Phil Starr

Hi Lawrence, you've probably cut your speaker holes by now but if you are stuck with using a jigsaw then you need a blade which is ground so the teeth are wider than the rest of the blade rather than a cheapy where the teeth are just offset. T101B is good or a T101BR which cuts on the down stroke. If you have to cut smaller than 10" holes then you would be better with a T101A0. Set the blade speed fairly slow and take your time. Use a new blade, I find old ones wear more on one side than the other and they wander off true as a result. Interesting you have chosen a PA driver for bass with an essentially flat response. I have done the same and I'm not sure of the results. Having true bass is interesting in a gigging situation as room acoustics become quite important. I almost always end up rolling off the bass, sometimes quite a lot. The relative absence of peaks in the 2-3k range means that the cabs lack character a bit. The speakers do what it says on the tin but I wondered if I might have preferred some of the 'inaccuracies' of the Eminences and the made for bass Celestions to the clean sound I have. It's all down to taste and I'm looking forwards to seeing what you think.

This depends upon how much twiddling you want to do and which drivers you have. As Bill has pointed out it is probably more to do with implementation than any inherent problem with the piezos. Most piezos act like a leaky capacitor in terms of load so you can trim down the volume by putting a capacitor in series with them. Try a 2uF polyester and see what it does to the sound. Bigger if you want even more cut and smaller if it is too much.. the other problem I have had with Piezos is that they don't have a very flat response and some are better than others although they all look similar. A lot of the cheap ones only have much output above 4kHz which leaves an empty gap between them and the bass driver. As Bill has said you'd be better with something crossing over at 2kHz or even lower for bass. My experience is that even fairly cheap coil based tweeters sound better than nearly all piezos though the absolute need to have a crossover makes them much more expensive

If it is in your price bracket the AER amp one [url="http://basschat.co.uk/topic/157525-aer-amp-one-the-best-amp-i-have-bought-evar/"]http://basschat.co.uk/topic/157525-aer-amp-one-the-best-amp-i-have-bought-evar/[/url]

You can run submixes in though you will need to match them, they might need to go to a jack or a phono input (line input) if the output from the submixer isn't a balanced (XLR) output. You might like to also think of looking at a mixer which takes all of your inputs and just feed the stereo output to the Stagepas which will act as an amp. The Yamahas have a great sound if you can put up with the relatively low sound output.

Don't know if this might help, there are other related articles as well, though you might need to go via my profile page to track them all down [url="http://www.ultimate-guitar.com/columns/gear_maintenance/a_guide_to_live_sound_speakers_and_amps.html"]http://www.ultimate-guitar.com/columns/gear_maintenance/a_guide_to_live_sound_speakers_and_amps.html[/url]

If you are in a covers band playing pubs, like a clean sound, and storage is a problem then take a look at AER's amp one. It's a tiny combo and it achieves a remarkable sound by the equivalent of an optical illusion (auditory illusion?) It compresses the bass end of your signal to reduce the demands on it's little speaker. At the same time this makes the bass sound louder and more 'in your face'. Compression is why the ads on telly sound louder than the programs. It also cleans up your sound. Because of the way our brains and ears work we can't really hear that this isn't genuine loud bass. Honestly I wouldn't have said this until I heard these things at gigs but the little so and so's work really well and if you are the sort of player that just likes to plug in and play then they are unbelievable. You'll love them or hate them but you really should have a look.

The Chain, Fleetwood Mac or Pump it Up, Elvis Costello or Psycho Killer, Talking Heads Oh, and I once played Tobacco Road with our new drummer who responded with "I used to play with the Nashville Teens" so that's now out.

Modding cabs isn't worth it in most cases unless you view it as a way to teach yourself about speaker design. For any given speaker there are sizes of cabs that work best and changing speakers means changing the cab (usually) or putting up with less than optimum results. Swapping speakers round without doing the maths is rarely successful. Your cab is worth something as an original but will lose cvalue if it doesn't have the original drivers so it is usually cost effective to trade up rather than add the cost of two new 10's that may or may not work well. I too use a Black Widow but when i checked found the original Peavey cab designed in the 70's was too big, I built a smaller cab coincidently the same size as my 2x10 and it sounds much better than the original Peavey cab. Peavey still make the Widows and sell new cones that will restore your speaker to original (at a price). If you were keen you could look to make a new cab for the Widow. You'll need to know which one it is though.

