New speakers!!!

Dedicated to those large boxes at one end of the room
chris661
Shed dweller
Posts: 2588
Joined: Mon Feb 22, 2010 7:29 am
Location: Sheffield

#1 New speakers!!!

Unread post by chris661 »

So, today I visited the Topps residence to pick up the speakers I'd designed.

Okay, first some technical stuff...

Not being happy with how the little 4" Fostex handled the lower midrange (to 80Hz, where the subwoofers come in) at higher volumes, I decided that, in order to get some more dynamic range, both the woofers and mids should be in the same cabinet. That way, I can move the crossover frequency higher and give the Fostexes an easier time.

First of all, I bought me a Behringer active crossover unit, and some XLR cables.
Set all that up and all works fine.

After that, I needed some cabinets that'd allow both drivers in a smallish cabinet. With university on the horizon, some reasonably small desktop speakers were in order, and who better to build them than our very own Colin T.

So, I sent the design over to him, and soon enough a pair of actual speakers materialised.
After a brief consultation about veneer, Santos Rosewood was chosen, with some nice...


You know what, I'm gonna stop writing and show you the pictures - they're (each!) worth a thousand words IMO...

Chris

PS - there'll be more pictures (and some listening impressions) tomorrow evening when I've got the drivers mounted: I don't want to rush drilling the holes now to find I've messed up.
Attachments
bookshelf03.jpg
bookshelf02.jpg
bookshelf01.jpg
User avatar
Paul Barker
Loony Bin!
Posts: 9413
Joined: Mon May 21, 2007 9:42 pm

#2

Unread post by Paul Barker »

Cute. Very sensible thought about university.

I remember seeing a pair of wallnut stand mounted speakers not much bigger that cost £2,000. Don't recall the make. It was 15 years ago and my grey matter has been tattered and torn turned inside out shaken together and loosely put back a few times over since those days.

But I heard them with a pair of Leak TL12's for a whole evening in the man's flat. (He was Mike who ran a hifi shop in Victoria Road last I heard many years ago he moved to York. Completely lost touch) It was a stupendous sound. We were listening to his Zapper Vinyl collection and drinking wine.

Actuially that alone is reason for my memory loss.

I have often regretted not learning properly what those speakers were, because they were that good, that apart from Bruce Edgar's I don't think I have been that satisfied by speakers at any other time.

PErhaps it was the world's biggest Zappa collection and the wine though. If you know the right Zappa to play there are sounds which sprinbg out from everywhere. Really show speakers off.

I don't know the right Zappa, he knew, and had it all on vinyl.

He was the man who taught me vinyl was the way to go.

But if I was in your position going away to uni I would just have my music on my phone and plug that into a small amp and those speakers you are showing here.

Now are you not meant to be studying? I am meant to be finding all my papers for the accountant to do the VAT return. Never as much fun as this stuff though is it?
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Toppsy
Shed dweller
Posts: 2425
Joined: Mon Jul 23, 2007 12:10 pm
Location: red rose country

#3

Unread post by Toppsy »

Hi Chris,
glad you are happy with the cabinets. They were a nice easy build away from the FH3 kits and Edingdale builds.

I look forward to seeing them with the drivers installed and hope they perform to your expectations.

No doubt I'll be hearing these at Owston.

Must get on and do some work on a couple Edingdale builds and 2 FH3 kits :lol:

As a teaser and depending how the above builds go I'm hoping to have a smaller version of the Edingdale speaker - 'The Rossendales' - to bring to Owston. That is if I get them built and there is room in the car. I may have 2-pair of Edingdales to take for collection at Owston and in which case no room.
User avatar
shane
Social outcast
Posts: 3459
Joined: Sun Sep 16, 2007 12:09 pm
Location: Kept in a cool dry place.

#4

Unread post by shane »

Just out of curiosity, what are the holes in the top for?
User avatar
Dave the bass
Amstrad Tower of Power
Posts: 12310
Joined: Tue May 22, 2007 4:36 pm
Location: NW Kent, Darn Sarf innit.

#5

Unread post by Dave the bass »

shane wrote:Just out of curiosity, what are the holes in the top for?
Lava lamp in each speaker.

Gotta be 'cool funky and retro-aware' when ya go to Uni I beleive :-)

(I never went....).

DTB
"The fat bourgeois and his doppelganger"
User avatar
pre65
Amstrad Tower of Power
Posts: 21465
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#6

Unread post by pre65 »

shane wrote:Just out of curiosity, what are the holes in the top for?
Thoza cup holders silly. :lol:
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
Toppsy
Shed dweller
Posts: 2425
Joined: Mon Jul 23, 2007 12:10 pm
Location: red rose country

#7

Unread post by Toppsy »

Shane wrote
Just out of curiosity, what are the holes in the top for?
The 60mm hole in the top of each cabinet is for the port tube exit. Any fool should know this.:wink: This will come clear when Chris posts up photos with the port tube and drivers installed.

The small 25mm hole in the rear baffle is for a Speakon chassis jack. Chris prefers this method of speaker wire connection rather than the standard speaker binding posts.
chris661
Shed dweller
Posts: 2588
Joined: Mon Feb 22, 2010 7:29 am
Location: Sheffield

#8

Unread post by chris661 »

Yep, as Colin said - the hole in the top is for the bass reflex port for the woofer. The ports are adjustable in length so I can tune the cabinet to whatever I like.

Bit of a teaser shot attached - they'll be up and running later this evening.

Chris

PS - DTB, I already have a lava lamp. Perhaps a photo of the lamp with the speakers is in order?
Attachments
000_0002edit.jpg
User avatar
Dave the bass
Amstrad Tower of Power
Posts: 12310
Joined: Tue May 22, 2007 4:36 pm
Location: NW Kent, Darn Sarf innit.

#9

Unread post by Dave the bass »

chris661 wrote: PS - DTB, I already have a lava lamp. Perhaps a photo of the lamp with the speakers is in order?
I knew it! I knew it! :lol:

Save it for yer Babe-Lair Chris!

DTB
"The fat bourgeois and his doppelganger"
User avatar
shane
Social outcast
Posts: 3459
Joined: Sun Sep 16, 2007 12:09 pm
Location: Kept in a cool dry place.

#10

Unread post by shane »

Toppsy wrote:Any fool should know this.:wink:
Alright alright already.....

I'm just used to ports being in the front or the back, that's all.


Beautiful job as usual, Colin!
User avatar
Audio_Works
User
Posts: 77
Joined: Thu Dec 01, 2011 10:03 am

#11

Unread post by Audio_Works »

Looks very good, love the veneer.

Can you post more info on the design itself? Volume, tuning freq more on the equalization etc.
I have seen alot of these decorated fostex cones lately. what is it?
chris661
Shed dweller
Posts: 2588
Joined: Mon Feb 22, 2010 7:29 am
Location: Sheffield

#12

Unread post by chris661 »

Okay, in no particular order...

The Fostex drivers occupy a 2L internal volume that's sealed off from the rest of the cabinet. That enclosure is fairly well stuffed, in order to prevent short-distance reflections passing back through the cone.
The Fostex enclosure is seperated off from the main enclosure, which houses the woofers.

The whole speaker is about 12L internal, so there's about 10L for each woofer. The ports are tuned to about 42Hz, giving a -3dB point of 40Hz.
Ideally, the woofers would have a larger enclosure, but this would mean sacrificing more desk space.
The result of the slightly-too-small enclosure is a slight rise in bass from 100Hz down to 45Hz, before it starts to roll off. The rise is (simulated) 1dB at its peak, so this really didn't bother me.

The "decorations" on the Fostex cone are eNable - this is a mysterious pattern that's suppose to help the sound. I'm dubious of the benefits of the pattern specifically, but there are those that swear by it.
The added mass to the cone of coating it in various largers means a slightly subdued treble response - no bad thing in these particular Fostex drivers (nominal sensitivity = 93dB, but the response chart peaks at 99dB at 7kHz, giving a very sibilant sound).
Dave (planet 10) treated these speakers, and I got them (relatively) cheap as they'd been damaged, resulting in phase plugs being installed.


So, how're they doing now?

Well, I fired them up, dialed a 350Hz crossover into the active crossover gismo, put something on, and turned it up.

Okay, first off, there's enough bass to start re-arranging furnature. Sounded great for some rap music with heavy bass thumps, but pretty dire for everything else.
After playing a bass-heavy track of my sister's request (and enjoying the vibro-massage from the sofa) - the woofers are capable of over 1" p/p of excursion. I played around with adding stuffing to the ports.

Lots of stuffing (effectively sealed) gave a thin sound.
Took some out, so there's still some air movement at the port.

Phhhhhhwwwwwooooooooaaaaaaaaarrrrrrrrrrrrrrrr

Much better.

Tried For Those About to Rock - loud! - sounded like he really was trying to murder the drum kit. The whole sound just stayed together - a complete departure from the usual small-full-ranger-turned-up-too-loud sound.
Next up, played Buena by Morphine, again, fairly loud. Very nice. Bass sounds like it goes all the way down to the cellar.
Private Investigations - plenty of dynamic range, the big echoey drums at the end sounded like they were in a much larger room than where they are at the mo.
Choir/"classical" (opera-esque singer w/piano) that Dad's more into. Apparently they're pretty good at that, too.

Playing the latter half of DSoTM now.

After a little head-scratching, I worked out why the bit that's meant to sound like he's right behind you, didn't - sounded almost non-existent.
iPod set to mono audio.

iPod set to stereo, he's right behind you. Neat.

Gonna carry on listening for a while. I have to say, this is rather good.


Shane,
The ports are in the top because there's not enough room lengthways to fit them in with the woofer and seperate Fostex chamber. There's only bass coming out the ports (which is omnidirectional), so the location doesn't make much difference until you come to put them near walls.


Still grinning like a maniac,

Chris
User avatar
Audio_Works
User
Posts: 77
Joined: Thu Dec 01, 2011 10:03 am

#13

Unread post by Audio_Works »

Very nice description, thanks for taking the time to post it.

Sounds like your project idea was a success and turned into a real jewel with the help of Toppsy.

I dont know about those decorations but when i see a driver with rising response with increasing frequency, the voices in my head always say "front horn loading!" Ofc it wouldnt be the case considering your space requirments.

I hope you will enjoy many hours of good music on these speakers and good luck at university. Btw i thought i was the youngest on these boards (27y but all my friends say i have an old man's taste in music :P ).
chris661
Shed dweller
Posts: 2588
Joined: Mon Feb 22, 2010 7:29 am
Location: Sheffield

#14

Unread post by chris661 »

Yep, I turned 18 earlier this year.

I'm hoping these sound as good at Owston: from what I've heard so far, they've a fair shot at driving the big room without sounding anaemic.

Once again, thank-you very much Colin. If you fancy a listen, give me a shout and we can get something arranged.

Chris
Attachments
cab dimensions 3.png
Lee S
Old Hand
Posts: 664
Joined: Fri Aug 10, 2007 9:39 am
Location: UK

#15

Unread post by Lee S »

A nice design beautifully executed.... Well done all involved..
©2020 Lee
Post Reply