Hi everyone,
I recently managed to blow the woofer of one of my Energy Point 1e speakers by being stupid. I really loved these speakers and have already bought a new identical pair, but I'd really love to do something with the old ones seeing as it's only one woofer that's blown. I've never made/designed a speaker before so I'd love to get your input on what I could get to replace the woofers on these guys, preferrably a drop-in replacement but I haven't found anything that has the exact same measurements. Here's the data I've been able to find/measure:
-7L enclosure volume
-height * width * depth (internal - for the external dimensions add 1 inch as they're made with 1/2" MDF): 282*160*155 mm
-Port length: 4"/10cm
-Port location: 5.5"/138mm below the (outside) top of the speaker, on the back
-120mm diameter between the mounting screw holes of the woofer, 137mm outer diameter (I'm assuming 5.5")
-The hole the woofer is mounted in has a diameter of 112mm
Now unfortunately, I have no data about the crossover - all I know is that it uses two bipolar electrolytic caps, one 8uF and one 3.3uF as well as two inductors, which would make it a second-order design. No resistors are used in the crossover. The inductors are not marked, and Energy has not (yet) replied to the mail I sent them asking for more data on the speakers. I'd be making a new crossover anyway, but knowing at what frequency it's currently set to cross over would of course be helpful...
The woofer was made by Bravox and is listed in the parts sheet at http://ndgservice.ca/data/pdf/energy_1.pdf as a 5" (actually it says 5.1/4" - not sure whether that's supposed to mean 5.25"?) unit. However, all 5" mid-woofers I've looked at on sites like partsexpress have bigger measurements than this one...
So, does anyone have any input on what might be a suitable replacement for these woofers? If I have to redrill some holes, that would pose no problem, however I think it would be difficult to make a new cutout into the speaker front as they're glued together, so it should preferrably fit into the currently present hole. I'm also looking to keep the tweeters as those both still work and are said to be excellent given the price point these speakers were originally sold at.
If anyone needs more information I'd be glad to see if I can find or measure it.
And now some pictures:
Crossover:
Front with the rock wool (??) damping inserted:
And without the damping material, with the intact speaker next to it:
Thanks in advance!
Edit: Well, turns out I jumped the gun when I said I'd already bought another pair - I'd actually only bid on one on ebay, and some nasty sniper came and outbid me literally in the last ten seconds. I thought ebay handled this by extending the auction for 2 minutes or something whenever someone bids, but apparently not anymore - I can't believe this, I'd already put in a bid that I'm certain would have won, but apparently there's some lag in the website or something and by the time the page had reloaded, the auction had ended already. I'm fuming right now.
I recently managed to blow the woofer of one of my Energy Point 1e speakers by being stupid. I really loved these speakers and have already bought a new identical pair, but I'd really love to do something with the old ones seeing as it's only one woofer that's blown. I've never made/designed a speaker before so I'd love to get your input on what I could get to replace the woofers on these guys, preferrably a drop-in replacement but I haven't found anything that has the exact same measurements. Here's the data I've been able to find/measure:
-7L enclosure volume
-height * width * depth (internal - for the external dimensions add 1 inch as they're made with 1/2" MDF): 282*160*155 mm
-Port length: 4"/10cm
-Port location: 5.5"/138mm below the (outside) top of the speaker, on the back
-120mm diameter between the mounting screw holes of the woofer, 137mm outer diameter (I'm assuming 5.5")
-The hole the woofer is mounted in has a diameter of 112mm
Now unfortunately, I have no data about the crossover - all I know is that it uses two bipolar electrolytic caps, one 8uF and one 3.3uF as well as two inductors, which would make it a second-order design. No resistors are used in the crossover. The inductors are not marked, and Energy has not (yet) replied to the mail I sent them asking for more data on the speakers. I'd be making a new crossover anyway, but knowing at what frequency it's currently set to cross over would of course be helpful...
The woofer was made by Bravox and is listed in the parts sheet at http://ndgservice.ca/data/pdf/energy_1.pdf as a 5" (actually it says 5.1/4" - not sure whether that's supposed to mean 5.25"?) unit. However, all 5" mid-woofers I've looked at on sites like partsexpress have bigger measurements than this one...
