My speakers were perfect! Until...

[gregz]

My finally had the sound I liked:

http://www.pbase.com/gregz/image/34771521

I've enjoyed them for years, and then I leave my bonehead friend with them to watch some movies with his girlfriend...

To make a long story short, he overdrove the $@!* out of my woofers with low bass at almost max volume and now one of them has a wretched 60Hz buz overtone during low frequencies. It's a JL 12W1, and it's not made anymore.

So now I'm in a quandry. Since I'm using the JLs as part of a three way speaker system, a mismatch would destroy my balance and imaging. Do I try to match the 12W1 with a 12W0, or do I try the superior NHT 1259 instead?

In my calculations, I can come up with arguments for either one, and there's always the possibility I can tinker with the crossover to make either one work... Sigh.

 

[WmAx]

You failed to mention if you were using 4 or 8 ohm variant of this subwoofer. If you used 4 ohms, then it's your lucky day:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=39776&item=5724114093&rd=1&ssPageName=WDVW

-Chris

My finally had the sound I liked:

http://www.pbase.com/gregz/image/34771521

I've enjoyed them for years, and then I leave my bonehead friend with them to watch some movies with his girlfriend...

To make a long story short, he overdrove the $@!* out of my woofers with low bass at almost max volume and now one of them has a wretched 60Hz buz overtone during low frequencies. It's a JL 12W1, and it's not made anymore.

So now I'm in a quandry. Since I'm using the JLs as part of a three way speaker system, a mismatch would destroy my balance and imaging. Do I try to match the 12W1 with a 12W0, or do I try the superior NHT 1259 instead?

In my calculations, I can come up with arguments for either one, and there's always the possibility I can tinker with the crossover to make either one work... Sigh.

 

[gregz]

Sadly I am using the 8ohm versions.

I appreciate the thought, though.

 

[Rip Van Woofer]

There's another factor you have failed to consider: retribution against the bonehead friend! At the least I hope he was enough of a mensch to offer compensation.

As for the main problem, all I can think of, alas, is look for drivers from various mfrs. with similar Thiele-Small parameters, try them out, and hope you find one you like.

Or haunt audiogon, eBay, etc. and hope someone will have some of your originals for sale. Maybe put out a 'wanted' notice on the Madisound forum and other DIY forums, too.

Good luck.

 

[gregz]

I cranked the numbers over and over, and found that I'd end up with the same Qbox with the NHT driver, but I'd end up with very close to the same in-box resonant frequency (and cutoff) with the JL.

Really, both are a mis-match and both are a match.

Since I'm only using the frequencies between 20 - 85 Hz, technically I should be able to get away with a different driver (though it may take some re-tweaking of the crossover and some resistive fine-tuning).

Alas, my wife pushed me over the fence by saying "Just do what you know is the right thing; buy two drivers of your choice and we'll use the spare JL as a sub for another system."

If she insists! Two NHT drivers are on their way. From my calculations, they should behave well in the 2.78 cu ft boxes.

 

[Rip Van Woofer]

What a gal! I love happy endings!

 

[WmAx]

BTW, are you using an active crossover and bi-amping the subs/monitors or did you rig a passive crossover? If you are using a passive, perhaps this is a good excuse to get a low cost active xover and a 2nd amp.

-Chris

I cranked the numbers over and over, and found that I'd end up with the same Qbox with the NHT driver, but I'd end up with very close to the same in-box resonant frequency (and cutoff) with the JL.

Really, both are a mis-match and both are a match.

Since I'm only using the frequencies between 20 - 85 Hz, technically I should be able to get away with a different driver (though it may take some re-tweaking of the crossover and some resistive fine-tuning).

Alas, my wife pushed me over the fence by saying "Just do what you know is the right thing; buy two drivers of your choice and we'll use the spare JL as a sub for another system."

If she insists! Two NHT drivers are on their way. From my calculations, they should behave well in the 2.78 cu ft boxes.

 

[gregz]

Actually, at first I had it bi-amped and the sound was pretty good. But when I gave back the extra amp I had on loan, I build a passive crossover that turned out to give me a better sound than the bi-amp configuration ever did.

That's not to say I haven't considered trying again, only this time building my own first order crossover on the preamp side. There's a Behringer amp I've been looking at that would be happy to drive my subs...

I'm going to wait and see. If I have a problem I can't fix on by tweaking my current crossover, I always have the other strategy to fall back on.