[quote name='wateroftyne' timestamp='1318943772' post='1408047'] [b][font=courier new,courier,monospace]STOP PRESS: Money changes the laws of physics.[/font][/b] [/quote] [quote name='LawrenceH' timestamp='1318948712' post='1408109'] Speaker management incorporating multiband limiting can accomplish quite a lot, though...which is why as I say I've wondered whether these units use it. Apparent loudness of bass in recorded pop music played through any cheap-o PA is way higher than what you can typically achieve with a live instrument for similar reasons. Of course, I don't actually know whether they do use it but having heard the AER stuff the amount they pump out does seem rather more than what you'd expect from the somewhat puny specs. [/quote] Clearly they do obey the laws of physics. There has to be some explanation and i am quite curious as to how they do it. I suspect Lawrence may be right. For those of you who are not techies compression 'squashes the difference between the loud and quiet bits of music. If music has a 40dB range then the 'average' power of a 200W amp is 20dB below the peak or 2W, compressing the dynamic range to 20db means the 'average' power can be moved up to 20W without distorting on peaks. Compressed sound is also a lot louder subjectively which is why the heavily compressed sound used in ads on telly seems so much louder than the programmes. If you use compression on your bands vocals you'll know that it helps them cut through the mix. Our brains also are pretty easily fooled into hearing things that aren't really there. If you filtered the bass frequencies and applied extra compression to them making them louder in the quiet bits then the overall balance might well seem bassier but without the need for extreme excursions at the high levels that only happen for a few thousandths of a second anyway. All this is guesswork though, I wonder if anyone (Alex) has taken one of these apart to see how they do it?

I have to say these are remarkable. I went to see a pub band and the bassist had one of these. It really filled the pub with sound and I assumed the bassist was DI'ing, but no just the little AER. Great sound too. Unbelievable.

Peavey IPR 1600 (530W a side) is currently on offer at HTFR [url="http://www.htfr.com/p/377623/peavey_ipr_1600_530_watts_per_channel"]http://www.htfr.com/p/377623/peavey_ipr_1600_530_watts_per_channel[/url]

Interesting question. We don't know from your post how the subs crossover to the 10's. If the bass to the 10's is filtered you have no problems. Your cabs are tuned to a particular frequency, by changing speakers they may not match the new speakers. Filling the volume with blocks will raise the tuning frequency of the cab. Having a tuning frequency which does not match your speakers will affect the frequency response low down and if it is particularly bad might cause you to suffer over excursion of the speaker cones at lower powers than if it were tuned properly. You'd hear this as a farty rattly distortion that wasn't there before and it would be a warning to turn down. If you are not noticing it you probably don't have a problem though you are carrying around a cabinet which might not be getting the best out of your new speakers and which could be smaller. When you get time you can feed the new speaker specs and the box size into winISD and see what size the ports should be and try these out. you obviously don't mind a little fiddling.

If it isn't working it is a complete gamble. It could be just the valves gone and replacing them will re start it. You'll then need to replace a lot of the other components to get it working properly but it would be worthwhile. If the output transformer is gone then it is a major and expensive repair. Sniff the transformers and examine them for signs of burning or any malted goo/resin seeping out. Old valve stuff like this is valuable when working though.

I've got to thank everyone again for taking time to answer my questions, judging by the number of hits there are other people who are interested in your answers. Of course they may just be wondering how stupid my questions can get Bassman7755 Honestly I get what you are saying. I'm going to do some ear training along the lines you suggest. Personally I think the evidence is that we are all somewhere on the bell curve of abilities ranging from those with perfect pitch to the tone deaf. Having said that we are not trapped by our genetics, practice and learning will take us a long way. All I can say is I personally find rhythm easier than tone so I need to work on tone more. Doddy, I seem to be reserving my most stupid questions for you, sorry. Yes I can play scales up one string and playing over two octaves is just another spider exercise for me. In the end they are both more patterns, I'm incorrigible. Perhaps I should just move on to Nashville notation and accept my limited abilities. I suppose what I am asking for is for someone to explain how musical theory will improve my playing in a practical sense. I don't doubt that it will, and I read as much as I can. In a theoretical sense I understand modes, scales, triads pentatonics and can even convert sheet music into tab so I must know what all the little squiggles mean. None of this is any practical use to me so far. If I'm playing a new song and it moves from G to C then I know the patterns for both, I know what notes there are between them and which ones they have in common and I play some variation of those, it works. Lots of books, teachers and bassists and other musicians I respect seem to emphasize the learning of scales all over the fretboard and knowing, usually by calling out, all the notes in each scale. Major scales followed by minor scales and eventually all the modes and so on. I don't think they are all wrong, I just don't get it. It's a huge investment of time and it is immensely boring to just play scales even for 10 min's each practice so I need to have a reason I understand to start this. Can anyone explain? Uncle psychosis, that's really interesting, what sort of things did you learn and how has it helped?

