Newby DIY speaker project

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Hi - I am a new member here. I've been lurking and searching past posts for inspiration for a while. Can't decide what to do nor how to narrow my search.

What I want to do is build a pair of single driver speakers - but there are so many designs and makers to choose from - from Fostex to Lowether to the CSS fr125s! (But I've decided already after reading that my listening tastes suggest that I should probably still continue to use my Shu powered subwoofer once I finish the project). And I want to use a 2A3 amp...

My problem is that I want to know what something will sound like in my listening room before I build it!!! So any guidance is much appreciated.

My listening room is 24L X 14W X 7H and I prefer to position my speakers along the 24L wall. My listening tastes run from gregorian chants to acoustic trio jazz to solo/electric blues to chamber music to Metalica/Sepultura.

Any suggestions for a design given my broad listening tastes and room size? I've been reading the Frugal-Horn Spawn sight lately and I also enjoy reading about the Hemp Acoustic FR8OC and CSS fr125s.

Suggestions for a newby much appreciated - Thanks, Chr3is
 
Basically, because of the size of your room and choice of amplification, any of the smaller drivers are a no-go based on their efficiency. The CSS FR125 is the least efficient of the drivers you have listed.

You may not be happy with anything less that an 8" driver with at least a 95dB rating, given your varied listening tastes. A 6.5" driver may work for you used with your powered sub, but for jazz or acoustic material the sub may be redundant, or unwanted.

Hemp Acoustic FR8C/ Fostex FE207E would be a good place to start. You just need to decide on a suitable box, 'cause it's going to be BIG.

I'm sure others will have more/better ideas on what to build.

Jeff
 
frugal-phile™
Joined 2001
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Your choice of amp probably eliminates the FR125 -- for sure eliminates it if it is SE (for some reason the FR125 does not like SE amps of any flavour (EL84.845 or DD.

Except for the Metalica, you listening tastes are similar to mine... the sub also gives you more latitude (as long as you can get it to blend (it can be tricky).

Choosing a FR means you have to choose your tradeoffs... i'll just tick off a general ones ...

1/ bigger drivers tend to be more efficient than little ones (which mean they play louder with a small amp)

2/ smaller drivers usually have better mids & tops.

3/ bigger drivers go lower & tend to be able to do dynamics better

4/ small drivers usually go in smaller boxes, with higher WAF, and lower cost to build

5/ bigger drivers tend to cost more (and i haven't meet a driver i can't improve)

6/ and a corollary to 5... a modded small driver for the price of a similar priced large driver will usually have more finese. (disclousure: i sell modded drivers)

And a couple specifics with your room...

1/ the 7' ceiling is going to cause problems in between 80 & 100 Hz

2/ listening across the short dimension will tend to favour smaller speakers.

3/ you cab narrow your choices by considering which ones won't work in your room (no BIBs, no Frugel-Horns, nothing that needs to be 4' out from the wall

My room has over 3 times the volume & i use amps that are on the order of 5W. I tend to choose smaller drivers because i won't compromise the midrange magic (currently listening to a set of GR Fonkens with FE127eN (if i had corners i'd likely have the Frugel-Horns up here for the bit higher efficiency -- when i get the time to load drivers, i will bring up the RonHorn A126 -- i recently cleared enuff space to get them against the wall).

What kind of budget do you have? Size considerations?

dave
 
Thanks for the thoughts so far.

I've been thinking about your trade-offs list, planet10 and I understand that in any speaker (DIY/commercial) there are trade-offs. I'd have to say that a larger driver would probably suit my listening preferences, given your list - but I wouldn't be hostile to trying a smaller driver either.

Speaker size isn't an issue, look isn't an issue and neither is WAF - my listening room is my basement man-cave.

My budget would be around +/- $700 (start to finish) and I am fairly handy with power tools (but not a soldering iron:( ) and have lots of clamps and a fair amount of patience, so I'll should be able to judge beforehand when a design I see is beyond me. I am also not in a hurry - so it doesn't have to be a single weekend project! I don't want to design anything (I haven't a clue how) and am looking for proven design plans.

Your idea of considering which types wouldn't work in my room was very helpful.

What about something in the Spawn family, like Harvey?
 
frugal-phile™
Joined 2001
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Chr3is said:
What about something in the Spawn family, like Harvey?

I was going to suggest you poke around the Frugal-horn site and thru the box plan library at planet10-hifi -- our aim is to ensure no shortage of choices.

I hope to hear a local set of Harveys sometime before the summer, and the curved mouth Changs have some real appeal... fortunately we are in a position that we just keep building them

From Scott's initial Harvey build and the comments of those who have built it, it is outstanding.

dave
 
too many choices?

For a less physically domineering enclosure than could still fill a pretty big room, the Demetri with FE207E/FT17H would be worth considering.

You'd not likely need a sub, you can drive them crazy with less than 10W, and they're a far easier build than any of the big-a$$ BVR or Nagaoka style horns.

If you're willing to sacrifice teeth-rattling bottom and SPL levels, his "little sister" (Mileva) with FE127eN is very musical. Indeed the single FR* driver delivers all the magic to which Dave alludes in his above post, and FWIW, so far it has won the WAF at my house. Not counting the 2 computers, there are currently 3 audio systems and 5 different speaker systems in residence.

*without debating what exactly "Full Range" means - to me it is the sense that not enough is missing to take anything away from the emotional connection with the music. - i.e. "what was the artist trying to say?"


I've heard enough obscenely priced retail products over the years to appreciate that the number of drivers and complexity of filter networks / driving electronics guarantee nothing.
 
>>> the 7' ceiling is going to cause problems in between 80 & 100 Hz...

