Help choosing a mid driver for my 4x8"

[ghiadub]

I just picked up an SWR 4x8" cab. The tweeter is horrible, I think it might have been replaced at some point.

The cab sounds fine when I turn off the tweeter. Nice tight lows.

Here is the idea; I would like to replace the tweeter with a midrange driver, and I assume I would be changing out the crossover. It seems pretty straightforward, but I am a speaker neophite.

So, the question to the speaker gurus; I have room for a 5" or 6" mid driver, which one and where can I get the appropriate crossover?

The 4x8 is back ported
Here is the info from SWR:
Impedance: 8 ohms
Power Handling Capacity: 250 watts RMS
Four custom 8" PAS drivers
One Piezo tweeter
Weight: 55 lbs
Size: 23"W x 19.8"H x 16.5"D

[Ric Vice]

Originally Posted by ghiadub

I just picked up an SWR 4x8" cab. The tweeter is horrible, I think it might have been replaced at some point. The cab sounds fine when I turn off the tweeter. Nice tight lows.

I had a similar problem with the original Baby Blue 2x8
the highs were just to edgy and bright.

Originally Posted by ghiadub

Here is the idea; I would like to replace the tweeter with a midrange driver, and I assume I would be changing out the crossover. It seems pretty straightforward, but I am a speaker neophite.

Don Oatman used a tweeter in my LDS 2x8 three way that sounded really good and it wasn't a soft dome. You could contact him via email and ask him what is was. Don also built a 4X8 for Ken Jung that had a selenium tweeter. EA used two mid drivers in the VL 208 along with a single tweeter that works beautifully.

Originally Posted by ghiadub

So, the question to the speaker gurus; I have room for a 5" or 6" mid driver, which one and where can I get the appropriate crossover?..........

It's going to be tricky matching a mid driver that's almost the same size to those 4 8" Bass drivers I'd want to ask someone how thats done. SWR used Celestion Drivers I believe and they are probably 16 ohm's

Ric

[will33]

That's a tough one. If it sounds like 1/2 a Henry 8x8 it reaches high enough for most folks with the tweeter down unless you want some zing on your slap.

Dispersion is the other reason to use one. I assume it's four 8's in a square. Could look for a different hf driver you could pass a little lower.

Could have someone do a custom crossover to split off one of the 8's you have to carry the highs. That would help the dispersion but you'd end up with a funky impedance cab like 5.33 below the crossover freq. and 16 above it or something wierd like that.

[chadds]

LDS is who you should contact. That horn is poor. The cone for the highs in the BBs is nice and smooth. Perhaps LDS has a crossover. The cone for the BBs was available last I checked.

[will33]

Well, splitting off or replacing one of the 8's would also change the cab vol./tuning for the remaining 3 so that's gonna make even more work.

I guess see what's wrong with the current tweeter/filter first. Could maybe just improve it. Anything beyond that would require a purpose built crossover and looking for a tweet you can pass lower or a fairly high spl 6.

[ghiadub]

THanks guys. I don't slap, but am just looking for some treble to help the cab cut thru a little without being harsh. I have a coaxial BagEnd single 10" cab that does this nicely. The treble is smooth and not harsh.
If nothing else, I need to replace this tweeter, it has a kind of Buzz like a car horn when on.

[Lo-E]

Rather than arbitrarily deciding to use a 5" or 6" driver, it's best to think in terms of what's available that has the frequency response you need.

Using a driver that has a sealed back will save you a lot of headache, as you won't need to think about designing a sub-enclosure, and the change in volume in the rest of the cab will probably be close enough to not worry about.

Building, and even designing your own simple crossover is not really all that hard, but you need to have an idea of what you're building it around so it would be a good idea to try and get T-S parameters for your woofers and the frequency response and impedance curve of the new mid driver. If you can't get specs on the existing woofers, don't lose sleep. You can still base your design on the parameters of the mid driver only and just take into account where 8" drivers will start to beam to help you choose your mid driver and your crossover frequency.

At what frequency four 8" drivers in a square pattern will start to beam is a good question for the real speaker experts here - and there are several, but I'm not one of them. I've only dabbled.

Let us know how it goes!
E

[spiritbass]

IIRC, Don has access to an 8" driver with a coaxial tweet. If he uses it, it must be decent. It would be a slick solution if it sounds good to your ears...

[anonymous02282011]

You could build a fEARful headcase (6" mid driver + tweeter) and bi-amp with the 4x8.

[Chef]

That LeSon tweeter is probably blown.
You can get them off ebay for really cheap.
I replaced the one in my 8x8 twice before I learned to keep it turned down.

[1n3]

Replacing the tweeter makes more sense (to me) than trying to come up with a cone mid that works well with 4 8s.

Originally Posted by Chef

That LeSon tweeter is probably blown.
You can get them off ebay for really cheap.
I replaced the one in my 8x8 twice before I learned to keep it turned down.

You turned down to match sensitivity, to protect the tweeter, or both? Should the OP try to find a better tweeter?

[ghiadub]

Originally Posted by Chef

That LeSon tweeter is probably blown.
You can get them off ebay for really cheap.
I replaced the one in my 8x8 twice before I learned to keep it turned down.

I will probibly go that route, it looks like there is only about 6" of clearance between the 8's which is less than what I was thinking I had.

Oh, and everyone loves a pic:

[seamonkey]

You could change out one of the 8" for a mid-range driver.

And use a crossover just to is.
3x8 for the bass + 1x8 for the mids

I assume your current drivers are 8 ohms, wired parallel the GK can handle it.
The crossover will not be ideal, but would work.
You could also adapt a 6" sealed back so you wouldn't need a separate chamber inside.

Of course, just using the same drivers, and running a crossover to one, and sealing the back by putting in a can would help with the mids. Those drivers are spaced too far apart horizontal - they are probably cancelling out mids.

[Joe Louvar]

Originally Posted by ghiadub

I just picked up an SWR 4x8" cab. The tweeter is horrible, I think it might have been replaced at some point.

The cab sounds fine when I turn off the tweeter. Nice tight lows.

Here is the idea; I would like to replace the tweeter with a midrange driver, and I assume I would be changing out the crossover. It seems pretty straightforward, but I am a speaker neophite.

So, the question to the speaker gurus; I have room for a 5" or 6" mid driver, which one and where can I get the appropriate crossover?

The 4x8 is back ported
Here is the info from SWR:
Impedance: 8 ohms
Power Handling Capacity: 250 watts RMS
Four custom 8" PAS drivers
One Piezo tweeter
Weight: 55 lbs
Size: 23"W x 19.8"H x 16.5"D

BTW, if you have an empty speaker cabinet and need help with speaker selection you can ask US Speaker at Cabinet Dimension Help usspeaker@optonline.net

[ghiadub]

I just got the new tweeter in and that was definetly the issue. It sounds fine now, no more buzzy treble. Thanks for the tip Chef, it did not occur to me that a working tweeter could be fried, but this one definetly was exactly that.

[Chef]

Good deal; enjoy!
Be careful; it's a nice sounding cab, but, not rated for lots and lots of power, or, lots of bass eq.