LawrenceH

Oh, sorry for double posting, but although it's an 'industry standard' the SM58 is often not a great mic on female vox, especially through cheaper (read: not turbosound, nexo etc!) speakers. It does male rock voice very well, but for women it often lacks clarity and body in the mix which equates to not enough perceived volume and feedback problems. 9 times out of 10 I've had more success using a stage condenser with a bit of treble roll-off to tame feedback. Or the Sennheiser dynamics (e845/945 up). But mic choice is very much dependent on the voice, there's no one-size-fits-all solution so you HAVE to try them out for the person. Shure SM87a is often a pretty good bet though. Food for thought, anyway.

[quote name='spinynorman' post='657626' date='Nov 17 2009, 11:13 PM']Ok, thanks so far. The mic is Shure SM58. I take it the cheap plastic speaker is the SRM350 - it felt quite expensive to me, but agreed it isn't primarily a monitor. Gear is a constant compromise between size, weight, cost and performance. Can you give me an example of a monitor with smooth response, since we've more or less decided to replace the Mackie with something else? EQ may well be the answer, as there is limited EQ on the mixer. FOH is generally ok, the problem's always with the monitor.[/quote] If it's feedback that's limiting your volume then you've not run out of monitor power. EQ is the way forward and cheaper than a new speaker that will probably need EQ to maximise its performance in any case. But also good monitor placement is crucial. If the singer moves out of the firing line of the treble driver in particular then she will not hear herself no matter how loud it's cranked. One unconventional solution that has always worked brilliantly for me in smaller venues is to have the monitor on a stand behind the PA speakers firing diagonally back across the stage. The horn directivity is optimal with this placement and you don't get so much sound bouncing off the ceiling muddying things up and hitting the mic from a bad angle. The bonus is the rest of the band hears the vocals more clearly too. I don't know why more bands don't do this for smaller stages, you need fewer speakers overall and you hear it better. Wedges are better for larger theatre-type stages where you can't get close enough to the performers without obsuring them otherwise. BTW in my experience Mackie SM350s are a lot better than many dedicated monitors at the cheaper end of the market, plastic box or not.

secondhand is definitely the way to go, you can get a lot of small gig-able combos for £150.

[quote name='Spoombung' post='656330' date='Nov 16 2009, 08:07 PM']Under £300 in a shop in Herne Bay: Really slim, nicely contoured body in pearl white, and a slim, laminated maple neck. the finish was immaculate. Not so convinced with the sound, however, but now I'd like to investigate the fretless model - which apparently has a ebonol board. Anyone know who stocks them in the London area?[/quote] Hmm, interesting. I have an Ibanez SR500 which is a joy to play, but the tone of the woods used is dark - mahogany body with bubinga/wenge neck and rosewood fretboard. I replaced the Bartolini MK1 pups and pre with passive Nordstrand Big Singles which really helped (after a bit of jazz growl) but I still think maybe I'd be better off with a bit of maple in there. How was the top end tone on this, especially acoustically?

[quote name='7string' post='656609' date='Nov 17 2009, 12:46 AM']Any dirt that isn't moved by that can be treated with saliva (which works a treat)[/quote] +1. I once had a long conversation with someone who worked as a conservator for museums. They said the number one safe solvent for paintings, statues, pots, whatever, is a dollop of spit! A bit of water is fine on a bass as long as it's dried off thoroughly - it's long-term storage in a wet atmosphere that causes problems. Water is safer than many other solvents - if basses had water soluble finishes they'd run with the sweat from when you played.

