DukeL

Thanks, John and Bert... yes, someone has already purchased the compression drivers for me, and is shipping them to me.

[quote name='BassTractor' timestamp='1349042529' post='1821134'] I'm sorry to read that they're crossover-intensive, coz I suppose that that means the crossover gets more complicated than wished for. If it indeed does mean that, I can see how you would fight against the demon of declining sound quality.... BTW, and unrelated but fun: a buddy of my uncle was a fanatic speaker builder. He had his stereo in the basement, with horn speakers starting there, but ending in the living room. So he'd put on a vinyl record downstairs, set the volume, and run upstairs to enjoy the music in his comfy chair. I loved it, but wouldn't want it.[/quote] Well the things I like to do really can't be done well with a simple crossover; I like to use constant-directivity PA-style horns, and such horns call for a somewhat complex crossover and often some additional equalization, but the payoff is fairly uniform sound across a fairly broad horizontal arc. No sound quality issues if I do my job well. The main drawback, in my opinion, is the added cost of the crossover. For a while I was selling cabs whose crossover components cost more than the woofer, until the price of neodymium went up enough that the woofer now costs more. So my cabs tend to be relatively expensive, but they can double as home audio speakers or studio monitors, if you can get past the utilitarian looks. Love the story of your uncle's friend's system! That beats anything I've ever heard of!! I'm still a dealer for a high-end home audio electrostatic speaker that's bigger than a door, but at least with those speakers you can still have everything in the same room!

Too bad if that beast is no more. My background is home audio speaker-builder hobbyist since 1979. In 1999 I became a dealer, and then in 2005 a speaker manufacturer. [Darth Vader voice] "And now my journey to the dark side is... complete." [/Darth Vader voice] Then a couple of years ago the US economy tanked, and "expensive toys" (like home audio speakers) got very hard to sell. So I looked around for other possible opportunities, and it occurred to me that a bass guitar cab is a "tool of the trade", and therefore falls into a very different category. A serious worker will still buy a good tool of the trade even in a weak economy, so I've been building bass cabs since roughly mid-2010, My bass cab designs tend to be somewhat unorthodox and crossover-intensive, for better or for worse, so that's why my virtual ears pricked up at your mention of the word.

[quote name='Musicman20' timestamp='1348999604' post='1820426'] Nice to see you over here Duke...welcome! The new 2x12 looks fantastic. [/quote] Thank you, Musicman20! For some reason, your avatar makes me want to take evasive action... [quote name='JapanAxe' timestamp='1349007856' post='1820551'] +1 to smaller manufacturers chipping in on this forum. The opportunity to chew the fat with the players (like Fender's reps did in the 50s) far outweighs any concerns about product-pushing imo. [/quote] Thank you! I don't think I'm a pushy salesman type, but one seldom knows how one comes across until it's too late, so please thump me on the head if I start to go too far.

[quote name='warwickhunt' timestamp='1329667357' post='1545539'] I was under the impression that scientifically it makes no difference if a cab is front or rear ported with regard to placement; a ported cab acts like a ported cab no matter where the port is. Sound doesn't come out of the ports so front or back is immaterial... a cab should be correctly tuned no matter where the port is! [/quote] Well very low-frequency sound does come out of the port, at and near the tuning frequency, but in general I agree with you. I also think there can be small but audible differences in how the cab interacts with the room at low frequencies based on where the low frequency sources (woofer cones and ports) are relative to the room boundaries, but if anything I think a rear-ported cab might have a slight advantage in this area. You see, if the woofer cone and port each have a different path length to the reflective wall behind the cab, they will each interact with the room's modes a bit differently, which tends to reduce the magnitude of reflection-induced peaks and dips. Also, if the ports are right behind the woofer cone, you get some midrange energy radiating out the ports. In my opinion this can be a good thing - for example, if your drummer is behind the cab, this can make it a little bit easier for him to tell what notes you're playing. Front-ported cabs can have more apparent impact if you are standing very close to the cab. This is because, at very close range, the path length around the cab to the rear port is significantly longer than the path length to the woofer cones, and because sound pressure level theoretically falls off by 6 dB for each doubling of distance, the sound from the front of the cone is louder at close range than the sound from the rear-firing port. But by the time you get out into the audience area, the difference is negligible. More important than where the port is located, though, is how well the system is designed. Port location can play a minor role in the design, but in general other things make more of a difference.

