls seemed to be better controlled, especially the 3rd harmonic, which seems to be ~ 3-4db less with the 1/5 line length placement. Whether that'd be audible in-room or not when damping's in place I don't know. You're probably right Greg, but anything that might help's worth a shot, right?
Something's just occured to me -exactly which driver are we talking about here? The FR8? Or the new FR8C? The published specs are different. Assuming both are accurate (I'll believe that when I see it) the old driver had a lower Vas 88 litres, rather than the new unit's 95.5-odd. Motor seems the same, but the old unit's (equally smoothed out) response looks like it has slightly less of a rise. 2KHz: new unit ~99db. Old unit ~95db. Cone material's changed too.
Alethos said:
Your description seems to jive pretty good with GM's theoretical analysis. The bass is lacking because most everything is plateaued up.
This plateau can only be EQed out... this is a standard trick that goes back to at least to Henry Kloss (at least the 1st time i encountered it). Add a parallel RLC shelving filter. The L controls where the LF are let loose, the C where the top is. The size of the R determines how much the mids are shelved down. (with your sensitivity to the top you may get away without the C, in which case it becomes what we know today as a BSC filter). I will go to great lengths to avoid passive filters, but sometimes you just have to bend. An added filter like this turned the Blue & Yellow specials i built from a table radio type sound to kick-*** (and made them happier with the Pioneer AV receiver they are being used with -- my godson (& his mother) love them)
As to the ripple, since you are prepared to abandon the box, cutting a k-slot would be a beneficial experiment to the entire community.
The only was to really deal with any spikes in the FR (the stuff the heavy metal guys like), is likely going to be cone treatment, and that is unreversible and at this point approachable only in very broad, generalized, non-specific strokes.
dave
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.