[quote name='fatback' post='656047' date='Nov 16 2009, 03:55 PM']Looks like the LM2 XLR out is line level then (they say 10vpp, whatever pp is). From what's being said about DI, it seems that a mic level XLR Out would be vastly preferable. You don't want to have to use a sound guy's crappy DI box after spending a fair sum on a head, so you? Especially if you want to use the head's eq. Food for thought there. fatback[/quote] DI outs are often quite hot. Some desks share the same extended range pre-amp between line and XLR anyway so you can plug in no problem, while others actually have a 20dB pad so they can cut 'hot' signals before routing them to a mic-level preamp. Most modern desks I've encountered will cope with the signal. But a few desks, especially older ones, don't have the range on the preamps and/or they switch off the XLR input when you engage the pad switch even though the signal ends up running through the same circuitry (I think the older Soundcraft Spirits might have done this?). The solution is to buy/build an inline attenuator. This is equivalent to the 'pad' switch on a DI box which as far as I'm aware is normally just a resistor. You could probably wire this into one end of an XLR connector and have a short lead with your kit. I think you can use expensive resistors if you're a dedicated audiophile but in reality I think it's not gonna be a problem. This is the jobbie you need if you want to just buy one: [url="http://www.studiocare.com/store/index.php?main_page=product_info&products_id=63259&zenid=s8n7p3ekadh0816ih6baklic22"]http://www.studiocare.com/store/index.php?...0816ih6baklic22[/url] Bear in mind it's better not to use the attenuator unless you have to since you've got a better SNR at high level, and more pertinently it's one less connection to potentially fail!

[quote name='henry norton' post='652868' date='Nov 12 2009, 06:15 PM']God! That's a really good idea - I assume you're talking about wiring the Jazz singles in series. Now I'm going to have to try it....[/quote] Yup. It totally changes the tonal balance of the sound. What's crazy is that I've seen reviews of jazz basses with s1 switches online that list it as a negative feature which I just can't understand. t's not like you HAVE to use it! For me, it's very good for providing that solid, reassuring bottom some tracks need without treading on the toes of other instruments. A problem-solving tone that just fits in a mix instantly. Like drenching a pudding in double cream, just makes it work pretty much whatever the situation. And it costs virtually nuh-uh-uh-thing, the best price of all when you come down with a bad dose of GAS.

[quote name='TheButler' post='650397' date='Nov 10 2009, 09:43 AM']Well, you know where to find me if you want to sell it Seriously [/quote] Heh, will do - I need to see what it's like in proper action before I decide. So if you know of any gigs going, I'd love to know! Just moved to Edinburgh and still on the lookout.

I did regular pub gigs quite happily with an Ashdown Electric Blue that pushed out 130 watts into a single 12". Don't worry as much about watts as whether it's a loud combo or not - speaker sensitivity and cab design matter a lot. As does who you play with, as others have said! It takes a LOT more power to get a deep fat reggae tone audible than an up-front mid-heavy Jaco sound. I'd suspect a 300w 10" combo would be as loud as my Electric Blue, but not much louder if at all. It's enough for me, but then I don't play against (as opposed to with!) Marshall stacks! For those kind of bands, getting them to turn down is a lot better than trying to compete. Any guitarist who claims to need more than a single 12" is lying.

[quote name='karlthebassist' post='648812' date='Nov 8 2009, 02:42 PM']Yeah I'm cool with Jazzes, but I've had a hard time in the past getting a beefy enough tone out of them.[/quote] Jazz-type PU config gives the most versatile instrument IMO, but the 'beef' can be lacking as you say. But have you tried one with an S1 switch? I made this mod to my el-cheapo secondhand Ibanez SR500 after I fitted it with jazz-style pups for more growl (Nordstrand Big Singles), and the added low end thump with S1 engaged is unreal. It's like having another instrument at the flick of a switch - total cost of mod £2! I don't know why more bassists don't install this option, especially those looking for a 'do-anything' workhorse instrument. One day I'll find a bass with a modern neck/body profile, but proper 70s jazz-style growling tone. I'll fit an S1 switch plus an audere pre, and I'll be in absolute bass heaven.

