agedhorse

If they use the Honda inverter style generators and take them out of Eco mode, they have even more effective voltage regulation built into the generator's control system. They are also VERY quiet.

2 hours ago, stevie said:

I entered the Celestion Pulse 10 and the Sica driver into my modelling program and the Celestion performs marginally better in the 41-litre cab, but I'd persevere with the Sica rather than going out and buying a another driver. My software recommends a slightly longer port than @agedhorse. The standard length of the usual 100mm ports is 115mm. According to my software, that would tune your cab to around 52Hz, which would be fine. 

Again, just a design choice/preference.

Ashdown DIDN’T get the volume so wrong. It was simply a design choice. 
 

By any chance was that tweeter ADDED to the cabinet in the existing port???

Ok, I just ran the numbers and I think you may have gone down a rabbit hole.

If the internal dimensions of the box are really 41 liters, a 3" diameter port 2" deep is going to be fine at 100 watts RMS. If you go to a 4" diameter port, the depth will increase to 4" and you will increase the power handling to a little over 150 watts RMS (a better choice).

Bill's right here. What's necessary is to make the best choices so that the compromise can be lived with.

Looking back at your first post, are you SURE that your port velocity is being calculated correctly. for a 75mm diameter port, I would not expect that much velocity from a single 10" driver. I'm starting to think that there is an error somewhere... since you are using WinISD, that's the first place I would look. Buggy software is a charitable way of saying it.

The port area is too small, increase the diameter by ~2cm and see if the length remains reasonable.

With that driver in that size box, you may not be able to achieve an acceptable tuning.

26 minutes ago, Killed_by_Death said:

 

Apparently 14 AWG isn't great for power cords, because they're too stiff & cause issues, but the SJOOW 14 AWG pair that I used for SpeakON didn't seem stiff.

 

 

It's ok for power cords IF a heavier gauge is necessary and the strain reliefs are appropriate.

Speaker cords are generally a heavier gauge because the voltage is lower and the current is higher for the same amount of power transmitted.

4 minutes ago, BassmanPaul said:

If the loudness of the 'pop' increases when the volume control id turned up then the problem has nothing to do with the power section and lies in the pre-amp. Possibly a failing tube or a leaky cap. 

Correct, it’s unrelated to the power amp (power tubes/valves, transformers, etc.)

Proper troubleshooting will narrow down the area responsible for the noise, then it can be appropriately repaired.

6 hours ago, Dad3353 said:

Quite true, for avionic use, but for things like audio jack plugs or speakon cables, it's not a problem, especially if there's a compression plate system. If the cable is correctly restrained, there'll be no force on the connection at any time. In my experience it's fine. I'd rather the ends were tinned than have loose brins of multi-strand on the loose. 

Neutrik specifically warns OEM manufacturers of cables against using tinned wires with their SpeakOn plugs for the reasons I mentioned earlier.
 

Assembly with tinned wires also invalidates the safety approvals of the plug since the plug’s safety certification is for untinned wire termination only. 

As far as the sound differences in "premium priced cables" and solid commercial/pro/tour grade cables is generally indistinguishable to those participating in double-blind testing. I have seen these tests many times, and seen folks claim things that proved unconfirmable.

The exception to the rule is high impedance sources into high impedance loads (instrument cable), when the cable gets long there can be a significant difference between cables due to the capacitive reactance of the cable and how that reactance interacts with the reactance of a passive pickup. You can experience reduced high end, you can experience resonance effects, and you can experience additional noise. The longer the cable, the more noticeable.

This has been my experience (over and over again).

