Hi Tinitus!
Thanks for your input. I'll check out the MCA14 as well, I wasn't aware of it. I might investigate the Peerless HDS tweeter as well, thanks. grant
Thanks for your input. I'll check out the MCA14 as well, I wasn't aware of it. I might investigate the Peerless HDS tweeter as well, thanks. grant
Well, my mistake - there is no MCA14 - typo error
I would think the MCA15RCY would be the better choice
Maybe a simulation could tell something
I would think the MCA15RCY would be the better choice
Maybe a simulation could tell something
Hi Sreten,
Wow, the MCA15RCY seems even better than the MCA12RC! To quote Troels: .."MCA15RCY: Not an everyday sight. Flat from 200 Hz to 5 kHz and modest wrinkles from 5-10 kHz. Sensitivity = 90 dB/2.8V. This driver is flat over almost 5 octaves! Too good to be true. Playing music on the midrange alone didn't sound bad at all. The sound appears neutral with no aggressive tendencies".... You couldn't get a much better recommendation than that, thank you!
To me the MCA15 has some advantages (over the MCA12), higher SPL, nicer looking response curve, slight 'BBC dip', no peak at 10kHz and it would probably fit better into the existing hole!
Have you listened to both of these/ any experience with them?
Troels mentioned (in 3wayClassic) that the MCA12RC transient response was superb. Would this be related to the voice coil height? For the MCA12 its 5.8mm. To quote Troels again:.."the only thing that differentiates the MCA15RCY from the CA15LRY is a slightly higher Fs for the MCA and most importantly, a short voice coil. You can make a short voice coil as the membrane doesn't have to move much and you get increased sensitivity as more of the voice coil will be in the magnet gap. The MCA15 has a 9.4 mm voice coils (height) compared to 16 mm for the CA15RLY. So the membrane in the MCA15 can only move +/- 1.7 mm and still be fully in the magnet gap". ...So would the transient response of the MCA15 be nearly as good as the MCA12?
I see that both the PMS and 3wayClassic both use the 27TFFC (the PMS also has options for SS and Vifa, and a TFFC 'mod') so I'm thinking I should probably use either of these two acclaimed designs for my mid&tweet as I haven't bought the drivers yet. I'm wondering which design, in your opinion would possibly sound best in conjunction with my ancient poly 10" Vifa P25WO? I was thinking of buying 27TDFC's but I might be better off by copying part of a published design, then possibly only making minor changes in Speaker Workshop. Do you think my new 'approach' has any merit? I've asked you a lot of questions! Any advice you give me would be greatly appreciated. Many thanks and best regards, grant
(I presume the TFFC would be ok in a 1.5L mid-box?)
Wow, the MCA15RCY seems even better than the MCA12RC! To quote Troels: .."MCA15RCY: Not an everyday sight. Flat from 200 Hz to 5 kHz and modest wrinkles from 5-10 kHz. Sensitivity = 90 dB/2.8V. This driver is flat over almost 5 octaves! Too good to be true. Playing music on the midrange alone didn't sound bad at all. The sound appears neutral with no aggressive tendencies".... You couldn't get a much better recommendation than that, thank you!
To me the MCA15 has some advantages (over the MCA12), higher SPL, nicer looking response curve, slight 'BBC dip', no peak at 10kHz and it would probably fit better into the existing hole!
Have you listened to both of these/ any experience with them?
Troels mentioned (in 3wayClassic) that the MCA12RC transient response was superb. Would this be related to the voice coil height? For the MCA12 its 5.8mm. To quote Troels again:.."the only thing that differentiates the MCA15RCY from the CA15LRY is a slightly higher Fs for the MCA and most importantly, a short voice coil. You can make a short voice coil as the membrane doesn't have to move much and you get increased sensitivity as more of the voice coil will be in the magnet gap. The MCA15 has a 9.4 mm voice coils (height) compared to 16 mm for the CA15RLY. So the membrane in the MCA15 can only move +/- 1.7 mm and still be fully in the magnet gap". ...So would the transient response of the MCA15 be nearly as good as the MCA12?
