Sure. There will be floor bounce, ceiling bounce, wall bounce ect. But that is not BSC.
I recently converted my Plutos to LXmini. In fact these are LXmini clones as I use software crossover (not miniDSP) and I equalised drivers myself, using REW measurements. These speakers sound so good and IMO are very significant upgrade in sound quality compared to Plutos, as already pointed out by others on this forum.
However, since I already own a pair of SS 18W-8535, I couldn’t resist temptation to try replacing LXmini Seas woofer in 4” tube with SS woofer in 6” tube. These become Lxmidi. I equalised both speakers to almost identical FR, using close up in room measurement, with microphone at tweeter axis and 6” distance from tweeter rim plane.
To my ears, Lxmidi sounds more pleasing in lower end and much more effortless at higher SPL.
However, I was surprised to discover that SPL at which 3rd harmonic distortion of 50Hz test signal goes over 1% is about the same for both speakers. Which is either great compliment to little Seas woofer or I am doing something wrong here. worth noting is that in these enclosures SS woofer is 6dB more efficient compared to Seas woofer (SS sound card output level i set 6dB lower than Seas output).
My Lxmidi woofer tubes are 6” ID filled with 330g acoustastuff (LXmini has 200g stuffing) and same length as LXmini 4” tubes. They are sealed by silicone glue at woofer rim and at MDF base.
I am newbie here and I would appreciate advice on any Lxmidi improvements which I could make.
Should I try and reduce or increase stuffing of SS woofer tube? Or maybe reduce tube volume which I can simply do by placing some sand bags to tube bottom?
However, since I already own a pair of SS 18W-8535, I couldn’t resist temptation to try replacing LXmini Seas woofer in 4” tube with SS woofer in 6” tube. These become Lxmidi. I equalised both speakers to almost identical FR, using close up in room measurement, with microphone at tweeter axis and 6” distance from tweeter rim plane.
To my ears, Lxmidi sounds more pleasing in lower end and much more effortless at higher SPL.
However, I was surprised to discover that SPL at which 3rd harmonic distortion of 50Hz test signal goes over 1% is about the same for both speakers. Which is either great compliment to little Seas woofer or I am doing something wrong here. worth noting is that in these enclosures SS woofer is 6dB more efficient compared to Seas woofer (SS sound card output level i set 6dB lower than Seas output).
My Lxmidi woofer tubes are 6” ID filled with 330g acoustastuff (LXmini has 200g stuffing) and same length as LXmini 4” tubes. They are sealed by silicone glue at woofer rim and at MDF base.
I am newbie here and I would appreciate advice on any Lxmidi improvements which I could make.
Should I try and reduce or increase stuffing of SS woofer tube? Or maybe reduce tube volume which I can simply do by placing some sand bags to tube bottom?
You've implemented your own design....pretty much.
You can further fiddle with the measured response to achieve your objective (whatever that is) but I'm not sure anyone can give you knowledgeable advice. The larger driver will become directional at a lower frequency, so maybe you'd want to experiment with the crossover frequency too.
The trade-off is the larger woofer will obviously yield more low end. But that was your intent I take it.
Cheers,
Dave.
You can further fiddle with the measured response to achieve your objective (whatever that is) but I'm not sure anyone can give you knowledgeable advice. The larger driver will become directional at a lower frequency, so maybe you'd want to experiment with the crossover frequency too.
The trade-off is the larger woofer will obviously yield more low end. But that was your intent I take it.
Cheers,
Dave.
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Hi Dave,
Thanks for your reply.
Yes, apart from curiosity, my motivation was to improve lower end because I prefer the sound of these speakers when they are placed further away from front wall. In which case I get less bass boost from wall reflection. I know that LXmini was designed for placement closer to front wall and I suspect this is one of the reasons LXmini woofer is equalised less aggressively towards low end compared to Pluto.
But I remember that idea of using larger woofer for Pluto was floating around on this forum earlier. It was then also pointed out the argument about beaming effect of larger woofer and need for lower crossover frequency. However, looking at data sheets of two drivers
http://www.scan-speak.dk/datasheet/pdf/18w-8535-00.pdf
http://www.seas.no/images/stories/prestige/pdfdatasheet/H1480-08_L16RN-SL_Datasheet.pdf
I can see quite opposite, that 8535 starts beaming at higher frequency. Is it maybe due to different shape of dust cap?
Compared to Pluto 1KHz crossover frequency, LXmini is crossed over even lower, which also reduces effect of beaming. I am worried that reducing crossover frequency may reduce SPL capability of FR driver.
By the way, after I built my Plutos, I had a setup where I could quickly switch between my Proac 2.5 clones and Plutos for AB testing. I also asked my friends for opinion and consensus was that although Plutos are fine speakers they are not worthy replacing Proac clones. With LXmini clones it seems to be quite opposite and that is how I ended up with pair of spare 8535.
cheers
Kerim
Thanks for your reply.
Yes, apart from curiosity, my motivation was to improve lower end because I prefer the sound of these speakers when they are placed further away from front wall. In which case I get less bass boost from wall reflection. I know that LXmini was designed for placement closer to front wall and I suspect this is one of the reasons LXmini woofer is equalised less aggressively towards low end compared to Pluto.
