Hi!
I'm planning a second speaker project, and am considering using mid drivers from either seas or scan speak.
On the one hand I am looking at the 4.5 mid (12M/4631g) revelator from scan speak.
On the other hand, the seas Excel line, 5.5, 6.5 or 7 inch drivers.
I know that the scan speak drivers are somewhat more expensive, but ignoring that, how do the drivers compare?
And, as far as the Seas's woofers go, is there much of a difference in midrange quality with the differnt sized seas mids?
-thanks!
I'm planning a second speaker project, and am considering using mid drivers from either seas or scan speak.
On the one hand I am looking at the 4.5 mid (12M/4631g) revelator from scan speak.
On the other hand, the seas Excel line, 5.5, 6.5 or 7 inch drivers.
I know that the scan speak drivers are somewhat more expensive, but ignoring that, how do the drivers compare?
And, as far as the Seas's woofers go, is there much of a difference in midrange quality with the differnt sized seas mids?
-thanks!
Monroe,
Based on what I've seen I'm inclined to think that Seas are slightly better, but it is in part a matter of opinion, and how you rate them. Seas drivers are lower distortion, SS are low distortion as well, but some people prefer their sound.
Here is a good comparison by Linkwitz, some food for thought:
http://www.linkwitzlab.com/mid_dist.htm
The drivers you are considering are quite different, and you really need to compare drivers for the same purpose. IOW, you need to decide on the type of driver before you can really compare properly.
regards,
Paul
Based on what I've seen I'm inclined to think that Seas are slightly better, but it is in part a matter of opinion, and how you rate them. Seas drivers are lower distortion, SS are low distortion as well, but some people prefer their sound.
Here is a good comparison by Linkwitz, some food for thought:
http://www.linkwitzlab.com/mid_dist.htm
The drivers you are considering are quite different, and you really need to compare drivers for the same purpose. IOW, you need to decide on the type of driver before you can really compare properly.
regards,
Paul
Thanks for the link - was helpful.
I like the looks of the seas drivers, was just looking for a comparison to the smaller scan speaks because I see them on sale sometimes at a price that puts them on par with the seas excel.
If building a two way system (or a 2 way with subs), what sort of difference would i expect with using different sized mid drivers, in the seas excel line?
I see that the larger drivers (7 inch say, vs 5.5) are more sensitive and have lower crossover points - assuming the same tweeter (one of the excel tweeters, if thats appropriate), what sort of sonic difference could be expected between the larger / smaller drivers?
Thanks!
I like the looks of the seas drivers, was just looking for a comparison to the smaller scan speaks because I see them on sale sometimes at a price that puts them on par with the seas excel.
If building a two way system (or a 2 way with subs), what sort of difference would i expect with using different sized mid drivers, in the seas excel line?
I see that the larger drivers (7 inch say, vs 5.5) are more sensitive and have lower crossover points - assuming the same tweeter (one of the excel tweeters, if thats appropriate), what sort of sonic difference could be expected between the larger / smaller drivers?
Thanks!
I think the 12M/4631g is relatively new which accounts for higher cost.
I don't think there is a (large) quality difference. But the extra displacement offered by the larger cones brings them to the forefront (especially for a two way IMO). One reason to stay away from the Mag cone excels is the infamous response spike around 5kHz for 8" (around 10kHz for the small units) which adds to the crossover components.
According to someone I consider an expert with these drivers, you can cross over up to 2.5 kHz, but its not optimal. Both the 6,5" and 8" Seas Excel start to get increased distortion above 1.2 kHz.
The 8" should optimally be crossed in the 1.2 to 1.6kHz range which you may not like to do as it's in the supposed sensitive area of our listening range, and reduces the choice of tweeters considerably. In both instances (SS or SE) you should probably make a choice together with a tweeter to ensure they mate well and have crossable frequency range overlaps.
I've never used either, but for whats it's worth, I hope to use the SE 8" for my next project.
