| need cabinet for 4 1/2" fullrange, please... - Click HERE for Original Thread |
| gychang |
I have a pair of these "el cheapo" speakers, excellent in BIB I had built before, so I bought more.
http://www.mcminone.com/product.asp...oduct_id=51-075
Please recommend a larger cabinet (not a bookshelf) so I can try these. Can they be put in Cyburg Needle or TABAQ like cabinet? Thanks,
Specifications:
Power capacity: 20W/30W RMS/peak
Sensitivity: 96dB (1W/1M)
Impedance: 8ohm
Re: 7.6ohm
Le: 0.25mH
requency response: 68Hz ~ 15KHz
Fs: 68Hz
Qts: 0.38
Qes: 0.47
Qms: 1.40
VAS (liters): 8.7
Xmax: 1.0mm
thanks,
gychang |
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| Scottmoose |
Another? You're addicted, my friend... ;)
So, you want another cabinet for these MCM units, but not a bookshelf. 'Larger' you say? OK, that we can do. To those that ask, shall recieve.
They'll go into Harvey, no modiications required: http://homepage.mac.com/tlinespeake...lans-030107.pdf Don't be put off by the apparantly complicated box -in reality, they're a very easy build. I constructed the prototypes in my leaking garage, with no mitre-box, no clamps, no power-tools of any kind, and a 30 year old handsaw (got the local DIY yard to cut the side-panels and the rest of the material into strips of the correct internal width, and did the rest myself. I'm a rotton woodworker too. So if I can do it, anyone can.
However, if you want to improve things further, a few changes to ~optimise the cabinet for these units will reap rewards in a flatter response & greater extension. If you fancied trying it, then reduce the back-chamber volume to 12.1 litres (mass-load the chamber with sandbags or pebbles, or use a couple of blanking plates), reduce the height of the single throat at the rear of the chamber to 1/2 inch, and the depth of the twin throats to 6/16 inch each. Everything else stays as per the plans for Harvey. These modifications are basically those I made for Bob, which I developed from Harvey for the CSS125. As it happens, they appear to improve things for other drivers too, especially the smaller throat CSA.
Any use?
Scott |
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| Scottmoose |
| Frequency response: These appear to be pretty accurate in terms of F3 & F10 -in-room performance tallied nicely to what you'd expect from the predicted plot, despite the over / under vent location. With room-gain, expect them to be useable down to the bottom string of a bass guitar -that's what we get out of Harvey with the 126. |
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| gychang |
| quote: | Originally posted by Scottmoose
Another? You're addicted, my friend... ;)
They'll go into Harvey, no modiications required: http://homepage.mac.com/tlinespeake...lans-030107.pdf Don't be put off by the apparantly complicated box -in reality, they're a very easy build. I constructed the prototypes in my leaking garage, with no mitre-box, no clamps, no power-tools of any kind, and a 30 year old handsaw (got the local DIY yard to cut the side-panels and the rest of the material into strips of the correct internal width, and did the rest myself. I'm a rotton woodworker too. So if I can do it, anyone can.
However, if you want to improve things further, a few changes to ~optimise the cabinet for these units will reap rewards in a flatter response & greater extension. If you fancied trying it, then reduce the back-chamber volume to 12.1 litres (mass-load the chamber with sandbags or pebbles, or use a couple of blanking plates), reduce the height of the single throat at the rear of the chamber to 1/2 inch, and the depth of the twin throats to 6/16 inch each. Everything else stays as per the plans for Harvey. These modifications are basically those I made for Bob, which I developed from Harvey for the CSS125. As it happens, they appear to improve things for other drivers too, especially the smaller throat CSA.
Any use?
Scott |
Scott: Indeed u have turned me into an addict. I think should thank u since I get enjoyment out of this without hurting others ...