[quote name='Bass Culture' post='650374' date='Nov 10 2009, 09:06 AM']Ah ha, right, I think the penny's dropping. So, by my rudimentary calculations that should mean I won't have too much to worry about? If my (4 string) bass has a range of 4 octaves to accommodate (low E to the E - for example - on the 21st fret on the G string) and I'm using both my 8 ohm cabs each cab would draw 250w of available power from an amp that puts out 500w at 4 ohms. Meaning there wouldn't be more than 150w available to go into each driver in the low end - from bottom up 150w + 75w + 37.5w + 18.75w = 281.25w. Or, more power than the cab would be receiving and therefore not enough to push past the 150w in the low end required to make distortion a worry. Is that correct? Of course, this only includes fretted notes. With overtones and harmonics to contend with I guess - logically - the maximum power available in the low end could even be less...My brain hurts now. Cheers, Mark[/quote] I think it more depends on the harmonic content of the individual note you're playing at any one time, since you don't output all notes simultaneously! I have been trying to get to grips with this sort of thing recently, and it seems Celestion use the 'traditional' method of calculating Xmax which is Xmax = (Voice Coil Length - Height of the Magnetic Gap) divided by 2. From what I've read this tends to give conservative Xmax estimates in comparison to other methods, including that used by Eminence which is based on the excursion at which 10% THD is reached. Ignoring the merits of one type of measurement versus the other, it still means that comparing different brands of speaker, eg Em v Celestion, is going to be like apples and oranges. More relevantly to you, it might mean that you've got a little bit of wiggle room. No-one's yet answered my question in the tech/repair forum about loudspeaker behaviour beyond Xmax (pleeease, anyone?!), but my limited understanding from t'internet would be that if xmax is reached at 150W LF, then an amp capable of 250w max is about right - it'll drive this speaker to full potential with enough headroom to prevent nasty amp clipping and you shouldn't get near the safety limits of the driver. That Celestion actually models quite well in small boxes (he says cluelessly playing with the pretty graphs in WinISD)

How sudden and how obvious is the drop? You'd expect some power compression as the speaker heats up, my little Ashdown 1x12 always does that if it's working hard for long periods.

This thread is ace. Congratulations!

[quote name='Mr. Foxen' post='649325' date='Nov 9 2009, 01:13 AM']Isn't the answer to the first one xlim? The second bit, if you have the cabs, try it and see, get a long cable and wander about, to se if there are bad cancellations. The people madly criticising mixing cabs and drivers and such are either people in pro audio that are very fussy on the minutiae of good sound, or people who have read their statements and taken it to mean the world will implode of you go against them, because they are experts. In most cases, you won't cause many real problems mixing cabs. Some stuff is going to upset totally modelled stuff, but is fine in practice, for example, if you do the highly reccomended pair of 2x10s stacked on their sides, the bottom one is radiating in half space cause of the floor, but the top one isn't, so they are mismatched.[/quote] Ah, yes, sorry I should have been clearer - many manufacturers don't produce Xlim figures so is there a reasonable 'guesstimate'? But I also don't understand if the modelling of input power versus excursion beyond Xmax can be considered accurate, if not Xlim could be reached much earlier than expected. I'm thinking really about what's acceptable for the hump above the tuning frequency. Re cabs, the thing is I'd rather not build it to try out without having avoided obvious pitfalls! I definitely hear what you're saying re 'real world' and it's good to hear that you find mixing can work in practice. OTOH my experience of sound engineering with a bassist's ears has certainly shown me how bad some set-ups can be at the low end! What I've learnt is that it's worth getting each component of the signal chain as close to optimum as is reasonable/affordable, as errors are additive, but beyond a certain point for each individual component the price/performance ratio places a limit on what's worth it and time/money's better spent elsewhere (e.g. a semi-decent entry level condenser mic on vox always makes an improvement compared to the SM58 with even the crappiest PA, but a Neumann+pre through a guitar amp probably isn't worth it!). Thanks a lot for the reply!