The Excel units has lower distortion and a cleaner sound than SS. To some ears the slightly colored warm sound from Scans are preferable. I find Scans musical but not the best performers.
The breakup must be surpressed with a notch filter and measurements is a must. Look at the Seas kit page... not many x-over components is required to achieve the lowpass.
I agree that a low x-ing with a good tweter is preferable with the Seas... on the other hand that goes for almost any driver.
The most critical area for crossing.... there are as many opinions on this as ther are speaker designers...
SL´s Orion is considered one of the absolute best speakers by the people that have auditioned it.. it crosses at 1440Hz...
/Peter
The breakup must be surpressed with a notch filter and measurements is a must. Look at the Seas kit page... not many x-over components is required to achieve the lowpass.
I agree that a low x-ing with a good tweter is preferable with the Seas... on the other hand that goes for almost any driver.
The most critical area for crossing.... there are as many opinions on this as ther are speaker designers...
SL´s Orion is considered one of the absolute best speakers by the people that have auditioned it.. it crosses at 1440Hz...
/Peter
Hmm...
What about a 7 inch excel woofer, such as W18EX001, or a 6.5?
The 6.5 inch model seems to have quite a bit less distortion around 1.5/2k - at least according to the datasheet.
Is this (the 6.5 inch) likely to be a better woofer in practice?
I'm not sure which tweeter to mate it with (for a 2 way system), was thinking about one of the seas excel tweets, the 002 probably - would this be appropriate, or is there a better way? The spec says that the tweeter can cross as low as 2000, would that be ok w/the 6.5 inch?
-Thanks!
What about a 7 inch excel woofer, such as W18EX001, or a 6.5?
The 6.5 inch model seems to have quite a bit less distortion around 1.5/2k - at least according to the datasheet.
Is this (the 6.5 inch) likely to be a better woofer in practice?
I'm not sure which tweeter to mate it with (for a 2 way system), was thinking about one of the seas excel tweets, the 002 probably - would this be appropriate, or is there a better way? The spec says that the tweeter can cross as low as 2000, would that be ok w/the 6.5 inch?
-Thanks!
Well there are a number of people that have built two ways using the W17 and W18. Doing a search should give you some ideas.
I think I remember reading (Linkwitz maybe) that the increasing distortion is misinterpreted sometimes due to the response spike. Once that's taken care of with a notch, I think it's a lot better.
Besides, I wouldn't pick the the w18 over the w21/w22 just because of the distortion figures. I would decide how much bass extension is required and go from there. You probably also need to bring the topology and size restrictions into account to make a choice...
Was this thread useful at all?
Finally, the Seas kits use both the 6.5" and 8" drives. See what x-over and tweeters they use together to get some ideas perhaps.
I think I remember reading (Linkwitz maybe) that the increasing distortion is misinterpreted sometimes due to the response spike. Once that's taken care of with a notch, I think it's a lot better.
Besides, I wouldn't pick the the w18 over the w21/w22 just because of the distortion figures. I would decide how much bass extension is required and go from there. You probably also need to bring the topology and size restrictions into account to make a choice...
Was this thread useful at all?
Finally, the Seas kits use both the 6.5" and 8" drives. See what x-over and tweeters they use together to get some ideas perhaps.
Thanks for the replies!
Perhaps I should just build one of the seas kits - that seems to be a logical direction, considering my lack of design experience.
The choice seems to be between the two ways (I like the Trym, an 8 inch excel w/the 002 tweeter), or one of the MTM designs.
What sort of difference would be had w/the MTM's? Is there much improvement in the sound?
Err; what is the difference (same tweeter, the 002) between a MTM with 5.5 or 6.5 drivers, and a TM with an 8 inch?
-Thanks!!
Perhaps I should just build one of the seas kits - that seems to be a logical direction, considering my lack of design experience.
The choice seems to be between the two ways (I like the Trym, an 8 inch excel w/the 002 tweeter), or one of the MTM designs.
What sort of difference would be had w/the MTM's? Is there much improvement in the sound?
