Upgrade my 1x10" ported combo to 1x15" sealed?

[Bigwan]

I'm having one of my crazy ideas again. I have an Ashdown ABM C110, loaded with a celestion bg10-150. Sounds fine at low volumes, but isn't going to set the world alight on its own.

I've been considering replacing the speaker for years, and while perusing the eminence site the other day I noticed that the box volume (about 1.7 cu ft) would just suit the Eminence BP1525 if it were sealed. It wouldn't offer a particularly deep low end, or a particularly extended high end for that matter, but I'm after out and out volume from the combo at this point. Thoughts?

Have I gone mad

Edited January 8, 2017 by Bigwan

[Phil Starr]

You only have one way of finding out!


The volume you have calculated I suspect is the external volume, I haven't exact figures but i think the internal volume is nearer 1.5 cu ft. That's right at the bottom of the Eminence recommended volume, it would improve power handling over the bigger box but would show a rising response down to 120Hz then falling at 12dB/octave after that. Little deep bass then but some nice solid punch. As to how loud it would be I haven't enough detail of the original speaker to say if it would be louder or not. A lot of that will be down to how it handles mids. The legend isn't mega sensitive but it does have a rise in response at 1-2kHz which will make it shout out a little. You'll have an old school smiley face response with little real top or bottom. If you don't like the sound you could always build a bigger box or sell the Legend on and get some of your money back. Mildly eccentric rather than mad

[Bigwan]

I took combo dims and took off 1.5" from width, 3" from depth and 5" from height which left me with 1.728 cut ft, but when you account for the volume of the eminence it'd probably be down there right enough!

[Bill Fitzmaurice]

What does a comparative modeling of the two show you? Yes, the BP1525 will deliver a good low end in a sealed cab...if it's at least 4 cubic feet.

[Bigwan]

Can't find TS parameters for the Celestion, Bill. Modelling the BP1525 would tell me what I already know, it won't do LOW, but if it did low enough (i.e.the same as the current speaker does) but louder I'd be happy.

[Balcro]

Looks like you'll get there, but more by luck than judgement!

See here,
http://www.eminence.com/pdf/Legend_BP1525_cab.pdf

and scroll down to pages 19-21. It's loud, but....


Balcro.

[Bigwan]

[quote name='Balcro' timestamp='1483923921' post='3211211']
Looks like you'll get there, but more by luck than judgement!

See here,
[url="http://www.eminence.com/pdf/Legend_BP1525_cab.pdf"]http://www.eminence...._BP1525_cab.pdf[/url]

and scroll down to pages 19-21. It's loud, but....


Balcro.
[/quote]

Yeah I'd seen that - that's the doc that initially got me thinking about this. I might suck it and see... As Phil suggests I could build another cab if the combo proves too bass shy - Kringle77 on that other bass forum has built a pair of cabs using these and a sealed 6" midrange driver that I'd be interested in trying out too.

Edited January 9, 2017 by Bigwan

[Phil Starr]

[quote name='Balcro' timestamp='1483923921' post='3211211']
Looks like you'll get there, but more by luck than judgement!

See here,
[url="http://www.eminence.com/pdf/Legend_BP1525_cab.pdf"]http://www.eminence...._BP1525_cab.pdf[/url]

and scroll down to pages 19-21. It's loud, but....


Balcro.
[/quote]

I'd assumed Bigwan got the idea from the Eminence site. You can see what the bass response would be from the Eminence modelling. There are certainly cabs out there with this sort of response you might like it, you might not. Celestion will send you the TS parameters for their speakers usually if you email them, use the ask Dr Decibel service on their site. If it's something they only ever made for Ashdown you may need to go to Ashdown for the info though.

I'd think about whether to look at other speakers at a similar price though, it's at the top end of what you could squeeze into a box that size and it might be that another 10 or a 12 would give you more sensitivity without the loss of bass. The Eminence Deltalite 12 is a similar price for example and would match your cab well.

[Bigwan]

[quote name='Phil Starr' timestamp='1483952317' post='3211279']
I'd assumed Bigwan got the idea from the Eminence site. You can see what the bass response would be from the Eminence modelling. There are certainly cabs out there with this sort of response you might like it, you might not. Celestion will send you the TS parameters for their speakers usually if you email them, use the ask Dr Decibel service on their site. If it's something they only ever made for Ashdown you may need to go to Ashdown for the info though.

I'd think about whether to look at other speakers at a similar price though, it's at the top end of what you could squeeze into a box that size and it might be that another 10 or a 12 would give you more sensitivity without the loss of bass. The Eminence Deltalite 12 is a similar price for example and would match your cab well.
[/quote]

That's a good call Phil. I should really have asked what the best replacement driver would be for the given volume of cab I suppose, but I just had that driver in my head at the time! That Deltalite 12 does look pretty good.

[Phil Starr]

The 15 you chose is perfectly good if that's the bass response you want, but it's towards one end of the spectrum.

Are you happy using winISD? if so then model them both in your box and you can directly compare them. The Deltalite would work as a ported cab at that volume too giving you a bit of extra bass lower down, you might want to look at the Beyma SM212 as well.

If not one of us will model it for you.

[Bigwan]

I've had a quick go with winISD just now. Not entirely sure I'm using it correctly.

I've put in the TS parameters for the BP1525, the Deltalite 12 and the deltalite 10 and modelled the 15 sealed next the 12 sealed and vented and the 10 vented. The 12 vented gives a similar drop off to the sealed 15, but without the boost in the 120Hz region. But looking at the SPL chart it would seem the 12 would be a better bet... Would that sound about right?

I'll try the Beyma SM212 now

[Bigwan]

Beyma looks pretty good too.

[Bill Fitzmaurice]

The vented 2512 should be about 2dB more sensitive in the lows than the sealed BP1525, without the hump that causes boom, giving it the advantage unless you have more than 250w on tap. Then the higher Vd of the 1525 gives higher output, though you'd need a way to contend with that boom, such as a parametric EQ. I don't care for the SM212, or for that matter most European offerings, as they lack a rising response into the midrange. That's OK crossed over at less than 2kHz to a midrange driver, but IMO only then.

[Phil Starr]

[quote name='Bill Fitzmaurice' timestamp='1483978441' post='3211629']
The vented 2512 should be about 2dB more sensitive in the lows than the sealed BP1525, without the hump that causes boom, giving it the advantage unless you have more than 250w on tap. Then the higher Vd of the 1525 gives higher output, though you'd need a way to contend with that boom, such as a parametric EQ. I don't care for the SM212, or for that matter most European offerings, as they lack a rising response into the midrange. That's OK crossed over at less than 2kHz to a midrange driver, but IMO only then.
[/quote]

That's all useful comment. The SM212 does lack the usual midrange peak and has a rather neutral tone, it wasn't really designed for bass guitar but as the bottom end of a PA speaker. It is a great cheaper option over here though, I use mine exclusively at the moment, they work best with a graphic where you can boost the frequencies you want and it was way easier to get a good tone out of my Hartke 3500 than it is with my MB Tube500. If you did want a cheaper option the Beta 12A-2 would work. All in all the Deltalite would be my personal choice.