SHADOW Posted May 23, 2010 Share Posted May 23, 2010 I'm about to replace all four 15" drivers in my bass bins but unsure as to which ones to go for. I've been using EV's but been recommended that I now use Precision Devices PD 1550 or 154's or 156's or JBL 226's for better bottom end and 'thump on the chest' from the bass drum. ( Live band situation ). Cabs are 500 x 500 x 890 internal dimensions which I think is 220 lites with a rectangular port along the top 500 x 60mm with both drivers facing out front. I'll be using a QSC PLX amp giving 1100watts per side at 4ohms or possiblity of getting a QSC MX3000A amp giving 1200 watts.Can anyone advise me as to which drivers would be best. PD's are about half the price so that's obviously a major factor but JBL's have a good record. HELP please ! Link to comment Share on other sites More sharing options...
Simon Lewis Posted May 23, 2010 Share Posted May 23, 2010 Hi, and welcome to the Blue Room! Forgive me if you already know this, but the enclosure is designed to suit the parameters of a particular driver specification. Although you can put other drivers in, they may well not perform at their best, and could even be damaged through over excursion. With regards to power, an amp delivering 1100W at 4 Ohms will run out of power before the rated capability of (say) two PD 1550s. Although not set in stone, many users like to have 3dB headroom, so you would need an amp capable of delivering 2400W into 4 Ohms. The difference between the 1100 and 1200W amp (all other things being equal) is less than 0.5dB more output - which is an inaudible change. If your existing bins and drivers are properly matched, why not try (borrow or hire) a suitably rated power amp to see what the extra headroom sounds like. If the existing drivers are not of sufficient quality, or cannot deliver the low end you need, then have a look over at the speakerplans forum and check whether the boxes actually suit your intended replacements. You may still need to change your amp to something with twice the output.Other possibilities include moving the existing boxes on and purchasing (or making) something with more horsepower, or adding some 2x18s to your system, if you have the space/transport. Simon Link to comment Share on other sites More sharing options...
Jivemaster Posted May 23, 2010 Share Posted May 23, 2010 If the existing drivers are not blown then don't change them! If the current cabs are driven by an amp of 2x the speaker rated power and are not sufficient then look for new cabs and amps. Consider 18" cabs and check that the crossover suits both sub and mid boxes. If you mess with drivers neither the spare drivers not the modded cabs are really saleable afterwards. Mix and matching cabs and drivers doesn't usually produce the best performance, esp in a ported cab where the resonances of the drivers and the cabs must be tuned together for either bass extension or bass level. For one set of speakers the cost of the analysers needed to optimise everything simply isn't viable. Link to comment Share on other sites More sharing options...
SHADOW Posted May 23, 2010 Author Share Posted May 23, 2010 Thanks for that. Problem is that I don't know if cabs and drivers are matched as they're not a name brand so were just put together with what drivers were avaialble at the time, which was EVX 150's - rated at 1000watts, three of which have had the spiders come unstuck, had them reglued but are now buzzing and a bit distorted so assume they need a re-cone. Currently using a qsc plx 3002 so only using 900watts per side. I thought the this would only tickle the EV's but maybe amp is underpowered and that has caused the spiders to unstick ? I don't really know enough about it to sort out what went wrong but I now need to upgrade pretty quickly whatever happens as I need to get the bins functioning properly asap, thus the cry for help. I don't really want to go to 18's as I think we get a punchier sound from 15's but again I could be way out !I've heard bins with 2 x JBL2226's per side run with 1200watt QSC MX amp and sounded great so maybe I should look at that option but JBL's are VERY expensive compared to PD's. Apparently there is quite a difference in QSC MX amp and QSC PLX amp, the MX being much beefier ( but also three times the weight of PLX ! ) so am torn between lightweight PLX 3402 with 1100watts and very heavyweight but better sounding MX 3000 with 1200watts Just pretty mixed up about options and budget and want to get another amp and drivers and have bins up and running again ASAP !! Link to comment Share on other sites More sharing options...
Simon Lewis Posted May 23, 2010 Share Posted May 23, 2010 Given this information, you need to either get drivers that specifically match those cabinets, or simply walk away from them. It's likely that the mismatch is causing the damage, and buying new drivers will simply give you the same problems and a big hole in your wallet.You may be better off buying proper cabs with a guaranteed performance... Link to comment Share on other sites More sharing options...
Tony.a.s.s. Posted May 23, 2010 Share Posted May 23, 2010 I can only support what's already been said. The cab should be tuned for what ever driver goes in it. If you have the facility to do this, it would be possible to alter the ports to suit. Easy for me because I have the equipment, but if you don't have anything to calculate the figures, then you'll just be taking pot luck with the performance. Link to comment Share on other sites More sharing options...
obikwan Posted May 23, 2010 Share Posted May 23, 2010 JBL's (in my personal experience) do not produce clean low end sound. I have not worked with the other two brands you mentioned but I humbly suggest avoiding JBL's for professional use. Link to comment Share on other sites More sharing options...