Hi there, Looking to upgrade my amp to something lighter and louder, I managed to pick up a Tecamp combo thanks to guitarguitar's offer (discussed elsewhere). Thinking about the limitations of my previous kit and looking for cost-effective solutions, before this deal came up I was thinking about self-build. Finding the amazing wealth of information online about DIY loudspeaker cabinets and the superior performance of these to many 'big name' cabs has been fascinating and I am still wondering about adding a home-made extension cab. Reading discussions from Alex, Greenboy, Bill Fitzmaurice, Bgavin and others has been very illuminating, but I am struggling to find answers to a couple of questions, perhaps someone here can help. 1) Particularly with the modern high-end Neo drivers, roughly how far can one exceed Xmax a. most importantly safely, but also b. useably in musical terms with bass guitar? I ask because playing with driver parameters in WinISD I notice that with a typical reflex cab with a tuning frequency somewhere around the driver Fs, excursion rapidly rises below the box tuning frequency, effectively placing a lower limit on the safe operating frequency the box can handle. However there is a hump roughly an octave or less above this which for lower box tunings acts more as a limit on the wattage the unit can handle. This is of particular concern because with typical cab tunings of 40-50Hz the excursion 'hump' is placed right in the range of the lower string first harmonics, where guitar output is very strong. Lots of my cab designs look good freq response-wise but the hump will skirt over Xmax at this point, at the wattage I would likely feed it when running full-tilt. I'd love a rule-of-thumb estimate of what's acceptable. I've read somewhere Xmax plus 10% but this didn't seem to be referencing PA drivers particularly, and I've read elsewhere that Xmech can be 2 or even 4 times as much as Xmax with some of these! If Xmax is currently typically measured as THD=10%, then this seems to an extent slightly arbitrary without understanding how the THD versus displacement curve up to Xmech plots out or how THD relates to musicality. 2) My second question relates to combining multiple full-range cabs: with cabinet matching, is the main concern for bassists one of matching group delays? I realise that bi-amping with crossovers is the 'gold standard' here but with single channel micro-amps that's not an option. Lots of what I've read says that combining multiple cabs is only acceptable if they contain the same drivers and presumably are identical in size and tuning. Different frequency responses of different drivers will give the cabs different colorations but that in itself is not necessarily a problem, in fact when attempting to extend the bottom of a smal combo with an extension cab it could be beneficial. But I can see that group delay at the lower frequencies could result in nasty cancellation or booming. I'm guessing that what matters is aligning the phase plots of two cabs versus frequency, but I'd like to know if I'm barking up the wrong tree or if there are any other serious problems. Many thanks to anyone who has bothered to read all this!

