In retrospect, I guess this is what keeps me from embracing small speakers except in near-field apps since I grew up in a mostly mono 'world', so if it can't do mono 'good enough'........
GM
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That's it, no conclusions?
I would like to know if you've build the pair and if you intend to keep them.
I've made some simulations with Hornresp with Tang Band W4 1320SJ and MarkAudio CHR70, and the TangBand is sort of similar but I presume better in reality because of the lower Fs and greater Xmax, however the CHR70 is very strong down to a tuning of 40Hz, stronger than the nominal SPL; one would expect it from a driver with a bassy reputation but when this is also confirmed by simulations the conclusions are obvious, it's a better driver for this kind of TL, and it should really rock the house even bellow 50hz. Actually I remember seeing somewhere in the CHR70 application thread a tapered TL which was hearable even under 40hz (it was a white enclosure, 10 to 1 taper).
By the way, for those who seek a 3" version for this enclosure might want to take a look at the TABAQ before starting to build a very long pipe for the their 3 incher - http://coolcat.dk/bjoern/TABAQ_TL_for_TB.pdf - as you can see you get down and flat to 55Hz with this design, simple build, column shape, and cheaper/simpler than the Fostex TL; the driver can be placed anywhere above the original position with no problem (you will get some ripple in the frequency response but the low end extension remains the same).
That's it, no conclusions?
I would like to know if you've build the pair and if you intend to keep them.
I've made some simulations with Hornresp with Tang Band W4 1320SJ and MarkAudio CHR70, and the TangBand is sort of similar but I presume better in reality because of the lower Fs and greater Xmax, however the CHR70 is very strong down to a tuning of 40Hz, stronger than the nominal SPL; one would expect it from a driver with a bassy reputation but when this is also confirmed by simulations the conclusions are obvious, it's a better driver for this kind of TL, and it should really rock the house even bellow 50hz. Actually I remember seeing somewhere in the CHR70 application thread a tapered TL which was hearable even under 40hz (it was a white enclosure, 10 to 1 taper).
By the way, for those who seek a 3" version for this enclosure might want to take a look at the TABAQ before starting to build a very long pipe for the their 3 incher - http://coolcat.dk/bjoern/TABAQ_TL_for_TB.pdf - as you can see you get down and flat to 55Hz with this design, simple build, column shape, and cheaper/simpler than the Fostex TL; the driver can be placed anywhere above the original position with no problem (you will get some ripple in the frequency response but the low end extension remains the same).
This thread is going nowhere...
I managed to discover the original track that was playing on those Fostex TLs, that was giving the wall shaking bass sounds from the video: it's called Kevin MacLeod - Basement Floor, and here is where I have found it - Royalty Free Music - if link does not work in you future epoque there was a code associated and it's ISRC: US-UAN-11-00538 . You can download it at the link ... it's "royalty free".
I managed to discover the original track that was playing on those Fostex TLs, that was giving the wall shaking bass sounds from the video: it's called Kevin MacLeod - Basement Floor, and here is where I have found it - Royalty Free Music - if link does not work in you future epoque there was a code associated and it's ISRC: US-UAN-11-00538 . You can download it at the link ... it's "royalty free".
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I don't have access to the M.King MathCad worksheets but I can show you what Hornresp shows in simulation. In the image there is a 46hz tuned TL which might be slightly different than the one build by Jameslc but it's the design I would chose, why? no need to go under 45 hz. But that's not the whole story... the simulation shows that you loose 2-4 db from the nominal SPL which is not good and I must add that there are other factors that may contribute to weak bass - mostly the placement of the terminus far from the floor or ceiling; in the video you can see that one of the enclosures was relatively close to the corner of the room, and both where in the immediate vicinity of the back wall (practically almost in contact - My Other Listening Room - YouTube - at 1:20). Another thing that may have an effect on the overall tonal balance is the distance to the listening position, in this case probably in bed which may be far enough to loose some of the highs, and being close to the opposing wall the bass might be stronger.
And if I got this far, here is what I thing might be a better idea: either you make a version of the enclosure with a driver offset of 0.2-0.3L and place the terminus in the back, basically you just put the driver in the back of the enclosure at 0.2 offset or move the terminus down as if it where on a chain the obtain the correct offset, or even better, design an enclosure that would for sure have enough bass, with the terminus near the floor, use expanding geometry etc. But since hexibase knows what he is doing and in both designs I showed earlier (the one in the video and this one Ok, I lied. Here are a few pics of my “almost” most recent build | MiltonBilt ) don't have expanding geometry or floor/ceiling loading it might work.
