Hi-Fi driver .vs. Instrument Driver

[38eighteen]

Hi,

I have been reading a bit and planning to build a Guitar amp for my son.

One thing that seems to come up a bit is driver selection and people wanting to use Hi-Fi type drivers for their guitar amp. I am also in this position - I have a couple of old 12" drivers that I thought might be OK to get started with and then upgrade later - but I now think this is wrong.

But, is using Hi-Fi drivers such a problem if I am building a chip based amp rather than tube? I am starting to understand how electric guitar is all about distortion etc. But, if I am building something from runoffgroove or tonepad as a pre and feeding that through a LM3886 isn't all the distortion being simulated in the pre? Therefore, shouldn't the power amp and the driver reproduce the signal from the pre-amp and a pretty linear manner??

If so, then wouldn't a Hi-Fi driver (and even a Hi-Fi tuned cab) be more appropriate?

Thanks,

Brian

[Graydon]

You can do it that way because with many of hte modern effects devices, the distortion sounds are indeed generated inside the device. There is a big difference however between simulated distortion and real distortion. Some of the new solid state devices do a decent job of it but still, I haven't yet heard one that I could live with. You really do need tubes to generate the distortion and you need low powered speakers designed for guitar to add to the distortion. If you try to get these sounds out of hi-fi equipment, it always sounds bad because hifi equipment is designed not to distort. So, when you force it to distort, it does so in a distasteful way. Equipment that is built for guitar is designed with the distortion factored in right from the beginning and so when it does its thing, it sounds great.

I highly recommend you investigate some of the tube amp projects such as the AX84 site or www.18watt.com (which is obviously my favourite. Or at least it will become obvious if you check out my site.)

I also hold strongly to the belief that it is far more important to have a great amp and a good guitar than a great guitar through a merely good amp. I can play a cheap guitar as long as it is through a great amp. The sound will be great. If I play a $10,000 guitar through a cheap amp it will sound awful.

HTH

[Brett]

Use MI, or some old 'console' 10 or 12" drivers can be very good. I've used old Isophon, Magnavox and Plessey drivers to good effect. Not saying as good as dedicated MI units, but very nice and different.

[sreten]

Hi,

Dedicated hifi bass units for multiway speakers simply will not do,
though as stated any 12" attempting full range, high efficiency
and no real attempt at low bass will likely be pretty good.

Any real hifi 12" bass unit will be useless, unless its JBL old school style.

/sreten.

[38eighteen]

Originally posted by sreten
...12" attempting full range

Ah yes, this is the bit I had lost sight of when I decided to post my question - the 12" drivers I have are from 3-way speakers. They are not (I assume) anywhere near full-range.

I know there is another thread about what range a guitar produces - I'm off to re-read that.

I have been experimenting with some software called ARTA so I also plan to try to measure the range of my 12". I don't expect to be able to use them - it will be a learning exercise.

Thanks,

Brian

[Brett]

Brian, FYI.
http://www.aikenamps.com/Marshall4x12response.htm

[vangelis]

Originally posted by 38eighteen


Ah yes, this is the bit I had lost sight of when I decided to post my question - the 12" drivers I have are from 3-way speakers. They are not (I assume) anywhere near full-range.

I know there is another thread about what range a guitar produces - I'm off to re-read that.

I have been experimenting with some software called ARTA so I also plan to try to measure the range of my 12". I don't expect to be able to use them - it will be a learning exercise.

Thanks,

Brian

Hi. Brian,
All electric guitars, especially lead or rhythm need adequate amp/speaker to produce unique sound and dynamic. In my experience, speaker is most important. In rebut, you will lost some needed harmonics or boost some unneeded. For example: you will get better guitar sound if you connect bad hi-fi amp to good guitar cabinet, rather then best guitar amp to best hi-fi box. Maybe some full range driver can work enough good, but much better solution is purchasing one or more 8, 10 or 12" guitar driver. Very good choice is Celestion or Eminence Legend guitar series.

Second thing is guitar amp. Tubes makes really good guitar sound. For me, preamp with tubes like Marshall, Fender or similar produce 80% of desired sound. Tube power amp will work better, but solid state or chip based amp also be very good in combination with tubes.

Like Graydon say, difference between simulated distortion and 'natural' amp overdrive is big. I have been try some guitar processors, but nothing make me happy like small tube amp at maximum gain.

That is my opinion, but your ears or ears your son is judge.

Oly

[Brett]

+1 Oly.

[38eighteen]

Thanks for all the advice.

Here is my updated plan (sorry, I seem to have combined this with my "Please review my guitar amp plan" thread):
- Build a nice combo box
- Build the runoffgroove.com Thor (that I have already ordered parts for) as a pre-amp
- Build the 2 x LM3875 kit that I have in my drawer as the power amp
- Buy new drivers
- Wait for my son's tastes to "mature" :-) and do some more research and learning and replace Thor with a nice tube pre-amp one day.

The LM3875 is rated at 56W and I have a 300VA toroid so they should be able to deliver.

My new question is - what driver(s) should I get? I was initially thinking 2 x 12" because I was going to use the ones I had to start with but now that you have convinced me not to bother my choice is only limited by practicality, money and what I can get in Australia.

I have been searching for Celestion or Eminence Legend in Australia most of the afternoon (off and on...) and can only seem to find speakers with these drivers of used ones on eBay. A couple of Legend 105s would seem to be a good match to my proposed power amps and fits my budget but I can't seem to find them in AU. I know I can buy from the US and have them shipped, but I'd like to try local if I can.

Thanks,

Brian

[38eighteen]

...or, is 112W just silly overkill for a 13 year old who jams with his mates and plays in the Church band? Should I use my LM3875 kits for the nice Hi-Fi amp I bought them for and build my son something based on LM1875??? Argghhh choices, choice....

Thanks,

Brian