Great to see how much attention my little Thunderchlid cab has generated here! Now if only that attention had been [i]positive[/i] instead of [i]negative[/i]... alas, we can't have it all, can we?? There's a method behind the madness of that big PA-style horn. You see, what I'm doing is radiation pattern matching in the crossover region. Let me explain: The dispersion of a cone driver narrows as we go up in frequency, and big cones can be quite beamy at high frequencies (case in point: The on-axis icepick effect of many guitar cabs). So I'm crossing over to a 90-degree constant-directivity horn at the frequency where the woofer's radiation pattern has narrowed to roughly 90 degrees. If I do this well, you won't be able to hear any transition in the crossover region. If I do it poorly, than we have a crappy-sounding cab that's ugly too. Radiation pattern matching in the crossover region is hardly a new concept, people have been doing it in PA cabs for decades, and I was doing it in the home audio market for years before getting into bass cabs. The advantage is that it makes the sound more uniform throughout the audience area. One hopes that said relatively uniform sound is pleasing rather than painful, of course, and that's where crossover design plays a big role (to be more specific, that's where [i]equalization[/i] plays a big role, equalization being one of the jobs of the crossover). My hope is to broaden the choices open to bass players, and along the way I've been fortunate enough to have a backlog of orders ever since I launched my first bass cab in 2010. Bass players have treated me very well.

[quote name='pete.young' timestamp='1344533072' post='1766144'] The Hartke is unusual in having two sets of voice coils, one at 4Ohm the other at 8Ohm. There aren't many others like it on the market. [/quote] I didn't know Hartke did that. I didn't know [i]anybody[/i] did that. Imo, switching between two different voice coils is the only right way to make a cab switchable between 4 and 8 ohms. There is a [i]sligh[/i]t efficiency penalty from the additional moving mass of the inactive coil, but it's still imo a better solution than using resistors or transformers. I tip my virtual hat to Hartke. Well done!

[quote name='Mr. Foxen' timestamp='1347056746' post='1796667'] You'll have to feed the Legend CA154 about twice the power to get the same volume as the Delta 15A, and it takes less power to break the Legend. [/quote] The modest 2.7mm x-max of the Delta 15A means that it will go into fartout long before the Legend CA154. The theoretical difference is sustantial, about 5 dB. If the limiting factor in this application is thermal power handling (unlikely) or amplifier power (possible if we're talking low-powered valve amps), then the Delta 15A will play louder. If the limiting factor is fartout, which is more likely the case, then the Legend CA154 will play louder. If the Legend CB158 is within budget, might be worth looking at - good combination of efficiency and excursion in a midpriced 8-ohm ceramic magnet woofer.

Hi BassTractor, Thanks for the welcome! Cool avatar - we have some big tractors around where I live, but nothing quite like that! Are you really into crossover design? That's usually what separates the enthusiastic weekend DIYer from the serious semi-pro. We have ready access to modelling programs that make good enclosure design fairly accessible, but the crossover is usually more difficult to get right... modelling programs can't do it for us. Think I'll go poke around on the amps & cabs forum a bit, that's sounds like my kinda place.

Testing one two... Okay, hello everybody, my name is Duke and I'm from the US... specifically, a little town called Preston, Idaho (celebrated home of Napoleon Dynamite). Anyway, I could use some help. I'm trying to buy a pair of compression drivers that are sold out in the US and won't be available for a while, and none of the European vendors will ship to me. I actually have a case of these drivers on order (I'm a small bass cab manufacturer), but it may be a couple of months before they arrive, and it would be really helpful if I could get a pair sooner rather than later so that I can get started on crossover designs. I think I can purchase the drivers from a vendor in the UK and have them shipped to you, and then would pay you a commission + shipping to send them on to me. Anyone interested, shoot me an e-mail at [email="[email protected]"][email protected][/email]. EDIT: Someone came to my aid and has purchased the compression drivers for me. Thank you, Bill.