[quote name='Doddy' post='1366282' date='Sep 8 2011, 12:34 PM']You can read about things like chord tones anywhere and then apply them to the instrument when you get chance. It's not overly time consuming to read that a C major chord contains the notes C,E,G.You could read and understand this in a few minutes while watching telly or having a crap or anything. Then when you get to pick up the bass,you just have to play them. If you only did one of these a day,you would know what notes make up every major chord in less than 2 weeks,and will have seriously increased your fingerboard knowledge. Of course,you could learn the shape in 10 minutes and move it up and down but you won't actually know what you're playing-only the shape.[/quote] OK that sounds fairly practical. If I'm honest I'm most of the way there with this and it wouldn't be hard to fill in the gaps. I already know about triads, bits and pieces about modes, circles of fifths and snippets of other musical knowlege, just enough to scare myself with my own ignorance I suppose. None of it is systematic though and it is knowing where to start. I also want to understand how things make me a better player. Its easy to see how ear training will improve things and I'm trying to work on that. Music theory is trickier. If I'm playing F# then my fingers know where the 5th above is without thinking and my brain knows it is C#. I can play scales of F#,C# without thinking but how does knowing the note names help other than when I'm talking to another musician. That is probably a dumb question but I suppose it is the bit I don't get.

[quote name='bassman7755' post='1366242' date='Sep 8 2011, 12:06 PM']The audio courses I already mentioned will give a very good return on invested time. Not only that but you can often make use of otherwise "dead" time such as when your travelling/driving, or even at work if your a bit cheeky Really the old "Ive got a talented mate who can effortlessly do X and therefore its pointless for me to even try" is the oldest excuse in the book for inaction, just order the courses today and get started.[/quote] Yeah, I'll have a look at the courses, no point in asking for advice unless you intend taking it! I'm not saying they do it effortlessly but that they spent thousands of hours as a kid learning these skills with proper teachers taking exams. Grade 8 piano A level music, that sort of thing and that that sort of effort and training has given them what i would like. I know it is the formal knowledge that makes it look like magic. My problem is that I would love to spend hours learning this stuff but I can't. So which bit do I tackle first and why?

[quote name='Dave Vader' post='1365396' date='Sep 7 2011, 04:09 PM']Unless you are a lazy git like myself, and just look at the first note on the stave, and move relative to that in semitones/tones (best not to, it encourages mistakes)[/quote] Yeah I do that too.

[quote name='Doddy' post='1365383' date='Sep 7 2011, 03:55 PM']No...do both.It's never an either/or choice. If you get your ear together you will be able to hear what the chord is,if you get your theory sorted you will be able to know what notes are in the chord-it will also give you the knowledge to know where a song is going before it gets there (this is where understanding at least the basics of diatonic harmony comes in very handy.) By using a combination of theory and ear training it becomes easy to learn 20 songs in an afternoon.[/quote] The trouble is that I know you are right but I wonder at the cost in time. I've two friends who learned classical piano as kids to a good standard and they both have an uncanny ability to listen to a song once and play it back fairly accurately first time with all the chords in their correct inversions. It would take me a day to play the melody only and twenty listenings. They both had good ears though before they started though. I don't have enough life left to do the 10,000 hours at the hour a day i can spare for practice or formal learning. Equally I don't expect to become expert, just better than I am now. I'm not looking for shortcuts, just the most effective way of using the time I have and some practical next steps.

This is getting closer to the sort of advice I was looking for. I'd say my 'ear' is pretty poor. My sense of rhythm seems to be OK, some of our songs are in 12/8, 6/8, 5/4 and others have other Latin rhythms that I cope with. the only thing I've struggled with is the little bit of 7/4 in 'Times Like These'. I can 'hear' rhythm pretty well and that gets you halfway there I suppose. Whilst I am getting better I can't really hear the notes very clearly. I struggle just to pick out the root from a song and tend to work out songs by trial and error. I avoid songs where I don't have an accurate set of chords and tend to ask our guitarist to help out a lot of the time. I can't sing in tune at all confirming all the bass player stereotypes. So are we saying it is a choice between ear training and formal music theory? I've another 20 songs to learn in the next two months.

