A loudspeaker kit with active x/o, any?


Rod Elliot convinced me, as he seems to have convinced many others, on the benefits of active crossovers. I have here a pair of old Seas Emblas and a subwoofer. My plan is to keep the subwoofer and find a nice 2-way design, plan or a kit to replace the Emblas.

Problem is, can't find any. Phoenix is, of course, an excellent design, but it's a dipole and dipoles are not to my liking, since I like both sit in one place and move around while I listen. And as far as I know, dipoles do not work if one wants background music.

Linkwitz did not recommend making Phoenix into a sealed enclosure, and instead pointed me to an Yahoo group where someone had made a sealed active 2-way with Seas Excel drivers. But I wasn't quite sure how refined the design was, and the homepage that had the details disappeared quite a while ago.

I cannot afford measuring equipment and don't want to fiddle forever with details, so I'm more into solid theory, just as Linkwitz was with Phoenix. And I also like measurements done ready by someone else.

Do any of you know why Phoenix would not work in a sealede enclosure, if the dipole-spesific parts are removed from the crossover?

Also, is there something in the Scan-speak drivers he uses that make them good for dipole but not for sealed?

Or does there exist a kit or proven design to my liking? Rod Elliot's 3-ways are too big for that.


2001-12-26 9:04 pm


I just finished a pair of Phoenix two weeks ago. I guess I'm still in the honeymoon stage, but I love them. While they do sound better while sitting in the sweet spot, I also think they sound excellent anywhere in my apartment. Also, don't underestimate their size - they take up a lot of floor space, more if you intend to place them at proper distances from walls, etc.
I don't have enough room for Bottlehead's towers. Otherwise they look nice. But because that room question, I didn't examine the active crossover option any closer.

Besides, unless the active crossover is really _designed_ for the use, as in Linkwitz's Phoenix, the remark that speaker this and that can use active crossover is totally useless. I know even my Seas Emblas could use an active crossover, but that would take away all freq. response compensations, just as well as the baffle step compensation, _unless_ I go the long way and learn to design such beasts myself.

About that Northcreek site. I know how to find a dozen ordinary speaker shops full of superlatives and nothing about active crossovers, so this was definitely not what I was looking for. If you have more links and they have something about what I asked, then please do post them.

I just wonder... could you read this whole thread and it's topic and not notice that the whole point is the active crossover, not just nice 2-way satellites.

-Kimmo S.
I do appreciate that you understand. Even though you did not say yes or no to my last paragraph. But finding a speaker kit with an active crossover is frustrating indeed. Just go ahead and try by yourself.

I have almost given up searching. Next step is to thoroughly study Linkwitz's site and see which parts of it are applicable for sealed boxes. I even asked the Finnish Seas importer to design an active kit with Seas drivers, since he is a known designer here, but he refused. I did ask kindly.

To my credit I must say that I browsed the link you gave me at least one hour. It was nice, but unhelpful. Maybe my hate of superlatives (since they are no information) and suspicion about their emphasis on passive crossover parts contributed heavily to my reaction.

-Kimmo S.


Disabled Account
2002-07-08 8:42 am
I have not heard of any such kit.

And the loudspaekerbuilders in common seems not
have understood the benefits of an active system.

To say active loudspeaker, is not fully correct.

An active soundsystem includes:

1) Crossovers, can be paasive or with OP amp
2) One amplifier for each frequency range /woofer
3) Woofer Tweeters in boxes

Does not include:

1) Loudspeaker cables (of any lenght that comparable to ordinary)
2) Large coils, with Ferrit or Aircore
3) Capacitors of those relativly high values found in common LSP

The abscense of this 3 items are all a good thing.

The lack of active soundsystems on market
can depend on that a producer of a such system,
have to have capability/skills to make BOTH
amplifiers AND loudspeakers.
most producers are speacialists in one area of Audio,
while they can have good knowledgde of other areas of audio.

It is easier to be good in a narrower field,
aswell as making factories for one kind of product.
Of one or another reason Marketers might have
active system as not enough profitable.

This lack of producers is a chance for any entrepenoer
that want a Nisch, a corner of audio field
where competiters haven't arrived yet!

So the few people that really have understood
what an superior way of making a hifi soundsystem
and have designs to offer are clever individuals,
with homepages on internet.

I hope some of DiyAudio.com members belong to
that small gruop.

If you chose to build your own Active System,
you might not want to go back to anything else again.

an active man
too much active thinks a few,
other read him


Disabled Account
2002-07-08 8:42 am
Check out our Fellow Member's Site!

We have a brother among our members
DIYaudio elder Bill Fitzpatrick.
At his Site and Enterprise
you will find some info in the area of
Active X-overs, and Bi-Amping.

I think our fellow has too much politeness
for to advertise his own business here.

So I do it instead, as I do not make a single buck
out of what I eventually know about Audio.


On this very nice Website you find Clear
and Beautifully layouted descriptions
ofwhat you are looking for.

At the same time I welcome Bill F.
to join us in this Thread.

And if you like what I can contribute with,
your satisfaction will be my reward, Musher!

still active
Hi Kimmo,

I understand your situation completely!

I think that this hobby can be divided into those that are obssesive about amps and those that are obssesive about speakers. and never the twain shall meet...

Rod, ( and others), are definately correct, active systems are just so much better than passive, but, the cost and complexity of crossovers and extra amps puts many people off.

To be brutally honest, the only way to make any set of drivers in a generic box work together without spending serious amounts of time and money playing,( which can be great fun, if you can afford it),is to use a fully adjustable professional crossover such as a BSS omnidrive, which has more tweeks than you can possibly think of.

I have never found a small active kit that looks any good on the web, and I suspect you need to do some research on drivers etc. and maybe you can pin down what you want to achieve, and pull together stuff from different places.

Or you could build a pair of boxes with your favorite drivers, build Rod's basic
crossovers, be blown away by how much better it sounds without baffle step compensation, etc, etc, and just enjoy your music!

This is the closed-box design that Siegfried Linkwitz was referring to:


I had to table this project before I really finished it, but the performance is still outstanding. I believe the active crossover design is pretty well sorted out, but there is some improvement still possible. As is, I still think it beats the performance of anything that could be constructed with a passive crossover.