Drivers with different impedances?

[chrisbee]

I have 8 drivers:

4 x 8 Ohms and 4 x 4 Ohms.

There is no obvious way to wire each set of four to provide matching (safe) impedances into the two stereo channels of the EP2500 to avoid imbalances in output:

Except perhaps?



What do we think?

Good, bad or downright ugly? ;D

[edfowler]

can you combine one pair of 4s with one pair of 8s in a series/parallel configuration and show the amp 4ohms per side?

[ThomasW]

The right way to do this is with 2 power amps.

Don't mix different impedances on the same channel. Regardless of how they're wired they won't get the same amount of power. So there will be a problem equalizing the output between the drivers

I'm not how it would work to have the 4 ohm drivers on one channel and the 8 drivers ohm on the other channel of the same amp....Given the differences in these drivers I think balancing the output levels would be problematic.

[chrisbee]

Thanks. I was afraid that would be the answer. I'll try separating the new and old drivers on separate channels to start with. Plenty of scope for balancing levels.

I wanted to try pushing the Total Vas barrier with the new and old AE IB15 drivers in one 6' tall 2 x 4 manifold. Nowhere else is acceptable but I'm fed up with the old drivers just sitting in their boxes. All that potential displacement is just going to waste and I have far too much time on my hands. I may even clear out the junk in the enclosure.

Thanks again.

[jimcant]

Chris,

In your blog, you indicated that you were considering two, two driver manifolds for these drivers, to supplement your existing four driver manifold

Have you gone cold on that idea?
I think maybe you should send them to me instead, just to get them out of your way, mind you ;D

I am sure they are longing to be arrayed again, and I have the perfect spot for them, as a second array in my shed, directly opposite the first one
I reckon if I put enough drivers in enough locations, then placement becomes a rather moot point

I am only half joking here, because I have been seriously considering a second array, just to get my room symmetry back (everything has been rotated 90 degrees )
I would also like to achieve the desired 4 ohms per channel on my amp.

I can't wait to see what plan you come up with to utilise those drivers somehow, but I know it will be good

Cheers,
Jim.

PS
My soon to be patented, wood heating device is complete, and about to undergo trials.
We have plenty of hardwood here that burns really well, and if you wait for 300 years, you can do it all again ;D

[chrisbee]

Hi Jim

My ingenious plans to use the space between the underside of the roof covering and the insulation were scuppered by "management" yesterday. I was caught red-handed, innocently holding cardboard circles up against the dormer ceiling and arbitrarily dismissed. All protests were futile.

In a revolting fit of insolence I started on a tall manifold which should be finished today. Two layers of 18mm Baltic birch plywood this time. Probably with window bracing shelves. All to be assembled in the enclosure. Plans were rushed through and quickly approved as a safe alternative to turning the house into Swiss cheese.

Now I really ought to blow away the dust and cobwebs and awaken the ghosts of my old thread (according to Cult policy Para 73. Clause B(2) Line 3 ) in order to report further progress. I really didn't want to do this because I know how much you value having the longest ever Cult thread. ;D

I hope you know what you're doing with this heating system?

[ThomasW]

Jun 25, 2009 1:24:45 GMT -7 @chrisbee said:

Now I really ought to blow away the dust and cobwebs and awaken the ghosts of my old thread (according to Cult policy Para 73. Clause B(2) Line 3 ) in order to report further progress. I really didn't want to do this because I know how much you value having the longest ever Cult thread. ;D

Since this is a 'new' project, a new project thread would be fine, unless you want to unseat Jim as the reigning king of long threads...

[chrisbee]

Jun 25, 2009 6:46:29 GMT -7 ThomasW said:

Since this is a 'new' project, a new project thread would be fine, unless you want to unseat Jim as the reigning king of long threads...

Thanks, Thomas.

I was making good progress before rain stopped play. Should have some pictures to pad out the gory details sometime tomorrow.

[jimcant]

Long thread? Moi?
You go for it Chris

BTW, I have never seen your build thread here.
Has it been archived, or could you perhaps give me a link?

I need something to read, that will last me well into my senior years

I have enough knowledge about wood heating to be dangerous (a bit like REW really ), but am confident that all the concrete and steel I am surrounded by, will not combust readily, and if it does I will be sure to post pics of the conflagration, followed in short order by a call to my insurance company about my IB exploding after a very tame session of Jeff Beck's, Guitar Workshop
Not my doing at all, blame it on that bass head in Denmark ;D

Cheers,
Jim.

[chrisbee]

Jun 25, 2009 23:42:57 GMT -7 jimcant said:

BTW, I have never seen your build thread here.
Has it been archived, or could you perhaps give me a link?

I had no idea you could read hieroglyphics?

I need something to read, that will last me well into my senior years

So you're not really as old as you look?

blame it on that bass head in Denmark ;D

Sticks and stones... ;D

Cheers,

Cheers.

[jimcant]

Chris, my friend,

I see no build thread, or resurrection of an old one, for your new project, and have had to keep up to date with your activities via your blog link

Those here that wish to see an IB Master at work, will need to click on the link at the bottom of any of Chrisbee's posts

Looking good there mate
I see another challenge to my own IB'ness in the offing ;D, but am enjoying watching a true LF artisan at work.

Just watch that hoist up to your lair, and your ladderwork

Cheers,
Jim.

[chrisbee]

Jun 28, 2009 0:48:47 GMT -7 jimcant said:

Chris, my friend,

I see no build thread, or resurrection of an old one, for your new project, and have had to keep up to date with your activities via your blog link

Those here that wish to see an IB Master at work, will need to click on the link at the bottom of any of Chrisbee's posts

Looking good there mate
I see another challenge to my own IB'ness in the offing ;D, but am enjoying watching a true LF artisan at work.

Just watch that hoist up to your lair, and your ladderwork

Cheers,
Jim.

Stop nagging! ;D

I didn't think my crude wood butchery amounted to anything of interest so far.

I've also run out of plywood again and it's Sunday so my local timber merchant isn't open.

I need four more panels to double up the top, bottom and to add two more bracing shelves.

For some reason my wife objects to me cutting up the furniture.