Phil Starr

You shouldn't have a problem as a load with the cab in parallel with another presumably 8ohm cab at all. The only situation I can think of where I'd worry would be using the cab on it's own with a valve amp and your cab presenting a high impedance within the amps pass band. Even then I wouldn't expect a problem but I'd want to investigate, it's early 50 years since I've used valve amps so it's beyond my pay grade to offer advice about that.

It will filter as you say as a first order filter, 6dB/octave and as such will offer a small amount of protection from over excursion for your 10. Usually you'd want a much sharper cut off as 6dB down at 60Hz isn't going to give you complete peace of mind, though you could model it in WinISD easily enough. However you will still get interference between the two speakers from phase differences and you will hear the combined frequency responses of both speakers at most frequencies. In a way you are doing the opposite of what Barefaced are doing where they allow the speakers to double their output below the crossover point though in this case it isn't really a crossover of course. Your combination is going to sound bass light with a bit of a bass shelf below 120Hz. 3dB down at 80-100Hz is going to be quite noticeable. The advantage is that it is a really cheap fix and you can try varying the value of your capacitor to see what sounds best. I personally tend to roll of below 100Hz in most venues so it could be a sound you like but the only way you'll find out is to try it. You might be better off just building a smaller cab for a second SM112, In a really small cab power handling wouldn't be much of an issue and you'd have the same frequency response above 200Hz so you wouldn't need to re eq when adding the second speaker. It depends upon just how much you want to experiment though. I quite like the SM110 on paper and I can understand the appeal of constant experimentation, it's a sort of intellectual GAS

There is a whole world of PA that sits in between the higher number RCF cabs and upmarket line arrays and those Behringers and at your budget that's where you should be looking. The Behringers lose out because of the speakers, I've had cause to pull some apart recently and they have very small magnets. They are a wonder of engineering to a budget and they sound good for the price but those tiny speaker magnets mean two things, they don't handle bass well and they won't go loud without distorting. If that's all you can afford then they are remarkable for the price but they aren't an upgrade to anything. If you are fairly technical and don't mind a slightly fiddle set up then there are some real bargains out there with used passive PA systems. Everyone is moving to lightweight active systems with mega powered class D amps/switch mode power supplies/Digital processing for convenience and there is suddenly a lot of older good quality PA on the market. You could probably pick up a pair of the old Yamaha Club series PA speakers for £150 which would blow the Behringers away. Look for S112V's or S115V's You'll obviously need a separate power amp. Old passive Electrovoice (EV) JBL and so on are all worth a listen too. Avoid the old passive Peaveys, super reliable but the vocal sound is really not great, they never really sorted their horn drivers/crossovers. the bass bis are OK if you go down that route. If you want to go down the route of active and bought new then the Wharfedale Titan 12's (£200ea) are great value so long as you keep the bass out of them, the vocal sound is excellent and sax and guitar will sound great but the cab is a bit resonant at lower frequencies. For everything else they go loud and clear. You could look to see if the RCF 310 mk3's are still on offer at Thomann (I paid £250ea recently). Stunning quality but again they won't really do bass for a band, this time because they are only 10's. If you don't mind weight you might pick up some used Wharfedale EVP's at a good price but they really are quite weighty. If you want to try some stuff out then PM me.

I just meant why not ask matrix if the amp you have will work with 6ohms. It has a class A/B Mosfet design so depending upon the current handling of the output transistors and the protection circuits it may be fine. They will be able to tell you. It's not a huge miss match.

Why not email Matrix http://www.matrixamplification.com/

I started playing at the age of 55, still loving it and learning loads 10 years later. If I had one tip it is to play whole songs. It's amazingly satisfying and more importantly it makes you learn the difficult bits, and the bits you thought were easy but teach you so much about how songs are structured. I'd recommend the Hal Leonard books. They are well written and thought out, easy to understand and come with a CD so you can hear what you are trying to achieve. Finally you really should play with other people. Bass really comes alive when you play with others, particularly with a drummer. A lot of what we do is shaped around what the other instruments are playing and it is such a buzz. If you remember back to the first time you drove without thinking about the controls? That's nothing to the feeling you get when you realise that sound driving the band along is coming from your fingers without you having to think about it.

There's nothing in the bass above 7k that anyone should be very interested in unless your band have a very odd set up. How much does your guy know about sound? It's often left to a band member who is the only one who knows how to wire the PA up and becomes the one eyed man in the kingdom of the blind. He may be complaining because he is panicking about the lack of 7k+ without truly knowing what that means, or it may be a taste issue, he wants to hear a traditional P-bass with Rotosounds and you are using tapewounds. He's never going to get that from your current set up. The first thing I'd do to resolve this is to spend some time at rehearsal sorting the sound with him, you need to get out into the FOH area and listen to your bass tone with the band going, a couple of long leads with a jack-jack joiner will sort that. Are you getting your tone? Are you cutting through? If you are happy with your tone then he is going to have to trust you, I don't suppose he'd be happy with you adjusting his guitar tones so put it to him that this is the tone you are aiming for and he is doing a good job, not to worry. If you have a way of doing it you could also record a performance I do this for a lot of gigs and it helps you be objective about what you are doing as a band. It can be a painful experience though, there's no hiding place Maybe there is room to compromise though? It's slightly worrying that you don't want to compromise your monitors for FOH though, that kind of says the audience experience is less important than yours. I'm sure you didn't mean it like that but it's worth a couple of minutes thought.

