My First DIY Speaker Project

[GDAVIS40]

Would like to build a set of speakers (7) for a dedicated HT I'm designing.
I plan on using an IB for sub and would appreicate any thoughts or ideas for the mains. This is what Im thinking (2) Dayton 12" sd315-88 ea in a 1.5 cuft enclosure. (1) Eminence compression driver psd 2002s with a h290 horn.
Because I'm not sure if I'd like the horn thinking of building two verisons. The other would use a Seas 7"coaxial (H1333) instead of the horn in a ~.45cuft enclosure.What crossover to use is a real mystery to me.I plan on using a pair of Citation 7.1 amps to drive these. Thanks for your help

[AJINFLA]

Would like to build a set of speakers (7) for a dedicated HT I'm designing.
I plan on using an IB for sub and would appreicate any thoughts or ideas for the mains. This is what Im thinking (2) Dayton 12" sd315-88 ea in a 1.5 cuft enclosure. (1) Eminence compression driver psd 2002s with a h290 horn.
Because I'm not sure if I'd like the horn thinking of building two verisons. The other would use a Seas 7"coaxial (H1333) instead of the horn in a ~.45cuft enclosure.

There is a lot of info missing from your post needed to generate good answers. Like budget. SPL goals. Etc.
The two designs are radically different, save for the bass units. The Eminence version would make a poor design for a garage band monitor, because the (sub)woofers would be hopelessly mismatched to the horn. The Seas version would be closer to a hi fidelity device, but may fall below your SPL requirements. I gather that you like bass.

What crossover to use is a real mystery to me.

That's a mystery that needs to be solved well before designing and building one's own loudspeakers, not an existing design.
Welcome aboard.

cheers,

AJ

[GDAVIS40]

That's why I'm here........... Might not be the sharpest tool in the shed so please bare with my ignorance. Here's what I'm after. . The room is roughly 14'x21'. I will primarily watch movies here .I want strong in yours chest midbass but would like the speakers to be balanced if that makes any sense.I plan on putting the surrounds into the wall so they should have a small foot print. I was going to make them them all the same for simplicity.I LIKE SIMPLE.I'd like the highest possible fidelity with reasonably high SPL. And I dont want to spend more than $300.00 per speaker. And Yes, I like bass.

[---k---]

Have you ruled out building someone else's design?

Designing you're own speaker from scratch is a long and painful process to do right (which people here believe is the only way to do it). You have to model, build the boxes, test the drivers in the boxes, design the crossovers, assemble, test, tweak, enjoy.

You sure you're up for that? Or are you just looking to use a simple pre-built crossover? I would probably recommend building one of Jon's or Zaphs existing designs for your first.

[GDAVIS40]

Starting from scratch sounds great can't wait to get started. I have lots of patients. Besides im hoping i might learn a thing or two.For me it is very satisfing when a project is executed well.

[technimac]

Starting from scratch sounds great can't wait to get started. I have lots of patients. Besides im hoping i might learn a thing or two.For me it is very satisfing when a project is executed well.

As a doctor, with lots of patients, you will appreciate that using existing, proven tools is one of the keys to success. :W :W :W

The design process is seriously complex, taking into account the needs of the end user, characteristics of the components, performance variables of the components and the amount of $$$$$$$$$ one is willing to invest. Then you have to design and build crossovers from raw components ........ test, measure and adjust/tweak what you've built (probably several times) and hope that the impedance isn't too low for your receiver/amp. Whew, after all that, it just might sound close to something someone else has already designed.....but probably not, if you're new to this.

I've built several designs posted here and believe me, just doing that will result in you learning more than a "thing or two". In addition, it's comforting to know that extremely talented members of this (and other forums) have spend countless hours of time designing speakers (often at the behest of other forum members).

These designs are as custom as you can get, meeting a plethora of needs of those who build and use them.

The ultimate conceit for me would be to presume that I could design a speaker whose performance would even remotely approach that of one designed by Jon Marsh, Curt Campbell or John Krutke.

Now if I were an EE, I might think differently. :B

For me, the job of building and finishing the enclosure, building the crossover and installing all the components is enough to give me tons of satisfaction and a sense that the job has been well-executed.

And there's no loss in satisfaction or pride when you give a tip of the hat to the designer who made it all possible. :T

Good luck in your speaker-building endeavors

Cheers :T

[GDAVIS40]

Is what i'm attempting a mission impossible DIY? :B I realize i can not do this right on my own. And that any speaker i would built would not be of my own design but from the talents of others. i just think you develop a better appreciation of what going on when you built from scratch. For me building the enclosure is the easy part. Im just looking for somthing a little more challenging.

[Tommythecat]

How about using more reasonable drivers:

B&C DE200 1" exit compression driver(bolt on) OR BMS 4540ND 1" exit driver (threaded)

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=294-602

http://www.assistanceaudio.com/02_bms.html

12" PE waveguide

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=270-312

12" Eminence Delta Pro-A

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=290-510

This would be (in bulk, 7 each) about 1400 if you got the B&C's and everything from PE (free shipping). So thats $200 per speaker not including XO'er and cabinet - but plenty in budget to keep them close to $300 a pop.

