Bookshelf horn speaker!

[dsan]

I finished the speakers a couple of weeks ago. I wasn’t going to post an update until the stands were finished, but the weather has turned to crap so I haven’t been able to get them done. They are 90% finished; I just need to varnish them and put spikes in the bottom.

The top of each stand is made from 2 x 17mm ply and the bottom is 3 x 17mm ply, with the middle layer hollowed out and filled with sand. The uprights are old bbq legs, bought from the dump recovery store for $1! They are also filled with sand.

The pics also show the damping material before I wired them up (I tore apart an old pillow). Please excuse the carpet and bad lighting I haven't taken a pic of the other speaker, as it is in a terrible position between the TV and a table.... looking forward to moving out of this flat next year!

 

And how do they sound? Damn good really. They were a bit bright when paired with the Trends, so I moved them into the lounge to run off the Cambridge, which is a bit warmer sounding. I find that with the bass up a fraction, and the treble down a fraction, they sound spot on (that probably makes you guys cringe)! :eek:

The detail really is amazing, there is just so much there that I haven’t heard before. I might try the notch filter to see if I can tame the top end, as I would like them back in the bedroom system.

 

Here is an approx breakdown of costs for those who are interested (just from memory, so prices aren’t too accurate):

 

Drivers: $200

Ply: 1 x 17mm sheet at $50

Carpet: $10

Binding posts: $20 (Jaycar)

Damping material: $20 (Jaycar)

Varnish: 2 cans at $15 each

Other bits and bobs: $10 (uprights, glue, sand, etc).

Total: $340 approx. Not bad really, and had great fun along the way.

 

Thanks for everyone’s help and advice! I'll keep you posted on any furher developments.

Attached files

[AudioKiwi]

Mmmmm sweet looking finish on those :cool:

 

Great job!

[dsan]

 

DodgyConnection;104145 wrote:

Mmmmm sweet looking finish on those :cool:

 

 

 

Great job!

Cheers, I'm pretty happy with how they came up, especially considering it was c grade ply. Took a lot of patience though; 5 or 6 coats of varnish with a light sand in between.

[little blue penguin]

You should be happy with the finish, as you've done a really nice job. And, speaking from personal experience, nothing ever sounds as sweet as music played thru something that you have built yourself

 

I'm hoping that the new plywood cabinets for my Frugel Horns look similarly good, although I suspect your ply is better than mine.

 

Regarding the bases; for stability the section in contact with the floor should be wider than the speaker. I prefer triangular shaped footers to avoid rocking, especially when spikes are used.

 

Enjoy.

[dsan]

 

cloth_ears;104186 wrote:

You should be happy with the finish, as you've done a really nice job. And, speaking from personal experience, nothing ever sounds as sweet as music played thru something that you have built yourself

 

 

 

I'm hoping that the new plywood cabinets for my Frugel Horns look similarly good, although I suspect your ply is better than mine.

 

 

 

Regarding the bases; for stability the section in contact with the floor should be wider than the speaker. I prefer triangular shaped footers to avoid rocking, especially when spikes are used.

 

 

 

Enjoy.

 

Thanks for the feedback. The ply I used is only C/D grade from Mitre10, just takes a bit of sanding the external face, you could be pleasantly surprised.

 

Good point re. the stands. They are slightly wider (by a couple of cm), but maybe I could build outriggers for them. That could help add a bit of height too, as they are a bit low.

[little blue penguin]

I see that you have made some IC's from Cat5e. I've got some Cat6 off cuts from an installation job which I could drop off to you if you are interested.

[Guest Guest]

dsan your speakers look absolutely lovely! Nice work!

:cool:

[dsan]

 

cloth_ears;104198 wrote:

I see that you have made some IC's from Cat5e. I've got some Cat6 off cuts from an installation job which I could drop off to you if you are interested.

 

That would be great, I'll send you a PM. I have been meaning to post pics of the cables, that was quite a fun process.

 

 

sirAndy;104297 wrote:

dsan your speakers look absolutely lovely! Nice work!

 

:cool:

 

Cheers!

[Bonzo]

Good morning to everyone!

It's my first post on this site: I wanto to build this enclosure but I can't find the plain to cut the plywood.

Would you be so kind to post a quoted drawning of your speaker or, at least, the measures of the internal braces?

Thank you very much!

[Shane Hanify]

Gidday Bonzo,

 

welcome to the forums.

 

Solo103 link

 

There you go. (Thank you to dsan who had the link in one of his posts).

 

Cheers, Shane.

[dsan]

In a moment of madness and frustration, I pulled out the Fostex drivers and replaced them with the $17 Jaycar drivers I bought a few weeks ago and......I really like what I’m hearing! They aren’t as detailed as the Fostex’s and don’t extend very high, but they do have a very pleasant, full, punchy, and surprisingly clear sound. They work surprisingly well in the solo103 cabinets!

