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Old 5th January 2013, 09:47 PM   #11
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There may be benefit to using 2 tweeters mounted on the sides of the box and side firing.
This issue is discussed in my latest version of the "Cook book" by Vance Dickason
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Old 6th January 2013, 01:56 AM   #12
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For best sounding HT all the speakers should have the same tonality so making a new centre would also be a good idea
This statement should be repeated over and over and over and over again.
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Old 6th January 2013, 03:28 PM   #13
Siggma is offline Siggma  United States
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Originally Posted by DrNick View Post

The requirements for the speaker are simple, in that there will always be a sub on whenever the rear channels are called on, so the lower limit for flat response can be set at 100 Hz. This means they can be sealed, and the second requirement will be that they should be small. Finally, I don't want the total cost to go over 200 for the pair (I mean, not by much anyway ).
I just finished designing an HT sat using a Visaton W130S 8 Ohm woofer and either a Vifa BC25SC06 or Vifa XT25SC09 dual ring radiator tweet. I've listened to it with the BC tweet and it's a good match although it requires a lot of padding to match the woof. Just getting started on measuring and tweaking the crossover for the XT25 dual ring. Without any baffle step correction f3 is about 81Hz. Parts list below, all parts are available at Parts Express. The cab can be either a "Knock Down" .23 cu ft or a finished .25 cu ft but that will drive the cost up to over $100 per unit. The unfinished cabs are easy to seal and paint and will weigh about 12 lbs including drivers when finished. The Vifa XT tweeter is slightly more expensive. I don't have the crossover finished yet but will within 10 days or so. It's basically a standard Quasi-forth order asymmetric LR crossover (credits to Jeff B.). Tweet has third order slope and woofer has second order slope to get phase to align. If you want an even cleaner midrange we can add a crunch filter to kill the breakup mode this woofer has at about 6K but it will reduce efficiency to below 85db 1w/1m and change the crossover a little. The woofer has two peaks, a small peak at 4K and another peak at 6K. I don't think the first resonance is a breakup mode. It does not show an increase in distortion at that peak but I could be wrong. Regardless it sounds very good having an especially good sounding bottom end for such a small woof. The Vifa BC25SC06 is a well known, well documented tweeter used in many projects and kits. The Visaton woofer is a little newer. Haven't see too many uses for it yet... But it's low cost and decent response make it a target for future projects.

Cabinet 24.90 (PE .23 knock down)
Woofer 24.12 (Visaton W130S 8 Ohm)
Tweeter 17.25 (Vifa BC25SC06)
Cup 5.50 (PE Wire cup 3 7/8" with spring clips)
Cap 1.70 (Not finalized yet)
Cap 2.60
Cap 4.33
Coil 4.21
Coil 6.69
Wire 3.00
Screws 2.00
Crossover board 5.70
=================
$100.00

This is NOT a kit, just a parts list and a crossover diagram. You have to mount, solder up then mount the crossover, cut openings in the baffle (2" and 4 1/4" hole saws work fine) and glue the cab together. But it's a good quality HT sat that fits your bill. Flyer PDF is attached. Also see attached distortion sweep. I might have been wrong, there is a small distortion peak at 4K but it's very small.
Attached Images
File Type: png Distortion-THD-D3-D2 VisatonW130S 6th octave.png (66.8 KB, 89 views)
Attached Files
File Type: pdf HT-Satellite-1.pdf (192.4 KB, 12 views)
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Last edited by Siggma; 6th January 2013 at 03:47 PM. Reason: correcting errors
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Old 6th January 2013, 04:54 PM   #14
Siggma is offline Siggma  United States
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Looking at what you've done in previous posts you could probably design the crossover yourself given the raw data. I do have raw sweeps but I was having trouble getting phase to align and I suspect my measurements are off or I forgot something. I think I need to go back and take better measurements using ARTA and converting to minimum phase. That and my test baffle indicates I need to move the drivers so I'm waiting till Tues or Wed to get over the the shop and cut the baffle off this box so I can remount them. I really like the PE knock-down boxes, they are very well made and make it very easy to make a decent quality finished speaker. They are also very inexpensive if you purchase enough stuff and get free shipping.
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Old 6th January 2013, 05:49 PM   #15
DrNick is offline DrNick  United Kingdom
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Quote:
Originally Posted by Moondog55 View Post
For best sounding HT all the speakers should have the same tonality so making a new centre would also be a good idea
Quote:
Originally Posted by Soundtrackmixer View Post
This statement should be repeated over and over and over and over again.
I totally agree. I'm starting to wonder if I pick the right tweeter and midwoofer, could I make some two way TMs or dipoles for rear speakers, an MTM for the centre with the tweeter off centre and the phase adjusted to make it fire up slightly to aim at ear level at 2.5 metres, and either some TMMs or three ways using the tweeter and mid unit for main left and right speakers. I'll have to pick the right time to explain this brilliant concept to my wife.

I'm aiming to build the rear speakers first as I don't have any at the moment, and that way I can try them out in place of the front speakers and see if I still like the idea of using the same drive units.
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Old 6th January 2013, 06:25 PM   #16
DrNick is offline DrNick  United Kingdom
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Originally Posted by Siggma View Post
I just finished designing an HT sat using a Visaton W130S 8 Ohm woofer and either a Vifa BC25SC06 or Vifa XT25SC09 dual ring radiator tweet.
Thanks! I can get this woofer from Conrad Electronic UK. I'll have to make my own enclosures though, I've looked for the Dayton kits before and they do not seem to be distributed over here (UK). Shipping things over is usually very expensive, if you want to be sure they'll arrive.

Is the crossover diagram in the pdf file? I could see the image of the driver and the title text.

Please let me know how you get on with this one, thanks.
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Old 6th January 2013, 06:43 PM   #17
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Shipping things over is usually very expensive, if you want to be sure they'll arrive.
If the value of the item shipped from the USA is over 20 you not only have to account for shipping costs but also for customs&excise duty and VAT.
That alone usually doubles the cost even without shipping costs.
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Old 6th January 2013, 07:21 PM   #18
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The phase you have posted looks like electrical phase and not actual driver phase. Have you measured the phase or extracted minimum phase from your frd files? If not, you need to start over. Sorry.
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Old 6th January 2013, 09:38 PM   #19
DrNick is offline DrNick  United Kingdom
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The phase you have posted looks like electrical phase and not actual driver phase. Have you measured the phase or extracted minimum phase from your frd files? If not, you need to start over. Sorry.
Thanks for pointing that out. I've used the Response Modeller to do this, and it did make a difference. I also modelled the box effects, and this has dropped the bass a fair bit once the baffle step comes in. To compensate for the change, the L3 inductor in the crossover has changed to 0.55 mH from 0.8 mH.

Click the image to open in full size.

I don't think this is satisfactory any more, so I think it must be back to the drawing board.
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Old 6th January 2013, 09:48 PM   #20
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Thanks for taking my advice and not misunderstanding it as a put down. I get that often it seems. And I'm glad a major problem was solved before expensive parts were purchased.

Also remember that using response modeler gives minimum phase. You'll need to enter the driver x, y, z coordinates if you're not measuring the drivers. For z, you'll just have to take a stab in the dark. I suggest -0.025 for the woofer and 0 for the tweeter. You won't be far enough off that it matters. You are, after all, using them as surrounds. So you'll likely rarely be on axis vertically.

Good luck
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