Bill
Great to hear you're onboard, can't wait to get these built up...
As i have ordered 5 drivers there is a chance of playing wih a twin woofer option - the crossovers feel a lot cleaner in simulation with 2 than 1, and I'm quite keen on the increased power handling - at least for my main two speakers.
As said, I'll get some in-cabinet measurements before i do anything else, currently I'm thinking to do listening tests in 2 stages:
1. Compare crossover topologies for 1st/2nd/4th orders (electrically) wih phase alignment for the 2nd/4th orders, and build a final, more complex xo with a flatter FR but no phase compensation
When a topology has been chosen I'd like to compare the exact same xo with a few different capacitors, and see if it's really worth spending more or not. Choice of capacitor candidates will of course depend upon the final chosen xo design... there's no way I'm buying mundorf supremes for a 4th order electrical, wouldn't bat an eyelid if its for a 1st order.
Problem is, if better caps really do sound better, would a 4th order xo with midrange caps that sounded better than a 1st order then be bested by the 1st order xo if higher quality caps were used? no way to tell without listening i guess... maybe I'll compare caps in two topologies to be sure
Great to hear you're onboard, can't wait to get these built up...
As i have ordered 5 drivers there is a chance of playing wih a twin woofer option - the crossovers feel a lot cleaner in simulation with 2 than 1, and I'm quite keen on the increased power handling - at least for my main two speakers.
As said, I'll get some in-cabinet measurements before i do anything else, currently I'm thinking to do listening tests in 2 stages:
1. Compare crossover topologies for 1st/2nd/4th orders (electrically) wih phase alignment for the 2nd/4th orders, and build a final, more complex xo with a flatter FR but no phase compensation
When a topology has been chosen I'd like to compare the exact same xo with a few different capacitors, and see if it's really worth spending more or not. Choice of capacitor candidates will of course depend upon the final chosen xo design... there's no way I'm buying mundorf supremes for a 4th order electrical, wouldn't bat an eyelid if its for a 1st order.
Problem is, if better caps really do sound better, would a 4th order xo with midrange caps that sounded better than a 1st order then be bested by the 1st order xo if higher quality caps were used? no way to tell without listening i guess... maybe I'll compare caps in two topologies to be sure
have a look for clearance deals on good quality caps, there are a few. Europe Audio site is worth browsing occasionally. Otherwise, Ansar supersounds are good budget caps, Mundorf Evo Oil's are a good value and well performing mid cap imo
Hi Nannoo, just make sure you don't get hung up on the electrical slope/phase of the crossovers. What matters is the final accoustic slope and phase matching!
Using a combination of 2nd and 3rd order on woofer/tweeter is often the way to go to get 4th order acoustic. Depends on the drivers (something flat way past the crossover point may need a 4th order electrical). It may also be possible to use either a second order electrical or a 3rd order electrical filter on the same driver to end up with similar fr curve, but the phase matching will be much better with one, than with the other.
Tony.
Using a combination of 2nd and 3rd order on woofer/tweeter is often the way to go to get 4th order acoustic. Depends on the drivers (something flat way past the crossover point may need a 4th order electrical). It may also be possible to use either a second order electrical or a 3rd order electrical filter on the same driver to end up with similar fr curve, but the phase matching will be much better with one, than with the other.
Tony.
nannoo if u have not been on hifi collective then try, they have a great selection of crossover components, bit pricey though. Audio Components is another and Wilmslow Audio.
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Loudspeaker components, restoration, design and build
Speaker Repair, Speaker Kits, Loudspeaker Repair, Kits and Drive Units, Subwoofer Amplifier Kit
Hi,
I've no axe to grind. 1st order acoustic x/o are horribly
difficult compared to 1st order electrical which aren't
generally anywhere in reality near 1st order acoustic.
rgds, srerten.
I've no axe to grind. 1st order acoustic x/o are horribly
difficult compared to 1st order electrical which aren't
generally anywhere in reality near 1st order acoustic.
rgds, srerten.