I see that both the PMS and 3wayClassic both use the 27TFFC (the PMS also has options for SS and Vifa, and a TFFC 'mod') so I'm thinking I should probably use either of these two acclaimed designs for my mid&tweet as I haven't bought the drivers yet. I'm wondering which design, in your opinion would possibly sound best in conjunction with my ancient poly 10" Vifa P25WO? I was thinking of buying 27TDFC's but I might be better off by copying part of a published design, then possibly only making minor changes in Speaker Workshop. Do you think my new 'approach' has any merit? I've asked you a lot of questions! Any advice you give me would be greatly appreciated. Many thanks and best regards, grant
(I presume the TFFC would be ok in a 1.5L mid-box?)
Attachments
Thanks Tinitus,
Yes I'm thinking the MCA15RCY could indeed be my best choice.
Many thanks! grant
Yes I'm thinking the MCA15RCY could indeed be my best choice.
Many thanks! grant
Hi everyone,...about Seas tweeters... ( I hope I'm not making a nuisance of myself!, lol ).
I've been reading Zaph's 'Tweeter Mishmash' again, and the TDFC, TBFCG and TFFC all seem equivalent? I looked up the Seas website specs and the TDFC looks like a drop-in replacement for the TFFC?
Is this correct please?
According to Zaph (quote): "Seas 27TDFC ($29) - Exactly the same as the TBFCG, but with a fabric dome. Slightly rising top end response but overall very smooth. No ugly hexagrid. Similar to the old 27TFFC, but
with a polymer surround and slightly cleaner performance".
So, I'm wondering could I substitute (in Troels' designs) the TDFC for the TFFC? thanks, grant
I've been reading Zaph's 'Tweeter Mishmash' again, and the TDFC, TBFCG and TFFC all seem equivalent? I looked up the Seas website specs and the TDFC looks like a drop-in replacement for the TFFC?
Is this correct please?
According to Zaph (quote): "Seas 27TDFC ($29) - Exactly the same as the TBFCG, but with a fabric dome. Slightly rising top end response but overall very smooth. No ugly hexagrid. Similar to the old 27TFFC, but
with a polymer surround and slightly cleaner performance".
So, I'm wondering could I substitute (in Troels' designs) the TDFC for the TFFC? thanks, grant
Hi,
with Vas = 12L and Qts =0.25 optimum Q=0.71 volume = 1.7L.
So a well stuffed 1.5L will be fine.
I'd go with any of the fabric dome Seas tweeters mentioned.
They are very near equivalents. Also consider Troels modifications.
The transient response of the MCA15 will be as good as the MCA12.
🙂/sreten.
with Vas = 12L and Qts =0.25 optimum Q=0.71 volume = 1.7L.
So a well stuffed 1.5L will be fine.
I'd go with any of the fabric dome Seas tweeters mentioned.
They are very near equivalents. Also consider Troels modifications.
The transient response of the MCA15 will be as good as the MCA12.
🙂/sreten.
Sreten, Hi, I've done it again, Aarrgh!
Please ignore my last post. As you pointed out in my message to 'Kyselym' in early December, according to Zaph, the TDFC and TFFC could be interchangeable. Sorry about that, I forgot! I guess I was wondering how interchangeable they were, i.e, if any modifications were required at all?. grant
Please ignore my last post. As you pointed out in my message to 'Kyselym' in early December, according to Zaph, the TDFC and TFFC could be interchangeable. Sorry about that, I forgot! I guess I was wondering how interchangeable they were, i.e, if any modifications were required at all?. grant
Sreten, Hi!
This is great news! In a word...'woohoo'! thanks so much! ..Ok, ...what I'm now thinking of doing is this:
buy the MCA15RCY mids (if available here and using the existing mid-box, thank you!), and use the existing P25WO woofers and see how the old D25's sound as an interim measure until I can afford the 27TDFC's. I'll probably need to go 2nd order electrical as Troels mentioned, his critique was enlightening! So I certainly MIGHT just end up with a Poor Mans Strad! lol.