Wow! I've only been gone a couple of hours. Thanks everyone. I suppose the question I'm asking is how best to spend a limited time improving. I'm old enough not to expect shortcuts but I know I haven't time to do everything. I play in two bands including an acoustic duo and I have about 200 songs learned. I need to practice pretty hard to keep them all up in the air and I try to learn a new song about every other week, mostly from chords, tabs tend not to be very accurate anyway and I only go to them if I'm stuck. I practice about an hour a day. Sadly keeping this up for another 30 years isn't an option as i will be well into my eighties by then! So lessons, learning formal scales or musical theory would all have to come out of practice time, at least in part. What would be the one thing you would do next?

I'm not a good bass player. You probably tear your hair out when you hear people like me playing in pubs. You know the sort of thing; plays the root in time and has copied the odd bass line from the tabs, and that on a good day. I started playing as a middle aged adult from scratch 4 years ago, went straight into a band so the bassist could move on to other things and was playing pub sets of 2 hours in just over a year from playing my first notes. My learning experience has been a desperate scrabble to learn the next song for the next rehearsal and gig a week later. This means that I have seized on what works with no attempt to master theory or scales. Not that I am averse to a more thoughtful approach I just haven't had time to get off the merry-go-round. Currently I grab the chords play in the root a lot and have found the fifth, minor seventh octave and chromatic progressions are my friends. I'm just starting to play with the major and minor pentatonics. I tend to think in terms of box patterns rather than scales, so most of the time I don't even know which note I'm playing, just where they are relative to the root. I never improvise except when working on a new song and never live. I've never had a lesson in my life. So that's me. Where do I go next?

[quote name='alexclaber' post='1358557' date='Sep 1 2011, 10:50 AM']Your conclusion that you prefer 15"s to other sizes is flawed because you can't accurately group the sound of speakers by woofer size. It sounds like you prefer smoother, fatter cabs - doesn't matter what size speakers you use to get that sound as long as you get that sound![/quote] [quote name='bobpalt' post='1358980' date='Sep 1 2011, 04:47 PM']Now I'm getting really confused!! Bob[/quote] [quote name='51m0n' post='1359351' date='Sep 1 2011, 11:29 PM']Nope, you are very misguided, diameter has nothing to do with tone at all.[/quote] It can be confusing but sometimes over simplifying doesn't help. I'm a bit worried that the OP is being told that size isn't important and that nothing in the 'Physics' makes it so. This just isn't true. Large cones shift more air and are generally more efficient than small cones. If they are the same thickness they will be heavier and have a lower resonant frequency, if they are are thinner they will flex more and give more (but probably uneven) mids and tops. You can make a small cone reach lower down by adding mass with a thicker cone but this will reduce the higher frequencies and the efficiency. A small cone needs to move further than a large cone to produce the same absolute sound levels at low frequencies and I won't go into the problems of radiation patterns and multiple drivers. There are certain things that are easier with a 15 and other things that are easier with a 10. There are also ways round the 'problems' of designing a cab around either. There is a tendency for 15's and 10's to have similarities but no iron laws on their overall sounds which depend upon so many factors. This is why Alex said "you can't accurately group the sound of speakers by woofer size." and went on to say "doesn't matter what size speakers you use to get that sound as long as you get that sound!" He was being careful, it is not that all 15's have a 'sound' but that ultimately you need to not have preconceptions and just listen to the sound a cab makes. He was also telling you to trust your ears. Sometimes the careful, thoughtful advice gets drowned out by the categorical and though a bit of technical knowledge helps you should really trust what you hear when it comes to tone.

If your amp is 200W into 4ohms stereo it will give 400W bridged into 8. It may well also give 400W bridged into 4ohms. This is because of the power supply. Solid state amps are limited by the voltage they run at. Running them as a bridge means the voltage is effectively doubled which theoretically gives 4x the power (power is Vsquared/R). In practice asking them to provide masses of extra power demands a lot more current which could damage the output devices or more likely simply demand more than the power supply can provide. Protection circuits may cut in too. Running bridged into 4ohms is much like running an unbridged amp into 2 ohms. You might be trying to draw more power than the amp is happy with and may in extreme cases damage it. You need to check the handbook as each amp is designed differently. Generally the more expensive amps have bigger power supplies, better output devices and better protection though you don't always get what you pay for. Power supplies can always provide high currents for brief periods. This enables some manufacturers to claim greater power outputs than the amp could manage over an extended period even if they are 'RMS' values.