In general people tend to believe what suits them fine and
it seems to be the same in this area of interest. The truth as I
see it, neither too many, nor too few of parts. Just enough to
achieve the goal and the importance of defining it is essential.
You've gathered enough information to do your own research.
Have faith and think like an engineer.
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I kept two Thiel_inc. jpegs on my computer as a reminder of the complexity of a "good quality" ACOUSTIC 1st order crossover. The SPL vs. Freq. of any speaker is bumpy, and has natural roll-offs from physical mass and suspension compliance. Since a true 1st order acoustic crossover demands an overlap between the two drivers over a wide frequency range, the crossover must have many complex passive components to compensate for these SPL blips.
An ELECTRICAL 1st order crossover can be built from one capacitor and one inductor, but the ACOUSTIC response will be too funky to reproduce music.
Everything we needed to know we learned in kindergarden... "music is sound that is pleasing to the ears."
An ELECTRICAL 1st order crossover can be built from one capacitor and one inductor, but the ACOUSTIC response will be too funky to reproduce music.
Everything we needed to know we learned in kindergarden... "music is sound that is pleasing to the ears."
Attachments
Afternoon all,
just to bring this thread up to speed, the drivers are now in cabinets, very ugly sealed MDF boxes but I can finish them later when I'm happy with the sound.
The XO sim from crossover designer 7 has proved to be very accurate, which is always a total win. Have built into sealed boxes, which sound great by oh-my do I miss bass! In the middle of moving house so hopefully when I do I can get my sub to start taking over about 120 and it won't feel so much like something is missing, but in the mean time the clarity is great.
Right now I'm running these with 2nd order crossovers, cheap ish components and very pleasurable to listen to, if a little forward - but that was to be expected given the XO design (is a little hot at the top end as I was looking for an electrical 2nd order that worked with what I had laying around once I'd built the cabinets)
From playing with crossover sims it seems inevitable I'm going to end up going for a 4th order electrical crossover - I can get an almost perfectly flat response, impedance and phase alignment with no additional components, bar a voltage div on the tweeter.
Only problem with that of course is cost of caps and inductors - the 4th order model uses a 10uF and 15uF cap on the tweeter, as the drivers have high potential I'm fairly keen on using mundorf supreme caps for the tweeter circuit.. that leaves me at a bill of over £100 just for tweeter caps... probably worth it, but maybe a more long term solution.
In the mean time I have lots of other caps laying around if anyone wants to do some swaps 😉
just to bring this thread up to speed, the drivers are now in cabinets, very ugly sealed MDF boxes but I can finish them later when I'm happy with the sound.
The XO sim from crossover designer 7 has proved to be very accurate, which is always a total win. Have built into sealed boxes, which sound great by oh-my do I miss bass! In the middle of moving house so hopefully when I do I can get my sub to start taking over about 120 and it won't feel so much like something is missing, but in the mean time the clarity is great.
Right now I'm running these with 2nd order crossovers, cheap ish components and very pleasurable to listen to, if a little forward - but that was to be expected given the XO design (is a little hot at the top end as I was looking for an electrical 2nd order that worked with what I had laying around once I'd built the cabinets)
From playing with crossover sims it seems inevitable I'm going to end up going for a 4th order electrical crossover - I can get an almost perfectly flat response, impedance and phase alignment with no additional components, bar a voltage div on the tweeter.
Only problem with that of course is cost of caps and inductors - the 4th order model uses a 10uF and 15uF cap on the tweeter, as the drivers have high potential I'm fairly keen on using mundorf supreme caps for the tweeter circuit.. that leaves me at a bill of over £100 just for tweeter caps... probably worth it, but maybe a more long term solution.