Err; what is the difference (same tweeter, the 002) between a MTM with 5.5 or 6.5 drivers, and a TM with an 8 inch?
-Thanks!!
Thanks for the replies!
Perhaps I should just build one of the seas kits - that seems to be a logical direction, considering my lack of design experience.
The choice seems to be between the two ways (I like the Trym, an 8 inch excel w/the 002 tweeter), or one of the MTM designs.
What sort of difference would be had w/the MTM's? Is there much improvement in the sound?
Err; what is the difference (same tweeter, the 002) between a MTM with 5.5 or 6.5 drivers, and a TM with an 8 inch?
-Thanks!!
Perhaps I should just build one of the seas kits - that seems to be a logical direction, considering my lack of design experience.
The choice seems to be between the two ways (I like the Trym, an 8 inch excel w/the 002 tweeter), or one of the MTM designs.
What sort of difference would be had w/the MTM's? Is there much improvement in the sound?
Err; what is the difference (same tweeter, the 002) between a MTM with 5.5 or 6.5 drivers, and a TM with an 8 inch?
-Thanks!!
The distortion at 1.5 k is not affected by a notchfilter.
Also the difference between the 7" and 8" Excel units is not much when it comes to where the 3rdH peak occurs. "Only" drawback with the bigger unit is slightly worse dispersion in the upper range of the passband... that may be a small problem depending on the design. The W22 also has the lowest distortion at all frequecys below 1.5k or so.
Monroe,
Starting out with one of the Excel kits would be wise.. then you have a good reference to improve upon
.
/Peter
Also the difference between the 7" and 8" Excel units is not much when it comes to where the 3rdH peak occurs. "Only" drawback with the bigger unit is slightly worse dispersion in the upper range of the passband... that may be a small problem depending on the design. The W22 also has the lowest distortion at all frequecys below 1.5k or so.
Monroe,
Starting out with one of the Excel kits would be wise.. then you have a good reference to improve upon
./Peter
Hi Eric
"The distortion is reduced at the breakup/notch filter, i.e. 5kHz, not 1.5kHz.
Vikash,
I believe the distortion is not affected at the ~5k peak either. The amplitude is surpressed but the % of THD is still (probably) roughly about the same. I´m not sure about this but it seems like the magnesium cones has a "lot" of distortion at the point of break up... this is hardly visible at measurements on ceramic cones.
And.... if this distortion products is from the cone itself, then reducing excursion will not give less THD as a function from the motor and suspension non-linearitys.
Possibly, if the cone adds distortion as a direct function of the break up resonances (which I believe but have nothing to back it up) this is something that may be an effect that is or is not, related to excursion. ie. the harder the cone is driven, the more severe the breakup. I would love to see some deep investigation on this subject as it is still open to debate.
SL among others believes the cone/dome breakup resonances does not add distortion. Martin Colloms, Peter Moncrief and I suspect the engineeers at Seas, JM Lab/Focal and Accuton do believe the opposite.
/Peter
"The distortion is reduced at the breakup/notch filter, i.e. 5kHz, not 1.5kHz.
Vikash,
I believe the distortion is not affected at the ~5k peak either. The amplitude is surpressed but the % of THD is still (probably) roughly about the same. I´m not sure about this but it seems like the magnesium cones has a "lot" of distortion at the point of break up... this is hardly visible at measurements on ceramic cones.
And.... if this distortion products is from the cone itself, then reducing excursion will not give less THD as a function from the motor and suspension non-linearitys.
Possibly, if the cone adds distortion as a direct function of the break up resonances (which I believe but have nothing to back it up) this is something that may be an effect that is or is not, related to excursion. ie. the harder the cone is driven, the more severe the breakup. I would love to see some deep investigation on this subject as it is still open to debate.
SL among others believes the cone/dome breakup resonances does not add distortion. Martin Colloms, Peter Moncrief and I suspect the engineeers at Seas, JM Lab/Focal and Accuton do believe the opposite.
/Peter
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