Just after some informed opinions, and this looks like the go-to place!
I am yet another dude considering replacing the tweeter units in the above mentioned speakers. Not that there's much wrong with them. They were the best £30 i've spent in years, but i'm game to try the odd tweak! Anyway, i've got some SEAS Excell units, the same ones as used in the WD25T. Anyone tried these in the Dynaco cabs? If so,did you need to do much modification to the crossover, and would you say it was successful or not?
Any and all opinions welcome.
I am yet another dude considering replacing the tweeter units in the above mentioned speakers. Not that there's much wrong with them. They were the best £30 i've spent in years, but i'm game to try the odd tweak! Anyway, i've got some SEAS Excell units, the same ones as used in the WD25T. Anyone tried these in the Dynaco cabs? If so,did you need to do much modification to the crossover, and would you say it was successful or not?
Any and all opinions welcome.
Member
Joined 2003
Different tweeter = different crossover.
Could maybe design a new crossover around this datasheet for the A25 woofer:
http://www.madisound.com/catalog/PDF/25F-EW.pdf
Could maybe design a new crossover around this datasheet for the A25 woofer:
http://www.madisound.com/catalog/PDF/25F-EW.pdf
Before swapping the tweeter, there are a couple things you can do that greatly improve the top end performance.
1/ the cross-over parts suck. Replace the cap. Then figure out where on the level switch the system sounds best, then toss the switch and replace the string of resistors with a better quality one of the same value as the string that is active with the switch at the preferred position.
2/ remove the metal grill over the tweeter. Careful, the bolts that hold it on also hold the tweeter together, Remove the tweeter from the box, and do the surgery with the tweeter face up on a solid surface.
dave
1/ the cross-over parts suck. Replace the cap. Then figure out where on the level switch the system sounds best, then toss the switch and replace the string of resistors with a better quality one of the same value as the string that is active with the switch at the preferred position.
2/ remove the metal grill over the tweeter. Careful, the bolts that hold it on also hold the tweeter together, Remove the tweeter from the box, and do the surgery with the tweeter face up on a solid surface.
dave
progress
Thanks very much for all your responses. Much appreciated. Just thought you might like to see where i'm up to in all of this.
Got these off ebay, described as Scandynas. there was no tweeter level control on the back, or any type of connection cup or block. Just a wire fed through from the inside of the cabinet.
Replaced the original L-pad components and Jensen electrolytic cap with good quality modern equivalents from Maplin. The original cap value was a puzzler; 8uF, instead of the 5 quoted as the standard everywhere. Still, didn't question it. Just replaced them, took the grilles off the tweeters, and had a listen.
First impressions were, a nice, weighty sound with good coherence and carries a tune like few others i've heard. Stereo image has depth and width but is a little unfocussed, and there is a slight peakiness in the lower treble due, i suspected, to the larger value cap.
Took out the 8uF, to be replaced by a 5.7uF.
Sound more balanced now, but lacking in extreme top end. Still very lively and tuneful though.
At this point i thought, f**k it, try the Excells! They have the same faceplate and magnet dimensions as the originals. The tweeter cutouts only need a tiny bit of work to accomodate the slightly wider spacing of the tweeter terminals, but if it sounds crap, it's all retrofittable.
It sounded anything but crap! Stereo image snapped sharply into focus. Loads more air and expression in the extreme treble. Acoustic guitar in particular sounded beautifully warm and delicate. If there's a negative, there might be slightly less energy in the lower treble/upper mid, though that could be down to the Excell unit lacking the hardness of the original. I've only had about an hour's worth of listening to them set up this way, and i would really like a good 10-20 hours before i form a definite opinion, but I have to say that i really wasn't expecting to get such an impressive sound without adjusting some crossover values first.
Anyway as it's me, and i'm incapable of leaving well alone, I will be fiddling with the crossover. Well, you've got to live a little, haven't ya?!! If you're interested, I'll let you know how I get on.
Thanks very much for all your responses. Much appreciated. Just thought you might like to see where i'm up to in all of this.
Got these off ebay, described as Scandynas. there was no tweeter level control on the back, or any type of connection cup or block. Just a wire fed through from the inside of the cabinet.
Replaced the original L-pad components and Jensen electrolytic cap with good quality modern equivalents from Maplin. The original cap value was a puzzler; 8uF, instead of the 5 quoted as the standard everywhere. Still, didn't question it. Just replaced them, took the grilles off the tweeters, and had a listen.