Oh Look it's Bartleby's tone settings

Thanks for joining in. I tend to agree with you about no need to be switchable, why would you want stuff that you can only hear because it messes up the vocal mic's and sets off room resonances? Maybe that's just the sound engineer in me though. Actually I really doubt that there are any bass specific amps out there that don't have some sort of filtering. It's pretty hard to design an amp where there isn't some need to decouple different sections of the chain to stop stray voltages getting through, even if that is only on the input from the bass. Just deciding on the size of the capacitor in each link means you have to have a design goal in mind before you do the calculation. It isn't really an option to switch that out of the circuit. Anyway good to have you on board and if you can tempt Mark Bass or even Marco himself to comment.

Hey Steve, I think you do need new ears, or if not you soon will. Seriously as a friend you need to think about this. The 310's claim 127dB @ 1metre, that's in the over inflated peak values that PA cabs usually use but they will still consistently produce levels of around 120dB+. These are the WHO figures for what sort of exposure is 'safe' ie unlikely to cause permanent damage to your hearing. 'Normal' levels for a rock band are around 100dB for everyone except the drummer. People here won't know that I know your band, an excitingly loud three piece rock band with a full blooded, head down, showman lead guitarist. I know you've had trouble blowing speakers in the past too. You seriously need to consider using in ears. I don't play at anything like your volumes and I thought I was invulnerable but I now have tinnitus and struggle to follow conversations in noisy environments. Something is wrong if you can't hear those 310's flat out they will cause permanent damage in (checks chart below) ….7secs. Maximum Recommended Noise Dose Exposure Levels Noise Level (dBA) Maximum Exposure Time per 24 Hours 85 8 hours 88 4 hours 91 2 hours 94 1 hour 97 30 minutes 100 15 minutes 103 7.5 minutes 106 3.7 minutes 109 112 seconds 112 56 seconds 115 28 seconds 118 14 seconds 121 7 seconds 124 3 seconds 127 1 second 130–140 less than 1 second 140 NO EXPOSURE

That's really interesting, they've clearly chosen a roll off with a -3dB @ 40Hz which makes sense in terms of letting everything from bottom E upwards through. The roll off is about 12db/octave too. I'd go for your setting, lots of added warmth around the crucial octave 80-160 to boost the second harmonic and a roll off to clean out the mud and protect the speakers below40Hz. I also dial in a bit of extra 1-3kHz and roll off the top end. There's potentially a lot of energy though below 40Hz which could threaten a lot of speakers if anyone became heavy handed with the bass boost.

with a valve amp you have successive stages of the amp connected by capacitors, each of these would act as a 6dB/octave filter, most stages would filter at similar frequencies and this would determining the roll off of the amp. Most class AB solid state amps would have similar decoupling capacitors. In fact very few audio amps will go right down to DC. They pretty much all roll off the bottom end at some point.

If it is for just your own monitoring the Behringer B205D is a really good bet. I had the chance to compare it with the Mackie and there was little if any difference. I 'upgraded' to the TC Voice Solo ad wish I'd stuck to the Behringer. Without a band around yout the TC sounds much better but in a band situation the Behringer gives no real highs or lows just lots of mids so it cuts through and gives few feedback problems unlike the TC which sounds brilliant but feeds back far too easily. I've used the Behringer F1320D which sound great. but I've upgraded to the RCF 310 mk3 which Thomann are selling cheap. I've also used the Wharfedale Titans and the EVP's are my main PA speakers. That EVP looks a great buy for an active speaker. The advantage of a 'proper' floor monitor is that the rest of the band will get more vocals, if that is what you are trying to achieve.

It's the rectangular hole in the bottom of the cabinet. It's used to tune the cab to the speakers and at the lowest frequency it is the air that vibrates in the port that makes the note not the speakers. That's a very small port for a 4x10. It may create some distortion and wind noise at high volumes. You may not notice though and there are a lot of commercial designs with over small ports.

My HA3500 is still my best sounding amp if a bit unreliable nowadays, and yes 30hz right the way down and 64Hz half way up with a bit of mid boost. A nicely judged graphic, but no HPF information as far as I can tell.

So that's Berg and Genz. Any more we know about?

These things go in cycles, people go crazy on something that is heavily advertised like 'servo amp', 'OFC cable' or 'damping factor' and then it all moves on. Genzlers idea of a 30Hz 24dB/octave filter is a great design feature. If they called it built in speaker protection we'd all want it. I'm sure it could be made a selling point if they so wanted. I suspect a few people reading this will already be thinking "oh the Magellan has a Thumpinator built in for free, I'll put that on the list". It may be that others are offering a similar 'free' feature but I didn't know about the Magellan and I don't know bout the others either. I'm not necessarily expecting that this will be a headline figure, just that it is freely available in their sales literature and the amp's manual. Clever people will check the others won't notice unless it becomes a selling point.