You have given me another project, will study every detail of this before getting things sawed up, thanks again.
gychang |
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| Scottmoose |
Playing with single drivers is a harmless and enjoyable pursuit that can offer potential to let creativity loose. It's great to be able to help when I can. Have fun... ;)
BTW: you can roll drivers with these cabinets. As essentially they're just reflex boxes with gigantic vents, and should be viewed as such (although as they couple to a large amount of air, they posess a real horn sound) they'll happily take the 126, 127, the 108 with a few tweaks, although the last might stuggle at high SPLs. Even the Monacor SPH-60X (great unit). Driver-rolling = an interesting way forward, and the antithesis of this throw-away socienty we seem to be living in at the moment. The BIBs are good for this too. |
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| hm |
Hello,
an alternative might be
the small Posaune: |
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| Scottmoose |
| Out of interest, what's the back unit on that one? Same as the front, or a smaller driver? |
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| hm |
Hello,
Frontdriver
Tang Band
W4-1320 SB
back, invers
and change the pol:
Tang Band
W4-657 B
or
Monacor
SPH-68X/AD |
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| gychang |
| quote: | Originally posted by Scottmoose
1. If you fancied trying it, then reduce the back-chamber volume to 12.1 litres (mass-load the chamber with sandbags or pebbles, or use a couple of blanking plates),
2. reduce the height of the single throat at the rear of the chamber to 1/2 inch, and the depth of the twin throats to 6/16 inch each.
Scott |
1. Are u suggesting "C" be smaller volume?
2. don't understand...
exciting stuff...
gychang |
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| Scottmoose |
1) Well, the volume of the chamber to the rear of the driver could do with reducing for these units. It's currently set to 14.1 litres: reduce this to 12.1 litres however you like, either by blanking part of the chamber off, or adding sandbags or pebbles.
2) See the vertical gap at the rear of the chamber between the two throats? It's currently 1in tall. Make it 1/2in tall instead (i.e move the throats closer together, narrowing the gap between them).
The two throats currently are 3/4in deep each (i.e. both are 3/4in away from the internal back wall of the cabinet). Change that so that each is 6/16in deep (i.e. 6/16 away from the internal back wall of the cabinet.) It'll mean changing the angle of that panel fractionally, but you'll get a smoother response. BTW -the optional mouth-braces are mandatory if you use MDF. With birch ply, you should be OK without them. |
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| gychang |
| quote: | Originally posted by Scottmoose
1) Well, the volume of the chamber to the rear of the driver could do with reducing for these units. It's currently set to 14.1 litres: reduce this to 12.1 litres however you like, either by blanking part of the chamber off, or adding sandbags or pebbles.
2) See the vertical gap at the rear of the chamber between the two throats? It's currently 1in tall. Make it 1/2in tall instead (i.e move the throats closer together, narrowing the gap between them).
The two throats currently are 3/4in deep each (i.e. both are 3/4in away from the internal back wall of the cabinet). Change that so that each is 6/16in deep (i.e. 6/16 away from the internal back wall of the cabinet.) It'll mean changing the angle of that panel fractionally, but you'll get a smoother response. BTW -the optional mouth-braces are mandatory if you use MDF. With birch ply, you should be OK without them. |
Is the volume of chamber reduction in 1), refer to "C" in my attached figure above?, I understand 2)
This is a sealed cabinet, right?
thanks so much. gychang |
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| alandarkdale |
Scottmoose,
I'm contemplating an upgrade for my FE103 drivers. They are currently in the Fostex recommended enclosure. If you please....What chamber and throat modifications would they need?
Dale |
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| Scottmoose |
Re the chamber question, yes, the section you labelled 'C' is the bit that you need to reduce the volume of. It's not sealed though -it's got the throats in it at the back remember. It's only sealed off from the sections you labelled A & B which are completely sealed off from the rest of the cabinet.
Pioneer units? That would explain why they're decent little drivers. Good array fodder, providing they're crossed over to a tweeter line and people don't try to run them full-range.
The FE103E will drop straight into Harvey, no mods needed. BVR enclosures dominate the driver in the LF so they'll accept a wide variety of drive-units with very little change in the response. However, you'll have to go easy with the volume knob as the 103 doesn't have much excursion, and of course, reflex cabinets don't support the cone at high volumes as well as longer-path horn designs. OTOH, as they couple to a large amount of air, they sound physically large, so you don't need to crank them up so high.
