My first speaker project. Any advice?

[Jim85IROC]

Right after Christmas I'm going to embark on my first speaker building project. I currently have a pair of Boston Acoustics T830 towers that I really like, but I can't get matching center & rear speakers. I can't afford to buy a full home theater setup that sounds good enough to keep me happy, so I'm going to build it.

But first, I'm going to "practice" on an inexpensive pair of 2 ways for my girlfriend's apartment, since anything will be a vast improvement over the crap she's got now. Anyway, here's my plan:

Peerless 832732 bass driver. The price is right, the resonant frequency is low, and is well suited to a ported application, which I'd prefer since I won't be running a sub. This should give me a flat response well below 40hz, which is good enough for the pop/country/rock that we listen to.

For the tweeter I've chosen the Morel MDT-20. Again, it's affordable, and seems to have a good reputation. The frequency response of this tweeter is broad enough that I should have plenty of crossover options, although I'm leaning toward a 3k crossover frequency.

Since I'm the impatient type that doesn't want to sit there and fight with crossover design for 2 months until I get it right, I'm going to pay the $25 for madisound to design it for me.

Total investment will be $200 plus enclosure materials.

I had a couple questions:

1. What do you think of my driver selections? I want a smooth response, not something overly "crisp" or harsh, but of course I don't want it so smooth that I lose detail. My Boston T830s are the last Bostons to use a soft dome, and that's why I'm still using them. I just love the smoothness, although they seem to be a bit lacking in midrange clarity.

2. What do you guys think of the madisound designed crossovers? The car audio guys seem to love them, but I always like to get opinions from more than one place. Since they have in-house measurements of all the drivers they sell, it seems that they would be able to design a better crossover than I can, at least until I learn a lot more.

3. Are there any good tutorials or websites dedicated to cabinet construction? Since I'm on a budget here, I'm going to use 3/4" MDF, but if I ever expect these to make it into the girlfriend's apartment, they need to look NICE. I'd like to do a black vinyl laminate, but I've never done anything like that before. I'm from the car audio world, so we just slap carpet or vinyl on the box after it's built.

Thanks.

[Ken L]

Originally posted by Jim85IROC
What do you guys think of the madisound designed crossovers? .....drivers they sell, it seems that they would be able to design a better crossover than I can, at least until I learn a lot more.

definitely!

The crossover is the heart of what you want to do. Attempting to design it from scratch with little or no knowledge will almost certainly ensure your efforts will wind up with poor integration.


They also know which of their drivers make good combinations with each other - I would ask them for guidance there also.


regards

Ken L

[gary f]

I think you have a nice choice of drivers with good value and IMO me, the two drivers should integrate well. Try a crossover point between 2500 and 3000 hz.
Also, you may consider to put a few $$$ more and go with peerless 850-122. It's a CSX 7'' Woofer which features a sandwich cone that should be better than the CC line and also a better motor. For about 6$ more, go for it. Better Frequency response also.

I have used the cherry vinyl laminate from parts express and it is nice. Easy to use and it look good. Simple solution

F

[sreten]

http://www.speakerbuilder.net/web_fi...k/pcrkmain.htm

looks good to me, though you''ll need a longer port to get down to 40 Hz port tuning.

sreten

[sreten]

http://www.kaiaudio.com/diy2001/jasonopen.html

sreten

[Jim85IROC]

Originally posted by sreten
http://www.speakerbuilder.net/web_fi...k/pcrkmain.htm

looks good to me, though you''ll need a longer port to get down to 40 Hz port tuning.

sreten

Fantastic link! That Northcreek tweeter was one of the drivers that I had considered before tentatively deciding on the Morel, and I've had my eye on the Parts Express cabinets for a long time. That one link has given me a wealth of useful information.

[Jim85IROC]

I think I've decided to take a little different approach. I started reading about the Dayton III MTM and the Dayton II, and the Dayton II article mentioned the BR-1 kit from Parts Express. I looked it over and I think I'm going to give it a try. It's $70 less than what I had budgeted, and it comes with the cabinets already built.

[Hefty]

You should definately build your own cabinets. It's part of the fun buildning your own speakers.
I don't really know anything about the componets you're using but a 2-way project is the best way to start in my book.
If you want to get your hands dirty designing your own x-over, consider doing a 1'st order with drivers that have a broad overlap. There are ony two components, an inductance and a capacitance if I remember it correctly. (I havn't been very active in building x-overs for a while...) You can't really screw up too badly using this approach.
3/4" MDF is a very good choice and it will do nicely. Personally I do sandwich designs to dampen the cabinet but that is more trouble than you want at the moment.
Laminating is quite easy and not to expensive either. Use ordinary yellow glue. At least I think that's what you Americans call it.
Now... go and start building those speakers of yours

[sreten]

Sorry Hefty but I couldn't agree less.

When it comes to girlfriend stuff play it very safe in my book.

I think the BR-1 is an excellent choice, as you can
tell from reading about it in the Dayton II project.

One suggestion though :

Go to DIY store and buy a packet of the cheapest, thinnest
and nastiest plain self adhesive vinyl floor tiles you can find -
trust me these are the best ones for the job.

Work out a way of dividing the tiles in to pieces for the top/
bottom back and the two sides.
Note the important thing is to cover roughly 60/70% of each
wall in the centre so shape is not critical.

You'll need 6 back pieces, 12 top/bottom pieces and 12 side pieces.

Using a small wallpaper roller apply 3 layers of tiles in a pad
to the centre of the top/bottom/sides and back panel.

Don't bother with the front at all, and dont forget to clear the
cutouts in the back. Do one cabinet - compare with knuckles
to the other - you'll see why its a good idea.

sreten.

[Hefty]

LOL
maby you're right, one shouldn't play around with the girlfriends stuff. But then again where's the fun in playing it safe? It's not like I recomended French polish or anything exotic like that. Laminating the speaker will cover up any mess you made puting it togeather. Your choice...
I think you'll end up with a fair sounding speaker whichever road you take.
KISS is a good rule of thumb.
Keep It Simple Stupid, words to reflect upon when you start fooling around with wierd solutions in the future.