[killertofu]

I inherited a pair of HPM-60 from my father and did some minor repairs to them to bring them back to life. Several years ago, the 10" woofers dried out and were removed so I purchased a pair of Dayton Audio SD270A-88's to replace them. Unfortunately since I haven't heard the original woofers, I can't compare the two. The Daytons work well in my opinion but the speakers lack low end.
 
Anyways, I am confused as to why these woofers do now provide much low end! I figured since the speakers were 10's and had a starting frequency of 26hz, that they'd be able to provide more than enough bass.
 
Can someone school me on audio physics and how to get more bass out of these units, if it's even possible? I figured it might be because the boxes are ported, or that I might have bought the wrong woofers. I do not want to do any mods to the units besides possibly replacing the Daytons with better drivers.

 

[cifani090]

Try the "Vintage Speaker Thread".

 

[killertofu]

I noticed that thread but figured it was primarily used for members showing their equipment. I'll cross-post to see if I get a response.

 

[Edgar Wagner]

Dear Readers,
 
I made a pair HPM 60 speakers 30 years ago. But I replaced the high speakers to Vifa DX25TG-09-04  the mid speakers to HIVI DMB-A. Very good sound. The HPM super tweers has impedance matchig transformer, I don't how can I make this transformer.
1:8 the coil rate in 12kHz. 
Regard, Edgar
 

The HPM super tweeter