[quote name='wotnwhy' post='648797' date='Nov 8 2009, 02:28 PM']thats very strange.... mine is very consistent..[/quote] Hey So I wasn't able to explore the 110 combo any more because...it blew up! Well, actually what happened was second time I got it out and turned it on it would not output signal from either the main input or the line in, instead just outputting much more hiss than normal which was punctuated by bubbles and occasional 'cracks'. A telltale sign of a faulty cap. Sure enough, I had a quick peek inside and one of the larger capacitors had vented - one of a bank of four greenish ones on the side of the board showed the brown staining on the top. Damn. The good news is, I emailed Mark of guitarguitar and he was really helpful. He called me back on Saturday (!) offered me repair, refund or alternatively the option to exchange for a 112 combo which the original buyer had decided not keep, apparently working fine. Although he offered to arrange free pickup, since I'm in Edinburgh I popped into the branch there and grabbed the 112 (sorry to whoever had second option on it!) So now I have the 112 combo I'd like to say that Mark and the staff in Edinburgh (John, Andy) were extremely helpful and gave me great confidence in their customer support, so thanks guys! As far as I understood it, they have local amp techs that they'd probably send a faulty model to initially, which would likely be faster, but the warranty deal they picked up with these DOES include return to manufacturer if that turns out to be necessary. Comparing the 112 with the 110, one thing I notice is that the mids seem a bit smoother with this model. I suspect it might be something to do with the slightly extended HF response of the 10" compared to the 12", and this may result in more overlap with the mid driver. Certainly it reinforces my feeling that the 110 combo would benefit from a superior crossover network that included a low-pass filter, which shouldn't be too costly a mod. The 112 perhaps this is less of an issue. It's interesting that on talkbass they discuss manufacturer design changes with the cabs, changing the porting and replacing the tweeter/multiway selector with the hi/mid driver and a simple on/off switch. Which versions do people here have? I'm obviously a bit concerned about the 350 reliability now as I have no idea what caused the cap to pop - whether it's just unlucky, or comes from a bad batch, or if the amp is inherently poorly designed (though I suspect not since a quick google throws up nothing on the 350 heads). If either of the latter two one might expect more problems to crop up soon. One thing I notice right away with the new 112 is that the fan is mounted differently than the 110. Any techies out there care to throw some light over the relationship between faulty capacitors/design and hiss? I'm a bit more concerned if the hiss is intermittent - in mine so far it seems consistent, and actually with the 112 I thought it was less noticeable than the 110, I think perhaps the smoother mid output might be related. It's pretty directional at close range too and is far more evident from the hi/mid diver, so disconnecting your mid drivers might be a quick'n'dirty solution if you prefer a more old-school sound particularly with the 110. I'm not too bothered by it so far though. Crossing fingers that the 112 combo is stable, I think at this stage a single failure doesn't mean much - there's a few guys on talkbass that have been using the tecamp stuff for quite a while. We'll see.

[quote name='alexclaber' post='647544' date='Nov 6 2009, 07:11 PM']That tuning frequency calculation seems way too high to be accurate. Use the signal generator on WinISD Pro to get a sinewave, put your cab on its back, sprinkle some salt on the woofer, and then sweep down from 150Hz towards 30Hz. The salt will bounce more and more until the port starts to join in and at the tuning frequency the bounce will be minimal. Once you go below the tuning frequency the bouncing will rapidly escalate. You'll have to go back and forth to narrow down to an accurate measurement but you should be able to ascertain the port tuning to within less than 1Hz. Alex[/quote] Thanks Alex, that's exactly the kind of real-world experience with these parameters I don't have, I wanted someone to chip on on the plausibility! Built some vocal PA cabs that we ported and tuned with an oscillator 10+ years ago but that's about it. When I have the combo again I'll try some measurements.

I've realised the speaker is not cast alu but is actually pressed steel and is from the Standard Lite range, which has otherwise very similar specs to the Premium range. I've updated my original post accordingly including the link. Sorry about that. Some info from my explorations with the box measurements, the driver specs, and WinISD. Caveats are a) that I don't really know how this program works and what can/can't be taken as reliable from it and this is for the off-the-shelf driver not the actual variant used in the TecAmp cabs, so with this info you get what you pay for! First up the mid-range driver. It's a 4" unit, with some kind of quite thin plastic cone material. I can't see a maker's mark on it anywhere, just a stamp on the steel housing saying 25/06/29/0910039 and then possibl, t, or a smudge, or some Greek squiggle. It says 8ohms but that's all I've got! More usefully, I can see inside the cab that the speaker wires go straight from the 10" to the 4" with just a little block (estimate ~ 1x1.5x4cm) on one of the wires. I can't see clearly what this is but I'm guessing a simple cap as a HPF - can't tell the value. The mid driver is contained in a sealed box which is about 10x10x7 on the outside and made of thin (0.5mm?) ply. Again there is acoustic foam on the back face. I've now had a measure of the internal volume of the 110 combo. It's actually a shade smaller externally that the specs claim. I make it 40x33x18.6 internally, minus 700cc for the mid/hi driver box and a small amount more for the bracing. Taking this into account with a WinISD-calculated 1.35l driver volume I get an internal volume of just 22 or so litres. Extrapolating, the Puma 112 will probably have another ~8 litres depending on the port arrangement (haven't seen the back of one. Does anyone who owns one fancy measuring the slot size?) EDITED to remove calculations derived from WinISD since it's a slot port, and they're probably wrong. Will post back when I've measured the damn thing directly! Cheers Alex

