Hi,

I've got some old speakers built using transmission line principles
which generate a reasonable volume but I'm feeling that the amplifier is
not quite letting some of that 'low down' gutsy bass through to the
speakers, and that some sort of sub-sonic filter is to blame. Can't be
lack of power - these speakers are efficient at low volume settings. I'm
pleased with the performance otherwise (Kate Bush IS actually in my
room etc... ;-)

The equipment:
- TDL studio 1m
- Cyrus Straightline
- Rotel RCD971 CD player

Thinking of replacing the amp and would welcome some suggestions,
preferably not involving the abusive use of tone controls.... ;-)

Budget of about £300-£500.


---
Adrian

"Adrian C" wrote in message
...
Hi,

I've got some old speakers built using transmission line principles
which generate a reasonable volume but I'm feeling that the
amplifier is
not quite letting some of that 'low down' gutsy bass through to the
speakers, and that some sort of sub-sonic filter is to blame. Can't
be
lack of power - these speakers are efficient at low volume settings.
I'm
pleased with the performance otherwise (Kate Bush IS actually in
my
room etc... ;-)

The equipment:
- TDL studio 1m
- Cyrus Straightline
- Rotel RCD971 CD player

Thinking of replacing the amp and would welcome some suggestions,
preferably not involving the abusive use of tone controls.... ;-)

Budget of about £300-£500.


---
Adrian

You should have no problems with that and TL's.

Before you go spending big money, invest in the audio test disc from
Maplins - used to be £16.95 - and see if the bass really is there.
Speaker positioning can have serious effects on bass levels.

Silly question - they are correctly wired - in phase - aren't they? If
wrong, bass will just disappear.


--
Woody

harrogate2 at ntlworld dot com

harrogate2 wrote:
The equipment:
- TDL studio 1m
- Cyrus Straightline
- Rotel RCD971 CD player

Thinking of replacing the amp and would welcome some suggestions,
preferably not involving the abusive use of tone controls.... ;-)

Budget of about £300-£500.


---
Adrian

You should have no problems with that and TL's.
Before you go spending big money, invest in the audio test disc from
Maplins - used to be £16.95 - and see if the bass really is there.

It's there if I play back material where the record producer has been
somewhat heavy handed (Jungle/DnB) but for material hopefully recorded
flat on the eq involving natural instruments, it lacks a bit - I know
it's not the experience that people normally have with these type of
speakers.

Speaker positioning can have serious effects on bass levels.
Silly question - they are correctly wired - in phase - aren't they? If
wrong, bass will just disappear.

The electrical phasing is correct and speakers are away from a wall (not
hidden in a corner) firing into a 10ft square room.

I'm going to borrow some amps from my local audio dealer and do some
auditions. Has anyone found Hi-Fi amps that have an intentional
restricted lower bandwidth (I believe done to save speaker damage on
smaller/ported cabinets) and solved it by an upgrade? Or am I imagining
that this problem exists?

---
Adrian

"Adrian C" wrote in message
...
harrogate2 wrote:
The equipment:
- TDL studio 1m
- Cyrus Straightline
- Rotel RCD971 CD player

Thinking of replacing the amp and would welcome some suggestions,
preferably not involving the abusive use of tone controls.... ;-)

Budget of about £300-£500.


---
Adrian

You should have no problems with that and TL's.
Before you go spending big money, invest in the audio test disc
from
Maplins - used to be £16.95 - and see if the bass really is there.

It's there if I play back material where the record producer has
been
somewhat heavy handed (Jungle/DnB) but for material hopefully
recorded
flat on the eq involving natural instruments, it lacks a bit - I
know
it's not the experience that people normally have with these type of
speakers.

Speaker positioning can have serious effects on bass levels.
Silly question - they are correctly wired - in phase - aren't
they? If
wrong, bass will just disappear.

The electrical phasing is correct and speakers are away from a wall
(not
hidden in a corner) firing into a 10ft square room.

I'm going to borrow some amps from my local audio dealer and do some
auditions. Has anyone found Hi-Fi amps that have an intentional
restricted lower bandwidth (I believe done to save speaker damage on
smaller/ported cabinets) and solved it by an upgrade? Or am I
imagining
that this problem exists?

---
Adrian


In some cases it used to be the case of in-built (or switchable)
rumble filters in the days of LPs, but these days amp responses are
more often d.c. to light!


--
Woody

harrogate2 at ntlworld dot com

harrogate2 wrote:

"Adrian C" wrote in message
...

Hi,

I've got some old speakers built using transmission line principles
which generate a reasonable volume but I'm feeling that the

amplifier is

not quite letting some of that 'low down' gutsy bass through to the
speakers, and that some sort of sub-sonic filter is to blame. Can't

Silly question - they are correctly wired - in phase - aren't they? If
wrong, bass will just disappear.

If transmission lines, the bass will just disappear.
You get a gentle rolloff from a high frequency.
The best thing to do is put an equaliser in the amp's tape loop
to flatten the response. A passive equaliser with 2 resistors
and a capacitor per channel is ok if you have enough gain.

--
Eiron.

"Adrian C" wrote in message
...


I'm pleased with the performance otherwise (Kate Bush IS actually in my
room etc... ;-)

If Kate Bush was in *my* room, I wouldn't change a thing:-)

Does a valve amp take your fancy? Do you like the idea of a bit
of tinkering? There are sometimes excellent second hand amps
looking for good homes. Be cautious of e-Bay.

A pal of mine in the UK bought a pair on Kerr McCosh monoblocs
(circ 1970) for UKP300. His Denon SS amp is now in the cupboard
under the stairs.

Iain

You could see if the amplifier has bass roll-off, using a signal generator
program on your PC (I use Goldwave) to generate sine waves.

Measure the amplitude of the sinewave on the amplifier input and speaker
input, at normal listening levels. The ratio of output to input should be
constant.

Tim