LawrenceH

[quote name='oldslapper' post='1045664' date='Dec 2 2010, 09:14 PM']Hi Laurence. I'm probably being a blouse about the weight, but the combo is a UK made ABM EVO 300 with a 1x10 driver. It's basically the same size as the "mini" cab range and I use it with a mini 1x15 to get the full 325 watt at 4ohm. As I said, a 1x10 blue swap for a neo may not make a lot of difference to the weight, but may affect the sound adversely? I don't know, but thought I'd ask for some opinions. Thanks, John[/quote] If you can work out the rough internal volume, and the port(s) diameter and length, then you'll be able to work out which drivers would be a good match. I'm very roughly guessing a net internal volume of about 60 litres based on online dimensions and trying to take account of the room taken up by the head, which makes it a candidate for something like the Eminence Deltalite II - obviously that's without knowing what the cabinet's tuned to. This speaker'd probably change the sound, giving you more bite in the mids, but that may be a good thing. I'd certainly prefer it! The drawback with the Eminence will be that high power, high bass use will probably kill it due to excessive cone excursion, though I doubt the current speaker is much (if any) better in that regard. There are other, costlier options depending on how much you push your cab. What do you want from a new speaker?

From what I dimly recall of the specs for the 12" Sica/Jensen driver (which the blueline was based on) in my old Ashdown Electric Blue combo, it actually performed ok for a small box when I modelled it - obviously I don't know how much Ashdown tweak the spec but I suspected it was largely a matter of making the cone blue (!) since the model tallied with my impressions from playing through it. Excursion was certainly adequate, though not spectacular. From a bass point of view it wasn't worth swapping for any neo that I modelled, where it suffered a bit was the mid-range extension, and of course the weight. Chuffing was apparent when I REALLY hammered it, but in practice it was rarely an issue Obviously the limitations would have been more apparent with more watts, where excursion and port size would matter more. The older EB pumps out about 120w into 8 ohms IIRC, the similar Mag combos probably have a bit more in them. Also the 15" driver may well have more issues in a small box than the 12. Can I ask what combo you've got and how old it is? Can I also ask what you hope to get out of swapping speakers?

[quote name='Bill Fitzmaurice' post='1045081' date='Dec 2 2010, 01:51 PM']We've gotten a fair bit along since 1990. The very notion of different alignments (second order Bessel, second order Butterworth assorted Chebychev, QB3, BB4 etc) has been rendered obsolete. They date to the days of hand calculation; with modern software an infinite number of 'alignments' are easily realized, including vented which virtually duplicate sealed within a desired passband.[/quote] The design methodology has changed with the advent of modelling software but the underlying electromechanical principles haven't. Plus the benefit of things like LEAP, winISD, hornresp and the like are that anyone can have a play with the various parameters in fairly clueless fashion and quickly see how these characteristics will vary, so get a feel for what is and isn't possible. With your favoured Eminence drivers I've never seen a single vented box model that gives both frequency and time-dependent characteristics that match a sealed cabinet based on the same drivers (much less heard one). It's pretty clear from both looking at the maths and playing with the model that with essentially only two parameters to play with it's not going to happen. Unless you think TS-based model is drastically wrong (which it isn't). Obviously for many real-world applications the vented box will outperform the sealed, but for some people volume isn't everything.

[quote name='Clarky' post='1044522' date='Dec 2 2010, 12:11 AM']Yep, I always loosen the strings before adjusting the truss rod. What I meant about string tension is that higher tension strings exert more pull on the neck so the truss rod needs more tightening clockwise to compensate.[/quote] By the way, symptom of a maxed out truss rod for me was that it got very stiff to turn, like you're finding. That's probably not the case with yours but to be safe, I'd put some penetrating oil in to try and loosen it just so you know you're not at that limit. Or it could suddenly shear off given how much force you're having to use.

[quote name='lettsguitars' post='1042325' date='Nov 30 2010, 01:27 PM']as for max'ing out a rod, i can't imagine that ever happening. if somethings 'rattling' and the rod is in tension, you've got problems.[/quote] I've got a Fender with a maxed out truss rod, luckily it's a bullet-type with the truss at the neck end, so it was dead easy to slip some washers in and problem solved.

[quote name='Bill Fitzmaurice' post='1044482' date='Dec 1 2010, 11:26 PM']A cap alone won't work, you need at least cap and coil, and the price would be far more than a Thumpinator.[/quote] Agreed, you'd be far better sorting this at line level in the FX loop or similar. But I'd suggest you beg, steal or borrow something like an active crossover unit to play with first and seeing if you've actually got a problem with these frequencies before you spend actual money on something you then have to cart around everywhere. I'm still very intrigued to know which amazing vented box PA cabs will give equivalent bass roll-off and group delay characteristics to a simple sealed box based around the same driver, whilst retaining the excursion benefits of the vented design...