[quote name='RussFM' post='646943' date='Nov 6 2009, 08:30 AM']Don't know, only tried the left one, but the pic a few posts ago shows it plugged into the right, so I guess not?[/quote] The sockets should, unless TecAmp are completely mental, be wired parallel so you can daisy-chain to another cab. So whichever one you use won't matter. The only exceptions to this that I can think of are when cabs have a HP or LP filter on one input, or when they are bi-ampable and then the inputs feed separate drivers. This doesn't apply here. The rather mysterious +1/-1 refers to the wiring scheme for the speakons, which can carry up to 4 different wires in the 4-pole versions. This is useful for PA where you can send sub and top signals separately down a single cable, but for smaller applications it's usually just a compatibility headache! Here only 2 of the 4 poles are in use, the +1/-1 pair. Hope that clears things up if anyone was still confused.

[quote name='pete.young' post='645765' date='Nov 4 2009, 10:05 PM']I did manage to play it at 12 on pre and master in my house without destroying any windows but it was a close run thing. I could hear a very slight hiss (as in , I had to lay on the floor and put my ear on the grill) much to the amusement of my nearest and dearest, but I wouldn't describe it as 'very noticeable'. Given that my lugs are probably shot to bits through years of abuse, I intend to strap it to my carrier and cycle round to Dave C. at some point to see what he thinks![/quote] In which case, there is a fault with mine or else your ears ARE knackered! Mine's certainly audible from further away than the speaker grill. If I was recording I'd want to gate and/or run it through a NR filter.

[quote name='wotnwhy' post='645588' date='Nov 4 2009, 07:06 PM']a finer first post i think you will never see... welcome to the forum Lawrence! i think you'll be made very welcome here incidently, i assume from the lack of mention that you haven't had the hiss problem?[/quote] Thanks! I am amazed at the helpfulness of people out there amongst the bass community, so I feel it's only fair to contribute something back that I wasn't able to find, since there's so much useful info out there for free. Actually, there is some hiss. But whether it's a problem or not I can't yet say as I've not played at volume. However I noticed the hiss was additive between the two volume controls (pre and master). Since this was only noticeable from the pre when past 12 o clock I suspect that it will be more a problem with lower-output instruments as is usual in these cases. When mine arrived it was set to 12 both on pre and master. At this level the hiss is very noticeable, however I could not play at anything like that volume in my house! But if you turned it on at that level you'd definitely think something was amiss till you realised how hard you'd be driving it. I also think the accentuated midrange and extended top-end response make this noise far more noticeable than would otherwise be the case - but that's fine in reality since the musical output will be correspondingly higher - after all it's the ratio that matters. I'm sure many more amps suffer from this than is apparent simply due to running without mid/hi drivers. At least this hiss is very uniform, and I can't hear any mains hum whatsoever. I am curious about switching amp/speaker combinations with my cheap-o Ashdown EB12-150 but that's all on 1/4" jacks and I don't have the right stuff to convert at the mo. The Ashdown doesn't hiss at all (though there is a bit of hum) but then again if you run programme music through it, well there's bugger all happening above about 2k anyway!