Just so you know. The hole in your 15 is a port and it is meant to be the thickness of the board. The hole and the air trapped in the cab act as a tuned circuit and are tuned to a frequency which matches your speakers. if you added a tube it would be tuned to a different and worse frequency. If you wanted to port your 4x12 then the port would have to have exact dimensions to tune with the volume of air in the cab to match your speakers. Ideally you would also have to change the volume of the cab to match your speakers. The magnets on your speakers don't look huge and they are probably high Q speakers not particularly suited to reflex loading (ported cabs). I'd always encourage people to experiment with building their own cabs but you aren't going to improve these with a jigsaw. Speaker design isn't rocket science, but it is a bit complicated and it does involve maths and science unless you get a ready published design. If you start hacking bits out of your cab it is going to reduce it's value and probably make it sound worse unless you are prepared to spend a few months reading up about Thiele/Small parameters. I'd start experimenting on something a bit less valuable. Cheers

[quote name='fatback' post='1306026' date='Jul 16 2011, 05:35 PM']Presumably it's the longer scale length that's allowing for the different harmonics? How does that work?[/quote] A double bass is pretty complex acoustically. The string sits on a bridge which excites a resonant chamber. Movement of the bridge will damp the movement of the strings killing some harmonics quicker than others. The front face of the bass is under a bit of tension and will have its own series of resonances and the body of the bass forms a helmholtz resonator which will again have a resonant frequency. there will also be resonances and standing waves inside the cavity which is highly reflective and probably considerable sound contributions through the back and sides. Add in the possibility that the strings could be made from nylon, gut, polyester steel or some sort of hybrid and would in any case be different in construction from most electric bass strings and you can see there are plenty of reasons for the different sounds. [quote name='Mr. Foxen' post='1306369' date='Jul 17 2011, 02:07 AM']The ratio of harmonics depends pretty heavily on the sampling point I think. As in the pickup position.[/quote] Absolutely and also the point where the string is excited/picked. [quote name='stevie' post='1306453' date='Jul 17 2011, 10:14 AM']It's not a reflex cab. It's a Helmholz resonator - it more or less says so on the drawing. It has more in common with a classical guitar than a ported cabinet.[/quote] [quote name='stevie' post='1306601' date='Jul 17 2011, 12:55 PM']A reflex cab contains a Helmholtz resonator, which is the vent, but a reflex system is more than just the vent. This design seems to rely solely on the vent to produce sound - just like blowing over a bottle. The contribution from the rear of the driver would be what you would expect from a driver in free air (or from the air blowing over a bottle)- practically nothing. I think the only reason the driver is not boxed in is because it would raise its resonant frequency. However, if you imagine this system with the driver boxed in, it starts to look very much like a bandpass system.[/quote] I love these old cab designs, I don't think the designers knew themselves how they worked half the time. Reading the article in the link about adding weighs to the tone arm to extract more subsonics and needing to protect the room from the speaker reminds me of some of the loony articles more recently written about cables in hi-fi systems. For what it is worth, to me this is an attempt to get 'free' bass from the resonace of the cavity and to couple them along the pipe. The air space between the speaker and the cab would decouple the resonator from the speaker to a fair degree so it wouldn't act as a reflex cab in the conventional sense. I wouldn't want to have to do the maths to see how much of the pressure from the speaker went into the cavity and how much straight down the 'horn'. You could equally argue that the 'horn' would act as a port for the air space and you might with the right bit of luck get the resonances to work as a coupled design. Alex is right that the back of the speaker would radiate sound in the same way as the front but it's dispersion would be interesting with the basket and magnet in the way. The 'horn' would have its own resonances and also act as an acoustic filter losing almost all the high frequencies and selectively some of the lows. The design would be very sensitive to changes in the driver and to the way it would couple with the floors and walls of the room all things the designer alludes to. I suspect this speaker would have had a large resonant hump which would have been very satisfying at a time when very few speakers had any real bass, a bit like the in car systems the kids install, but not very accurate. I picture the owner only listening to 'Zarathustra' and the intro to the Toccata and Fugue in Dm so they can hear that lovely resonance. I love Basschat.