[JFT]

Just a thought, but wouldn't it make sense to build the Alpha cabinet about eight inches taller and have a crossover compartment with a removable cover at the bottom? The additional height would be in the outer baffle, sides and back only; inside dimensions of the speaker cabinet would not change. I'm suggesting this because I was recently helping a friend tweak the crossover on a pair of Bottlehead speakers, and removing drivers to access the crossover was a pain. All my diy speakers have had exernal crossover boxes like Danny's Alphas or accessible crossover compartments in the bottom. In my experience the internal but accessible crossover is the simpler solution. Would there be any technical problems with making the Alpha taller (other than WAF issues)?

[azryan]

The connection to the base and bracing would be weaker I think.

[JFT]

The connection to the base and bracing would be weaker I think.

Good point. There might be a tradeoff here, but it seems to me the parts that need to be strong and inert in the Alpha LS are already so bulletproof that it wouldn't make a meaningful difference to the strength of the cabinet. In the case of your Alphas, for example, with an accessible crossover it would have been very easy for you to try several variations of Danny's latest crossover mods and decide for yourself whether they enhance the sound in your listening room. I suppose the bottom line is that I'm a compulsive tweaker and can't leave anything alone, even if it's good to begin with. By the way, the photos you took during construction were a great contribution to the diy speaker kit cause.

[jonwb]

That's not a bad idea JFT.  I actually considered doing something along those lines on mine, but figured the enclosures will be hard enough to construct w/o making little drawers that slide out for the crossover bits.

As an alternative, I'll be making little external crossover boxes that will sit behind my speakers.  I plan on making the dimensions of the crossover box(es) complimentary to the speakers themselves and having them sit on the base just behind the speakers.  

One could argue (actually it'd take at least two to argue (unless you're that little guy in Lord of the Rings)) that by putting the crossovers inside the speaker box you'll have less terminals and connectors to reek havoc on sonic perfection, but I too want the ability to (easily) tweak later and even play with an active crossover if I want.

jownb

[azryan]

"-In the case of your Alphas, for example, with an accessible crossover it would have been very easy for you to try---"

If I wouldn't have REALLY glued down my x-over I coulda just went in through the bottom woofer.

You could figure out a way to make the x-over easy to get out yet locked in when you want it to be.

Plus there was no extra x-over options when I built mine so I never expected to ever remove 'em.

jon,

I'll play 'evil Golum' for ya'...


"-that by putting the crossovers inside the speaker box you'll have less terminals and connectors to reek havoc on sonic perfection-"

There's that, but then there's the idea that outside the cabinet the parts won't be getting hit by the internal vibrations.

Pros and cons to both I think.

I would have made mine external for that 'vibration' reason but I just wanted 'em to look nice and they already took up enough space.
I'm plenty happy as is so no prob.

[JoshK]

I have another idea, that I thought of for a speaker project I have in my head.   You can make a small box for the crossover on the back of the speaker with a removeable lid.  The wires go through small holes in the enclosure into the box and you can seal the holes with hot glue.  

If you are having a hard time invisioning what I am not describing well, take a look at Zybar's picture of the mid panel enclosure on the RM40s.  Same idea but for the crossover in the back.  You will just have to account for the volume of the enclosure your missing in the dimensions.  If the enclosure is effectively air sealed the lid could be engineered in a variety of ways and wouldn't affect the performance, care would just be needed to make sure it doesn't vibrate when the speaker is playing.

[JFT]

That's not a bad idea JFT.  I actually considered doing something along those lines on mine, but figured the enclosures will be hard enough to construct w/o making little drawers that slide out for the crossover bits...

