Millenium tweeter

[mitchb101]

Would the Seas Millenium tweeter be a good replacement for the Hales Vifa tweeter that is presently in my Hales. I recently redid my Hales crossovers with upgraded parts with apparent success and am now looking to upgrade my tweeters to the Millenium Seas tweeter. Any Thoughts? My new crossovers have the same values as the origional Hales crossovers (Transcendence 5's) but now I am using Dynamicaps in the tweeter section, audiocap, dynamicap and auricap in the midrange section and Solen /axon in the bass area. I replaced the coils to Solo foil coils and replaced the resistors to Mills. I as well rewired the speakers with Cardas chasis wire of three different guages to each of the three drivers. Would the Millenium Seas tweeter be a good replacement for the Hales tweeter that comes with the Hales. I would like to avoid crossover alterations if possible. Any help would be highly valued.

[JonMarsh]

Does your Hales tweeter look like this?

I couldn't find a picture of the Hales 5 with the grilles removed. Does your tweeter look like the Hales transcendence model on the left?





If so, the Excel Millenium is not a good drop in for it. The Hales tweeter on the left (of which I have a few) is a pretty nice unit as is; long throw, fairly power ful magnet, about 90 dB sensitivity. It's a four ohm tweeter, though. The most similar tweeter in frequency response and electrical behavior is the ScanSpeak D2904/9800 with the SD1 motor system. They have about the same resonant frequency and impedance. I use the Hales slightly modified, with the original ferro fluid removed, and some long fiber wool inserted in the pole piece vent; this helps tame a little roughness in the 2-6 kHz region. The 9800 measures slightly flatter, (have some of those, too), but both are flat enough that you have to take a lot of care with the baffle design and diffraction control to optimize either. I don't know if the 9800 would be a mechanical fit off the top of my head, the Hales is bigger OD on the mounting flange; the SS is the same size as the Vifa XT.

Of course, if your tweeter doesn't look like this one (which was used in the Transcendence 8 I think; a big system with dual 10" aluminum cone woofers) then it's a little harder to say what you need without doing some electrical measurements. This tweeter, like the SS9800, is flat to below 1 kHz, so the crossover design is relatively straight forward, and the tweeter roll off isn't a factor to handle. This is the way it should be done.... Replacing one of these with the 9800 or the Excel might be something more of a lateral move than an upgrade, but who knows?

If your speaker has one of the older Vifa soft domes, then using an Excel Millenium might work OK with the existing crossover, might not- depends where the LF resonance is, and how they handled it in the crossover. To substitute tweeters without a crossover change, the LF resonance should be well below the crossover frequency (say, two octaves), and ideally should be at about the same frequency. The Millenium is a very good soft dome tweeter, but just dropping it in without knowing the details is a little risky. Maybe not too risky, though.

The crossover component mods you've done sound fairly sound, especially the cap and wiring modes. I'm a little puzzled about your reference to Solen foil coils. Didn't think they made any foil type coils. My own experience and measurements/listening is that foil coils are a bit over hyped- though the sking affect phenomena does start making a difference at higher frequencies (over 40 kHz), it's impact in the normal crossover range is pretty much non-existent. (BTW, to confess, I am an EE and power conversion designer- I do work with specialty coils for SMPS supplies, mostly Litz wire). What is more useful is using coils with very low DCR, especially in the tweeter shunt and woofer series pass. Think Northcreek AWG 12 wound coils.

Good luck with your project.

Regards,

Jon

[mitchb101]

Same tweeter

Hi Jon, Thanks for your reply. The tweeter in your picture is the same as the one in my Hales T5's. I believe the T5's and T8's used the same tweeter. I meant to write Solo foil coils. Not Solen. I have a pair of new Millenium tweeters unused and am now wondering if I should try them or leave well enough alone. The Millenium are refundable unused and I have not yet had them installed. Why would you think the Millenium not to be a good replacement for my Hales tweeter? My speakers sound good with the crossover mods but I was thinking what about a tweeter upgrade? Would yo leave well enough alone or what other tweeter might you try. The attraction to the Millenium are that they are the correct size physically and they have a good reputation.

[JonMarsh]

The Hales tweeter is a 4 ohm nominal tweeter with minimal electrical impedance about 3-1/2 ohms. It's flat in response to about 700 Hz.

The Millenium tweeter is a nominal 6 ohm tweeter, with a greater impedance variation overall than the Hales tweeter. Becuase of the impedance difference, they won't have the same freuqnecy reponse with the original electrical network. The tweeter reponse will try to go lower, and will have a hump in the lower end of the crossover response.

A skilled person could meausure the electrical response of the Hales netowrk, and the acoustical response in the actual cabinet (baffle size affects tweeter loading in the low end, which has to be taken into account in the crossover), and design a new crossover that would work with the Millenium and duplicate the net acoutical function (to match with the cabinet and other drivers). But dropping in a Millenium without extensive crossover mods would NOT be a good idea.

Best regards,

Jon

[mitchb101]

Which tweetr

Which tweeter might work then.My only dilema with some of the other tweeters is that they are physically too small to fit in my Hales.
Are the Hales tweeters good tweeters or is there room to greatly improve?
I liked the idea that the Millenium excel are the same series as the excel midrange driver in the Hales. I need a tweeter that has an outer diameter of 110.4 mm to fit my Hales. Any ideas?

