Spikyhedgehog Posted June 15, 2007 Share Posted June 15, 2007 I bought this cab nearly 3 years ago, for not alot of money. It's been brilliant and I can't really fault it. I knew the drivers were B&C when I bought it, but because I have never had an issue with sound I never had a peek inside. Opened it up just now, and this is the result: As you can see I've got mismatched speakers, this pissed me off a bit at first because I thought that this could cause severe damage to the speaker cones due to speakers with different diameters being in the same enclosure. But I quickly realised that the top two drivers had significantly smaller voice coils, and I clicked that they were neo drivers. Turns out the drivers are: [url="http://bluearan.co.uk/menu/index.php?id=BAC12HPL76&product=B!amp!C_12HPL76_12!dquote!_350W_Low_Frequency_Driver_with_Neodymium_Magnet_8Ohm&browsemode=category"]Neo Drivers[/url] And the B&C PZ32, with a non Neo coil. Does anyone know whether changing the other two drivers so they match the Neo ones will make a noticeable difference to the sound? I wouldn't really want to splash out £250 on two new drivers if there isn't going to be a worthwhile difference.. It would shave nearly 8 kilos off the weight of the thing though... Anyone like to comment? Quote Link to comment Share on other sites More sharing options...
alexclaber Posted June 15, 2007 Share Posted June 15, 2007 [quote name='Spikyhedgehog' post='18478' date='Jun 15 2007, 06:32 PM']But I quickly realised that the top two drivers had significantly smaller voice coils, and I clicked that they were neo drivers.[/quote] That's the magnet you're looking at, the voice coil is inside that and is the same diameter on both. [quote name='Spikyhedgehog' post='18478' date='Jun 15 2007, 06:32 PM']Anyone like to comment? [/quote] Just googled them and found the specs: [url="http://www.cadaudio.dk/12pz32.htm"]http://www.cadaudio.dk/12pz32.htm[/url] [url="http://www.cadaudio.dk/12hpl76.htm"]http://www.cadaudio.dk/12hpl76.htm[/url] When I looked at these I was concerned because Qts, Fs and sensitivity are quite far apart though Vas is pretty close. The frequency response plots are not drastically different thought the PZ32s have quite a bit less HF extension due to the greater Mms and Le. On the bottom I expected to see quite a difference but on sticking them into WinISD Pro it appears the differences in various parameters almost cancel each other out. I think you got lucky there! Very good speakers - shame the cab's a bit of a bodge but I wouldn't bother changing them if I were you, not at the cost of B&C replacement woofers. If you were to do all HPL76 expect less bottom, more upper midrange. Nothing you can't change with EQ though. If you're interested in saving some weight, maybe build an Omni 10 and stick a pair of the neo speakers in that. It's all very well using neo magnets but it's pretty futile if the cab's a typical unbraced thick ply design. Alex Quote Link to comment Share on other sites More sharing options...
chris_b Posted June 15, 2007 Share Posted June 15, 2007 (edited) What Alex said. But what is the problem? You've loved the sound of this cab for 3 years. Why change it? Edited June 15, 2007 by chris_b Quote Link to comment Share on other sites More sharing options...
Spikyhedgehog Posted June 15, 2007 Author Share Posted June 15, 2007 I should've added, the cab was professionally built by 'IZ Bass Technologies' and is obviously a well designed cab. If anyone has any info on these people I'd love to hear from them, google yeilds no answers. Thanks alex, basically answers my questions straight up. I had a quick look at the parameters before I posted and I noticed they weren't exactly similar, hence the thread. And Chris, I was more thinking of reslae value, people aren't going to want to buy a mismatched cab. I'm also just curious, haha. But no, it's my trusty cab and I like it just the way it is! I just want an 810... Quote Link to comment Share on other sites More sharing options...
alexclaber Posted June 15, 2007 Share Posted June 15, 2007 [quote name='Spikyhedgehog' post='18546' date='Jun 15 2007, 08:35 PM']I should've added, the cab was professionally built by 'IZ Bass Technologies' and is obviously a well designed cab. If anyone has any info on these people I'd love to hear from them, google yeilds no answers.[/quote] Obviously a well designed cab? I don't know how you come to that conclusion! Looks like a bog standard under-braced, under-insulated box which is too small for the woofers to operate efficiently, has a speaker arrangement that causes poor off-axis response, has too small a horn tweeter to cross over well to the woofers and to cap it all the drivers don't even match. However, apart from the latter point, that would accurately describe the majority of bass cabs on the market... Impressive name though! Alex Quote Link to comment Share on other sites More sharing options...
chris_b Posted June 15, 2007 Share Posted June 15, 2007 [quote name='Spikyhedgehog' post='18546' date='Jun 15 2007, 08:35 PM']I was more thinking of reslae value, people aren't going to want to buy a mismatched cab. I'm also just curious, haha.[/quote] I understand. But if it sounds good to you it'll sound good to the next guy, and if whatever mismatch there is isn't very noticeable, then I reckon you should be able to sell on without any problem. Quote Link to comment Share on other sites More sharing options...