Interestingly *<just for a laugh>* Troels called his 3WayClassic a 'throwback' to the seventies, so with my ancient woofer, there's a kind of irony in that! haha
So you think it might be feasible to plagiarise/copy Troels PMS to 'fit' my P25? Things are looking up! Cheers, all I can say is THANKS! Sreten.... grant
This is great news! In a word...'woohoo'! thanks so much! ..Ok, ...what I'm now thinking of doing is this:
buy the MCA15RCY mids (if available here and using the existing mid-box, thank you!), and use the existing P25WO woofers and see how the old D25's sound as an interim measure until I can afford the 27TDFC's. I'll probably need to go 2nd order electrical as Troels mentioned, his critique was enlightening! So I certainly MIGHT just end up with a Poor Mans Strad! lol.
Interestingly *<just for a laugh>* Troels called his 3WayClassic a 'throwback' to the seventies, so with my ancient woofer, there's a kind of irony in that! haha
So you think it might be feasible to plagiarise/copy Troels PMS to 'fit' my P25? Things are looking up! Cheers, all I can say is THANKS! Sreten.... grant
Hi All! ...more about Seas tweeters...
From the Seas web-site, the choice between 27TFFC and 27TDFC seems to be a 'no-brainer' if the published charts are to be believed; because surely they would be correct. The 27TFFC has a nicer
response shape, better off-axis response and also slightly higher SPL. I guess thats why Troels uses it in his Poor Mans Strad (PMS), and as I could be copying his design, I guess thats what I'll choose together with the MCA15RCY (thanks Sreten for 'putting me on to it'!). I don't know why Zaph said the TDFC was 'smoother', could it somehow sound better given the attached charts? Any opinions please?
..Omni, Hi, I think I've found an Au Seas dealer, who can supply both the 27TFFC and MCA15RCY's, which I might end up using. I looked in Roman B's site for the latter's FRD/ZMA but unfortunately they're
not listed, so I might have a go at initially 'eyeballing' the Seas chart to get the files. I will try to buy all 4 drivers at the same time. How are your sims and enclosures progressing? best regards to all, grant
From the Seas web-site, the choice between 27TFFC and 27TDFC seems to be a 'no-brainer' if the published charts are to be believed; because surely they would be correct. The 27TFFC has a nicer
response shape, better off-axis response and also slightly higher SPL. I guess thats why Troels uses it in his Poor Mans Strad (PMS), and as I could be copying his design, I guess thats what I'll choose together with the MCA15RCY (thanks Sreten for 'putting me on to it'!). I don't know why Zaph said the TDFC was 'smoother', could it somehow sound better given the attached charts? Any opinions please?
..Omni, Hi, I think I've found an Au Seas dealer, who can supply both the 27TFFC and MCA15RCY's, which I might end up using. I looked in Roman B's site for the latter's FRD/ZMA but unfortunately they're
not listed, so I might have a go at initially 'eyeballing' the Seas chart to get the files. I will try to buy all 4 drivers at the same time. How are your sims and enclosures progressing? best regards to all, grant
Attachments
I don't think Zaph tested this did he? It's not in his tweeter mishmash page.
Check this out: http://www.madisound.com/cgi-bin/index.cgi?cart_id=1906936.2032&pid=1022
First sentence says "use 1189 (tdfc) instead" No reason as to why. Weird.
Check this out: http://www.madisound.com/cgi-bin/index.cgi?cart_id=1906936.2032&pid=1022
First sentence says "use 1189 (tdfc) instead" No reason as to why. Weird.
Hi Augerpro, Thanks for 'dropping by'!
In TweeterMishmash Zaph tested the 27TBFCG and the 27TDFC I think. Unfortunately I misquoted him in my last post regarding his comparison of the TDFC with TFFC. His desciption was that the TDFC had a 'slightly cleaner performance' than the TFFC (as I correctly quoted towards the top of this page). So yes its weird, and I'm confused! lol. However, as I'll be more or less copying Troels PMS, I'll probably stick with the TFFC anyway.
I assume you're considering building a project with a Seas tweeter? Any comments most welcome! ...thanks, grant
In TweeterMishmash Zaph tested the 27TBFCG and the 27TDFC I think. Unfortunately I misquoted him in my last post regarding his comparison of the TDFC with TFFC. His desciption was that the TDFC had a 'slightly cleaner performance' than the TFFC (as I correctly quoted towards the top of this page). So yes its weird, and I'm confused! lol. However, as I'll be more or less copying Troels PMS, I'll probably stick with the TFFC anyway.