So, does anyone have any input on what might be a suitable replacement for these woofers? If I have to redrill some holes, that would pose no problem, however I think it would be difficult to make a new cutout into the speaker front as they're glued together, so it should preferrably fit into the currently present hole. I'm also looking to keep the tweeters as those both still work and are said to be excellent given the price point these speakers were originally sold at.
If anyone needs more information I'd be glad to see if I can find or measure it.
And now some pictures:
Crossover:
Front with the rock wool (??) damping inserted:
And without the damping material, with the intact speaker next to it:
Thanks in advance!
Edit: Well, turns out I jumped the gun when I said I'd already bought another pair - I'd actually only bid on one on ebay, and some nasty sniper came and outbid me literally in the last ten seconds. I thought ebay handled this by extending the auction for 2 minutes or something whenever someone bids, but apparently not anymore - I can't believe this, I'd already put in a bid that I'm certain would have won, but apparently there's some lag in the website or something and by the time the page had reloaded, the auction had ended already. I'm fuming right now.
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I suppose a 112mm cutout is the crucial dimension here. You could make that bigger with a bit of filing too. 
Important to understand what sort of driver you want here. I would guess it's a polypropylene 4 ohm type to work on such a simple filter. Bit like the Epos ESL-3. Epos ELS-3 loudspeaker | Stereophile.com
It's significant that it has a near transparent cloth dustcap, but a phase plug works the same way too.
The Peerless 830860 on a 120mm cutout is this type of driver:
Peerless HDS PPB 830860
Haven't got much time today, so I'll just leave you some details of the Epos ELS-3 to mull over.
Important to understand what sort of driver you want here. I would guess it's a polypropylene 4 ohm type to work on such a simple filter. Bit like the Epos ESL-3. Epos ELS-3 loudspeaker | Stereophile.com
It's significant that it has a near transparent cloth dustcap, but a phase plug works the same way too.
The Peerless 830860 on a 120mm cutout is this type of driver:
Peerless HDS PPB 830860
Haven't got much time today, so I'll just leave you some details of the Epos ELS-3 to mull over.
Attachments
Thanks a lot for the info! You're spot on on it being a polyprop 4 ohm driver - I neglected to mention that in my OP. I just wonder whether I could file out the cutout and retain a somewhat circular shape... The tweeter on the Energys seems to be an 8 Ohm model by the way - measures at 6 ohm DC resistance.
I'll have to redo the crossover anyway, the problem is just that I have
a) NO idea how to go about that - I'm studying EE and understand how analog passive filters work, but we never got to the nitty gritty of designing filters for speaker systems and never focused on audio applications in general.
b) No kind of data on the tweeter at all, which I'd assume would be essential to designing a crossover to mate the tweeter together with any new woofer
Do you think there's even a chance that I'll be retaining the original tweeter and still get a good loudspeaker (as good as or - preferrably - even better than the original)? Apparently a whole lot of money went into designing this tweeter back in the day so it would be really nice to keep it as I doubt I'll be getting anything as good at a reasonable price point.
Thanks again for your help,
Georg
I'll have to redo the crossover anyway, the problem is just that I have
a) NO idea how to go about that - I'm studying EE and understand how analog passive filters work, but we never got to the nitty gritty of designing filters for speaker systems and never focused on audio applications in general.
b) No kind of data on the tweeter at all, which I'd assume would be essential to designing a crossover to mate the tweeter together with any new woofer
Do you think there's even a chance that I'll be retaining the original tweeter and still get a good loudspeaker (as good as or - preferrably - even better than the original)? Apparently a whole lot of money went into designing this tweeter back in the day so it would be really nice to keep it as I doubt I'll be getting anything as good at a reasonable price point.
Thanks again for your help,
Georg
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Hi Georg,
The original woofer seems to be the Bravox TM 130 PP/4: Impuls 1
There are not many drivers locally available in Switzerland. From the offering of A1 Sound Technologies (Lautsprecherbausaetze.ch - Shop für Lautsprecher-Selbstbau (Monacor, Tangband, OmnesAudio, Wavecor, Intertechnik)) I see two options:
Cheap: Monacor SP13/4
High quality: Wavecor WF146WA01
Unfortunately both woofers do not fit into the 112 mm hole and require some woodworking. But I expect them to play acceptable with the current crossover/tweeter.
