alexclaber

[quote name='ste_m3' post='157530' date='Mar 14 2008, 04:11 PM']Only a fool goes against Mr. Clabers Suggestions! [/quote] Ah, my mind games appear to be working. Now whilst I have control, would anyone like to give me a gig? Unfortunately our music doesn't fit into any tidy genre and we won't bully our friends to make up the numbers in the audience because they've already had a decade or two of that... Alex

[quote name='Mr. Foxen' post='157632' date='Mar 14 2008, 06:17 PM']Theres a correct answer now?[/quote] Of course, as ever posted by the infinitely wise alexclaber. To get a more detailed answer it helps to respond to the questions within the thread, like what are your 15" cabs? Alex

I've found some M5 allen head bolts that look like they'll do the trick, plus M5 T nuts. Something reassuring about allen heads when you're so close to a delicate paper cone! Alex

[quote name='andy67' post='157221' date='Mar 14 2008, 09:30 AM']Fieldy - Korn[/quote] Nu-Metal in the 80s?! Alex

Just noticed you said you like how the horn sounds - in that case definitely don't mess with it - at least 50% of the sound of a tweeter is attributable to the crossover design. Alex

The GK tweeter amp is highpassed at 5kHz which is probably a few kHz higher than the crossover in your Schroeder. If I were you I'd ask Jorg what the crossover point is because if it is as far apart as I expect then you'll probably end up with a big sonic gap between woofer and tweeter output, which rarely sounds good. Alex

[quote name='dlloyd' post='157345' date='Mar 14 2008, 12:34 PM']Middle C is fifth fret, G string unless you're taking the bass's octave transposition into account?[/quote] I don't think taking transposition into account is at all pedantic - you can't shift a note up or down an octave without significantly changing the sound of the music. Alex

[quote name='Mr. Foxen' post='157099' date='Mar 13 2008, 11:48 PM']Well that got suddenly in depth and complicated. Most useful tip I've had was 'buy a sansamp, forget backline'.[/quote] Well you should have said you'd just wanted the easy but probably incorrect answer, as opposed to the correct answer that may require engaging some brain cells. If you want to forget backline you better be playing gigs where you get seriously nice monitors. Alex

I've bought a tub of duratex like paint from Blue Aran, I think it's made by Aldcrofts. Seems to have good reviews online - we shall see how nice it turns out! Alex

Am halfway through the bracing fun and things are feeling a lot stiffer. Had one moment of confusion on the midrange sub-enclosure cutting one 45 deg angle the wrong way - doh! Slightly puzzled about the choice of bolts and t-nuts for securing the speakers - how small can I get away with? Alex

[quote name='bass_ferret' post='156435' date='Mar 13 2008, 12:30 AM']Not that I am at all interested in cabs that go down to A but I wish someone would write all this good cab/speaker stuff in the wiki.[/quote] Patience... In the meantime this is rather good: [url="http://fuzzbass.fuzzphoto.eu/"]http://fuzzbass.fuzzphoto.eu/[/url] Alex

[quote name='The Funk' post='156190' date='Mar 12 2008, 04:57 PM']So with plenty of Vd, there's a large surface area of the cone pushing air and a decent amount of movement of the cone without distortion?[/quote] Exactly! Your Acmes come out particularly well on that front. The port also contributes to moving air but across a narrow bandwidth and below the port tuning frequency the port's output and the speaker's output are out of phase which means they cancel each other out. What I've noticed happening with typical 4x10" cabs is they put the speakers in a smaller than ideal box which reduces low frequency output. By doing this they also reduce excursion, thus reducing the Xmax required to handle a given power input. They then tune the box to 40-50Hz, completely foregoing output below there but allowing the port to help the woofers out higher up in the bass region. Here's a plot of a typical neo 4x10"'s power handling. As you move left along the plot the power handling goes from being thermally limited (standard RMS rating the makers quote) to being excursion limited. Then the port starts to take over some of the air moving duties and the speaker excursion lessens, thus the power handling goes up again. Right around the port tuning frequency the power handling is again thermally limited (the speakers are barely moving at this point) and then below the tuning frequency the power handling drops very quickly (and the sensitivity drops very quickly too, so the max SPL - which is the sum of the two - really plummets). Alex

[quote name='The Funk' post='156112' date='Mar 12 2008, 03:58 PM']Ok. Sorry, I get what Xmax is but what's Sd?[/quote] It's the swept area, so the area of the cone that actually moves air (i.e. minus surround). Typically about 850cm^2 for 15", 520 for a 12" and 350 for a 10". Alex

