First Project

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Looking at building my first set of FR speakers. I have been intrigued by the concept for years but have never (knowingly) listened to quality pair of full rangers.
I was thinking of starting off small using a pair of el70 in the Woden Designed Derwents -> Link <-
Other designs being considered, Planet 10 micro towers (singe or dual drivers) -> Link <-
and the Mar-Kel70 -> Link <-
I am open to any recommendations, caveats, reviews etc.

Room placement is an issue along with over all size (WAF). Thinking a single driver cabinet will be more forgiving? Or could a dual driver cabinet work pulled a foot off the wall?

Current speakers Large Advents and KEF Calindas (swap them in out, can't have four speakers in one room...) powered by NAD 304, Rega 3 with Grace 707 tonearm for the vinyl collection. Bought the Advents new in 74, Calinda's a couple of years later) Yes a Frugal File. Listen almost anything excluding the over bassed techno, Hip-hop, Rap. Prefer Folk, Bluegrass and Classical.

I do not know what to expect sonic-ally from a full range speaker, especially with a comparatively small driver, but I do know I will enjoy building the cabinets. Who knows were this will lead to?
 
frugal-phile™
Joined 2001
Paid Member
Sounds like you could have bought that whole hifi from me when i worked retail hifi (except that we didn't get Advent till 77, and that NAD came after i left).

My godson has a set of frugal-phile(tm) speakers with a set of 8" FRs in a set of Calinda cabs i repurposed (and may well have sold when new)

Certainly the EL70 (stock or tricked out) are close to hand.

Any of those cabs will give you a good introduction to FR. I've not heard Derwent, but all the Spawn BVRs we've done have turned out well, and field reports have been positive.

Mar-Kel & microTower i have compared. The former has more finesse, the latter, especially with 2 drivers, has more slam, and will move more air. You would beed to go with a castle style or 2nd driver on the adjacent side if you can't pull it further out from the wall.

Mar-Kel is probably the more difficult build, & needs a stand (the 22" or 26" Paradigm stands are a bargin)

dave
 
rhn

"Or could a dual driver cabinet work pulled a foot off the wall?"

sure,
look my KORNETT, no only good WAF,
also measurements and imp, best soundstage, down to 34 Hz
 

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Regarding the Mar-Kel70...
I recently built a pair and i am very satisfied with them. They really do play louder than i first thought they would and they play any sort of music without problem (well, for rock you want a sub). I built mine in 12mm particle board. It was supposed to be just a test build and i was supposed to build in 18mm bb ply but i think they're good enough atm.
I haven't sorted out the damping and properly fixed the bracing and sealing of the box but i'd call them a good set of speakers. It might not be the easiest speaker to build for the beginner but it's a good challenge.

But i do have some questions though, to Dave ofcourse.
What Paradigm stands are you talking about? Could you link to them?
Is it important to sort of "lower down" the speaker in the baffle or is it okay to just make it sit "ontop" of it? And is it important to chamfer the inside of the mounting hole (on the back of the baffle)?

But there is one problem with the EL70 driver though... The screw holes are a bit close to the driver so the mounting hole will need lots of work to get it right and not too big to mess it all up.
 
Regarding the Mar-Kel70...
I recently built a pair and i am very satisfied with them. They really do play louder than i first thought they would and they play any sort of music without problem (well, for rock you want a sub). I built mine in 12mm particle board. It was supposed to be just a test build and i was supposed to build in 18mm bb ply but i think they're good enough atm.
I haven't sorted out the damping and properly fixed the bracing and sealing of the box but i'd call them a good set of speakers. It might not be the easiest speaker to build for the beginner but it's a good challenge.

But i do have some questions though, to Dave ofcourse.

will I do?

What Paradigm stands are you talking about? Could you link to them?
I could find no easy link on the manufacturer's web site, but look at item S-18 or S-22 on page 3 of attached PDF. To be honest, there are probably any number of similar products available more locally to you, or they could even be DIY'ed ( some MDF, ABS plumbing pipe and threaded "readi-rod")


OK, the file's too big to attach, try this:

http://www.paradigm.com/index.php?option=com_joomdoc&task=doc_download&gid=328&Itemid=8

Is it important to sort of "lower down" the speaker in the baffle or is it okay to just make it sit "ontop" of it? And is it important to chamfer the inside of the mounting hole (on the back of the baffle)?
If you're describing a "rebate" for flush mounting, to be honest I don't think there's a clear consensus on that, but I like it for cosmetic reasons. It's certainly possible to achieve by hand, but fortunately I have access to a CNC machine and very crafty operator.

