Eden D210T Speaker Swap?

[spike42]

Let me first admit that I'm not normally much for
tinkering with cabs and speakers. However, I saw
an ad on TB awhile back, and it got me thinking:

http://www.talkbass.com/forum/f127/eden-d210t-w-cover-$340-shipped-712744/

They'd taken a D210T, swapped in Eminence Deltalite II
2510's which are 8 Ohm, and seemed happy with the result.

I was considering doing the same to mine but I wanted to be
sure how the ohms would work out. The cab specs at 8 Ohm,
250w.

I can see (on paper anyways) how swapping in replacement
8 Ohm speakers would give you a 4 Ohm cab (8+8=4). But
what about the tweeter? Did the tweeter factor into the rating
for the original specs? Or are the original speakers
16 Ohm each X2 and that's how they get an 8 Ohm
cabinet?

[mmbongo]

The tweeter should have no effect on the impedance. Keep in mind you will need new crossovers as well.

[billfitzmaurice]

Originally Posted by spike42

Or are the original speakers
16 Ohm each X2 and that's how they get an 8 Ohm
cabinet?

That, or they're 4 ohms series wired.

[spike42]

Thanks. Again remembering that I'm looking to learn, how would
one determine what crossovers would be required? And where
would one go shopping for such items?

[GrowlerBox]

www.speakerhardware.com -- no affiliation, not even in the same damn country, but Leland seems like a helpful guy and often posts here.

[spike42]

And I may as well put my ()() totally out in the breeze and ask
what is the problem with the existing crossovers - like I said, I'm
the type of person that usually just buys a cab and leaves it alone.
While at the same time, I don't own a single bass that I didn't
build from parts!

[billfitzmaurice]

Originally Posted by spike42

what is the problem with the existing crossovers -

Crossovers must be matched to the impedance load, and for best results they're matched to the specific drivers and cabinet design. One size does not fit all.

[Blues Bass 2]

I had a pair of 4 ohm 210XLT cabs about ten years ago and they had a high pass crossover on just the tweeter and the tens just ran full range . With that setup the crossover doesn't work on the woofers at all . I'm pretty sure most of the Eden cabs with that gold horn are wired that way so they can use the same backplate/crossover with all their speakers ,8 or 4 ohm . Whether those Deltalites will work right in your cab I don't know but the crossover will work the same because it's just a high pass , not a true crossover ..

[billfitzmaurice]

Originally Posted by Blues Bass 2

I had a pair of 4 ohm 210XLT cabs about ten years ago and they had a high pass crossover on just the tweeter and the tens just ran full range .

That's not a crossover, it's just a high pass filter. It's not the best way to wire a cab, but it is a less expensive way.

[Arjank]

Originally Posted by billfitzmaurice

That's not a crossover, it's just a high pass filter. It's not the best way to wire a cab, but it is a less expensive way.

Most manufacturers of 210's and 410's do it this way cause it's indeed cheap(and easy) and most people(bassplayers) are so used to the conebreakup of these 10's around 2.5khz that most of us don't know any better .

[billfitzmaurice]

Originally Posted by Arjank

Most manufacturers of 210's and 410's do it this way cause it's indeed cheap(and easy) and most people(bassplayers) are so used to the conebreakup of these 10's around 2.5khz that most of us don't know any better .

More important from an engineering standpoint is that the typical ten only goes to 2.5kHz, tweeters don't start until 3.5kHz or higher, and at that point the acoustic roll-off of the woofer is fairly adequate to minimize cross-talk. If the tweeters were crossed over where they should be, between 2kHz and 2.5kHz, the lack of lo-pass filtering the tens would be a problem. But AFAIK no manufacturer uses a tweeter that goes that low, for the same reason they don't lo-pass the woofers: it's cheaper that way.

[spike42]

Folks, this is quite interesting - I really am wanting to learn here.
I appreciate all your input. I guess I'm a little confused now, maybe
I don't have crossovers since the cab just has a high-pass filter?
The 10s run full-range in that event. But if I did have crossovers, they would
have to match the impedence of the drivers. Maybe
I should pull the back plate off the cab and post a picture?

[GrowlerBox]

Originally Posted by spike42

The 10s run free-range in that event.

I don't buy all this free-range stuff. I get good ol' battery 10s.

[spike42]

ya ya, i eat only free range chickens and look what happened
to me! :}

[GrowlerBox]

According to the Eden website, the D210T has a crossover at 3.5 kHz at 18 dB. I can't find any more details than that (I even read the manual!) -- doesn't seem on the face of it to exclude the possibility that it's just a high-pass filter.

[greenboy]

Hardly anybody used true crossovers. Probably a good thing for several reasons including design skills ; }

[spike42]

Yes, I 'd looked at this page, but was not sure what it was telling me:

Eden World Tour Bass Amplifiers - D210T

[billfitzmaurice]

Originally Posted by spike42

Folks, this is quite interesting - I really am wanting to learn here.
I appreciate all your input. I guess I'm a little confused now, maybe
I don't have crossovers since the cab just has a high-pass filter?
The 10s run full-range in that event. But if I did have crossovers, they would
have to match the impedence of the drivers. Maybe
I should pull the back plate off the cab and post a picture?

It's easy enough to find out, if the woofers are wired directly to the jack without going through an inductor coil they aren't filtered.

According to the Eden website, the D210T has a crossover at 3.5 kHz at 18 dB.

It wouldn't be the first time a manufactured has mis-labeled a hi-pass filter. Nor would it be the last.

[spike42]

Thanks for that last, Bill. I'll take the cab home from my rehearsal
space this weekend and see what the wiring looks like.

[spike42]

OK, here's "what's inside the box":

HPIM3623.jpg picture by spike42 - Photobucket

I think I can deduce what's the tweeter at least. But
the leads from the speakers do go to that PCB, which
the input jacks are attached to. I guess that means the
speakers are thus wired to the jack? And that coil
mounted on the PCB is a filter rather than a crossover?

In any event, I grabbed a pair of the Deltalites at the
old price, while I still could. Bill was right, the originals
were 4 Ohm, wired in series. I rewired the Deltalites in
parallel and popped them in. Sounded excellent to my
old ears. I'll know better after the next rehearsal but all
other things being equal (amp, bass, etc) I can say that
I am getting much more punch than previously.