 

The Fostex drivers were really starting to bug me, I do love the clarity and detail, but the overall sound is just a too thin and fatiguing to my ears, especially without any eq tweaking. Really not sure what to do with them now.

 

By the sound of things, a great driver for me would be a hybrid between the Jaycar and Fostex’s. So... would it be feasible to use the Jaycar driver for mid/bass and crossover to the Fostex’s for the mid/high frequencies? I could put the Fostex’s back in the solo103 cabinets and build a little bass cabinet for the Jaycar’s to sit underneath them. How would I work out a crossover for this? Or, is it a silly idea with these drivers?

 

Here are the stats:

 

Jaycar 4” Woofer/midrange driver

25wrms

8 ohms

Freq response: 60Hz-1.5kHz

Sensitivity: 86dB

Tuning freq: 50Hz

Re: 6.5 ohms

Qms: 3.74

Qes: 0.44

Qts: 0.52

Vas: 4.5 litres

Fs: 56Hz

Volume: 5 litres

 

Fostex FE103E

8 ohm impedance

Frequency response 79.5 Hz to 22kHz

89dB sensitivity

Re 7.45 ohm

Le@1kHz - mH

fs 79.5 Hz

Qms 2.87

Qes 0.40

Qts 0.36

Mms 2.1 g

Cms 0.0019 mm/N

Sd 0.005 m2

BL 4.42 N/A

Vas 6.90 ltrs

Xmax 0.35 mm peak

VC 20 mm

Nom. Power 15 W

Attached files

[Papa Hemi]

Hmmm there could be a funky enclosure for the jaycar bass in the room there - thought about converting that radiogram for the purpose??

[dsan]

 

Papa Hemi;124121 wrote:

Hmmm there could be a funky enclosure for the jaycar bass in the room there - thought about converting that radiogram for the purpose??

 

Would need some major conversion! I just picked that up today, not working though unfortunately, powers up but not much else! I like the idea of getting it up and running... but I have a rather long list of current projects to get finished first

[C33]

Are you running the Fostex drivers without any filtering? I see the original used a notch filter to tame a wide peak in the response that may be causing the thin/very detailed sound.

 

If I was going to spend significant money on crossover components I would want a larger bass driver but then again the speed of the Jaycar driver may be an advantage.

 

What about running them both full range, that might be worth a try?

[dsan]

 

C33;124129 wrote:

Are you running the Fostex drivers without any filtering? I see the original used a notch filter to tame a wide peak in the response that may be causing the thin/very detailed sound.

 

 

 

If I was going to spend significant money on crossover components I would want a larger bass driver but then again the speed of the Jaycar driver may be an advantage.

 

 

 

What about running them both full range, that might be worth a try?

 

Yes, I am. That's a good point, I really should try the filter before anything else.

Where would be the best place to get these parts?

 

Filter components:

L = 0,82 mH air-core inductor 2,00 mm wire, R = 0,15 ohms

C = 4,7uF MKP foil capacitor - Audyn Cap Plus, Mundorf Supreme Cap or similar

R = 10 ohms / 10 watts metal film resistor

 

I thought about running both full range, but wouldn't the different efficiencies be a problem?

Good point re. a bigger bass driver. It probably makes more sense just to start again from scratch, but I'm just trying to see if I can make use of what I have.

[C33]

I guess budget will determine where to get the parts, high quality/more expensive components should result in a much better sound, pretty important for a speaker of this nature I would say. Then again you have to decide what is reasonable and also be prepared for some trial and error so perhaps some fairly cheap parts from Jaycar or the like would be a good start? If you like what you hear you could upgrade once you are sure.

 

I'm not sure what the Jaycar efficiency is (87?) but if both are run full range it might not matter too much unless the difference is large. If the difference is large it would mean using a crossover is more difficult and probably not a good idea.

 

If you have a mono source you could try a different driver in each box for an easy test.

[dsan]

Cool, cheers for the feedback. Looks like the specified components would add up to around $120, which might be a bit much for an experiment. I'll see how I go at Jaycar. I might also make some dedicated boxes for the Jaycar drivers, at least that way I can easily swap out the different speakers while experimenting.

Or I could always try the Fostex recommended horn cabinet

[Shane Hanify]

Gidday Dsan,

 

those little drivers look the part in those cabs. If you're going to use both drivers then level matching is a doddle - a resistor to bring the level of one driver down to the other.

 

calculators for this sort of thing here.

 

Cheers, Shane.

[sedge]

 

dsan;124137 wrote:

Cool, cheers for the feedback. Looks like the specified components would add up to around $120, which might be a bit much for an experiment. I'll see how I go at Jaycar. I might also make some dedicated boxes for the Jaycar drivers, at least that way I can easily swap out the different speakers while experimenting.