Absolutely right, they'll all know what their amps do and it's useful information. Especially useful to anyone who pushed the envelope with fx , bass boost or who uses modern highly portable speakers.

I'm going to start a bit of a hare running with the hope that with the power of Basschat we can get some improved practice from the amp manufacturers. I'm not knocking them and I certainly don't want a slanging match from anyone, I'm hoping that people who monitor these pages like @Ashdown Engineering and @MoJoKe who has Mark Bass connections will all join in. If anyone can alert any other manufacturers it would be good to hear their opinions too. Anyway the question is should all bass amps be built with an HPF that filters out subsonic bass, effectively like a Thumpinator but built in. Subsonic bass is only ever a bad thing, it damages speakers, sets off room resonances, get's picked up by every mic on stage and muddies the sound of your bass. In fact most bass amps (maybe all) just by their nature filter out bass below certain frequencies but most amp manufacturers don't tell you at what frequency or by how much. A switchable bass filter /HPF would be wonderful but just publishing some figures would help us all no end, it may be in most cases all we need is to see what the designers have provided for us. So come on manufacturers, tell us what you've got..... and how you can improve next years models

Just looked at the ads, they don't actually claim any more than that Marc designed his own circuits. Not something that is untrue but not a reason to buy or not buy a Markbass. I use an MB Tube, well designed and well made but so are many others. I've read in these pages that early MB's were A/B and later ones class D. Honestly it doesn't matter and any amp worth it's salt should give you a choice between clean or overdriven sound by just turning the input gain down and the master volume up. As ever try amps and speakers out before you buy them and if you like the sound better than the others you know which one to buy.

My sympathy, not least because I now have a little tinnitus too, playing next to the cymbals with inexperienced drummers, I put off ear protection for too long because I found it felt cut off from the rest of the band. Now I'm a little cut off from ordinary conversation in any noisy environment as well as the band. A case of don't do what I did

There is another possible explanation. Drummers more than anyone else tend to have hearing loss problems. Sound levels for drummers are frequently 3-6db higher than for the rest of the band and average out around the 103dB level. HSE don't have any recommended times for exposure at that level on their ready reckoner but 15mins exposure at that level will cause permanent hearing loss! Basically unless your drummer has worn ear defenders from the start then they will have damaged some of their inner ear and will struggle/fail to detect certain frequencies. As their hearing fails they will probably want everything turned up to compensate for their hearing loss. Might be worth gently suggesting to them that they get their hearing checked.

Here you go http://www.till.com/articles/PickupResponseDemo/

Yes, that is right, there's reference to that on one of our incredibly long 12" threads For anyone with a bass to hand it's easy to see, pluck the E string at the 12th fret and it will primarily vibrate around that point, touch your finger against the string just above the 12th fret and it will go on vibrating but will vibrate at it's lowest at the 12th fret. In fact if you leave it alone and watch you can see dead spots (called nodes) forming and breaking down along the length of the string. Easiest to see under a flickering light BTW. https://www.physicsclassroom.com/mmedia/waves/harm2.cfm The only way you'd get the full fundamental would be to pluck the string at the 12th fret and have the pickup directly under at that point. As any bassist will know when you pluck closer to the neck you get more bass (from the fundamental) and closer to the bridge gives you less bass. Somewhere there is a modeller which let's you see what happens to the mix of fundamental and harmonics when you move the position of the pickup. Again it's on one of the threads here. One of the genius things about a P bass is how the pup's are placed at a position with a great mix of fundamental and harmonics. In practice you get way less than 10% of the signal as fundamental, that will be modified by any bass cut or boost and fx, especially octavers and synth effects. Most of the time with most players there won't be a problem but equally cutting everything below 40Hz won't be heard by anyone in a band situation and potentially will distort the sound so why amplify it.

OK looking at the top graph it is excursion, how far the cone moves at each frequency. It's not there to tell you how the speaker sounds but if you look there is a red line at 7mm. That's the maximum the cone can move without distorting or Xmax. anything much above this and you will not just get distortion the speaker will be damaged. The other thing to notice is that the deeper the frequency the further the cone moves except at 50Hz where it moves less than you'd expect. That's the port tuning frequency. The air in the port is doing all the work and creating a back pressure on the cone stopping it from moving. Without the port the cone would be well outside the safe excursion limits and that is why we use ported cabs. Looking at the last graph and that tells you the maximum power you can use. Above 40Hz you can use the full power of the speakers rating 320W. It'll get very hot but won't burn out. Below that you can see that too much power will move it out of the 7mm zone and it will get damaged or distort. If you put in a 20hz signal it will only take 20W without distortion and you'd blow it with 30W'ish.