[quote name='Mr. Foxen' post='1043837' date='Dec 1 2010, 02:30 PM']Definitely go for the 40-50w, get a thermostatically controlled one if you are that fussed. Nothing much in guitars is heat sensitive, and pot casings and other heavy things need to heat in them. A solder station type one will come with a stand and sponge, so factor the cost saving on those in and it might not me more expensive for a more flexible tool.[/quote] +1. My 25 watts iron is fine for component and cable soldering but really struggles with wiring to pot casings.

*Edited as posted in wrong thread!*

[quote name='dood' post='1043812' date='Dec 1 2010, 02:21 PM']Oh, BK Electronics (www.bkelec.com) *used* to do a power amplifier module that slotted in to the back of a cabinet (with a bit of minor drilling) it could run 600W at 4 Ohms. Sadly, despite being awesome power amps, they stopped making them. 'VelvetKevorkian' on here may still own my old module[/quote] One of these? [url="http://www.bkelec.com/HiFi/ClassD/ClassD.htm"]http://www.bkelec.com/HiFi/ClassD/ClassD.htm[/url] Is that discontinued then? EDIT: Just realised that's 600 into 2 ohms, 450 into 4. Did they used to do a bigger one? They look pretty cool.

Warning - Rickenbacker employ incredibly advanced but poorly thought-through chemical weapon-based brand protection methods that exhibit unfortunate ebay side effects. Fitting a Rickenbacker trussrod cover to a cheap JapCrap copy is consequently very hazardous and almost invariably results in short term memory loss and an inability to solve even the simplest problems. You'll genuinely have no idea about where that bass came from, and won't even be able to work out from your buyer history that you bought both it and the cover on the 'bay less than 3 months ago. As far as you're concerned, it might well be a Ric 4005...but you can't promise anything. Sold as seen!

[quote name='Musky' post='1042984' date='Nov 30 2010, 09:19 PM']Not a chance - he bought many of the parts on ebay, including the stick on inlays! [/quote] So he did - AND a load of waterslide decal paper. The cheeky f****r. The pre-amp was a tenner. Some poor sod paid over the odds there. I really hope it wasn't bought as a christmas present for someone else

[quote name='Circle_of_Fifths' post='1042492' date='Nov 30 2010, 03:57 PM']I also play an older Precision with the wider neck, so it's not just that I cannot - but I actually prefer to have a bass with the neck profile and finish I like better than just the width. It's on a case-by-case evaluation for me, as I expect a Jazz to have a narrow neck and a Precision the fatter of the two. Somewhat sarcastically here - the fret board area of the Marcus Miller felt almost as rounded as the back of the neck, and I find that very uncomfortable. As for the chrome guards - that was obviously in my way, and to take it off would be sad to me. First - THE HOLES! Second - I PAID FOR THAT 1953 HUDSON BUMPER so why would I remove it? I am upset by seeing holes in gear - it looks like it's been a target for small caliber handguns and I don't care for that look. Don't EVEN show me a chip on your guitar either! I guess this indicates how I feel about RW and relic'd gear too. Actually - I know we all whore for one desire or another - some: tone, some: price tags, some: name plates, some: cosmetics. Maybe I'm an anal-retentive iconoclast of sorts, but I like my gear to look new and strive to keep them that way. Having excess holes and tinted shadows were something was installed showing in the woodwork makes me cringe a little. Anyway - <off soapbox now> I am eagerly awaiting the arrival of the Reggie Hamilton at GC on Dec 29th, this year (hopefully) and then I'll see if it's time to buy another bass.[/quote] Heheh, I respect your quirks Different strokes and all that. I suppose I wouldn't count holes as not looking 'new'. But I thought things like the 75RI (and I'd assumed others) came with the chrome in the box rather than mounted and you had to drill it yourself? I could be wrong, and maybe the shops add it on themselves. I don't get what you mean about the P versus J neck though - the modern P's I've played have had thin profiles, no real difference in that respect to a jazz but they have the wider string spacing at the nut. I just mentioned the Geddy Lee since it's got the usual jazz string spacing but is unusually narrow front to back unlike the typical vintage necks. Regarding the gloss, with your wish to keep things new you probably would baulk at the thought, but I wouldn't hesitate to take some 2000 wet'n'dry to the neck - it'll give a great clean satin finish and I'd just buff it to a shine again if I decided I didn't like it But all that's immaterial if you've found what you like anyway and don't have to tinker. Personally, the thing I liked about the VM jazz I tried was the warm, lively acoustic sound thanks to the soft maple body, and looking at photos of other people's some even seem to be 2-piece. But only the natural fretted has that which is a real shame. Agathis (on the 77 and Jag I think) IME sounds pretty dreadful, not my wood of choice for a passive bass and to me at least it seriously limits their upgrade potential.