Theoretically it is thin in the lower end but then again I don't have one in my house, Jameslc has a pair, he might confirm or not what the simulations indicate.
A TABAQ style enclosure can be designed with the right tool (MJking's worksheets) that might be simple to build, column shaped, and probably with the same external dimensions as the original, but with the terminus/port where it should be.
I don't have access to the M.King MathCad worksheets but I can show you what Hornresp shows in simulation. In the image there is a 46hz tuned TL which might be slightly different than the one build by Jameslc but it's the design I would chose, why? no need to go under 45 hz. But that's not the whole story... the simulation shows that you loose 2-4 db from the nominal SPL which is not good and I must add that there are other factors that may contribute to weak bass - mostly the placement of the terminus far from the floor or ceiling; in the video you can see that one of the enclosures was relatively close to the corner of the room, and both where in the immediate vicinity of the back wall (practically almost in contact - My Other Listening Room - YouTube - at 1:20). Another thing that may have an effect on the overall tonal balance is the distance to the listening position, in this case probably in bed which may be far enough to loose some of the highs, and being close to the opposing wall the bass might be stronger.
And if I got this far, here is what I thing might be a better idea: either you make a version of the enclosure with a driver offset of 0.2-0.3L and place the terminus in the back, basically you just put the driver in the back of the enclosure at 0.2 offset or move the terminus down as if it where on a chain the obtain the correct offset, or even better, design an enclosure that would for sure have enough bass, with the terminus near the floor, use expanding geometry etc. But since hexibase knows what he is doing and in both designs I showed earlier (the one in the video and this one Ok, I lied. Here are a few pics of my “almost” most recent build | MiltonBilt ) don't have expanding geometry or floor/ceiling loading it might work.
Theoretically it is thin in the lower end but then again I don't have one in my house, Jameslc has a pair, he might confirm or not what the simulations indicate.
A TABAQ style enclosure can be designed with the right tool (MJking's worksheets) that might be simple to build, column shaped, and probably with the same external dimensions as the original, but with the terminus/port where it should be.
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i can back up what krakatoa is saying it is very thin in the lower end from what i can judge with the human ear. i have relocated them into simular set up thats in the video with being in the corner of the room and after doing that the bass was strong but with this design there is stuff all SPL which makes it sound like it isn't much bass but after saying that i am happy with this design but i wouldn't mind getting another pair of fostex and placing them vertical on the top of the box or directly opposite the front pair just to see if it improves the bass to make it less thin then it is now
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i presume by a baffle step compensation filters you mean sound damping material but i reacon i'm wrong anyway i did put some stuffing into the box's and it made next to no differents at this point it might be a good idea to step up in driver size in order to get more bass but that doesn't mean i'm happy with the 103en just think that more will be achieved going up in driver size
Nahh its an eletrical filter that attenuates frequencies above a certain point by 3db. When the size of the baffle is small compared to a quarter wavelength (if im not mistaken) of the reproduced frequency. At that point the sound goes from radiating into hhalf space (forward) into full space (all around) and therefore sounds quieter. To combat that you put the filter above the baffle step (that wavelenght) make the response flatter over the whole range.
Basically, the effect is boosted bass. I dont like to do this because it can cause over excursion issues, I generally try to wall or corner load the speakers to make it unnecessary or when needed add a bit of eq from my computer. It's easier and more flexible, but not everyone uses a source with adjustable eq...
re
This is an article about the baffle width - frequency response issue: http://www.quarter-wave.com/General/BSC_Sizing.pdf However if you want more bass (in strength) you can start by moving the enclosure closer to the walls or corners, and try different positions around the room (not just one wall, or the same 2 corners). Try to find out the position with the strongest response and see if you like it; the only thing that will make it stronger would be to put it under a desk or in some king of space that reminds an open enclosure (but then you won't be able to use it for listening, but that's the way to see what is the maximum).