Simon Lewis Posted May 23, 2010 Share Posted May 23, 2010 Care to share what your personal experience actually is? Whilst not everyone favours the specific "voicing" of the JBL Professional range, that would be splitting hairs when it comes to comparing it with any of the other professional loudspeaker system. How many PA companies in the US make their living hiring JBL Vertec systems? I'd suggest that if they couldn't produce clean low end sound, JBL would have been out of business years ago... Link to comment Share on other sites More sharing options...
Tony.a.s.s. Posted May 24, 2010 Share Posted May 24, 2010 There's nothing wrong with JBL Pro products. They have probably slipped behind in the power ratings game but quality has always been there. Like most chassis speakers, they can sound useless in the wrong cab, but that's where knowledge comes in. Link to comment Share on other sites More sharing options...
Stan Hope-Streeter Posted May 24, 2010 Share Posted May 24, 2010 JBL's (in my personal experience) do not produce clean low end sound. I have not worked with the other two brands you mentioned but I humbly suggest avoiding JBL's for professional use. Would you like to elaborate on that statement? And, whilst you're at it, on just how much personal experience you have? -------------------- I would advise the OP against using JBL drivers (assuming he/she is in the UK) due to the outrageously high cost of recone kits. If you find yourself having to operate the speakers in situations where they may be abused, or if they are not properly matched to the cabinets, this is a serious consideration. Think "total cost of ownership" here. If you can find some speaker modelling software (I'm sure there's some free stuff online) you may be able to check what drivers will work in your cabinets. Link to comment Share on other sites More sharing options...
SHADOW Posted May 24, 2010 Author Share Posted May 24, 2010 Thanks for all advice so far but still don't know what to do for the best. The cabs I've got look pretty much like lots of other 2 x 15 cabs I've seen - approx. 3feet high x two feet x two feet square ( in old money ) with both drivers facing front and a slot/port/vent running along the top about 2.5" wide.. I'd ideally like to keep these cabs if possible but advice so far suggest I should go for a name brand or properly tuned ones, which would be seriously expensive and could possibly be almost the same size !! Is there such a huge difference in having bass bins 'tuned' etc and how can I find out exactly what drivers suit the cabs as I'm not into getting modelling software etc - can anyone help me with this or suggest someone who could do this for me ? It would be great if someone took my cab dimensions and worked out which drivers I should get - job done !!!! Any offers ?Regarding JBL versus Precision Devices, apart from JBL being almost twice the price of PD's, bit of a mixed opinion on that so far. JBL's definitely seem to be the industry standard and very few people have anything bad to say about them but no comments about Precision Devices so far. I'm led to believe they are excellent drivers and are used in some top name cabs so for the price difference could be tempted to go for them if I end up replacing drivers but again I'm open to suggestions for any other makes etc. Plan is to use a 1600 watt amp per side whatever cabs/drivers I end up with. I can only support what's already been said. The cab should be tuned for what ever driver goes in it. If you have the facility to do this, it would be possible to alter the ports to suit. Easy for me because I have the equipment, but if you don't have anything to calculate the figures, then you'll just be taking pot luck with the performance. Link to comment Share on other sites More sharing options...
ajlyall Posted May 26, 2010 Share Posted May 26, 2010 Thanks for all advice so far but still don't know what to do for the best. The cabs I've got look pretty much like lots of other 2 x 15 cabs I've seen - approx. 3feet high x two feet x two feet square ( in old money ) with both drivers facing front and a slot/port/vent running along the top about 2.5" wide.. I'd ideally like to keep these cabs if possible but advice so far suggest I should go for a name brand or properly tuned ones, which would be seriously expensive and could possibly be almost the same size !! Is there such a huge difference in having bass bins 'tuned' etc and how can I find out exactly what drivers suit the cabs as I'm not into getting modelling software etc - can anyone help me with this or suggest someone who could do this for me ? It would be great if someone took my cab dimensions and worked out which drivers I should get - job done !!!! Any offers ?Regarding JBL versus Precision Devices, apart from JBL being almost twice the price of PD's, bit of a mixed opinion on that so far. JBL's definitely seem to be the industry standard and very few people have anything bad to say about them but no comments about Precision Devices so far. I'm led to believe they are excellent drivers and are used in some top name cabs so for the price difference could be tempted to go for them if I end up replacing drivers but again I'm open to suggestions for any other makes etc. Plan is to use a 1600 watt amp per side whatever cabs/drivers I end up with. I can only support what's already been said. The cab should be tuned for what ever driver goes in it. If you have the facility to do this, it would be possible to alter the ports to suit. Easy for me because I have the equipment, but if you don't have anything to calculate the figures, then you'll just be taking pot luck with the performance.Hi, lots of manufactures of drivers produce speaker cabinet designs to suit there drivers I am a cabinet maker by trade and have had many customers come to me with plans.Beymer have a cabinet design book and I have just made some cabinets from one of there designs and fitted the 15" drivers recomended ,hey presto 5K of awsome bass Customer is over the moon and much easier then making furniture :** laughs out loud **: Tony Link to comment Share on other sites More sharing options...
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