 

[Polkfan]

Looks like one beast of a speaker system. With the bass maxed out I bet it felt like an earthquake.

 

[gregz]

Polkfan, I when I got home I could hear the bass from outside like gunfights and explosions. But when I opened the door, it was just a regular street scene - he had the gains turned up so high that the footsteps and traffic sounded like armageddon!

I can only imagine what the actual explosions were like. That's when the system was bi-amped with a Haffler running the bass. It's amazing the cones are actually still attached...

 

[anamorphic96]

Greg,

If you decided on the NHT 1259 drivers. You will not be disapointed. A friend of mine who use to work at Dolby Labratories was a huge fan of those. He uses one at home in the powered DIY package they sell at Madisound and it was scary how good it sounded.

Hope everything works out for you.

Glenn

 

[WmAx]

Must be your lucky day. Now a pair of the 8 ohm verson 12W1 subwoofers are up for bid:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=39776&item=5725203875&rd=1&ssPageName=WDVW

No excuses now.....



-Chris

 

[gregz]

Cruel, WmAx! As of Friday, my JL's have been sitting on my living room floor next to the new NHT subwoofers while I've been filing the cutouts to fit the slightly larger baskets.

Not only is the NHT more impressive on paper than the JL, but it's physically more than a match. No turning back now!

 

[gregz]

The saga continues

...So I pulled the JL's out and tried to "drop in" the NHT woofers. They didn't fit because the basket doesn't come off at the same angle.

No problem; I'll put back in the JL's, trace the outlines, measure .5" in all around and enlarge the holes where needed.

I can't trace all the way around the JL's because I made the inset for the speakers too narrow to get the pencil in there.

Ok; remove the JL's, borrow a friend's hand router, enlarge the inset, put back in the JL's and trace around the outside. Then remove the JL's again, make the .5" tick marks in from the outside edge, and enlarge the holes.


...Do you ever get the feeling you're on a sinking ship?...


So..... much later, I'm finally holding the NHT above the enlarged hole, and it drops in. YES!!

Then I go to place the screws in, and guess what? The outer ege of the NHT frame is thicker than the JL. This means the holes are set just a little too far out towards the edge.


This was supposed to be a drop-in replacement, but after hours of frustration, now I'm looking at sealing the existing holes, drilling new holes rotated slightly from "normal," and trying to install a new set of tee-nuts from inside the assembled box. Then I STILL have to pretty up the raw butt-joint boxes that I built while I was still in college.

So now I'm thinking it would be easier and much more rewarding to start from scratch. Perhaps I'll draw out the dimensions and give them to a cabinet maker to build my boxes "purdy." That means I can do more than just rectangles. That means I can have cherry finish to match the rest of my furniture...

Something like this:

 

[WmAx]

If you are gong to have a cabinet maker do the work, I would go ahead and give him the bookshelf speakers, too. Just remove the drivers from the cabs first. Why give him the bookshelves? Have him apply the same veneer/finish to the sides of the bookshelves so that you have a perfectly matching set with the subs.

-Chris

...So I pulled the JL's out and tried to "drop in" the NHT woofers. They didn't fit because the basket doesn't come off at the same angle.

No problem; I'll put back in the JL's, trace the outlines, measure .5" in all around and enlarge the holes where needed.

I can't trace all the way around the JL's because I made the inset for the speakers too narrow to get the pencil in there.

Ok; remove the JL's, borrow a friend's hand router, enlarge the inset, put back in the JL's and trace around the outside. Then remove the JL's again, make the .5" tick marks in from the outside edge, and enlarge the holes.


...Do you ever get the feeling you're on a sinking ship?...


So..... much later, I'm finally holding the NHT above the enlarged hole, and it drops in. YES!!

Then I go to place the screws in, and guess what? The outer ege of the NHT frame is thicker than the JL. This means the holes are set just a little too far out towards the edge.


This was supposed to be a drop-in replacement, but after hours of frustration, now I'm looking at sealing the existing holes, drilling new holes rotated slightly from "normal," and trying to install a new set of tee-nuts from inside the assembled box. Then I STILL have to pretty up the raw butt-joint boxes that I built while I was still in college.

So now I'm thinking it would be easier and much more rewarding to start from scratch. Perhaps I'll draw out the dimensions and give them to a cabinet maker to build my boxes "purdy." That means I can do more than just rectangles. That means I can have cherry finish to match the rest of my furniture...

Something like this: