I need to replace the drivers in an old Peavey 210TX and the stock drivers are getting hard to find at a reasonable price. So I'm looking at some drivers out of a BAM 210 (Peavey 70777213, Eminence 101208) and I have the t/s on them (from a 24 year old post.) I'm thinking if I can get the parameters of the Model 121 (Peavey 96000296, 96000067) and compare them, I might be able to figure out if this is going to work before throwing any money at it. But I have had no luck so far. Peavey has not replied, and my email to Eminence was rejected by bcspeakers.com I guess because they're on holiday or something, who knows. Any light that can be shed on this situation will be greatly appreciated.
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Trying to find t/s parameters on Peavey Model 121
- Thread starter Oldenphat
- Start date
- Feb 12, 2006
- 61,075
- 5
- 221,153
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
At this point, you will probably have better luck doing the math and seeing what drivers might be a good choice.
You might also think through how much you are willing to spend on an amp with very limited resale value. It won't be hard to spend more than it's worth.
You might also think through how much you are willing to spend on an amp with very limited resale value. It won't be hard to spend more than it's worth.
Thank you, sir, for your sage advice. My bad, I forgot to mention the 210TX is just a cab, not the combo. I can recoup the cost of the replacement drivers by selling the Kappa Pro 10A's that came in it. (You helped me out on that a couple of weeks ago.) Too heavy, and my understanding is that they don't have good bottom end response. The rough calculations that I have done seem to indicate that the 210TX enclosure is too small for the BAM's drivers but I was hoping to get some verification - up or down, by looking at the parameters of the stock speakers. I appreciate your response, and BTW, I do have a GBE 400 that they will have to pry from my cold dead hands. Keep up the good work.
- Feb 12, 2006
- 61,075
- 5
- 221,153
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
Yes, I am very cautious about over investing, but to paraphrase Freewheelin' Franklin, "Peavey will get you through times of no money better than money will get you through times of no Peavey." Stay safe out there.
OK, here's what I got:
Some of my measurements are precise, others are estimated, like on things would be difficult to measure precisely, like the volume of the throat of the horn, etc. But I got as close as I could.
The 210TX cab has a raw volume of 77.28 L. The rear port has a diameter of 3.75", total length of 3.75" and protrudes 3" into the interior space. If you take out all the little protrusions like tweeter driver, crossover, the little interior wall, and the handles protruding into the space, you get a net volume of right at 75 L. And there is aftermarket batting of blanket like material about a quarter inch thick. For two drivers that would be 37.5 L each. The Vas of each BAM driver is 49.21 L. My (limited) understanding is that this means the BAMs need more space than what the box can give them.
BAM 210 Peavey 70777213 t/s parameters
RE OHMS 6.10
FS HZ 46.88
LE MH 1.12
MMS GMS 39.10
QM 7.63
CMS mm/N .2946
QE .460
RMS NS/M 1.5097
QT .440
VAS LTRS 49.21
XMAX MM 4.00
SD SCM 344.88
BL TM 12.34
EBP 101.6
EFF % 1.06
SPL dB 92.2
Wattage 150rms
Some of my measurements are precise, others are estimated, like on things would be difficult to measure precisely, like the volume of the throat of the horn, etc. But I got as close as I could.
The 210TX cab has a raw volume of 77.28 L. The rear port has a diameter of 3.75", total length of 3.75" and protrudes 3" into the interior space. If you take out all the little protrusions like tweeter driver, crossover, the little interior wall, and the handles protruding into the space, you get a net volume of right at 75 L. And there is aftermarket batting of blanket like material about a quarter inch thick. For two drivers that would be 37.5 L each. The Vas of each BAM driver is 49.21 L. My (limited) understanding is that this means the BAMs need more space than what the box can give them.
BAM 210 Peavey 70777213 t/s parameters
RE OHMS 6.10
FS HZ 46.88
LE MH 1.12
MMS GMS 39.10
QM 7.63
CMS mm/N .2946
QE .460
RMS NS/M 1.5097
QT .440
VAS LTRS 49.21
XMAX MM 4.00
SD SCM 344.88
BL TM 12.34
EBP 101.6
EFF % 1.06
SPL dB 92.2
Wattage 150rms
- Feb 12, 2006
- 61,075
- 5
- 221,153
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
- Feb 12, 2006
- 61,075
- 5
- 221,153
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
Ran the numbers and actually it works quite well at 200 watts or less if you remove the port and just use the 3/4" thickness of the enclosure.
The yellow plot is the 3/4" deep port, orange is 1-1/2" deep and red is the existing port depth:
Now, if you would like to increase the power handling slightly (to between 250 and 300 watts), you could double up on the existing port. The FR plot is almost identical to the yellow plot but the port air velocity is no longer the limiting factor.
The VAS is plenty fine for this application.
The yellow plot is the 3/4" deep port, orange is 1-1/2" deep and red is the existing port depth:
Now, if you would like to increase the power handling slightly (to between 250 and 300 watts), you could double up on the existing port. The FR plot is almost identical to the yellow plot but the port air velocity is no longer the limiting factor.
The VAS is plenty fine for this application.
Very cool. I think I'll probably just leave the port in place for now in case I find some original Model 121's to go in there, but it's good to know the 70777213's will work and work even better with a slight modification.
You are much appreciated, sir!
You are much appreciated, sir!