Spikyhedgehog Posted June 15, 2007 Author Share Posted June 15, 2007 (edited) [quote name='alexclaber' post='18563' date='Jun 15 2007, 09:22 PM']Obviously a well designed cab? I don't know how you come to that conclusion! Looks like a bog standard under-braced, under-insulated box which is too small for the woofers to operate efficiently, has a speaker arrangement that causes poor off-axis response, has too small a horn tweeter to cross over well to the woofers and to cap it all the drivers don't even match. However, apart from the latter point, that would accurately describe the majority of bass cabs on the market... Impressive name though! Alex[/quote] Sounds good though. I might have a go at putting in some acoustic wool just to dampen the sound a little. It can be a little boomy when the notes start to drop lower. If I do end up getting a different cab, I'm really tempted to just wack out the Neo's and put them into an Omni 210. My woodworking skills are however, interesting... Edited June 15, 2007 by Spikyhedgehog Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted June 16, 2007 Share Posted June 16, 2007 (edited) [quote name='alexclaber' post='18563' date='Jun 15 2007, 04:22 PM']Obviously a well designed cab? I don't know how you come to that conclusion! Looks like a bog standard under-braced, under-insulated box which is too small for the woofers to operate efficiently, has a speaker arrangement that causes poor off-axis response, has too small a horn tweeter to cross over well to the woofers and to cap it all the drivers don't even match. However, apart from the latter point, that would accurately describe the majority of bass cabs on the market... Impressive name though! Alex[/quote] +1. If you took a course in audio engineering the typical 4x/tweeter configuration would be the example on the day they discussed 'How not to build a speaker'. It undoubtably sounds good in comparison to others of the same ilk, but the available room for improvement is vast. [quote]I'm really tempted to just wack out the Neo's and put them into an Omni 210[/quote] Aren't they 12s? Could go into one of these: [url="http://billfitzmaurice.com/phpBB2/viewtopic.php?t=3058"]http://billfitzmaurice.com/phpBB2/viewtopic.php?t=3058[/url] Edited June 16, 2007 by Bill Fitzmaurice Quote Link to comment Share on other sites More sharing options...
Spikyhedgehog Posted June 16, 2007 Author Share Posted June 16, 2007 [quote name='Bill Fitzmaurice' post='18680' date='Jun 16 2007, 04:08 AM']Aren't they 12s? Could go into one of these: [url="http://billfitzmaurice.com/phpBB2/viewtopic.php?t=3058"]http://billfitzmaurice.com/phpBB2/viewtopic.php?t=3058[/url][/quote] Sorry, yes they are 12's not 10's. I shall have a real look at doing something like that when I've got some more time on my hands. Thanks for the link. Quote Link to comment Share on other sites More sharing options...
d-basser Posted June 17, 2007 Share Posted June 17, 2007 [quote name='Bill Fitzmaurice' post='18680' date='Jun 16 2007, 04:08 AM']Aren't they 12s? Could go into one of these: [url="http://billfitzmaurice.com/phpBB2/viewtopic.php?t=3058"]http://billfitzmaurice.com/phpBB2/viewtopic.php?t=3058[/url][/quote] how would the bottom end on that kinda beast be? It looks uber cool but being the omni top model will it handle say a low B without a sub? Quote Link to comment Share on other sites More sharing options...
alexclaber Posted June 17, 2007 Share Posted June 17, 2007 That's an OmniTop 212 vs a decent production ported 2x12". Note that in the lows both cabs act as direct radiators so the output down there is dependant on the maximum cone excursion and not the sensitivity plus thermal power handling. What does handle a low B mean? Does it mean the cab can hit low B fundamental without noticeable roll-off - in which case only Acmes can do it? Or does it mean the cab can handle an unEQ'd low B at high volume without farting, in which case you just need to make the enclosure small enough to restrict the speakers' movement (like the small Schroeders) but that does mean that you get no real bottom? If you're curious about how real world cabs actually respond, as opposed to what their specs claim, model the DeltaLite II woofers in the approximate volume of the cab (take a couple of inches off the external measurement to get internal volume minus woofers and ports) and you'll get a pretty accurate picture of the Epifani UL cabs which are about as good as standard cabs get. You'll notice that the response below 100Hz is FAR worse than the specs and perceptions would have you believe. Alex Quote Link to comment Share on other sites More sharing options...
d-basser Posted June 17, 2007 Share Posted June 17, 2007 (edited) OK i will attempt to understand that lol. I know very little about the technical side and science of these things. I was just wondering how good it would sound with a low B. Basically at the moment I have trace elliot head and a peavey 15" cab and the low end i good but it is far to muddy sounding with very little top end. The cab in the link interested me because i have heard endless good comments about BFM design and i also liked the more traditional aesthetics. I am merely clocking up possibilities for when i have cash. Edited June 17, 2007 by d-basser Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted June 17, 2007 Share Posted June 17, 2007 [quote name='d-basser' post='19213' date='Jun 17 2007, 12:47 PM']how would the bottom end on that kinda beast be? It looks uber cool but being the omni top model will it handle say a low B without a sub?[/quote] That depends how much fundamental versus harmonic content you're looking for. The response of the OTop 12 is very much like a retro style bass cab, though a lot louder. I wouldn't use it for modern style playing with a lot of low end. OTop 15 would be better, but the best arrangement would be either an OTop 1x12 or Omni 10 atop a T39. Between the O10 and OTop 12 the 2x10 O10 is where I'd go, having a better low end stand-alone when you don't need the additional capability of the T39. Quote Link to comment Share on other sites More sharing options...
d-basser Posted June 18, 2007 Share Posted June 18, 2007 thanks Bill , I am just adding all these ideas to my list of things to consider when i have money (and somewere to build a cab) Quote Link to comment Share on other sites More sharing options...
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