Compact - continuous power rating

[dincz]

Just to satisfy my curiosity, have I got this right?

The Compact has a broadband sensitivity of 100dB, meaning 1W of input power produces a SPL of 100dB at a distance of 1 metre.

The maximum continuous broadband SPL is 126.5dB, i.e. 26.5dB (447 times) more than is produced at 1W.

Does this mean that the maximum continuous power rating is around 450W?

[alexclaber]

Yes! See the chart here: [url="http://basschat.co.uk/index.php?s=&showtopic=106090&view=findpost&p=989810"]http://basschat.co.uk/index.php?s=&sho...st&p=989810[/url]

Note that with clean bass guitar you'll struggle to reach 450W continuous without amp clipping with amps of less than 1800W RMS output. With heavily distorted and compressed bass guitar you could hit that 450W level with a clipping 450W amp but that would take some doing! I haven't figured in power compression just as I've ignored peak output, as whilst the one hand taketh the other giveth back.

[dincz]

[quote name='alexclaber' post='1000478' date='Oct 25 2010, 09:56 PM']Yes! See the chart here: [url="http://basschat.co.uk/index.php?s=&showtopic=106090&view=findpost&p=989810"]http://basschat.co.uk/index.php?s=&sho...st&p=989810[/url]

Note that with clean bass guitar you'll struggle to reach 450W continuous without amp clipping with amps of less than 1800W RMS output. With heavily distorted and compressed bass guitar you could hit that 450W level with a clipping 450W amp but that would take some doing! I haven't figured in power compression just as I've ignored peak output, as whilst the one hand taketh the other giveth back.[/quote]

Thanks for that Alex. Looks like I'll be safe with my current amp - even if I take to bowing - that's as in Boeing rather than meeting royals.

And what's the significance of the 450/1800 ratio?

Edited October 25, 2010 by dincz

[alexclaber]

[quote name='dincz' post='1000547' date='Oct 25 2010, 09:55 PM']And what's the significance of the 450/1800 ratio?[/quote]

6dB - standard AES thermal power handling test crest factor.

[dincz]

Applying the same logic to Aguilar's new SL112, something doesn't quite add up:

Specs
Power Handling: 250 watts RMS, 500 watts peak
Sensitivity: 99.9 dB 1W 1M
Max SPL: 120db

It looks like 100W should give you the cab's max SPL. What have I missed?

[Alien]

[quote name='dincz' post='1012407' date='Nov 4 2010, 06:46 PM']Applying the same logic to Aguilar's new SL112, something doesn't quite add up:

Specs
Power Handling: 250 watts RMS, 500 watts peak
Sensitivity: 99.9 dB 1W 1M
Max SPL: 120db

It looks like 100W should give you the cab's max SPL. What have I missed?[/quote]

The fact that the driver will run out of excursion before it runs out of power handling. They've probably factored some power compression into that as well, but most speakers reach a point where they just don't get any louder as you add more power.

A

[dincz]

[quote name='Alien' post='1013430' date='Nov 5 2010, 04:44 PM']The fact that the driver will run out of excursion before it runs out of power handling. They've probably factored some power compression into that as well, but most speakers reach a point where they just don't get any louder as you add more power.

A[/quote]

Ok, thanks. That makes sense. But is it usual or even common for a speaker to run out of excursion so far short of its thermal limit?

[markstuk]

Depending on the frequency, very much so..

[quote name='dincz' post='1013578' date='Nov 5 2010, 06:19 PM']Ok, thanks. That makes sense. But is it usual or even common for a speaker to run out of excursion so far short of its thermal limit?[/quote]

[dincz]

[quote name='markstuk' post='1013624' date='Nov 5 2010, 07:52 PM']Depending on the frequency, very much so..[/quote]

The BF Compact would appear to be a bit of a freak in that respect then.

[markstuk]

Or Alex uses expensive drivers with large XMAX's.... :-)

[dincz]

Would it be fair to sum up that the Aguilar is clean only up to 100W and that from there on it's more effective as a heater than as a speaker? Probably absolutely fine for anyone who's looking for dirt, but I can't help feeling that the specs are a little misleading.

All academic anyway as I recently bought a Compact and am only indulging in post-purchase justification.

[warwickhunt]

Driver/cab specs are so often misguided/misquoted that I tend to take no notice of any of them; saying that I'd not blind buy just any old cab.

If you break down the specs on just about any driver/cab you'll find that very little adds up. Though I've no experience with the new SL cabs from Aguilar, I do have a pair of the DB12 cabs and despite the fact that I'm sure that you could pull the design and/or spec apart and show that they are only rated at 100w and their limits can be met way before the quoted specs; they work for me, in my band setting, with my amp and cab, played with my fingers, listened to with my ears... ultimately that is all that matters!

[alexclaber]

I think that pretty much sums it up! There are lots of nice 1x12"s out there but very few that can handle LOUD gigs on their own. Add a second and you get 6dB more max SPL which is a lot. Alternatively use much more expensive drivers and you can end up with a 1x12" that is closer to two normal 1x12"s in max SPL, than it is to one common or garden 112. This does make it a lot harder to make it light because you're using a much heavier driver, which increases the cost further, but such is life...

[url="http://barefacedbass.com/uploads/Barefaced%20Specs%20Oct%202010.jpg"]Barefaced Specs[/url]

Note that the LF sensitivity is almost entirely proportional to the size of the cab - but deepen the response (i.e. lower the F3, F6 and F10) and you lose LF sensitivity unless you increase the enclosure size. So regardless of your budget, any cab that isn't boomy (you can cheat a bass cab louder in the true lows by making it under-damped but that's not good for tone) will be tied to the same LF sensitivity and roll-off points for a given size. So from that you can probably guess that the Aguilar sensitivity spec isn't a LF sensitivity one!

[Mr. Foxen]

[quote name='dincz' post='1014078' date='Nov 6 2010, 10:57 AM']Would it be fair to sum up that the Aguilar is clean only up to 100W and that from there on it's more effective as a heater than as a speaker? Probably absolutely fine for anyone who's looking for dirt, but I can't help feeling that the specs are a little misleading.[/quote]

Thing to remember is that your amp power rating is similarly misleading, a 500w amps will very rarely be outputting 500w into your cab whilst you are playing, so it won't be an issue most of the time. People looking for dirt don't generally favour 1x12s either. Dopesn't matter how clever your cabs get, more is still more. And more is Doom.

[alexclaber]

Is it that amp power is misleading or is it that most bassists don't realise that you only get full power just before your amp clips? And if you're playing in a loud band, using a smaller cab and don't have thousands of watts you will frequently hit full power on the attack of louder notes.

[Mr. Foxen]

[quote name='alexclaber' post='1019483' date='Nov 10 2010, 10:55 PM']Is it that amp power is misleading or is it that most bassists don't realise that you only get full power just before your amp clips? And if you're playing in a loud band, using a smaller cab and don't have thousands of watts you will frequently hit full power on the attack of louder notes.[/quote]

Bassists are mislead, or wrong-headed, put the blame where you will, about how much power is coming from their amp as soon as its plugged into a cab. Also, I would like to point out for the record that the second part of this statement is in no way directed at me, I do not have a small cab, or a lack of watts.

[BassBod]

Well, I've got a dirty 12" midget....but I wouldn't use it in a public place. I think that Nick must be a bad influence.