Hi guys, Excellent forum! I found it after noticing the amazing tecamp deals at guitarguitar last Sunday, and trying to find out more about the brand, and work out if the deal was real! So I thought I'd come on here and post a little more info on the Tecamp stuff since there's not much available tech details online. This is all from the smallest combo, 110. First up, the loudspeaker is manufacturered by SICA (same as Jensen?) and appears to use the identical [s]cast alu[/s] [b]steel[/b] frame that they use in their [s]Premium Lite[/s] [b]Standard Lite[/b] range, of which there are several variants. Since Tecamp claim to use custom-designed loudspeakers then I assume it's tweaked a little bit (eg 300w Tecamp versus 250w standard power handling) but the Tecamp's own speaker designation LE10-65 indicates that it's a 65mm voicecoil, most likely based on this: [s][url="http://www.sica.it/pdf_ftp/Z005910.pdf"]http://www.sica.it/pdf_ftp/Z005910.pdf[/url][/s] [b] [url="http://www.sica.it/pdf_ftp/Z007811.pdf"]http://www.sica.it/pdf_ftp/Z007811.pdf[/url] [/b] With an Fs of 57Hz and a sensitivity of 95dB I think we can take the claimed 99dB sensitivity and 38Hz frequency response of the combo with a pinch of salt, however note that there is a hi-bass/low-mid hump around 200Hz which, given the separate mid-range driver and large ports, could make the sensitivity claim at least plausible depending on crossover frequency. A brief look at the loudspeaker specs shows an Xmax of [s]5mm[/s] [b]4mm[/b] which is [b]reasonably(!)[/b] promising. I thought that info might be useful to anyone on here who wants a matching cab to their Tecamp gear but, thanks to the excellent guitarguitar, have now acquired a piece of kit way beyond their normal budget range! Like me There are 12" and 15" drivers available in the same range and in 4 and 8 ohms. I also thought it'd be handy/informative as a comparison with the excellent info I've seen on here by Alexclaber in reference to his own cabs versus the fantasy claimed specs by larger manufacturers. When I get the chance I'll have a rough measure of the internal cab dimensions and run it through WinISD with that speaker to get an idea of what the cab is really capable of. Next up the amp. In my case the 350. It is built upon the same chassis as the standalone model, and even the backplate contains the appropriate holes for (2x) speakon out, power input, FX send etc. Moving the sockets across would be therefore be very straightforward and the only thing required to convert to standalone would be a new top plate. I'm tempted to do this! Overall cab design/build: Good-faced ply which I guess is a good indicator of it being reasonable quality. The amp is in a separate sealed cavity as is the midrange driver so no gross mistakes there although this will obviously cut down on internal volume significantly. For this reason, since the external dimensions exactly match those of the 110 standalone cab, I think the claimed 'meticulously calibrated enclosures to deliver expanded low end' could be somewhat hyperbolic. In the absence of a decent test space I'll see what WinISD says! In front of the amp cavity, the back wall is lined with acoustic 'egg-box' type foam that looks to be the proper stuff. There is no other acoustic wadding. A ply divider separating the ports doubles as cab bracing and is matched by another along the top. It sounds reasonably dead when given a rap with the knuckles, if that means anything. I don't yet know what the mid-range driver is nor the crossover frequency (couldn't see the crossover, was just poking a torch/dig cam through the generously-sized ports). Playing music through the cab reveals quite a strong mid-range (1-3k I'd guess) which to my ears sounded a little harsh but it seems to extend quite high. I think some attenuation would have been a useful feature for some apps. I hope this info is useful to someone! I'll post more when I have explored more thoroughly, including a pic or two of some innards if anyone cares. FWIW I'd be fascinated to know some of the specs on the B&C drivers Markbass use, to see how they match up to the claimed responses of their implausibly tiny cabs - especially those 15"-ers, and also on the cab bracing. Not enough of that type of info is out there IMO. [b] *EDITED as I realised I was wrong about the driver and I don't want people getting mislead if they do a quick search - poking around with a torch and a mirror I'd seen the magnet housing clearly which appears identical. Sorry! I've made the edits so you can see where I went wrong [/b]

Hi Tony, I once bought a secondhand SB320 and as I recall had a similar issue, it was solved by adjusting the little pot inside the cavity - I needed it all the way at one extreme to get a good balance I think. Hope you sort it, they're nice basses!