DIY Focal Bookshelf Speaker

[zingo]

I have been looking at designing a bookshelf speaker using Focal drivers. (Don't worry, I'm still on the road to my Super MTMWW, but this is first stop :D) I was eyeing a MTM design, but now am also thinking about a TMM or TM. I like the added sensitivity of the extra woofer and MTM designs, but heard they can be tricky to correctly implement. I would appreciate any help or experience that people have had and any suggestions. (I will be using a sealed box as planned thus far)

Focal TC90TD5B Tweeter (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260337970303&category=3276&viewitem=&salenotsupported)
http://i21.ebayimg.com/01/i/001/0f/1f/e20c_1.JPG

Focal 6W4252 Midwoofer (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250337741331&category=3276&viewitem=&salenotsupported)
http://i15.ebayimg.com/03/i/001/18/1a/200e_1.JPG

If I can pull these off well, I think they would make a nice replacement for my Monitor 5Jrs. :cool:

[ben62670]

The Focal tweeters are very nice, but the mid woofers tend to be lacking down low. Your Monitor 5's would be better bass wise. You may want to look into a seas woofer. Check DIYaudio, and zalph's web sites. They have good info there.
Ben

[ShinAce]

My recommendation is to go straight 2 way(MT) and attenuate the tweeter as needed. I assume you have a sub and don't need this thing to play flat down to 10 Hz.

If you do go the Appolitto road, then know that the distance between the center of the tweeter tot he center of the mids is supposed to match the wavelength of the crossover frequency. This applies to second order crossover networks and has to do with lobing(directivity).

Best of luck, and don't forget you can always use a single panel to mount the parts to a baffle. Do some listening tests to tweak the crossover region.

[zingo]

What about the Usher 8945P 7" Woofer (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=296-602) for a two way TM with the Focal tweeter? It looks like keeping the tweeter above 2K would keep the response pretty flat, and the woofer seems up to the task.

http://www.parts-express.com/images/item_standard/296-602_s.jpg

[ben62670]

This guy does a lot of great research.
http://www.zaphaudio.com/

[ViperZ]

This guy does a lot of great research.
http://www.zaphaudio.com/

Wow, what an awesome and detailed site!

[zingo]

He does provide a lot of great info! I have a lot of reading to do...

[ben62670]

A lot of speakers look good on paper, but have issues with breakup, or distortion. Some manufacturer's specs tend to be a little a little lenient when it comes to the performance of their products;) Zaph has not IMHO shown any favor to any manufacture, and his info is highly praised in the DIY community.

[clearwave]

I just finished a TMM using the Seas DXT tweeter and SB Acoustics 7" that I think is excellent. The SB Acoustics have near Scan Speak level harmonic distortion levels at 1/4 the price. It's not a bookshelf, however.

Do you know how to design a crossover, Zingo? That will be the biggest issue.

[zingo]

I have a little experience designing crossovers, but I'm pretty good at taking advise too. :D

Lookie what I found...

http://www.geocities.com/woove99/Spkrbldg/

[zingo]

Usher 8945P 7" (http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=296-602&CFID=11333739&CFTOKEN=98817661) / Peerless HDS 1" (http://www.madisound.com/catalog/product_info.php?manufacturers_id=143&products_id=1744) MTM in a 1 cu.ft. sealed bookshelf configuration. Here is the designed crossover for the three drivers with impedance flattening for tubes.

http://www.geocities.com/woove99/Spkrbldg/Usher_MTM/XO_8945P_HDS_MTM_IC.gif

The initial cost is $814 ($160 for two tweeters + $240 for two cabs + $420 for four woofers), not including the crossovers, binding post, etc.

[clearwave]

The initial cost is $814 ($160 for two tweeters + $240 for two cabs + $420 for four woofers), not including the crossovers, binding post, etc.

That's a lot of money for a simulated design. In other words, he traced someone's else's IB measurements (zaph audio), added the diffraction prediction from the FRD Consortium software, added minimum phase data, and came up with the crossover without taking measurements in the actual box. Simulations can get you 90percent there but it's not an optimized design with real in box measurements. Only you can judge whether or not that is important to you.

I'd be happy to design you a TMM or TM type speaker using those drivers with a real measurements.

[zingo]

You're absolutely right, and one reason I have been eyeing the finished TM version (http://www.geocities.com/woove99/Spkrbldg/Usher_2way/Usher_2way.htm) since I last posted:

http://www.geocities.com/woove99/Spkrbldg/Usher_2way/Usher_pic1.JPG

I also really like the Zaph Audio Scan-Speak Revelator TM (http://www.zaphaudio.com/ZRT.html), but this is a pricey build...

[clearwave]

Show me the real measurements for that design. You won't find any. Zaph's on the other hand is perfectly documented.

[Early B.]

Zingo --

What's your budget and design goals?

You're budgeting $240 for cabinets? You'll save $200 by making them yourself.

I would highly recommend working with Jed on this project.

[zingo]

Show me the real measurements for that design. You won't find any. Zaph's on the other hand is perfectly documented.

Alright alright. :p I see what you're getting at...

[zingo]

Zingo --

What's your budget and design goals?

You're budgeting $240 for cabinets? You'll save $200 by making them yourself.

I would highly recommend working with Jed on this project.

My budget is around $600 and I would like a high performance 2 way. I have the skills to make the cabs, and would prefer to do it that way, but don't have the tools or the space in my apartment.

I feel stupid, but who's Jed? :o

[ShinAce]

Partsexpress shows the tweeter as discontinued and with an RMS power handling of 12 watts.

That would be a deal breaker for me.

[Early B.]

I feel stupid, but who's Jed? :o

Clearwave. He's the guy who designed the massive center channel I just built.

[GV#27]

Masdisound sells a complete Zaph SR71 kit.It uses SEAS (prestige series) drivers but more importantly the crossover has been expertly designed to seemless blend them together.
http://www.madisound.com/catalog/index.php?cPath=35_40_402_408

[clearwave]

I feel stupid, but who's Jed? :o

That's me.

http://clearwaveloudspeaker.googlepages.com

[zingo]

That's me.

http://clearwaveloudspeaker.googlepages.com

Now I feel even more stupid... but nice to officially meet you! Those are some great designs and I'll have to look over them.

[clearwave]

Now I feel even more stupid... but nice to officially meet you! Those are some great designs and I'll have to look over them.

Hey thanks! And don't feel stupid. Also, we can do any design you want really. As long as I have a test box that'll work. I'm finishing up the M5 bookshelf that is in your pricerange and I'll give you demo pricing on it if you are interested just send me an email clearwavespeakers(at)gmail(dot)com

[jonlereux]

Clearwater, did you ever get a chance to look at the Usher/ Peerless design posted? I am intersted in real world measurements with those drivers as they seemed like an excellent value for the performance.

[jonlereux]

Sorry, I meant Clearwave. my apologies