First impressions were, a nice, weighty sound with good coherence and carries a tune like few others i've heard. Stereo image has depth and width but is a little unfocussed, and there is a slight peakiness in the lower treble due, i suspected, to the larger value cap.
Took out the 8uF, to be replaced by a 5.7uF.
Sound more balanced now, but lacking in extreme top end. Still very lively and tuneful though.
At this point i thought, f**k it, try the Excells! They have the same faceplate and magnet dimensions as the originals. The tweeter cutouts only need a tiny bit of work to accomodate the slightly wider spacing of the tweeter terminals, but if it sounds crap, it's all retrofittable.
It sounded anything but crap! Stereo image snapped sharply into focus. Loads more air and expression in the extreme treble. Acoustic guitar in particular sounded beautifully warm and delicate. If there's a negative, there might be slightly less energy in the lower treble/upper mid, though that could be down to the Excell unit lacking the hardness of the original. I've only had about an hour's worth of listening to them set up this way, and i would really like a good 10-20 hours before i form a definite opinion, but I have to say that i really wasn't expecting to get such an impressive sound without adjusting some crossover values first.
Anyway as it's me, and i'm incapable of leaving well alone, I will be fiddling with the crossover. Well, you've got to live a little, haven't ya?!! If you're interested, I'll let you know how I get on.
Hi walriley, all,
You are working with an "antique". NPI
You have a vintage woofer (please make sure w/reference number, if you have one. DcibeL also references one, you should confirm) and a new tweeter (you didn't mentioned which one, please refer to the right reference you have on the SEAS Excel). That old tweeter was not supposed to have a very large extension for the HF, and it was a big 1"1/2. Now, what you are doing not very much people have achieved before. I will be close by.
About the xover: you say, all about your xover is/was a cap on the tweeter?
You are working with an "antique". NPI
You have a vintage woofer (please make sure w/reference number, if you have one. DcibeL also references one, you should confirm) and a new tweeter (you didn't mentioned which one, please refer to the right reference you have on the SEAS Excel). That old tweeter was not supposed to have a very large extension for the HF, and it was a big 1"1/2. Now, what you are doing not very much people have achieved before. I will be close by.
About the xover: you say, all about your xover is/was a cap on the tweeter?
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Member
Joined 2003
Unfortunately, there is nothing about the Seas Exotic line that I can see to justify the price. They are for people with more dollars than sense.
There is still available, a "modern" A25 woofer, the Seas A26RE4. It's $132 at Madisound, however, not entirely a drop-in replacement but as close as one could hope for.
Walriley, does your tweeter just have the cap, or a resisor as well? Glad to hear you are enjoying the simple driver swap.
There is still available, a "modern" A25 woofer, the Seas A26RE4. It's $132 at Madisound, however, not entirely a drop-in replacement but as close as one could hope for.
Walriley, does your tweeter just have the cap, or a resisor as well? Glad to hear you are enjoying the simple driver swap.
That tweeter is not going to work with same setup. I'm not saying is not good, just it will need a second order xover to tame the HF. Remember (I think) we are working with a woofer with no xover components(?!).
It all depends where walriley wanna go. If he is buying it, I mean another one (he has an Excel as he said). I will leave for now. Bye.
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The Excell tweeter is the model no. T25CF001 and the bass is the standard SEAS 10" for the A25's. I have a few ideas for what to do with the crossover but the sound was very impressive for a straight drop in, so i'll put a few hours listening in first, both in my house with a couple of different amps, then at my mate's place (he uses 845 valve amps and Lowthers) and then decide. I'll post my findings here.
Later, dudes!
Later, dudes!
In fact, after checking, the output curve and specs are very similar between the SEAS Excel Tweeter E0006-06 T25CF001 and the original Dynaco Dome 87 H. Also both at ~91dB what the multiple L-Pad will solve very easily (Attention: I have different resistor values 10R-4R7-4R7-3R9-3R9-3R9, w/the 5uF cap).The Excell tweeter is the model no. T25CF001 and the bass is the standard SEAS 10" for the A25's. I have a few ideas for what to do with the crossover but the sound was very impressive for a straight drop in, so i'll put a few hours listening in first, both in my house with a couple of different amps, then at my mate's place (he uses 845 valve amps and Lowthers) and then decide. I'll post my findings here.