I keep meaning to design a BVR specifically for the 4in units as really Harvey was intended for the 4 1/2in drivers like the FE126/7E and she's a bit large for them, especially in the chamber. I'll look into it this afternoon & I should be able to give you some suggestions as to how best to modify the enclosure for the 103 to boost it's performance.
Aiko would also be worth looking at for the 103 -I designed it, with input from Dave, for a 4in Lyeco unit, so the 103 should be quite happy in there as we deliberately went for a fairly high cut-off.Keeps excursion down as there's only so far you can push a little driver. |
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| gychang |
| quote: | Originally posted by Scottmoose
Re the chamber question, yes, the section you labelled 'C' is the bit that you need to reduce the volume of. It's not sealed though -it's got the throats in it at the back remember. It's only sealed off from the sections you labelled A & B which are completely sealed off from the rest of the cabinet.
Pioneer units? That would explain why they're decent little drivers. Good array fodder, providing they're crossed over to a tweeter line and people don't try to run them full-range.
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Scott, You have been very patient with me, thanks so much for all the advise. Will build one of these...
gychang |
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| alandarkdale |
Thanks Scottmoose.
The lower part count and closer to horn structure of the Harvey interests me for home construction and use.
I'm contemplating the Sachico for my classroom at school. My sixth graders have a program coming up and then about two weeks to fill before the end of school. If it comes off, I'll cut a flat pack at home and the kids will help with the assembly in the back of the classroom.
A hidden benefit of the Sachico is the interior shelf that will stop items from becoming unreachable inside the mouth of the horn. My students are generally well behaved but kids are kids..... :D
Someone has to help them see that some things don't have to come from WalMart. |
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| peterphan |
To Scottmoose and the gang,
I just bought a pair of these drivers for $9.80 each. Originally I planned to do a bookshelf, but then I stumbled across this thread :)
the Suzy Chang looks interesting and seems easier to build than a Harvey. What modifications would you recommend to the Suzy Chang to "optimize" it for these drivers?
Thanks,
Peter
edit: oops, the drivers i bought are NOT the same as the original poster's. They are Pioneers, though. Here are the parameters:
Re 6.95 [ê ]
Fs 109.14 [Hz]
F1 70.79 [Hz]
F2 167.88 [Hz]
Zm 23.52 [ê]
D 90.00 [mm]
Qms 1.96
Qes 0.82
Qts 0.58
Bl 4.51 [N/A]
L1K 0.59 [mH]
L10K 0.22 [mH]
Ms 3.50 [g]
Vas 3.43 [l]
dBSpl 89.92 [dB]
Cms 0.61 [mm/N]
Ma 17.00 [g]
FsMa 45.10 [Hz] |
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| GM |
| Hmm, very interesting! The MCM A11 has specs similar to those measured some years ago when we were using them on the original Fullrange forum, while PE has measured specs that aren't even close, requiring a ~2x larger cab with a much longer vent! Makes one wonder what the MCM units actually spec since the model numbers are the same. |
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| happy.gringo |
gychang,
Did you do any mods to the drivers, or are you using them stock? |
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| chuck55 |
For mods, I would suggest removing the dustcap and putting in a phase plug.
No guarantees, just a thought........... |
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| germpod |
| I am running fe126 drivers in Harveys and they do sound great. |
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| bmansz |
| FYI to anyone still active on this thread - Parts Express has CLIO measurements posted for that driver (#290-010). |
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| norman bates |
I'd love to know phase plug size, seems a fun driver than 4.5" pioneer........... It is a bose copy, I'm sure those peaks at 5.5khz and 7.8khz can be annoying............
"I've not heard the 295-010, but I would guess that the 10dB+ change in response from 4Khz to 5Khz 'might' color the sound a bit.
6X of the Pioneer work well in 0.5 cu ft sealed, or 1.4 cu ft vented.
It helps to dope the cone/surround joint with a couple of layers of liquid latex, I use DAP RC56, a hobby store item. "
from a friend on audioasylum.com
Norman |
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| gychang |
| quote: | Originally posted by happy.gringo
gychang,
Did you do any mods to the drivers, or are you using them stock? |
just stock, sounds very good to me.
gychang |
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