The original woofer seems to be the Bravox TM 130 PP/4: Impuls 1
There are not many drivers locally available in Switzerland. From the offering of A1 Sound Technologies (Lautsprecherbausaetze.ch - Shop für Lautsprecher-Selbstbau (Monacor, Tangband, OmnesAudio, Wavecor, Intertechnik)) I see two options:
Cheap: Monacor SP13/4
High quality: Wavecor WF146WA01
Unfortunately both woofers do not fit into the 112 mm hole and require some woodworking. But I expect them to play acceptable with the current crossover/tweeter.
Thanks a bunch for the input! I hadn't managed to find the driver model, so that's something new - too bad it's not produced anymore. Also, I'd be willing to import drivers if there's something better/more suitable available in other countries - I'm used to having to import everything when it comes to audio equipment
Also, I'll certainly remake the crossover. Electrolytics and ferrite-core inductors IMO do not belong in a good speaker's XO signal path. I have no experience designing crossovers whatsoever but if I'm gonna spend money on fixing these speakers up I might as well try to give them a proper crossover. That is, unless someone strongly suggests otherwise although I really doubt there's a compelling reason to keep the current one (except for the financial factor).
By the way, I'm from Winterthur too - funny coincidence!
Also, I'll certainly remake the crossover. Electrolytics and ferrite-core inductors IMO do not belong in a good speaker's XO signal path. I have no experience designing crossovers whatsoever but if I'm gonna spend money on fixing these speakers up I might as well try to give them a proper crossover. That is, unless someone strongly suggests otherwise although I really doubt there's a compelling reason to keep the current one (except for the financial factor).
By the way, I'm from Winterthur too - funny coincidence!
Why do people who know nothing about crossovers have such firm opinions about components like electrolytics and ferrites? Just sayin'...
The real answer on general principles is always that poor components shouldn't be used in stressful and highly tuned situations.
I'm struggling to find a 4 ohm polycone here. Nearest I've got is an SB acoustics 5" SB15MFC30-4 : SB Acoustics :: 5" SB15MFC30-4
124mm cutout. IMO the bass Filter will be almost identical to the ELOK kit that SB do, third order because this is a low inductance design.
The real answer on general principles is always that poor components shouldn't be used in stressful and highly tuned situations.
I'm struggling to find a 4 ohm polycone here. Nearest I've got is an SB acoustics 5" SB15MFC30-4 : SB Acoustics :: 5" SB15MFC30-4
124mm cutout. IMO the bass Filter will be almost identical to the ELOK kit that SB do, third order because this is a low inductance design.
Why do people who know nothing about crossovers have such firm opinions about components like electrolytics and ferrites? Just sayin'...
The real answer on general principles is always that poor components shouldn't be used in stressful and highly tuned situations.
I'm struggling to find a 4 ohm polycone here. Nearest I've got is an SB acoustics 5" SB15MFC30-4 : SB Acoustics :: 5" SB15MFC30-4
124mm cutout. IMO the bass Filter will be almost identical to the ELOK kit that SB do, third order because this is a low inductance design.
Well, I based my "opinion" (not very well founded as I am aware) off those of people much more experienced than myself such as Troels Gravelsen and Rod Elliott, who both seem to be of the opinion that a) crossover components should be of good quality (and 20 year old electrolytics are even worse than new electrolytics) and b) crossovers need to be carefully designed for a certain combination of chassis and drivers. The original crossover also has no impedance compensation whatsoever, which also makes me think that making a new one wouldn't be totally out of line. And reusing the old crossovers with a new driver that it wasn't designed to be used with just seems wrong to me, especially if I'm gonna be spending any kind of money on those drivers. Add to that the fact that I'll be able to relatively easy measure the impedance at my university (SPL testing is a different animal, unfortunately - I'll have to do attenuation matching by ear, if at all. Later versions of the Energy crossover had an attenuation network in the crossover so I'll see if I can get the values and schematic as an orientation) and I really don't see a reason not to make a new crossover as it'll also be a valuable experience. Rod Elliott has a great looking guide on constructing 2nd order crossovers on his website - I've been thinking about following that, although I obviously have no way to judge its applicability to my situation.
Thanks for the suggestion on the driver - I've managed to locate the specifications (well, at least some of them...) of the Bravox driver originally used here (scroll all the way down):
TS-Parameter diverser Chassis
It seems that the newer 5" midbass drivers suggested here all have much higher mechanical Q than the old Bravox unit.
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