As for the second, for drivers with as shallow a mounting depth as all Mark Audio (or the smaller Fostex etc.), I think it's very important, but it does conflict with your next point

But there is one problem with the EL70 driver though... The screw holes are a bit close to the driver so the mounting hole will need lots of work to get it right and not too big to mess it all up.
yup - even on the Alpair 7 with its very wide and thick flange, fortunately there are hole saws available in sizes close to those needed for the smaller drivers - just be sure to securely clamp the workpiece to drill press or workbench
 
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will I do?
Sure, why not? :D


I could find no easy link on the manufacturer's web site, but look at item S-18 or S-22 on page 3 of attached PDF. To be honest, there are probably any number of similar products available more locally to you, or they could even be DIY'ed ( some MDF, ABS plumbing pipe and threaded "readi-rod")


OK, the file's too big to attach, try this:

http://www.paradigm.com/index.php?option=com_joomdoc&task=doc_download&gid=328&Itemid=8

Well. I googled some Paradigm stands and they appear to cost 3-4 times as much the speakers themselves... So DIYing is more of an option. But i'm thinking of a stand that can hold both a subwoofer AND the Mar-Kel70. Will probably be an interesting piece... :)

If you're describing a "rebate" for flush mounting, to be honest I don't think there's a clear consensus on that, but I like it for cosmetic reasons. It's certainly possible to achieve by hand, but fortunately I have access to a CNC machine and very crafty operator.

Okay, but i think it might be a problem with my 12mm baffle. There would be like nothing to screw the driver to.

As for the second, for drivers with as shallow a mounting depth as all Mark Audio (or the smaller Fostex etc.), I think it's very important, but it does conflict with your next point
Chamfering the backside of the baffle? It will also be a problem because of the thin baffle. And unfortunately it's not that very easy to replace it with a thicker one... But maybe it's possible to put another piece of 12mm particleboard inside the cabinet, and then lower down the driver in the baffle and chamfer the backside? Or will it f**k up the volume too much?

yup - even on the Alpair 7 with its very wide and thick flange, fortunately there are hole saws available in sizes close to those needed for the smaller drivers - just be sure to securely clamp the workpiece to drill press or workbench

Well, i didn't have any hole saw so i did it with a jigsaw and i cut it a little smaller than needed but it was actually well enough. Just had to cut out for the... Basket sort of thing, and that's where the problem is. The screw hole is like 1-2mm from the basket. If you cut 1mm too far you can't put a screw there. It happened to me once... :S
But Dave told me he had mailed (is it Bob?) about it and they would sort of take a look at it and maybe fix it or so.

And there was another little question. It's about dampening. Seems like i wont get an answer in my thread (with a completely wrong name, lol) about how i should damp them with my 90mm rockwool. I could sort of mash it to pieces and stuff it in but i guess it's better to put in pieces. Right now i got two small "towers" of rockwool inside, about 5x5xheight of speaker on each side of the bracing and 10-15cm from the driver. How much am i really supposed to use, and where?
 
The local dealer sells them for something like $130/pr, a real bargin in stands. It helps that Paradigm is a Canadian company... as the OP is in Greater Vancouver, the suggestion is more of a local thing.

dave

Yes, might be.
I didn't know that Paradigm was Canadian. I've heard lots of good words about their products.

Do you have any DIY suggestion for a stand that can hold both a subwoofer and Mar-Kel70s?
Or a 50l box that can be around 70cm tall?

And what about the dampening in my Mar-Kel?
 
I haven't built any of these but when did that stop anybody chiming in :D

I like the appearance of the micro-Towers. I suspect that they have the best WAF - no big holes to collect dust and don't need stands.

I'd avoid the version with a driver in the top - collects dust on the cone (if no grill) and makes a poor beer glass holder!

...but those tall Lake District models would have some really nice presence in the room if you were allowed to construct the full height double mouthed version.
 