In the mean time I have lots of other caps laying around if anyone wants to do some swaps 😉
*though the acoustic slopes will be 4th order linkwitz-riley. I have enough inductors and caps laying around to make the 4th orders but they'll be pretty ugly - i.e. three inductors of different values to make the first inductor for the bass, mixtures of electrolytic and poly caps on the tweeters etc. will probably try it later on though as it would be very interesting to compare a poorly constructed 4th order to a 2nd order without the circuit mess, you never know, it may sound better anyway
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Hi nannoo, I am thinking of making a pair of 2-ways with the SB15's and a Seas tweeter paired with a sub and wondered how these speakers ended up for you and overall performance combined with the sub?
Thanks!!
Thanks!!
Hi,
Never really used them with a sub, but yes they're great high value drivers, certainly capable of performance beyond their cost. currently in a 7L enclosure tuned to approx 60Hz, this isn't ideal as was intended to be sealed but the bass response with baffle step was horrible (18*30cm baffle)
If you see my other threads you'll see that I'm now planning on re-building with a pair of 15's and the 12M midrange in a 3-way tower.
A few notes, with the 15 as mid woofer you want to cross low to avoid the nasty break up, this was best when I was running a 4th order at about 1750Hz, though ideally i would have liked that to be around 2.2kHz.
I chose the seas tweeters for their low distortion and ability to go low down, there's no doubt that seas tweeters work superbly with SB drivers.
Which particular drivers are you looking at and what type of enclosure? Also have you looked at the box calculators linked from the sb website? what do you think of them?
Never really used them with a sub, but yes they're great high value drivers, certainly capable of performance beyond their cost. currently in a 7L enclosure tuned to approx 60Hz, this isn't ideal as was intended to be sealed but the bass response with baffle step was horrible (18*30cm baffle)
If you see my other threads you'll see that I'm now planning on re-building with a pair of 15's and the 12M midrange in a 3-way tower.
A few notes, with the 15 as mid woofer you want to cross low to avoid the nasty break up, this was best when I was running a 4th order at about 1750Hz, though ideally i would have liked that to be around 2.2kHz.
I chose the seas tweeters for their low distortion and ability to go low down, there's no doubt that seas tweeters work superbly with SB drivers.
Which particular drivers are you looking at and what type of enclosure? Also have you looked at the box calculators linked from the sb website? what do you think of them?
Hi,
Thanks for the update on your project, I will check out your other threads, the 3 way tower sounds interesting.
This will actually be my first build and am looking at the 15NRX or 15MFC for mids and one of the Seas 27 tweeters, possibly 27TBCD as the off-axis performance looks appealing, though am undecided whether to go for aluminium or soft for the tweeter at the moment. As far as enclosure is concerned, I don't really want to go bigger than 10 litres, but they seem to look good for a 9-10 litre box tuned down to around 50Hz. Your comment regarding the size of the baffle is a little concerning though as that is the size I have pegged for this one, lol!
I have only simmed the different drivers so far and the sim seems to suggest the same as you're saying with regards crossing at 1750Hz.
I didn't notice the box calculators, tbh, but will check them out to see how they tally with the likes of WinISD and Unibox.
Thanks!!
Thanks for the update on your project, I will check out your other threads, the 3 way tower sounds interesting.
This will actually be my first build and am looking at the 15NRX or 15MFC for mids and one of the Seas 27 tweeters, possibly 27TBCD as the off-axis performance looks appealing, though am undecided whether to go for aluminium or soft for the tweeter at the moment. As far as enclosure is concerned, I don't really want to go bigger than 10 litres, but they seem to look good for a 9-10 litre box tuned down to around 50Hz. Your comment regarding the size of the baffle is a little concerning though as that is the size I have pegged for this one, lol!
I have only simmed the different drivers so far and the sim seems to suggest the same as you're saying with regards crossing at 1750Hz.
I didn't notice the box calculators, tbh, but will check them out to see how they tally with the likes of WinISD and Unibox.
Thanks!!
let me know how you get on, will be interesting to compare notes.