The next thing is to use a different driver that has a higher Qts, a more excursion (xmax) or lower fs - these are the reasons for which you don't have much bass. As I said before MarkAudio CHR70 looks much better for this kind of enclosure (type and deep bass extension). You trade off sensitivity (4-5db). As I can see you don't know much about the theory - Loudness and Speaker Sensitivity - diyAudio - just in case you don't know what I was taking about. And another thing, aluminium cones (CHR70) don't sound in the same way as paper cones(Fe103En).
What I'm trying to say is that you do not necessarily need a larger driver, even though a larger driver will tend to have more bass, it depends again of the enclosure and driver specs. The main problem is that you may need to build a larger (by comparison) enclosure. If you have a small room stick with small drivers and choose wisely. And since we are talking about 4 inch drivers that do bass, planet10 said about CSS EL70, somewhere around the forum, that he has never heard of anything like that in the 4" class when it comes to low end. The El70 is almost identical to CHR70.
This is an article about the baffle width - frequency response issue: http://www.quarter-wave.com/General/BSC_Sizing.pdf However if you want more bass (in strength) you can start by moving the enclosure closer to the walls or corners, and try different positions around the room (not just one wall, or the same 2 corners). Try to find out the position with the strongest response and see if you like it; the only thing that will make it stronger would be to put it under a desk or in some king of space that reminds an open enclosure (but then you won't be able to use it for listening, but that's the way to see what is the maximum).
The next thing is to use a different driver that has a higher Qts, a more excursion (xmax) or lower fs - these are the reasons for which you don't have much bass. As I said before MarkAudio CHR70 looks much better for this kind of enclosure (type and deep bass extension). You trade off sensitivity (4-5db). As I can see you don't know much about the theory - Loudness and Speaker Sensitivity - diyAudio - just in case you don't know what I was taking about. And another thing, aluminium cones (CHR70) don't sound in the same way as paper cones(Fe103En).
What I'm trying to say is that you do not necessarily need a larger driver, even though a larger driver will tend to have more bass, it depends again of the enclosure and driver specs. The main problem is that you may need to build a larger (by comparison) enclosure. If you have a small room stick with small drivers and choose wisely. And since we are talking about 4 inch drivers that do bass, planet10 said about CSS EL70, somewhere around the forum, that he has never heard of anything like that in the 4" class when it comes to low end. The El70 is almost identical to CHR70.
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Hmm, what matters is the listening distance and width of the listening position [LP] WRT room width since we ideally don't want any first reflections in front of the LP. IOW it's the speaker's directivity above ~800 Hz that matters, not how large the room is per se, so it's not uncommon to need a large driver [or horn] in a small room to get sufficient directivity at the LP.
Agreed, I was rather surprised at its ability to play Pink Floyd's DSOTM without EQing down the LF and Brian Bromberg's 'Wood' at SPLs normally too high for the apartment app they were used in. The downside to this kind of performance though is that there's no audible distortion to warn one about impending mechanical contact like one gets with a typical rising rate suspension, though at least with the pair I have they withstood several such episodes when I was experimenting with different tunings without any apparent damage.
GM
so would it be worth getting a CSS EL70 but from what i can see the only benifit is a flatter response in the bass instead of the dip that the fostex do ? (thanks for posting that link too i'm not really right into speaker design but everyone got to start off somewhere
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No! you get 5-6 db extra in the bass! look at the graphs at (my post) no 52, the Fostex has a loss of 2-3 db compared to nominal SPL (at which almost all the sound from the rest of the audio spectrum are) while the MarkAudio model has a gain of a few db, and it's flat down to tuning frequency. As I said before the CHR-70 will not be as loud as the Fostex (85.4<89db) but comparably it will have much more bass output.
Yeah, to get a similar tonal balance with the Fostex will require using dual drivers and rolling one off at the baffle step. Even the couple of [others] much larger FE167E MLTLs I've auditioned didn't do DSOTM any better overall at modest average SPLs than at least the early EL70s I have. The 167's forte was the much 'fuller' mids a larger driver typically has.
GM
My question was more like "is there a common practice to pump a few extra db bellow 100hz to please the ear rather than the measurement equipment"? Obviously the flat response over the whole audio range would be the ideal but perhaps practice had something different to say.
Is there something wrong (bass is too weak) if you see 2-3db missing like in the Fostex simulation - can you fix it by placing the terminus near the floor?
Is there something wrong (bass is too weak) if you see 2-3db missing like in the Fostex simulation - can you fix it by placing the terminus near the floor?
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