Later, dudes!
The SEAS T29CF001 is a little louder at 93dB. These first two seam to blend better (on paper) with the old woofer SEAS 25 TV-EW/4Ohm, or for that matter the 6Ohm SEAS 25F-EW. Very interesting and also used for the new kits is the SEAS 29TFF/W. http://wduk.worldomain.net/acatalog/wd25ahfw1a.html
The 5.7uF cap might be a very good idea. Choose a good quality one.
AUDIO CAPS TEST by Tony Gee - The Netherlands
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Mucho thanks for your input, folks. I've purchased some Claritycaps - a 5uF, a 1uF and a 0.68uF - which i'll be experimenting with different combinations of. Circumstance has meant that i've still been unable to get any serious listening in, but i'll keep you posted when i do. I did get to try an 8uF ICW from Maplin, which is the size of a small firework, but that flattened perspectives and hardened the sound up somewhat. Probably due to the driver working too close to it's resonance freq so, for me, the original value is a step too far with this tweeter. Up till now I have been using them with 4.7 and 1uF piggiebacked bog-standard Solens The crossovers are mounted outside the cabinets, to make access easier.
The reason i thought these two drivers might actually work together was cos i got a bee in my bonnet whilst reading a World Designs write-up on the various stages of crossover development that went into the WD25A WD25A Crossover Pg1. one of these stages used a crossover which quite closely resembled the Dynaco. However, in a later stage of development, Peter Comeau then put an inductor on the bass to tame the mids slightly. Now I remember reading somewhere (probably here!) that the original driver doesn't have anywhere near the sort of mid output as the incarnation used in the WD25A, so hopefully i could keep the driver directly connected to the amp. Might have to go 2nd order on the treble, but let's see what happens if we just drop the tweeter in and see. The rest, you already know!
The reason i thought these two drivers might actually work together was cos i got a bee in my bonnet whilst reading a World Designs write-up on the various stages of crossover development that went into the WD25A WD25A Crossover Pg1. one of these stages used a crossover which quite closely resembled the Dynaco. However, in a later stage of development, Peter Comeau then put an inductor on the bass to tame the mids slightly. Now I remember reading somewhere (probably here!) that the original driver doesn't have anywhere near the sort of mid output as the incarnation used in the WD25A, so hopefully i could keep the driver directly connected to the amp. Might have to go 2nd order on the treble, but let's see what happens if we just drop the tweeter in and see. The rest, you already know!
Just as an update, i've listened to these for a while now, and come to the conclusion that i need to lower the crossover point, as the bass driver doesn't reach far enough up to meet the earlier roll off of the Excell treble. As a result, upper mid is a bit recessed, which gives a bigger, deeper soundstage but can make it difficult to hear vocals on complex passages of music. Anyway, pinched the WD25A 2nd order treble section, added 1uF to it (surprising the difference a microfarad can make!) and left the bass driver directly connected as before.
Initial listening suggests a more upfront sound, with possibly slightly flatter perspectives than before, but vocals are much clearer now and the speakers are still very tuneful and listenable.
Initial listening suggests a more upfront sound, with possibly slightly flatter perspectives than before, but vocals are much clearer now and the speakers are still very tuneful and listenable.
Sorry I don't follow, I (maybe everybody else) just lost trail (...2.order?/6.7uF?/resistors-pad you using?/"original woofer" SEAS 25 TV-EW?)
Tweeter SEAS T25CF001 - E0006-06/response (being used at the moment)
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Sorry if i haven't made myself very clear. It's just that a while back in this thread i said that if i was to get a proper handle on the sound that this speaker was producing, then i would have to get a good few hours listening in, using a number of different permutations of equipment, rooms and music. Having done this, i have come to the conclusion that, using the original 1st order crossover, the speaker sounded great on simple acoustic material but has a slightly distant presentation due to the treble unit's low end response not going down far enough to meet the bass driver, resulting in a slight 'hole in the middle' effect. I had tried a bigger value cap, but this introduced a harshness into the sound and wasn't an option, so it looks like i will have to investigate a second order crossover. World Design's WD25A is a derivative of the Dynaco that i'm experimenting with, and uses the same excell tweeter that i am. However, it has a 2nd order treble section on the crossover, as opposed to the simple cap and L-pad on the Dynaco. All i've done is borrow this design, which is illustrated at the bottom of the page i've linked to, and fiddled with it a bit. The results are interesting but, as always, i'm going to give it a few hours listening before settling on a definate opinion.