I assume you're considering building a project with a Seas tweeter? Any comments most welcome! ...thanks, grant
Hi Grant, Tinitus, Sreten.....................Thank You for your Inquiries and support.....Baffles are done and mounted to Cabinets.......Finally......... Just a little touching up.....and on to the internal cabinet work...........I have resolved to finish crossover sims this weekend, which I will post beginning of week for reviews, if not sooner........ Hopefully, I will be able to order components soon..........Grant, looks like you are getting closer to gettin some drivers. Though the FRD and ZMA files for your drivers are not posted on the FRC website, I can Trace them for you.....no problem and process em for you when you finalize your choices. I will need cabinet specs, etc, when you are ready..........Keep me posted............Tinitus, I have been experimenting with your resistor concept and am getting some neat results, even in the woofer........check back here for graphs. I will definately look forward to your assessments.........I have missed a bit here in the last few days...............Looking forward to some wonderful things.....................Respectfully.......Omni
Hi Sreten, about Troels PMS....
The more I read about them, the more appealing they are becoming! Would you kindly help me out again please? I'm still wondering if it would be feasible to use my P25WO woofers in my boxes (published design for them) and upgrade to 27TFFC & MCA15RCY's, with the mid/tweet xo's based on Troels Vs5. My mid & tweeter mounting holes are basically 'golden-ratio' spacing and Omni has kindly offered to do the 'hard-yards' for me with the FRD tools. (Thanks 'heaps' Omni!!!) I'm hoping that I could then slightly? modify Troels xo in 'SW' to yield an acceptable result incorporating the P25's.
Do you think this approach would be viable please? I really would like to know if it has any chance of success in your opinion before I spend (which is for me) a lot of dollars! If so, I think your recommendation of the MCA15 and Troels PMS will be very valuable to me and ultimately be what I end up copying. And after all this time, I'm getting anxious to finally get started! hehe
Also, thank you for your suggested MCA15 box volume of 1.7L, closed and 'fully stuffed' from memory.
I'm confused in relation to Troels , quote from PMS: "The mid cabs are 4.3 litres net volume and the vent is a 40 x 70 mm PVC tube with an ID of 37 mm. Actually this vent doesn't do much in the
traditional way of a vented box. I made it because the mid shouldn't be in a closed box. I don't dig closed boxes for larger midrange drivers! It kills the midrange. Actually I have a small amount of wool material stuffed in the vent, so it's function is more like an acoustic vent. So take your pick".....
1.7Litres is fine by me, but surely the mid-box should be closed to avoid distortion from the woofer, as you described many pages ago, OR, would it be ok specifically for the PMS box because of Troels open infinite baffle design? ....Many thanks Sreten, grant
The more I read about them, the more appealing they are becoming! Would you kindly help me out again please? I'm still wondering if it would be feasible to use my P25WO woofers in my boxes (published design for them) and upgrade to 27TFFC & MCA15RCY's, with the mid/tweet xo's based on Troels Vs5. My mid & tweeter mounting holes are basically 'golden-ratio' spacing and Omni has kindly offered to do the 'hard-yards' for me with the FRD tools. (Thanks 'heaps' Omni!!!) I'm hoping that I could then slightly? modify Troels xo in 'SW' to yield an acceptable result incorporating the P25's.
Do you think this approach would be viable please? I really would like to know if it has any chance of success in your opinion before I spend (which is for me) a lot of dollars! If so, I think your recommendation of the MCA15 and Troels PMS will be very valuable to me and ultimately be what I end up copying. And after all this time, I'm getting anxious to finally get started! hehe
Also, thank you for your suggested MCA15 box volume of 1.7L, closed and 'fully stuffed' from memory.
