If you hang out at places like the Gearpage.net, you will see a lot of threads about matching speakers to a tube amplifier in order to get the “best” sound. However, describing sounds in words is not easy. One man’s “harsh mids” is another man’s “cutting spank” (or such expression, lol), which makes it hard to really decipher what someone is talking about – especially when talking about amp/speaker combinations.
I thought I would try something a little more scientific to help me decide on a suitable speaker combination for my Blackstar Stage 100 head.
The Blackstar Stage 100 has many fine qualities – not least its very competitive pricing and wealth of features in a 100 watt head – but I’ve yet to really gel with it. Part of the problem is that I’ve only used it at stage volume with a Mesa Boogie Rectifier 4×12 cab, loaded with Celestion Vintage 30’s, and I suspect that the voicing of this speaker is not best suited to this amp. Gearpage buffs often talk about the Vintage 30’s mid-range hump which, perhaps, is where the problem lies. I need to get rid of the mid-range hump…
A quick look at Blackstar’s site indicates that the matching cab for this amp is their HTV 4×12, loaded with Celestion Seventy 80 drivers. Actually, Blackstar’s site says nothing of the sort; I had to do a fair bit of googling to find out which drivers, exactly, are used in this cab. Anyway, moving on… The Seventy 80 is seen as being a “budget” speaker, but a good all round performer, reasonably neutral, though some say “toppy”. Although I am sure that cost played a big part in Blackstar choosing this speaker, I also like to think that they believe the voicing of this speaker suits their amp. All very well, but I have no intention of buying another 4×12 cab.
Now, it so happens that I have a Hughes & Kettner Coreblade slant 4×12 cab loaded with Celestion Classic Lead 80 speakers. However, before I drag this down to the Phazy Cave and actually try it out, I decided to take a look Celestion’s frequency response graphs to compare the Seventy 80, Classic Lead 80 and Vintage 30. A few minutes with Photoshop to superimpose these graphs on top of each other, and voila! Let the analysis begin!
Seventy 80 vs Classic Lead 80
Yes, I know, these graphs are a little tricky to read. The darker line is the Classic Lead 80.
- Almost identical curves from 80Hz up to just above 1kHz, though the Seventy 80 has slightly more in the 300Hz to 800Hz range
- Significant difference between 1k and 1.5kHz, with the Seventy 80 having more in this crucial area
- In the crucial 150 to 4k Hz range, their frequency response profiles are surprisingly close
- Virtually identical dip at 1.5kHz
- Classic Lead 80 has a few more dBs from 1.5kHz up, but graph lines are pretty consistent in terms of their ups and downs all the way up to about 6kHz
Seventy 80 vs Classic Lead 80 vs Vintage 30
Again, the darkest line is the Classic Lead 80. The Vintage 30’s line is the one that deviates most from the other two.
- I admit, this graph is not easy to read, but the line that diverges most from the other two is the Vintage 30
- The difference in mid-range of the Vintage 30 is quite apparent, even from below 1kHz
- Quite a marked difference between the Vintage 30 and the other two in the 3kHz range
Don’t take this exercise too seriously. These speakers have different sensitivity ratings, so the lines will never match exactly on the graphs. However, I think it is clear that the Seventy 80 and Classic Lead 80 are more akin to each other than they are to the Vintage 30. This bodes well for the Classic Lead 80 being a good choice to get close to the voicing combination that Blackstar’s designers have chosen.
So, there’s only one thing for it: try out the Coreblade cab with the Stage 100 and see if it sounds good. Whilst I’m at it, I will also do a side by side comparison with the Vintage 30 loaded Mesa cab. To be continued…