• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Advice on finding the right driver for a combo - the right way.

BobbyPoulton

BobbyPoulton

Jan 14, 2013
47
96
Brisbane, Australia
#1
I know this is putting the cart before the horse, but I already have the cart and may need a new horse.

I recently purchased a second-hand Ashdown ABM C115, which someone had "upgraded" the speaker. I'm not too sure about how that speaker works in the pre-existing enclosure.

So I'm wondering, what measurements do I need to take of the enclosure, and then are there any tools useful that would help to find the right speaker? I'm a Mac user, so WinISD is not going to work for me. I'm guessing that a need the internal measurements, the port diameters and lengths? Anything else?

Any wisdom is greatly appreciated.
 
#2
There are the external dimensions of the speaker enclosure:
610 W x 475 H x 335 D
Wood is 18mm.
There are 2 rear ports, both 75mm diameter and 110mm deep.

If I'm calculating correctly, taking into consideration the speaker baffle being recessed, the volume is approximately 81 litres or 2.8 cubic feet.
 
#3
That's a good volume for many 15" drivers. Ports at 3" dia x 4.5" deep are also in the ballpark.

What driver do you have in it now?
 
#5
That's not bad, -3dB at 60Hz and -10dB at 40Hz with an average sensitivity of around 99.5dB/1W/1M

The challenge is that you are displacement limited to a little less that 200 watts around 65-80Hz.

If the speaker were capable of handling more that 200 watts, I would recommend larger ports and then make them deeper as the air velocity in the ports is a little fast (but not the end of the world)

You "could" shorten the ports a bit to increase the box tuning frequency and improve the displacement limited power handling, but I wouldn't as what you have will probably sound better until you hit 200 watts.

This is just the limitations of this driver in this sized box, which is a little bit large. Make the box smaller (say 2 cubic ft) and the power handling goes up, but so do the -3dB and -10dB numbers so it's hard to win this battle.

This is why as a designer, I will look closely at the drivers and the box together. The greatest driver in the world for a 4 CF box may be a terribly choice for a 2CF box, then is has to have reasonable mid voicing, good power handling, good LF extension, etc. Having access to customized drivers can get more performance if there's not an acceptable off the shelf solution.
 
  • Like
Reactions: pcake, AstroSonic, dralionux and 6 others
#6
Thanks for the info, that's great. It's encouraging that it is "not too bad".

Is there an online tool or something that I can punch in the measurements to find a speaker that will better suit my particular requirements?

Or is there an easy way to compare speaker models with pre determined enclosure and port measurements?

I know, I know... the cart is before the horse.
 
#9
What does the current driver not do what you wished it did.
There is drivers that will take more power but efficiency drops. And high-end clarity is greatly reduced. If your looking for more volume. Eventually you just have to double the effective speaker area.
The cast frame kappa and Delta is about as good as it gets for ceramic drivers. There is more mid forward vintage drivers. But power handling is less and trade-off is different tone which preference is more individual to the end user.
 
Last edited:
#12
I had a similar experience with a C110-300. I replaced the original 10" driver with a Deltalite that didn't last. I emailed Ashdown for a recommendation. They suggested a Beta 10 and I'm pretty happy with it. You can check with Ashdown but Andy will not steer you wrong.
 
#18
BobbyPoulton said:
My main rig is a Hartke LH1000 and a Hydrive 410 and 115, sometimes I just take out the 115. It has always worked great!
What I have NEVER gotten to work for me is any class D amp of any power, even 1000 watt models.
Click to expand...
Well that's too bad, perhaps you just haven't found the right one?
 
  • Like
Reactions: BobbyPoulton
#19
I'd really like to find one that works for me... The big heavy stuff is not great for the back of a working player. I've tried heaps of MarkBass models, the Aguilar Tone Hammers, the Warwick LWA's, the Fender Rumbles and Bassman 800...
The big problem I have is they just don't feel right. They don't seem to have transient power. Great for smoother styles of playing, but not for my needs.

Anything you can recommend?
 
#20
Ok so I've been doing some reading, got WinISD to work through Wine, and am now reading up on how to use it :)


agedhorse said:
That's not bad, -3dB at 60Hz and -10dB at 40Hz with an average sensitivity of around 99.5dB/1W/1M

The challenge is that you are displacement limited to a little less that 200 watts around 65-80Hz.
Click to expand...

Is this something inherent to the existing enclosure, or the speaker?
 
  • Like
Reactions: Rody

Latest posts

Top Bottom
Back