DIY Bolton speakers

Hi !

I think that its the voice coil, mounting, input impedence and sensitivity that determine the required amp power rating and no the diameter of the drivers.

The DIY kit would specify the ratings. Anyway you could do a hit and trial to find what works the best - start with low power amp and then try higher power. Take care not to use very high volumes with high power amps.

Regards

Sanjay

It is easier to burn out a speaker/ speakers using a lower powered amp by trying to get more than what it can deliver. ie if the amp/speaker combo cannot produce sufficient sound pressure level you will try to get more output from the amp thus causing clipping of its output waveform, which is nothing but part of square wave which will burn out the HF driver faster than most hi powered amp can .

so it is always better to start with a medium powered amp something like 50w rms in case of solid state or a classic pushpull tube of about 30W.

This is quite an irritating situation for me. The speakers are around 25+ years old and my friend has long forgotten the specs of the drivers that he used in them

I asked him about the X-max and the sensitivity, but he was quite clueless. The enclosure is huge: breadth 42cm x depth 43cm x height 80cm. Wow [I was tempted to 'steal' them from him and make them into subs :)] My new neighbours would get to know me real soon

I was suggesting to him amps from Norge - 2060 80W at 4 ohms; Torvin TA300 - 80W at 4 ohms; Proton D540 dual mono - 40W; and a Luxman - 120W. Not sure of the ohms for the older amps. Besides, the truthfulness of manufacturers vary. Any other suggestions for Chennai?

I do hope that these amps will drive the speakers well. Sanjay, I think that the larger the diameter of a driver the more the surface area and the air moved. So driving these might be tough. On the other hand, the larger enclosure might make the acoustic volume and thus the sensitivity higher.

Yes ani, I would not try out amps specified lower than 40W as I know that this friend does get carried away sometimes. And a lower powered amp wouldn't hold up. BTW, how good would a Yamaha etc AV receiver be for such Bolton speakers - maybe the third model from the bottom. The entry-level stuff would be trash.

I would personally have preferred a pre-power combo like my own Pulz 60W or from Sonodyne, but his budget's a constraint (around 6K). Might not make sense to go higher for older speakers.

If those Boltons were made in 80's, than expect a power handling capacity of upto 70 watts RMS. As someone posted before, a lower power solid state amp has more potential for damage.

I used to make speakers with Bolton drivers for my friends in the 90’s. Making some extra pocket money for the bikes and booze during college days I have played around with a lot of their drivers. I would say you could use them with 60 to 80 watts per channel amps without any problems. Avoid them if you going for some serious listening. They are good as party speakers at best.

Sorry that you are far away from Chennai, Square! Otherwise, I would invite you over for some nostalgia. Yes, Peerless and Vifa make better entry-level drivers. But let's give the old dog its due. The fact that they have survived 20+ years is a tribute to good build quality and careful handling.

No two bolton drivers (of the same model) will measure the same. The T/S Parameters are very inconistent ...to make any dedicated design for them !!

BUT...they still sound much better than some of the chinese models that have become very popular these days.

I'm sure an amp like Norge combined with such speakers and a decent DVD player - will be better than most boom-boxes.

Go ahead and enjoy your Bolton project.

litte piece of advice ... try and avoid drivers more than 7" inch in size. There are practical reasons to consider. The transducers design has changed along with the change in amplification during the past couple of decades...just bcos speakers from 70s and early 80s used huge drivers (which was very much essential those days)....we don't have to, in our present day.

Cheers
Siva.

Yes. We essentially used to make them to replace the boom box speakers which came with the mini/midi combo systems. They used to sound much better and had a very high-loudness/party factor which we was what we needed those days. The finer points of audio were far away from our minds. But we used to have so much fun with those.