I'm confused in relation to Troels , quote from PMS: "The mid cabs are 4.3 litres net volume and the vent is a 40 x 70 mm PVC tube with an ID of 37 mm. Actually this vent doesn't do much in the
traditional way of a vented box. I made it because the mid shouldn't be in a closed box. I don't dig closed boxes for larger midrange drivers! It kills the midrange. Actually I have a small amount of wool material stuffed in the vent, so it's function is more like an acoustic vent. So take your pick".....
1.7Litres is fine by me, but surely the mid-box should be closed to avoid distortion from the woofer, as you described many pages ago, OR, would it be ok specifically for the PMS box because of Troels open infinite baffle design? ....Many thanks Sreten, grant
Hi Omni,
It seems that your 'on full steam ahead'! and going well, great stuff. Yes, I hope a PMS 'hybrid-type-thingy' could work 'in principle', with your kind offer of tracing etc. But that would be a lot of work for you!
I think I'll call my project 'Elvira' (with PMS of course!) a good match for Frankenstein!!!! <rolling on floor laughing> *chuckle*, well you gotta have a laugh, right! I'll have to paint 'Elvira' black of course! haha
Tinitus' notion of series resistors on parallel coils seems to have relevance, indeed Troels does this in the PMS mid, quote: "although I reduce the Q of the mid 4.7 mH coil by a 2R2 resistor". So maybe doing so makes this section an acoustic LR2 maybe?
Also Omni, you are indeed correct about the xo-point being where the lines intersect! Silly me, trying to make things more complicated than they are! The attached IS 340 and 3800 Troels PMS. Cheers, grant
(I hope you have a laugh from this post!)
It seems that your 'on full steam ahead'! and going well, great stuff. Yes, I hope a PMS 'hybrid-type-thingy' could work 'in principle', with your kind offer of tracing etc. But that would be a lot of work for you!
I think I'll call my project 'Elvira' (with PMS of course!) a good match for Frankenstein!!!! <rolling on floor laughing> *chuckle*, well you gotta have a laugh, right! I'll have to paint 'Elvira' black of course! haha
Tinitus' notion of series resistors on parallel coils seems to have relevance, indeed Troels does this in the PMS mid, quote: "although I reduce the Q of the mid 4.7 mH coil by a 2R2 resistor". So maybe doing so makes this section an acoustic LR2 maybe?
Also Omni, you are indeed correct about the xo-point being where the lines intersect! Silly me, trying to make things more complicated than they are! The attached IS 340 and 3800 Troels PMS. Cheers, grant
(I hope you have a laugh from this post!)
Attachments
Moderator, I know my last post was not 'politically correct', I just couldn't resist it, for a laugh. I hope I didn't offend anyone, thank you,
grant
grant
Hi, ... look at the graphs you posted from Troels
Look at the round "shoulders"....thats what I was talking about
BUT you will also see a very small dip at the point where bass tweeter meet, though I am sure its insignificant its there
A great danish innovator mr. Steen Duelund, who is sadly not among us any more, made his own filter to take care of this - put simple, the whole filter was calculated from this exact point
This filter is examined at Linkwitz - but I guess we would need the skills of Sreten to understand any of it
http://www.linkwitzlab.com/crossovers.htm
Look at the round "shoulders"....thats what I was talking about
BUT you will also see a very small dip at the point where bass tweeter meet, though I am sure its insignificant its there
A great danish innovator mr. Steen Duelund, who is sadly not among us any more, made his own filter to take care of this - put simple, the whole filter was calculated from this exact point
This filter is examined at Linkwitz - but I guess we would need the skills of Sreten to understand any of it
http://www.linkwitzlab.com/crossovers.htm
Hi Tinitus,
Yes I do think an ideally smooth and constant rate driver rolloff with 'round shoulders' would be beneficial in achieving a balanced acoustic response. I thought the slight dip at around 1400Hz was primarily a function of the mid's dip there, but the minimal contribution of the woofer and tweeter at that point could be a contributing factor too, I suppose. thanks, grant
Yes I do think an ideally smooth and constant rate driver rolloff with 'round shoulders' would be beneficial in achieving a balanced acoustic response. I thought the slight dip at around 1400Hz was primarily a function of the mid's dip there, but the minimal contribution of the woofer and tweeter at that point could be a contributing factor too, I suppose. thanks, grant
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