The xo for the 2-ways I'm currently running is just with parts I had laying around, will probably re-build soon but am having serious measurement problems in my new flat :/
Ideally I want to see how far I can push these before I go into the 3 way build
The xo for the 2-ways I'm currently running is just with parts I had laying around, will probably re-build soon but am having serious measurement problems in my new flat :/
Ideally I want to see how far I can push these before I go into the 3 way build
Hi nannoo, have you tried a notch on the SB15? Might be tricky due to the wideness of the peak. Have you got impedance measurements for the SB15 (for a sim)? The datasheet cuts off short.
I assume that the peak was giving you grief, were you going for a 2nd or 4th order rolloff, I'm not sure from the previous posts.
Tony.
I assume that the peak was giving you grief, were you going for a 2nd or 4th order rolloff, I'm not sure from the previous posts.
Tony.
Because I was/am crossing so low there's no problem with the peak, either 2nd or 4th order.
I've run various sims through PCD 7, but without the baffle step (which was basically a flat drop from 100 to 1000Hz of about 6db) so the sound wasn't right-very clear and bright obviously, but in a sealed cabinet 4th order electrical they sounded way too thin. My old room was smaller and the positioning of the speakers meant baffle step was minimal, so they worked a lot better there - one of the reasons why I consider a full 6db baffle step as usually bad practice, it makes no sense to drop so much when the energy is still there in the room and going to interact in some way (though obviously in a larger room and open space as I have now that really is minimal)
Porting the sealed enclosures has helped no end with bass response, however there is no doubt the tuning is bad and this is causing the midrange to sound a bit confused, that's a large part of the appeal of a dedicated 3 way and midrange, and aligns with my previous experience - invariable, the 3 way speakers I have built in the past have had a realism with vocals that seems to 'bring the artist into the room' rather than just 'sound really nice' - that's not to say the 2-ways can't be superb, on things like madonna's frozen or michael j's human nature they sound excellent, but again the lower mids just aren't quite right.
Another problem I'm facing is my set up is a big step down from what it used to be (due to being a student and hawking stuff on ebay) so I don't have a high end amp/cd player at the moment. I'm running a FiiO DAC (£30 of amazon) through a Denon PMA 250 integrated amplifier - I'm pretty sure I'm near the limit of what this front end can achieve, so improvements in crossover topology are hard to identify.
I used the measurements from zaph for both impedance and spl measurements, imported into PCD 7 using dagra, where curves ended early I simply continued the curve, I felt it was safer to work with data from one source as I didn't get around to measuring drivers in cabinet - ideally this is the next move before anything else.
I've tried everything you could imaging regarding sims, my main objectives are to present a stable (flat) load to the amplifier, with minimal phase shift (electrical to the amplifier) a flat summed and power response and relative co-herant phase response from the drivers (within 10 degrees or so)
I do believe that crossovers should be kept as simple as possible, however fully accet that under certain conditions additional complexities are unavoidable, be it notch filters or flattening impedance.
I try to pay careful attention to what is really going on electrically so that there is a tru balance with the system, and do believe that great care needs to be taken when adding things like notch filters, which can be very useful, but the interactions of inductance and capacitance/resonances through the entire transfer function is something I want to minimize and therefore simpler is better in many ways. Obviously I have many other ideas about how I like to design crossovers but not worth mentioning here.
The benefits of a notch filter in the sims wasn't worth the hassle, either in financial component cost, increased complications or final results, the crossover frequency was low enough anyway.
Playing with the sim today I introduced a BSC for the first time with real seriousness.
(not just playing)
I came up with a 4th order electrical solution using LR4 targets hitting about 2.2kHz xo, however the cost of caps alone would be about £50, more than I'd want to spend on a 2 way when I know a 3 way is in the future (those big 2nd caps on higher order tweeter crossovers really put me off from a cost perspective, especially crossing this low where a 22uf cap is required)
I reconsidered with a 2nd order electrical and baffle step maintained. That's currently looking like a very good solution however still no point ordering the parts until I've measured and confirmed these actual drivers in these cabinets - then I'll get a lot closer.