After reading your venture with this design, that I very much appreciate from your patience, I have to say that I very much doubt of Mr. P. Comeau design, also because it was him the first person saying that was not working as expected, and I follow to (until) his publishing in the magazines. After saying this, that's why you are like a "first" also, you're dealing with very difficult options trying to get the old "pure" no X-over stile sound, that Mr. Comeau was not able to, and as a mater of fact if you notice the previous post driver response graph link, an almost bent curve were probably you are missing all your HF information.Sorry if i haven't made myself very clear. It's just that a while back in this thread i said that if i was to get a proper handle on the sound that this speaker was producing, then i would have to get a good few hours listening in, using a number of different permutations of equipment, rooms and music. Having done this, i have come to the conclusion that, using the original 1st order crossover, the speaker sounded great on simple acoustic material but has a slightly distant presentation due to the treble unit's low end response not going down far enough to meet the bass driver, resulting in a slight 'hole in the middle' effect. I had tried a bigger value cap, but this introduced a harshness into the sound and wasn't an option, so it looks like i will have to investigate a second order crossover. World Design's WD25A is a derivative of the Dynaco that i'm experimenting with, and uses the same excell tweeter that i am. However, it has a 2nd order treble section on the crossover, as opposed to the simple cap and L-pad on the Dynaco. All i've done is borrow this design, which is illustrated at the bottom of the page i've linked to, and fiddled with it a bit. The results are interesting but, as always, i'm going to give it a few hours listening before settling on a definate opinion.
Also and most important the drivers, yours and Mr P. Comeau new woofer driver are not the same (attention when posting the drivers references, you just mention "original" when I asked you), and second he is using a second order xover on the woofer network arm and you are using only on tweeter, from my understanding. I will abstain from more critics because this kind of experimenting always take a long time, and you will need it as you said.
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I appreciate and thank you for the points that you have made.
To be honest, as i have said earlier on this thread, i have done nothing to these speakers that is not reversible, i.e. the original drivers can be hooked up and the crossover reconfigured for them. Also, i have no test or measuring equipment, except for a multimeter, the lugs on either side of my head and maybe a little lateral thinking/hunches that, on the odd occasion, work out. What the hell! It makes it interesting, educational, frustrating but, just occasionally, hugely rewarding when a plan comes together. I have learned absolutely loads about my own sound preferences, how absolutely crap most commercial systems are, and what it is i think that makes a speaker sound good or bad through tinkering in this way, and not just with these Dynacos either. I grant you, getting a good sound just by ear is a long-winded, needle-in-a-haystack process, but it worked for Bob Surgeoner of Neat Acoustics, so there's a vague hope for me!
By the way, Peter C used an inductor and some impedance compensation on the wd25A 10" driver, because it is quite a bit livelier in the mid than the one used in the Dynacos. that was my reasoning for leaving it out and just using the 2nd order treble section.
Have fun!
To be honest, as i have said earlier on this thread, i have done nothing to these speakers that is not reversible, i.e. the original drivers can be hooked up and the crossover reconfigured for them. Also, i have no test or measuring equipment, except for a multimeter, the lugs on either side of my head and maybe a little lateral thinking/hunches that, on the odd occasion, work out. What the hell! It makes it interesting, educational, frustrating but, just occasionally, hugely rewarding when a plan comes together. I have learned absolutely loads about my own sound preferences, how absolutely crap most commercial systems are, and what it is i think that makes a speaker sound good or bad through tinkering in this way, and not just with these Dynacos either. I grant you, getting a good sound just by ear is a long-winded, needle-in-a-haystack process, but it worked for Bob Surgeoner of Neat Acoustics, so there's a vague hope for me!
By the way, Peter C used an inductor and some impedance compensation on the wd25A 10" driver, because it is quite a bit livelier in the mid than the one used in the Dynacos. that was my reasoning for leaving it out and just using the 2nd order treble section.
Have fun!
Unfortunately, there is nothing about the Seas Exotic line that I can see to justify the price. They are for people with more dollars than sense.
I think Alnico magnets have become very expensive.
This would have influenced the price.
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