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I haven't built any of these but when did that stop anybody chiming in :D

I like the appearance of the micro-Towers. I suspect that they have the best WAF - no big holes to collect dust and don't need stands.

I'd avoid the version with a driver in the top - collects dust on the cone (if no grill) and makes a poor beer glass holder!



mounting the second driver on the top significantly reduces placement issues that a "true" bipole generally creates, and anything that's built for WAF automatically assumes grilles (around my place at least)

...but those tall Lake District models would have some really nice presence in the room if you were allowed to construct the full height double mouthed version.
agreed, but just don't forget the minimum listening distance - less than 3 meters can cause some spotty integration with the big guys

then of course depending on drivers of choice, rear mouthed designs such as the FH or Maeshowe have placement issues of their own
 
Sure, why not? :D




Well. I googled some Paradigm stands and they appear to cost 3-4 times as much the speakers themselves... So DIYing is more of an option. But i'm thinking of a stand that can hold both a subwoofer AND the Mar-Kel70. Will probably be an interesting piece... :)



Okay, but i think it might be a problem with my 12mm baffle. There would be like nothing to screw the driver to.


Chamfering the backside of the baffle? It will also be a problem because of the thin baffle. And unfortunately it's not that very easy to replace it with a thicker one... But maybe it's possible to put another piece of 12mm particleboard inside the cabinet, and then lower down the driver in the baffle and chamfer the backside? Or will it f**k up the volume too much?



Well, i didn't have any hole saw so i did it with a jigsaw and i cut it a little smaller than needed but it was actually well enough. Just had to cut out for the... Basket sort of thing, and that's where the problem is. The screw hole is like 1-2mm from the basket. If you cut 1mm too far you can't put a screw there. It happened to me once... :S
But Dave told me he had mailed (is it Bob?) about it and they would sort of take a look at it and maybe fix it or so.

And there was another little question. It's about dampening. Seems like i wont get an answer in my thread (with a completely wrong name, lol) about how i should damp them with my 90mm rockwool. I could sort of mash it to pieces and stuff it in but i guess it's better to put in pieces. Right now i got two small "towers" of rockwool inside, about 5x5xheight of speaker on each side of the bracing and 10-15cm from the driver. How much am i really supposed to use, and where?


in no particular order:

rockwool might be a suitable damping material, but 90mm is much too thick for these little boxes, but if it's batted the same as product we have here, it's relatively easy to peal into layers as thin as you'd need (I've found the 1/2" Ultratouch to be an absolute dream to work with)

Creative Sound - Product Details


Yes, the flanges on Mark Audio drivers are thick enough that rebating them in 15mm material leaves not much core for screws, and in 12mm hardly any at all - I wouldn't bother for now ( I have a feeling this won't be your last DIY speaker build :eek: )

When using 18mm (or thicker) material for baffles for drivers in the 3-5" range, you've got the issue of needing a deep chamfer on the backside of cut-out, even if rebating for flush mounting.


I guess I'm lucky to be able to afford to say that for the amount of time and material involved in reworking the boxes as you describe, it'd just be easier to build another pair (BT/ DT more than a few times - and we have a nice bonfire at least once a year around Halloween)

Freight is definitely a killer on speaker stands- fortunately there are numerous options for DIYing these. Of course designing (sub)woofer enclosures to act as stands will kill 2 birds with one stone.
 
in no particular order:

rockwool might be a suitable damping material, but 90mm is much too thick for these little boxes, but if it's batted the same as product we have here, it's relatively easy to peal into layers as thin as you'd need (I've found the 1/2" Ultratouch to be an absolute dream to work with)

Creative Sound - Product Details


Yes, the flanges on Mark Audio drivers are thick enough that rebating them in 15mm material leaves not much core for screws, and in 12mm hardly any at all - I wouldn't bother for now ( I have a feeling this won't be your last DIY speaker build :eek: )

When using 18mm (or thicker) material for baffles for drivers in the 3-5" range, you've got the issue of needing a deep chamfer on the backside of cut-out, even if rebating for flush mounting.


I guess I'm lucky to be able to afford to say that for the amount of time and material involved in reworking the boxes as you describe, it'd just be easier to build another pair (BT/ DT more than a few times - and we have a nice bonfire at least once a year around Halloween)

Freight is definitely a killer on speaker stands- fortunately there are numerous options for DIYing these. Of course designing (sub)woofer enclosures to act as stands will kill 2 birds with one stone.