[quote name='thepurpleblob' post='1042892' date='Nov 30 2010, 08:28 PM']I can play fingerstyle and that's it. I'd really like to learn to play with a pick but I find it really difficult. The sound would suit a lot of things I play, though. Unless I suddenly join some sort of eighties revival band, slapping seems completely pointless and, if I may say so, a little vulgar too [/quote] Pointless ! No way! Vulgar? Definitely, just how it should be. Gotta prefer that fat 70s Larry Graham style to the 80s stuff though.

[quote name='stingrayPete1977' post='1042877' date='Nov 30 2010, 08:17 PM']I usually find the guys who think plec isnt cool cant use one?[/quote] That's me! But then, the reason I can't use one is because I've never ever bothered practising it due to thinking it sounds so uncool In all seriousness I can't think of any tracks I like that use one...thinking...Carol Kaye on Pet Sounds? Doesn't sound too challenging though.

[quote name='lemmywinks' post='1042400' date='Nov 30 2010, 02:20 PM']The crossover would be bypassed if i stick with a replacement neo speaker as the tweeter is on the back of the original driver, not mounted on the front of the cab like you'd expect The reason i was interested in an Eminence unit was because of the guy from TB, he said it gave a really clear, crisp sound which is what i'm after. The Celestion i have in there at the moment is a very poky low-mid sound, much like my Schroeder, which is great but i wanted something a little more hifi (even though i hate using that phrase!) Basically i want something which suits the cab and, being completely clueless about this sort of thing, figured if someone else had done it and it worked then there might be a good chance of me not cocking it up![/quote] Ah, I see, sounds like it's a coaxial driver. The Em deltalite will give quite a boost around 1.5kHz to 3k, so you'll have pretty prominent mids compared to the Celestion. I wouldn't call it 'hifi' but if you equate hifi with mids that cut then it's probably what you're after! To get a proper 'hifi' (I agree, it's a rubbish phrase!) response you'd probably want some kind of tweeter in there, but to start with I'd see how you go with the deltalite II. If you were in Devon you could try one of mine out, but I'm guessing north-west doesn't mean Barnstaple!

[quote name='Bigwan' post='1042274' date='Nov 30 2010, 12:54 PM']The 4 ohm rating of the driver doesn't mean anything since there's a crossover involved. The crossover design determines the ohmage rating of the cab. Use caution when selecting a replacement - an 8 ohm driver used with a crossover designed for a 4 ohm driver will give unpredictable results, impedance wise.[/quote] I doubt the crossover is going to make a difference down low where you typically get the impedence minimum that, as far as the amp's concerned, determines the effective cab impedence. But yes, an 8ohm driver will change the crossover frequency. If it sounded good with the 4ohm Celestion I'd say go with one of those, they're cheaper than the Deltalites anyway, unless you specifically want an 8 ohm cab. Then just use the 8 ohm Celestion and don't worry too much about the crossover! It would be good to know the specs for the EA driver but I doubt you'll be able to find them.

Sumbro jazz bass: [url="http://cgi.ebay.co.uk/70s-Jazz-bass-Sumbro-Fender-copy-collectable-/220703657796?pt=UK_Musical_Instruments_Guitars_CV&hash=item3362f68f44"]http://cgi.ebay.co.uk/70s-Jazz-bass-Sumbro...=item3362f68f44[/url]

Ha! The Peavey Classic is definitely the best, by which I obviously mean wrongest. Though these disparaging comments about the woman are a bit harsh - if you look at the guy's website you'll probably agree he's actually done quite well for himself there...considering

[quote name='icastle' post='1041696' date='Nov 29 2010, 10:00 PM']Biggest catch that I can see has to be that you can't run it in bridged mode into anything less than an 8Ω load.[/quote] The other thing is that so many cheaper power amps struggle with the bass end compared to their rated spec because the power supplies can't keep up for more than a brief burst. The good amps have hefty transformers to match and (if they use traditional designs) are pretty weighty - though I've not tried them I understand the Hartke falls into this category, it's reputedly very solidly built. Don't know about the Samson Servos, if it's heavy then there's more likelihood it's capable. But at the final analysis and assuming it doesn't blow up - if it sounds good, it is good.