But I remember that idea of using larger woofer for Pluto was floating around on this forum earlier. It was then also pointed out the argument about beaming effect of larger woofer and need for lower crossover frequency. However, looking at data sheets of two drivers
http://www.scan-speak.dk/datasheet/pdf/18w-8535-00.pdf
http://www.seas.no/images/stories/prestige/pdfdatasheet/H1480-08_L16RN-SL_Datasheet.pdf
I can see quite opposite, that 8535 starts beaming at higher frequency. Is it maybe due to different shape of dust cap?
Compared to Pluto 1KHz crossover frequency, LXmini is crossed over even lower, which also reduces effect of beaming. I am worried that reducing crossover frequency may reduce SPL capability of FR driver.
By the way, after I built my Plutos, I had a setup where I could quickly switch between my Proac 2.5 clones and Plutos for AB testing. I also asked my friends for opinion and consensus was that although Plutos are fine speakers they are not worthy replacing Proac clones. With LXmini clones it seems to be quite opposite and that is how I ended up with pair of spare 8535.
cheers
Kerim
Stereophile article of RMAF, with some raving about LXmini
RMAF 2014: Reichert on Sunday | Stereophile.com
RMAF 2014: Reichert on Sunday | Stereophile.com
Wow, hard to believe anyone with even a half-way decent center channel could ever have that experience - unless - they did not try boosting the volume of the center channel.
I often found that if I did not want the movie playing so loudly that it disturbed my neighbors, I sometimes had trouble easily hearing the dialog clearly. Setting the center channel to around +3 db was a quick and easy solution to this problem, for that alone I would not even consider eliminating the center channel in any setup for movie playback other than a dedicated home theater room where sound isolation (or distance from other people's houses) protected them from the noise of movie sound tracks. But then again, it would seem absurd to have a dedicated home theater without a good quality center channel 🙂
My friend and I did lots of testing of several types of center channels including comparison to using modes such as "phantom center" or just plain old stereo and it was quite clear and conclusive that having a center channel was definitely superior for home theater use (watching movies / TV shows). For 99% of music listening I would not use any mode other than straight up "stereo direct" (no center, no surround, but I suppose if/how you have your subwoofers setup might influence the decision to use some form of processing in a receiver).
We also concluded that a center channel needs to do one thing well above all others: reproduce the human voice clearly. It seems stupid to even consider "matching" the center to your other speakers a priority as that is not nearly as important as going for the utmost clarity in vocal replication possible. Having said that, I still prefer a mediocre center channel over no center channel.
We watched hundreds of movies and TV shows throughout our testing and chose a selection of test tracks to expose the weak points of speakers in regards to their vocal reproduction as the human ear + mind is so finely tuned to receiving the human vocal range, and thus is prone to noticing when the reproduction is not quite right. One of my favorite test pieces is the speech at the end of Blackhawk Down: https://www.youtube.com/watch?v=t4YnPFsvSqs - of course, Youtube will not be the best quality source, the link is just to show you what I'm talking about.
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I've noticed that some additional reflections off of the back wall improve intelligibility.
This is intriguing, because logically, it would be the exact opposite.
A couple years back I saw a Harman paper which indicated the same thing, but I'm too lazy to Google it.
This is intriguing, because logically, it would be the exact opposite.
A couple years back I saw a Harman paper which indicated the same thing, but I'm too lazy to Google it.
Hi,
what x-over software are you using? running from windows? any details is welcomed.
My HTC is old apple mac mini running OS X. Crossover software is Au Lab with various plugins, as described here:
Andrew McPherson - Tech - using CrossoverUnit
This is all free software, but best best option IMO is Fabfilter Pro Q2 plugin which is quite expensive although free evaluation is available. Fabfilter works for windows too. With Fabfilter you can easily switch between min. phase and linear phase filters with single click
Andrew McPherson - Tech - using CrossoverUnit
This is all free software, but best best option IMO is Fabfilter Pro Q2 plugin which is quite expensive although free evaluation is available. Fabfilter works for windows too. With Fabfilter you can easily switch between min. phase and linear phase filters with single click
About speech localiization,
My Yamaha HT receiver has adjustable delay for center channel (and rear channels) in milliseconds. My Onkyo HT receiver has adjustable speaker distance setting. These settings work for DD and ProLogic likewise
Center speaker distance /delay setting is crucial for eg. speech localisation, just try it! One millisecond will do miracles! No need for dB correction usually. I usually set it By listening to news or some other progamme that I know to be mono or well focused.
My Yamaha HT receiver has adjustable delay for center channel (and rear channels) in milliseconds. My Onkyo HT receiver has adjustable speaker distance setting. These settings work for DD and ProLogic likewise
Center speaker distance /delay setting is crucial for eg. speech localisation, just try it! One millisecond will do miracles! No need for dB correction usually. I usually set it By listening to news or some other progamme that I know to be mono or well focused.
I'm interested in experimenting with these kind of speakers, but I find the pdf for the project rather expensive. And I'm not even sure if the principle is explained well enough there. I don't want to build the exact project, but rather get an idea of what's all about and experiment with materials and speakers that I can find where I live.