Well, this Rockwool wasen't very easy to work with. It was very... non-dense and tended to fall apart. I think i can get some 45mm rockwool too if needed. You see, my father and my brother is "working" at building a little cottage not far from here and they use rockwool for insulation. So i think i can get 45mm aswell.
I will check in gothenburg this weekend if i can buy some dampening material.
And no, this will really not be my last speaker build. When i get older and start getting real income i will build something really fancy!
And what do you mean BT/DT?
And freight?

Yes, a sub that is tall enough to be a stand would be the best.
 
Chamfering the backside of the baffle? It will also be a problem because of the thin baffle. And unfortunately it's not that very easy to replace it with a thicker one... But maybe it's possible to put another piece of 12mm particleboard inside the cabinet, and then lower down the driver in the baffle and chamfer the backside? Or will it f**k up the volume too much?
You could also put another piece of 6mm (that seems to be the depth of the EL70 frame) ply/particle board on the outside of your baffle. If you cut the hole to the right size you kill many birds with one stone:
Your driver will be flush mounted.
You don't have to worry about internal volume.
You don't have to worry about the screws having enough material to screw into.
Your baffle will be better damped - especially if you use a different material.
If you use ply you get could paint the rest of the cabinet and put a clear coat/varnish on the baffle which might look nice.
You could put magnets behind the outer piece, to invisibly mount a grille.
 
You could also put another piece of 6mm (that seems to be the depth of the EL70 frame) ply/particle board on the outside of your baffle. If you cut the hole to the right size you kill many birds with one stone:
Your driver will be flush mounted.
You don't have to worry about internal volume.
You don't have to worry about the screws having enough material to screw into.
Your baffle will be better damped - especially if you use a different material.
If you use ply you get could paint the rest of the cabinet and put a clear coat/varnish on the baffle which might look nice.
You could put magnets behind the outer piece, to invisibly mount a grille.


Good enough points all 'round, except I think for burying the magnets - flush mounting under a layer of veneer certainly works (I've done than many times) and it might even work with "Post-form" grade plastic laminate, but not likely with a 3-4mm thick layer of any type of wood.
 
Thanks for all the replies.
Dave; I probably did buy some of my gear from you. I used to mostly hang out at Sound Plus in the late 70's and most of my stuff is from that shop. Also bought stuff at the Sound Room and Commercial electronics and a couple of small shops whose names if forget.

HM; your Kornett look awesome.
I think for now I will stay with the smaller full range drivers. This is my first step on the FR highway.
I want to keep the costs somewhat low at this point
Also in the Spawn family is the English Auto series, particularly the Morgan -> Link <-
similar to the Derwent but using the MA Alpair 6 (driver maybe getting a bit to small)

What kind of sound levels can be expected from a speaker with a 70mm paper cone in spawn MBVR or Mar-Kel70 cabinet? Lets say in a 15' x 20' and smaller rooms (don't know which room they will end up in yet)
 
frugal-phile™
Joined 2001
Paid Member
Sound Plus in the late 70's

Not from me, i was at Sound Hounds in Victoria. But at the time Sound Plus & Sound Hounds were under the same ownership, so much of the same stuff. And Doug Argue (top guy at SP) hooked me up at the Hounds when he was still a distributor's rep before he started Sound Plus. (if you got your Advents there it was 1977 or later)

What kind of sound levels can be expected from a speaker with a 70mm paper cone in spawn MBVR or Mar-Kel70 cabinet? Lets say in a 15' x 20' and smaller rooms (don't know which room they will end up in yet)

A lot more than you'd expect. It still surprises me. And one can always give yourself more headroom with the addition of powered woofers...

or, as we often warn "it is hard to stop at just one cookie" :)

dave
 
A lot more than you'd expect. It still surprises me.....as we often warn "it is hard to stop at just one cookie" :)dave
Getting excited!
Is there a glossary or FAQ on speaker design/construction?
For instance what does the Acronym MBVR mean (sorry I am a total newb)


PS: thinking of it again the Advents were purchased in '75 at Commercial electronics, along with a Quad 405 and 33.
 
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