My ceilings are only that high. Is there a way to minimize problems in that freq range? Maybe this is why sound absorbing materials seem to help so much in this room. I can just walk into the room with a handful of fiberglass and things sound better.

Great list Dave! I think it will be helpful.

My recommendation is a Half Chang using the Pioneer B20 or the Fostex 207e driver and a helper tweeter of your choice. It will fit the room and probably fill the room with sound better than some of smaller drivers mentioned.
 
I can't suggest the Metronomes with a Hemp FR8 enough (FR8c now, I guess). The plans are available on Dave's website. At the Burningamp festival in october, they were there with a lot of other awesome speakers, and they were killer. I think there were details posted in the burningamp thread, a few days after the festival. I'm working on a different pair of speakers, and sometimes wonder if I shouldn't just switch over to the metronomes...

I used to have a 'man-cave', and it actually worked fine. Not beautiful, but I didn't hear any bad low frequency problems (although I wasn't there long, and had uneven, exposed wood stud, partially filled with fiberglass ceiling). If you need to tame vertical, low frequency modes like that, I think I've seen plans specifically for that at audioasylum.com, and Jon Risch's diy tube traps might also do. They were tall PVc tubes stuffed in specific ways (called a 'room lense'?). It isn't easy to absorb LF waves (it takes a lot of material depth).
 
Chr3is said:
My carpentry skills/budget well fit the Half Chang. But I don't see in the plans how to make the center driver brace with the holes in it.

Ideas?


I can probably speak to that - and apologies in advance if my explanation seems insulting to your skill set, or varies from your practice, but I've used this technique for all my recent projects with excellent results. It takes a while (in most cases longer than cutting all the cabinet parts), but is well work the effort.


The width dimension for the driver brace appears to be missing from this particular drawing, but assuming 18mm material as noted*, that figure would be 292mm.

*it's always best to confirm dimensions for your actual material thickness, as even a fraction of a mm can compound over several layers.

While it should be obvious, it bears repeating that the point of the brace is to provide a tight connection between the driver magnet and the cabinet front and rear panels, as well as the top panel and bottom "shelf" of port slot. The holes should amount to at least 40% of the surface area of the brace panel.

Leave marking out the dimensions of the driver cut out on the brace until after the rear chamfer has been machined and you can dry fit the driver into the front baffle cut-out particularly if you're planning to rebate the driver for flush mounting.

With the driver securely mounted into the front baffle and lying face down on a protected surface (cardboard or carpet scrap), stand the driver brace panel vertically as close to the driver frame as possible. Lay a small block of wood or try square on the back of the magnet housing and mark a reference line on the underside.

Then remove the driver and dry fit the panels together that form the top, front baffle and bottom port shelf (masking tape makes a great third hand for this), to mark the locations where the driver brace intersects the driver opening. Cut to the inside of the marked out opening (band saw is best for control and squareness of cut)

Reinstall the driver in the baffle, and test fit the braces until they're deadly tight. If you've cut close enough to the inside of the reference lines, a few minutes with a 60G sanding block should adjust for any differences. Clamp both panels together during any sanding to ensure consistency.

A 3" or so hole saw should make "relatively" quick work of the remaining part of the job. :cannotbe: I'd suggest it's a wise investment to acquire a carbide tipped saw for this purpose - bimetal or HSS blades will dull and burn pretty quickly, but I've cut hundreds of holes with the carbide bit without any problems. Clamp the 2 panels together whether drilling by hand or in a press.

The upper portion of rear notch around the top of the slot is less critical - band saw or jig saw is fine.
 
>>> But it's easy to absorb WAF waves when you have a man-cave...

Agreed. I have BIBs in my man-cave along with half my horror novel collection, a speed bag and some dumbells.

http://www.zillaspeak.com/systems.asp

It went from a totally unused room to a great room for daddy! Need to fix the room accoustics and get comphy chair soon!

Godzilla

PS. Can i just buy the largest diameter pvc pipe i can find and stuff it with fiberglass to absorb echo slap and fix bass issues?
 
frugal-phile™
Joined 2001
Paid Member
Chr3is said:
My carpentry skills/budget well fit the Half Chang. But I don't see in the plans how to make the center driver brace with the holes in it.

Ideas?

Keep bugging me and i'll add them... for each driver they are a bit different. And conceptually they are simple. I may just do a generic page that details how to design/implement them.

If you go thru the plans on the frugal-horn site and the P10-hifi box-plan library you will find illustrations.

dave
 
I recommend a Fostex FE-108EZ paired with an Eminence Alpha 15A in an open baffle. You can find plans on my site if you are interested. You will get the single driver sound in an extremely easy build and as a added benefit a strong bass response. It is well within your budget and I think would be very hard to beat.
 
'tis 250 miles. Quite a long way in my car, tbh. It is one of these, and it doesn't really like motorways. OTOH, I am rebuilding the engine at christmas, so it would be a good running-in exercise.
caledonian_transp.gif


I am adding up selling a few things, and maybe getting a contribution for christmas- although I think my prezzie is already bought. It is looking more likely- by the day.

James

EDIT- my car isn't as shiney though- lots more rust, filler, primer and flat red (read pink) paint.
 
jrevillug said:
It is a Hillman Imp. Made 1963-76 (mine is right from the end- 75), rear engine, flat out at 80mph. Reputation for blowing head gaskets (mine is going) and being unreliable- but they are fun to drive, despite being slow.

The Nash is an odd beast- like it though.

James

In all honesty, I can't think of a single British made automobile, until lately, that was remotely reliable. I once owned an MGB, and the paint started peeling after 10 months. My BSA Hornet never worked right. It nickled and dimed me to death. My classmate once owned an XKE and it had a strange habit of emptying his check book on a semi-monthly basis.

Have they changed recently, or are they still made to be worked on with regularity?


;)
 
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