So tell me if I got this right: you basically have a woofer mounted in a sealed and stuffed tube facing upwards. Then you have a fullrange which acts as a mid-high range (so they're crossed over at about 300Hz), and the full range's phase is inverted.
How do you calculate the length of the tube, the position of the fullrange, the tube behind the fullrange? What drivers should be used?
Sorry if I'm being dumb, but for a begginer like myself all these cardioid, monopole, dipole stuff is really confusing.
So tell me if I got this right: you basically have a woofer mounted in a sealed and stuffed tube facing upwards. Then you have a fullrange which acts as a mid-high range (so they're crossed over at about 300Hz), and the full range's phase is inverted.
How do you calculate the length of the tube, the position of the fullrange, the tube behind the fullrange? What drivers should be used?
Sorry if I'm being dumb, but for a begginer like myself all these cardioid, monopole, dipole stuff is really confusing.
This seems to have gone pretty quiet lately but I can say I heard the LX Mini Studio's at Burning Amp and they were damn fantastic. The Studio version adds a pair of dipole subwoofers used with the LX521. I would imagine other sub options (like MJK's H Frames) might substitute as well. I'd say the Mini's give a tremendous amount for the money.
I am 1/2 way through the building of my minis but made some revisions. I decided to use a 6" pipe instead of a 4" to minimize the bottleneck in the area of the magnet assembly. This also allowed me to simply mount the MR on a 6" pipe cap with a hole cut for it using a coping saw. FR testing confirmed a response similar to SL's but maybe 2 db below his on the low end which I figured I could EQ. I'm hesitant to post graphs since I'm not proficient enough in REW to guarantee the results. I also changed from acousta-stuff to rolled sheets of polyester after seeing some irregularities in response with the acoustic stuff which I attributed to its bunching up after awhile. The poly stays put and produced a slightly flatter response but w/ slightly more distortion. Possibly adjusting the quantity of it might help. So far so good. But in listening tests I stuck my ear to the side of the pipe and was quite annoyed at the amount of sound radiating from it. ( I wonder if there would be more or less from a 4" pipe...? ) I tamed it using acoustic treatment material similar to that for cars but intended for roofing insulation - the kind that has a metal foil on one side and a tar-like substance on the other - cheap at the hardware store. - I put it on both the inside and outside and am happy with the results so far 🙂
6" pipe has a much larger internal volume than 4" pipe of the same length. As you noticed this will change the bottom end response of the L16 driver quite a bit. The existing equalization of the driver needs to be changed.
I used 6" green pipe from the local home center. It works well. If using the white 6" PVC pipe you might have procured some that has much thinner wall thickness. I don't like it. 🙂
I also like the idea of using rolled sheets of polyester. I used that myself and even density stuffing is obviously much easier to attain. It also provides a more defined "center" that you can run the woofer speaker wire through.
Good luck with your build.
Dave.
I used 6" green pipe from the local home center. It works well. If using the white 6" PVC pipe you might have procured some that has much thinner wall thickness. I don't like it. 🙂
I also like the idea of using rolled sheets of polyester. I used that myself and even density stuffing is obviously much easier to attain. It also provides a more defined "center" that you can run the woofer speaker wire through.
Good luck with your build.
Dave.
I was wondering if there would be any benefit of sticking some panel damping to the inside of the pipe such as 5mm bitumen sheet as used in critically damped thin wall enclosures like LS3/5A, LS5/9, BC1 etc? The use of 6" pipe would make this a lot easier as 4” pipe has too small a radius to bend the bitumen sheet without cracking.
How does a cylinder compare with a box when it comes to panel resonance/radiation?
Only reason I ask is I have loads of the stuff left over from another speak build.
How does a cylinder compare with a box when it comes to panel resonance/radiation?
Only reason I ask is I have loads of the stuff left over from another speak build.
There is also an inexpensive (well, very inexpensive) alternative to the Studio woofers on the forum website, utilizing two Peerless woofers and two flat-pack boxes from Parts Express. Designed by Davey, by the way.
Dave,
Do you mind sharing how you approached this modification? Did you use a shorter pipe to maintain the same internal volume, or did you re-equalise for a larger volume?
A related question is how important is the particular shape of the long heavily filled pipe for matching to the original equalisation? Would a rectangular conventional enclosure of the same internal volume and equally heavily stuffed produce close enough to identical bass response? I do understand that a key part of the LXmini design is the very narrow baffle, but my question is about the lower bass response.
I'm asking because I am about to build a second set of the LXminis for use in my kitchen where I can't accommodate the original length tube. I'm looking at using 6 inch tube or maybe a box enclosure, and I'm wondering how to design around that.
Thanks,
Graham.
I have the LXMinis as well. they are truly spectacular for the presence and the lack of coloration. some simpler music and vocals they execute really well. However on more demanding music they seem to lack the radiating surface to pull off upper bass-lower mid without congestion, and they definitely are not for anything disco-like. but one wonders if a speaker with a significantly bigger low end driver (a 10incher maybe?) and a similar dispersion pattern would have been a true kick a-- 🙄?
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