[quote name='countjodius' post='1041690' date='Nov 29 2010, 09:54 PM']So would I be looking at getting some closed pickup covers to solve this (as fetching as the insulating tape is )? Do these affect the tone at all?[/quote] They won't affect tone, no. They might get in the way a bit for certain playing styles if you don't want the pole pieces sitting any further from the strings since that'll raise the effective height of the pickups. One thing you could try is putting the electrical tape straight onto the uncovered pickup and then mounting the cover on after, if it'll squeeze into place? If not you could get some replacement covers and just enlarge the holes slightly on those, with a bit of wet'n'dry wrapped round something like a chopstick (I've done this before to make some aftermarket covers fit)! Should look a lot neater. But keep the originals covers as they are or it'll devalue the bass.

[quote name='BassBod' post='1041606' date='Nov 29 2010, 08:34 PM']Sorry to hear about the dead driver....having used that cab for at least 6 years, I even feel a bit sad! But its very interesting that the driver is 4ohms. I used to use a pair with an Eden WT300, and it would overheat/shut down if pushed. Now I know why! Sorry Eden......[/quote] If they used 2.83v then at least that explains in part the implausibly high sensitivity spec for these speakers

[quote name='countjodius' post='1041562' date='Nov 29 2010, 07:55 PM']Hey all, I wonder if anyone could shed some light on a problem that has surfaced with my beloved 73 jazz! It's hard to describe, but when slapping the E string I'm getting this really loud "clunk" (not all of the time, only when I dig in a lot) and have no idea what could be causing it! It doesn't cause a volume clip when recording, just a really abrasive thump. The only thing I can think of is that the string might be impacting with the pickups or something, although they are not set particularly high. I wouldn't want to mess about with the pup height either as the fingerstyle tone/output is spot on! It's definitely not a technique issue either, and has only surfaced in the last month or so! I've attached a wee sound clip so you can hear what I mean- notice how it is only the more rigorous slaps that cause this to happen! Thanks for any info![/quote] Sounds to me like it is indeed hitting the pickup. Assuming you slap between the neck heel and the neck pickup, try using the bridge pickup alone just to see if it goes away and also gently push the string against the pole-piece of the neck pickup to see if it gives the same kind of noise. You could try putting some insulating tape over the pole-pieces. Does tapping the pickup just with your finger also produce a noise? In that case, your pickup is microphonic. Whether potting a vintage pickup is a good idea from the point of view of value, I don't know.

[quote name='Bill Fitzmaurice' post='1041539' date='Nov 29 2010, 07:40 PM']The volume of a cab is not related to watts, it's related to voltage. At a given gain setting the amp output voltage is constant, irrespective of the load impedance. Two cabs parallel wired both receive the same voltage as one, so if identical they will each run at the same volume.[/quote] This is only true in practice at lower output levels. Amp power supplies are rarely capable of providing the maximum voltage at all impedences, otherwise our amps would all have watts ratings that doubled with every halving of impedence. So if you're running an amp close to maximum then adding another speaker cab will result in a volume drop per cabinet. Another confounding factor might be the higher resistance-associated losses from increasing the current, cos that's exponential, so the more speakers you add the worse it gets.

[quote name='lemmywinks' post='1041489' date='Nov 29 2010, 06:43 PM']One last thing, the driver is 4ohm and the tweeter is 8ohm, yet the cab is listed as 8ohm. Why is that?[/quote] I may have missed something, but how do you know the driver is 4 ohms if it's dead? The recone kit will need to be the advised one from EA since it's an Eminence driver built to their custom spec.

[quote name='Mr. Foxen' post='1041277' date='Nov 29 2010, 03:35 PM']Top one is closer to ear height for the mids/highs. Acoustic coupling will mostly affect lows, and lows are affected by loads of other room effects. Since most of the 'sound' is in the mids, that would be a more signifcant factor to perception.[/quote] Both you and Ghost have a point I think...most of my preferred tone's certainly in the mids but a fair number of players I've heard with rockier bands have a lot going on between 80 and 500 and comparatively little above. A lot of rooms I've engineered and played have nodes that make them very lively in this upper-bass/low-mid region. In a smallish rehearsal space all sorts of weird and wonderful (or more likely terrible) things can happen. Acoustic coupling between single 10" speakers won't do much above 500Hz anyway - the main advantage of vertically stacked 4x10s, or 8x10s, over the 2x10 is going to be a little bit of coupling to boost the low mids and then getting the upper mids closer to your lug 'oles! There could well be something wrong/unusual about the cab setup here but I wouldn't discount a quirky combination of the room's acoustics, cab and listener placement.