11 hours ago, Dad3353 said:

I've been doing connectors of all sorts for musical equipment and PA's for well over half a century now. My 5-year Avionics training with BEA gave me experience and theory as to the best connector for the job (crimps in much aircraft stuff...), and real-life experience in workshops, at home and in the field has shown to me what is best, for me, for jack plugs, speakons, RCA, XLR and much more (as well as my model aircraft...). A good solder joint, mechanically restrained, will not fail. A tinned multi-strand cable is fine (again, if restrained, but all connectors should be restrained, anyway, so...). Bare multi-strand is fine, too, if the strands are not so fine as to be ground away by screws, so tinning would be better there. Otherwise, no problem with bare cable. A spreader in much better in a screw connector. Crimping is excellent, with the right tools (not just any old pliers...). It's all good, if the technician knows what he/she is doing. I can't remember ever having a failure, whatever the method, except for abuse. I'd not advise any soldering, though, without the right gear and experience, and good wire strippers do not come cheap. 

Tinning wires with binding screw pressure terminations are a problem because the solder will cold flow under pressure. It's not allowed in avionics here in the states. The regulatory approvals for most pressure screw connectors will specify un-tinned wire only.

There may be some exceptions for tin overbond wire in some applications, but only because pure tin does not cold flow as easily. 

16 hours ago, nilebodgers said:

I meant either crimp or compression ( I.e. screw terminals with an intermediate load spreader for compression without damaging the strands).

The problem with soldered multi strand cable is that solder wicks back up the cable and can cause failure if there are mechanical stresses/flexing. This has long been known in electronic circles. (I also found it in a commentary on the IEE wiring regs: Soldered conductor ends on fine wire and very fine wire conductors are not permitted (Regulation 526.8.3) where relative movement can be expected between soldered and non-soldered parts of the conductor.)

 

This is why soldered connections on plugs should always have a mechanical strain relief. Even mechanically attached plugs like SpeakOn have robust strain reliefs built into the connector.

19 hours ago, dmccombe7 said:

The expert cable manufacturers recommend soldered connections rather than screwed ones for reliability and endurance.

Any cables i've bought have all been soldered.

Dave

Not for Neutruik SpeakOn plugs.

Under high current, the pressure of the termination (without tinned wired) is better than solder and will not loosen with use either.

1 hour ago, Killed_by_Death said:

 

ahem,

spraying directly onto the plug & then plugging & unplugging

yay or nay?

 

This is generally fine. 

Spraying into the amp usually gets incompatible substances where they don't belong, creating new and messier problems to deal with.

16 hours ago, skidder652003 said:

buy some servisol and give the inputs a bloomin' good spray!

Good God I hope not, for the sake of the tech that needs to clean up the resulting mess at least.

6 hours ago, Dan Dare said:

Unless it was a valve amp, probably just means they brushed the dust out of the vents and sprayed the contacts and sockets with switch cleaner.

Sure hope they don't go spraying things down with "magic cure-all spray", I see plenty of gear damaged from such treatment. ESPECIALLY switch contact cleaners.

Why does your amp need servicing? 

The foot switch is no longer available? Didn't it get introduced just last year?

Ok, that's a GB 410 standard, had to go back deep into the archives but it was a model from the mid to late 1990's and was shipped 8 ohm as standard with a 4 ohm optional version as well.

I do still have a limited number of recone kits available for this model in both 8 ohms (standard cabinet, series-parallel wiring) and 4 ohms (optional cabinet, 16 ohm driver parallel wiring).

Can’t open the pictures 

Can you post a picture?

11 hours ago, nilebodgers said:

I seem to recall the Mesa chap that posts on Talkbass saying that their cabs are specifically designed to work together re. tuning / response etc.

@agedhorse is who I meant.

Yes, this is correct.

IME, most 300 watt RMS speaker that will handle this kind of power may be quite colored due to the heavier suspension and long wound voice coil (compared with gap depth) required for mechanical robustness. This results in significant high frequency rolloff compared with a full range or extended range design.

5 hours ago, DiMarco said:

Thanks for the responses guys. It is hard to find this kind of info if you don't know where to look.

Do bass amp manufacturers state the instrument input impedances and is there a difference between passive and active signal inputs other then the level?

Thanks again.

 

Some but certainly not all manufacturers provide these specifications.

Depending on the circuit topology, the input impedance may be different or the same between passive and active inputs. On the Subway amps, the input impedance is ~1M in both passive and active positions.

The specifications for the Subway amps are located in the back of the respective owner’s manuals.