When minor note that I liked, using the BSC circuit and a VERY large cap in the woofer filter allowed me to avoid much of a peak in impedance at the xo frequency - from aout 150Hz the impedance stays within 7.5 to 8.5 ohms. This also means I can use a very low value inductor - lower DCR, lower cost, win win in my books.
I don't mind the cost of a standard M-cap for the woofer bypass...
would be really interesting to see if these ideas and opinions align with the experiences and opinions of others on the forum though
I've run various sims through PCD 7, but without the baffle step (which was basically a flat drop from 100 to 1000Hz of about 6db) so the sound wasn't right-very clear and bright obviously, but in a sealed cabinet 4th order electrical they sounded way too thin. My old room was smaller and the positioning of the speakers meant baffle step was minimal, so they worked a lot better there - one of the reasons why I consider a full 6db baffle step as usually bad practice, it makes no sense to drop so much when the energy is still there in the room and going to interact in some way (though obviously in a larger room and open space as I have now that really is minimal)
Porting the sealed enclosures has helped no end with bass response, however there is no doubt the tuning is bad and this is causing the midrange to sound a bit confused, that's a large part of the appeal of a dedicated 3 way and midrange, and aligns with my previous experience - invariable, the 3 way speakers I have built in the past have had a realism with vocals that seems to 'bring the artist into the room' rather than just 'sound really nice' - that's not to say the 2-ways can't be superb, on things like madonna's frozen or michael j's human nature they sound excellent, but again the lower mids just aren't quite right.
Another problem I'm facing is my set up is a big step down from what it used to be (due to being a student and hawking stuff on ebay) so I don't have a high end amp/cd player at the moment. I'm running a FiiO DAC (£30 of amazon) through a Denon PMA 250 integrated amplifier - I'm pretty sure I'm near the limit of what this front end can achieve, so improvements in crossover topology are hard to identify.
I used the measurements from zaph for both impedance and spl measurements, imported into PCD 7 using dagra, where curves ended early I simply continued the curve, I felt it was safer to work with data from one source as I didn't get around to measuring drivers in cabinet - ideally this is the next move before anything else.
I've tried everything you could imaging regarding sims, my main objectives are to present a stable (flat) load to the amplifier, with minimal phase shift (electrical to the amplifier) a flat summed and power response and relative co-herant phase response from the drivers (within 10 degrees or so)
I do believe that crossovers should be kept as simple as possible, however fully accet that under certain conditions additional complexities are unavoidable, be it notch filters or flattening impedance.
I try to pay careful attention to what is really going on electrically so that there is a tru balance with the system, and do believe that great care needs to be taken when adding things like notch filters, which can be very useful, but the interactions of inductance and capacitance/resonances through the entire transfer function is something I want to minimize and therefore simpler is better in many ways. Obviously I have many other ideas about how I like to design crossovers but not worth mentioning here.
The benefits of a notch filter in the sims wasn't worth the hassle, either in financial component cost, increased complications or final results, the crossover frequency was low enough anyway.
Playing with the sim today I introduced a BSC for the first time with real seriousness.
(not just playing)
I came up with a 4th order electrical solution using LR4 targets hitting about 2.2kHz xo, however the cost of caps alone would be about £50, more than I'd want to spend on a 2 way when I know a 3 way is in the future (those big 2nd caps on higher order tweeter crossovers really put me off from a cost perspective, especially crossing this low where a 22uf cap is required)
I reconsidered with a 2nd order electrical and baffle step maintained. That's currently looking like a very good solution however still no point ordering the parts until I've measured and confirmed these actual drivers in these cabinets - then I'll get a lot closer.
When minor note that I liked, using the BSC circuit and a VERY large cap in the woofer filter allowed me to avoid much of a peak in impedance at the xo frequency - from aout 150Hz the impedance stays within 7.5 to 8.5 ohms. This also means I can use a very low value inductor - lower DCR, lower cost, win win in my books.
I don't mind the cost of a standard M-cap for the woofer bypass...
would be really interesting to see if these ideas and opinions align with the experiences and opinions of others on the forum though