[quote name='The Funk' post='156072' date='Mar 12 2008, 03:27 PM']Alex, when you say "specs" do you mean as quoted by AccuGroove?[/quote] Regarding the Whappo Grande, yes. It's actually a very nice speaker for adding fatness to a rig because it has plenty of Vd (Xmax x Sd) and good sensitivity and power handling down to ~50Hz but its specs really do it a disservice. From a DIY perspective it isn't such a great choice of speaker because it costs $600. But if you're going to stick it in a simple cab and then mark it up hugely, the visual and marketing impact of a 21" diameter driver is very effective indeed. Alex

It's really nice to have good cab response down to the low note fundamentals but it just isn't practical and unlikely to be audible in a typical heavy down-tuned band. In groovier genres where you have more sonic space and less SPL response to low B fundamental is very nice but I don't know of any cabs that are happy with producing 27.5Hz well - even Acmes are 6dB down at 31Hz and they go lower than any. The various AccuGroove cabs are often mentioned when people talk about deep response but even the big El Whappo is tuned to 40Hz and thus at least 10dB down at 30Hz if not more, and the Whappo Grande - impressive though it looks - is equally far off. Here's a plot comparing AccuGroove's Whappo Grande specs (the green line) with three possible modelled responses with that speaker in that cab volume: That's as big a difference as between a bass and a guitar! Alex

It can be done as the bluEQube shows. But you could just as easily run a neck and bridge pickup in parallel to get the same effect, as the phase cancellation causes a similar midrange cut - the wider the spacing, the more obvious the cut. I think that's why the J-bass pickup arrangement works SO well. With neck pickup you get a low midrange accentuated sound, with bridge pickup you get a high midrange sound and with both you get the scooped sound. Simple yet magical. Alex

What you really want is a cab with reasonable response to the A above low A - i.e. 55Hz - and good power handling in the lows (high Xmax). What 15" woofers are in your current cabs? Alex

[quote name='Happy Jack' post='155318' date='Mar 11 2008, 02:35 PM'][i]Heard It Through The Grapevine[/i] by Marvin Gaye may be better known, but the bassline on the Gladys Knight version is absolutely THE one to play.[/quote] I disagree, although the Gladys Knight version is very groovy I don't think the bassline fits the song like on the Marvin Gaye version. The vibe of the bass, groove and lyrics is so much more in sync on the latter version (which was recorded first but released second). Alex

It's a communal mass relicing session, hence the name. Alex

[quote name='BOD2' post='153398' date='Mar 7 2008, 09:20 PM']Technically that is correct, but it would mean you could only ever pair the 410 IN SERIES with another cabinet that was also unusually wired to allow a series connection. And if you forget and hook up the 410 2ohm cabinet on its own...[/quote] Also running non-identical cabs in series causes all sorts of weird frequency response problems due to their varying impedance across the frequency spectrum acting as a shifting voltage divider. Bad. Alex

RIM Custom 5 '87 Warwick Streamer (if anyone wants me to!) Avalon U5 / PLX 3002 / Custom 3015LF/6ND410 cab Alex

This sounds very cool - I like it when a custom bass is so truly customer specific! Look forward to following the progress. Alex

Spent a bit more time looking at that Beyma speaker - the different y-axis scales threw me a bit. The 6ND410 plots out usefully flatter in response and just as good off-axis (Beyma plot is 30 deg, 18sound plot is 45 deg) and when you bear in mind the reduced power compression and higher sensitivity the 6ND410 has a max output 5.4dB greater. Haven't done any physical building but have started putting together a complex number spreadsheet to design a passive crossover version of the cab. A little hard on the brain but satisfying! Alex

[quote name='synaesthesia' post='153130' date='Mar 7 2008, 03:15 PM']Look into the Beyma 605Nd. It's about 64 quid in the UK. It'll match the kappalite for sensitivity and if you are not using a tertiary driver as a tweeter, this driver pushes out quite a bit beyond 5K for a bit more than your usual midrange units before dropping off.[/quote] Ah yes, nice speaker! Not one I'd found before but seems roughly on a par with the 6ND410 for less money. Thanks! Alex

[quote name='The Funk' post='152464' date='Mar 6 2008, 04:09 PM']Ah, I get it now. If you did crack the secret of the useful small cab then you could probably go into business making them.[/quote] I have some ideas about making a non-biamp version of this cab available, plus a more compact version with less bottom and a matching extension cab (also available as a 2x15") and maybe a simple 1x15" super lightweight cab (and a coax with tweeter version of this). We'll see how this turns out first! Alex