You can run the horn down to around 1.5k. Drop the mid in about 2 cubes with stuffing, and if you run a double thick baffle just cut a 4" hole for the port.

The BMS driver will add some cost, but its threaded like the waveguide. So you can either:
1) buy the bms
2) buy a cruddy bolt-on to thread adapter for the B&C
3) modify the waveguide by cutting some off the back, match up the exit of the compression driver to the size of the WG and then slap on some masonite/plywood to make your own bolt on rig.

[GDAVIS40]

That looks good. Aside from cost is there any reason to run the B&C driver? Don't get me wrong modifing that waveguide won't be a problem . Just wonder what would be the best choice. The last thing i want to do is build

a poor design for a garage band monitor

Would this combination make for a hifidelity speaker?

[ThomasW]

Not sure why you'd need horns and high efficiency midwoofers in a room that size, unless you planned on using tiny amps.

What's wrong with building 4 NatalieP or Modula MTM and our new small WMTW 'center'?

10-6.5"-7" drivers should have plenty of midbass output to match up with your IB.

Should you decide you want additional midbass "slam" make bass bins containing a couple 10" or 12" woofers for the mains to sit on.

[chasw98]

That looks good. Aside from cost is there any reason to run the B&C driver? Don't get me wrong modifing that waveguide won't be a problem . Just wonder what would be the best choice. The last thing i want to do is build Would this combination make for a hifidelity speaker?

If you were to put your location in the world so that it shows up by your avatar, you might find someone that lives near to you and would be willing to let you come over and listen to what they have built from either a 'proven' design or an experiemnt. Most people here are pretty good about letting other people come listen to their creations.

Chuck

[Tommythecat]

I wouldn't run any compression driver eminence makes, nor any of the cheaper drivers out there. I hate to say "dont pay less than 100 bucks" but most/all of the cheap ones are crap.

[GDAVIS40]

Need has nothing to do with it...........Want on the other hand.
Is there any reason why this approach won't work.

[ThomasW]

Need has nothing to do with it...........Want on the other hand.
Is there any reason why this approach won't work.

Cheap horns/compression tweeters don't sound all that great and good sounding horns/compression tweeters are on the $pendy side.

On the other hand low cost standard dome tweeters like those used in the NatP/Modula MTM sound pretty good.

BTW, you might want to study up on what's involved in designing a crossover since generic crossovers shouldn't be used if the goal is the best sound quality...

In order to design a proper crossover you'll need to have the necessary equipment to take in-baffle measurements, (~$200 min) combined with the requisite software and knowledge to generate custom crossovers with and without baffle step compensation using your measurements.

[GDAVIS40]

Thomas, thanks for your concern.I realize this task won't be easy nor cheap.
Do you feel neither the B&C or BMS will sound good?What compression driver would you recommend? Also any thought on the software Speaker Workshop.

BTW, those NatP/Modula MTM looked fantastic.I just want to go a different route.

[ThomasW]

Jon's using the BMS-4540ND and DSS waveguide for the Isiris project, I'll be building a version of those for my personal use. That combination has excellent potential but is fairly expensive.

I have no recent experience with any low cost compression drivers/horns, since I've not needed the kind of performance they offer.

My thoughts on Speaker Workshop is that it's so user hostile I won't use it. Others having more patience than I seem to use it successfully.

[GDAVIS40]

OK, Here what i've come up with so far.
(1) Eminence DeltaPro12
(1) BMS H4552 ND driver
(1) DDS ENG-1-90 waveguide.
3 cuft enclosure 7" dia port 6.95 long.

[JonMarsh]

If you use a larger waveguide/horn than the DDS ENG1, the BMS4552 will have a bit more low end extension, but with the ENG-1, the 4540 is a choice to also consider, as it has a more extended top end, which normally means less distortion down within the upper part of the audible range (10-20 kHz). Of course, you can't hear simple harmonic distortion, but intermodulation you can. Both are smoother in the ENG-1 than the BMS horn there published data is measured with.

Are you going to use these with a subwoofer below 100 Hz? The Eminence has a highish Fs, (51 Hz), and relatively low Xmax (~ 4mm). Using Unibox, you can probably come up with an optimized ported box design (large) with some extension, but it will be prevent it from unloading below 50 Hz.

[GDAVIS40]

Thanks Jon, I thought my arrangement might benefit from the low end extention the 4552 offers.

I plan on using an IB subwoofer.

I initially modeled the box using WinISD but my parameters where wrong.
Using UniBox i think i have a more favorable model. A 2.64 cu.ft box with
6.5 dia x 6.3 port gave me a very flat 118 SPL with 150 watts.
From what i've read i need to use a 24 db/octave high pass filter set to 50 hz or higher .