I cut the back panel full length, cut off the bottom section (typically about six inches high), and install an extra brace where the bottom would normally be with half inch holes (which I subsequently caulk) for the wires. I glue the main back panel, but since the bottom crossover access panel doesn't have to be airtight, I just hold it in place with four screws. Having an external crossover is just as good but it involves the extra work and expense of a separate box and extra binding posts. The outboard box on the back of the speaker would also work, but I believe you would want to keep the backs of the speakers flat so you can lay them down to work on them and transport them easily. I once owned a pair of Bottlehead speakers with their Big Stud binding posts which protruded from the back, and it was a terrible handicap when I had to load them in the truck - couldn't just lay them on their backs. Another advantage of adding a few inches to the Alpha: If you'r six feet tall or more the additional height would enhance the way they sound when you're listening while standing up. Also, as an aesthetic issue, raising the lowest drivers from the bottom would look nice too. Of course with the lower drivers raised a few inches they wouldn't sound as good when you're laying on a bearskin rug in front of the fireplace with your sweetie, but who other than Danny would care about the sound quality in that situation?

[Danny Richie]

Of course with the lower drivers raised a few inches they wouldn't sound as good when you're laying on a bearskin rug in front of the fireplace with your sweetie, but who other than Danny would care about the sound quality in that situation?

How did you know I like to listen on the floor with my sweetie in front of the fireplace?  

All that you described will work out fine.

[jonwb]

How did you know I like to listen on the floor with my sweetie in front of the fireplace?  

Well, since Danny is married, that'd make him "That Lady's Man"

[azryan]

"- If you'r six feet tall or more the additional height would enhance the way they sound when you're listening while standing up.-"

Gotta be over 6' for sure. Probably 6'5".
Remember it's the height of your ears not the top of your head.

"-Also, as an aesthetic issue, raising the lowest drivers from the bottom would look nice too.-"

I don't see how that would look better? I mean it would no longer have the full face covered in drivers. It'd look like a little gap at the bottom to me. I'm sure it'd look fine though.

I wonder if it'd effect the bass a bit not having the woofers reach all the way down to the floor?

"-Of course with the lower drivers raised a few inches they wouldn't sound as good when you're laying on a bearskin rug in front of the fireplace with your sweetie-"

Don't worry, it's not even a prob when she's on top. Just make sure she doesn't block either speaker. That's a rookie Alpha mistake. hehe

[JFT]

Of course with the lower drivers raised a few inches they wouldn't sound as good when you're laying on a bearskin rug in front of the fireplace with your sweetie, but who other than Danny would care about the sound quality in that situation?

How did you know I like to listen on the floor with my sweetie in front of the fireplace?  

All that you described will work out fine.

Remember when my wife and I visited you to hear your Alpha's, and you were not there when we arrived? While we were waiting for you your sweetie told us the two of you prefer to listen to them nude on the bearskin rug, but they don't sound as good that way. So my wife replied that she thinks nude drivers are sexy, but if they don't sound as good in the nude you should build some grills for them.

[Danny Richie]

Remember when my wife and I visited you to hear your Alpha's, and you were not there when we arrived?

I remember you coming.

While we were waiting for you your sweetie told us the two of you prefer to listen to them nude

There is no telling what she might tell you, but as modest as she is I doubt there was much about any bear skin rugs.  

Still though, I laughed.

So my wife replied that she thinks nude drivers are sexy, but if they don't sound as good in the nude you should build some grills for them.

How about a grill that just barely covers them a little?  

I wish you could hear those Alpha's again with the latest tweak and with my new amps and pre-amp that will be ready soon. They do get sexy now...

[JFT]

I wish you could hear those Alpha's again with the latest tweak and with my new amps and pre-amp that will be ready soon. They do get sexy now...

I remember they sounded magnificent with the little 30 watt amp you were using at the time. They were the first speaker I have heard that would reproduce a nine foot grand piano at concert levels and dynamics. I've listened to solo piano music through my Vandersteens, Magnepans, Klipsch Cornwalls etc and thought it sounded realistic, then I heard it through the Alphas and my first thought was "OK, this is the real thing. All the others were just weak imitations". I'm sure I'll want to listen to them again someday.