 

Or I could always try the Fostex recommended horn cabinet

 

Try this;

 

Download a copy of Squeeze center 7.3

Download a copy of inguz audio EQ for Squeezbox

Simulate the effect of the filter by running an EQ that does the same things as the filter

Run softsqueeze on your laptop/pc into the Trends.

 

Or, you know just EQ the thing in Media Player to do the same thing as your filter and play it through the Trends, if you like what you hear, drop the $120 on parts, if you don't, don't.

 

The Inguz Audio plug-in allows for nice definable shelving EQ filters (notches, BSC etc)

 

Cheers,

 

Sedge.

[dsan]

Cheers for the advice guys. I had a bit of a play around with the calculators that Low Orbit recommended and here: http://www.madisound.com/services/hifispeakerdesign.php

I think I really need to some reading into basic crossover and speaker design theory though, I was having some nasty flashbacks to 7th form Physics!

 

I did try equalisation, but only through itunes. I’d prefer not to rely on it as I would like to be able to swap the speakers into the lounge system etc.

 

Maybe I just need to be patient and save some $$ for a new project instead of trying to flog a dead horse. The Jaycar drivers are proving to be rather enjoyable, they definitely pack some punch!

[sedge]

 

dsan;124617 wrote:

 

I did try equalisation, but only through itunes. I’d prefer not to rely on it as I would like to be able to swap the speakers into the lounge system etc.

 

Hey, sorry, what I meant was use it as a test, if you EQ them equivalently to BSC and you like what you hear then fork out the $120 for the physical filter parts. If you can't get them to sound good using a decent EQ then they never will.

 

With a full range driver you're not really running a crossover, just BSC and maybe a notch depending on the driver.

 

Don't forget the 100 hour break in either.

 

Cheers,

 

Sedge.

[dsan]

 

sedge;124673 wrote:

Hey, sorry, what I meant was use it as a test, if you EQ them equivalently to BSC and you like what you hear then fork out the $120 for the physical filter parts. If you can't get them to sound good using a decent EQ then they never will.

 

 

 

With a full range driver you're not really running a crossover, just BSC and maybe a notch depending on the driver.

 

 

 

Don't forget the 100 hour break in either.

 

 

 

Cheers,

 

 

 

Sedge.

 

Ah sorry, good point. So can that software actually imitate the effect of the actual notch components, or is it just a matter of guessing what frequencies will be attenuated? What does BSC stand for? Sorry, I really am a novice!

The drivers have well over 100 hours on them, so that's not a problem. Thanks again.

[sedge]

 

dsan;124697 wrote:

Ah sorry, good point. So can that software actually imitate the effect of the actual notch components, or is it just a matter of guessing what frequencies will be attenuated? What does BSC stand for? Sorry, I really am a novice!

 

The drivers have well over 100 hours on them, so that's not a problem. Thanks again.

 

No worries, I'm novice too, BSC means baffle step compensation... How to describe it ? Yikes... The baffle helps to reinforce output from the driver, as the wavelengths get bigger (lower in Hz) than the baffle they are no longer acccentuated.

 

Hence, a giant baffle (like the whole wall) requires no BSC, but a very thin speaker will require a boost below the freq where the baffle stops being a factor.

 

Hence BSC, it's usually an attenuation circuit for the above BSC freqs as you can't really boost the signal below with passive components.

 

Simple answer, small thin baffles require a bass boost unless the cabinet is tuned to provide the assist, this tends to balance the sound and stop it ripping your ears off.

 

A notch filter is usually to smooth a peak somewhere.

 

Just EQ the speakers and have a listen, I suggested the Inguz EQ as you can choose the filter bounds so can do things like set up a notch of 2 DB between 1000 and 1500 Hz.

 

I'd probably start with your speakers an a flat EQ, then drop everything above 500Hz by 3DB-5DB (better to drop above than boost below in case you overdrive)

 

There's a calculator somewhere that tells you where BSC will cut based on your baffle width.

 

I'd also be tempted to drop output below 40Hz to take some of the load off the drivers, I'm not sure where you have the cabinets tuned to.

 

Wow, big post for me, remember this EQ thing only works on full rangers as you don't really have a crossover.

 

Why not give it a go though.

 

Sedge.

[sedge]

f3 = 115 / width in meters = where

 

EG for 300mm wide baffle...

 

f3 = 115 / 0.3 = 383 Hz

 

Stolen from http://sound.westhost.com/bafflestep.htm

 

Ta.

 

Sedge.

[dsan]

Cool, cheers for that. I think I'm getting the hang of this. I'll have another play when I get the drivers back in. Still can't get over the toe tapping good sound of the $17 jaycar drivers though, will definitely need to find a permanent home for them.