[Ten 99]

Jon,

Would he benefit at all from modifying the Hales tweeters that he has in the same fashion that you did to yours (draining the ferro fluid, and stuffing the vent with wool)?

Maybe this would be an easier, more economical, and better over-all upgrade for him?

[mitchb101]

Hales tweeter vs Millenium

Not to put too much of a point on it. Perhaps I'm in denial but I do know someone who exchanged his Hales T5's tweeter for the Excel Millenium with good results. The thing is that he did not completely modify his crossover but he did remove the 1/3 ohm resistance from the tweeter section. This person is an amp designer who in fact designed my amp so now I'm a little more confused as it's been done successfuly before but other people, not just Jon , have reccommened against it. Madisound claims it should be OK.
What to do?

[ThomasW]

Mitch,

Jon is packing to leave tomorrow for a 2 week trip to the far east, so I'll drop in here.

Unless you're operating in the exact same environment (same equipment, same room, same everything) of that guy that made the tweeter switch, his information is irrevelent to your situation.

The Hales tweeters are very good tweeters. Psychologically you may believe that the Millenium tweeter is a better match for the midrange. The reality is that Hales is a pretty sophisticated design and the speaker is a 'system'. This means that the components are specificially chosen and matched for optimal performance. So messing around with things could result in a speaker who's performance is worse than what you started with.

'Tweaking' the stock tweeter you run an equal risk of botching it's performance as you do of improving it. Since replacement domes for the Hales tweeter aren't available, I strongly suggest leaving the tweeter stock.

Also given that Hales is no longer; the parts in a Hale speakers have the potential to be worth quite a bit. People will be looking for replacement parts, so messing around with the stock components ruins their resale value.

If one wants to 'play' with speakers, it IMO is a better idea to built something from scratch or a kit with readily available parts. That way one actually learn something. And when you smoke a driver because the crossover wires got crossed, a replacement is just a phone call away.....

Having known Jon since 1969, I'm pretty sure he knows more about speaker design than the people you're currently asking (and yes that includes Madisound) . How many of your sources are twice published members of the AES?

So when Jon says

But dropping in a Millenium without extensive crossover mods would NOT be a good idea.

I'd follow his suggestion. Note that his use of the words 'mod' doesn't mean exchanging parts of the same value like you've already done. He's talking about re-engineering/re-designing the entire XO to match the performance characteristics of the Millenium tweeter

But in the end it's up to you. If the $300 bucks is just 'pocket change', then hey, what's too lose? Pop them in and see what happens. If however $300 represents an 'investment', I think your money is better spent elsewhere, since there are no guarantees of improved performance.

As they say 'reality bites' ......... :wink:

[Al Garay]

Have a great trip Jon. And come back safely... rested would be bonus.

Al

[mitchb101]

So I dropped in the Millenium a few days ago and they are sounding awesome in my speakers. My speakers sound like they are a much bigger speaker. It's hard to explain but I'm getting a more airy relaxed sound without the loss of detail. After 55 hourss or so with the Millenium installed I'm extremely pleased and do not regret this move. As I have the option to return them if dissatisfied I decided to give them a go. I cannot think of any negative aspect of installing the Millenium tqweeters in my Hales whatsoever. I even had a speaker company enter my crossover values into a computer with the use of the Millenium tweeters themselves to see what theoretically the tweeters would do with my crossovers. Apparently these graphs ended up looking pretty good. The graphs just confirmed thaat my ears were not playing tricks and that these tweeters seem to work for me in my particular situation. It worked for someone else as well with the same speakers using the Millenium as a drop in. as well. They appear to blend in nicely with the midrange and they give the bass characteristics a new sound which I enjoy. A bass string pluck will sound like a bass string pluck and piano notes sound like piano notes. There may be a tad less brilliiance with the Millenium than the Hales but I don't miss it. The sound now overall is more realistic. It is possible when these tweeters fully burn in that I won't like the sound but I doubt it.
I must thank Jon and Thomas for all their help and I realise that they know their stuff but I guess I just got lucky with these tweeters.

[Dennis H]

Glad you like the sound. Without measurements it's hard to know what's going on. It's entirely possible that the speakers were voiced with the tweeters a bit hot so substituting the less sensitive Millennium works well.

[mitchb101]

Hi Dennis, What I think happened is that after I did my crossover mods, although the values were the same as the origional crossovers, it seemed that the tweeters were a bit hot. With the new x-overs and the origional tweeter the sound was good but a little edgy on top. That's what got me looking to replace the origional tweeters. The Millenium seemed to take the very edge off on top while filling out the sound of the entire speaker.

[mitchb101]

tweeters

300 hours play now and the speakers with the Millenium tweeters are sounding quite nice. I will not know without the proper equipment how they measure in my speakers with my equipment in my room but they sound really good. I can virtually listen all day without fatigue until my wife makes me get out of the music room to eat, sleep, etc. My Hales have a whole new sound which is appealing to me. If I did not like the sound I would have put back the stock tweeters but the Millenium are in to stay. They give the whole speaker top to bottom a new and pleasing sound.