Peavey 410 TX 4X10 Inch Bass Cab

[DrNomis_44]

Update:


I just managed to remove all of the speakers from the enclosure, about two of the mounting-screws seized-up and broke while I was removing them, that's ok cause the speakers are going to be replaced anyway, turns out only one of the original speakers is still good, the voice coil measures about 6.5 Ohms or so on my digital multimeter, but that could be erroneous so I'm not going to take it as gospel.

The insides of the cab could do with a decent clean-out, which I might do later on this year.


I gave the insides of the cab a bit of a spray with some air-freshener cause it doesn't half have a bit of a pong to it, it's all sorted now though.


Ok, so why were the other three speakers not working?, pretty simple really, the short pieces of flexible wire connecting the voice-coils to the terminals were broken, and even non-existent in a couple of the speakers, rather than try and repair them, I'm just going to cut-to-the-chase and replace the lot, all the original acoustic dampening material needs replacing too....did I mention that the cab needs a decent vacuuming-out and clean as well?


I've pretty much done all I can with it for the time-being, so I'm going to leave it alone till I can get replacement speakers and new acoustic dampening material for it, and etc.

[Simon Barden]

Note that it was rated at 350 ohms RMS. That 700W is 'program', so the original speakers are likely to be rated at around 80W RMS each (maybe 75W with an allowance for the HF speaker). 'Program' (or 'music') power is a rating deigned to give a maximum suitable amp output value to match with the cab. RMS is obviously based on a continuous, fixed amplitude, sine wave, and as bass (and guitar) signals aren't continuous or fixed amplitude, but dynamic and with gaps between, then you can get away with using a bigger amplifier, normally rated at up to twice the speaker RMS value, as the overall power level handles by the speakers will be roughly the same when used with an instrument like a guitar or bass (less so with synths that can give constant amplitude outputs). The wattage rating of a speaker is a measure of how much maximum average energy the voice coils can handle (normally tested for 1 hour these days) before they run into thermal problems and voice coil insulation starts melting.

The 2:1 power amp:speaker rating really works best for solid state power amps, where the rating (normally measured at around 5% THD) is very close to the maximum power the amp will output, even with serious amounts of distortion. With a valve amp, where the rating is still made at a clean level, there is still often a lot of extra power available once the power amp is overdriven, maybe an extra 80% or more, so you are best limiting a valve amp to the speaker RMS rating. So anything above 200W RMS should be fine.

If you can compare the internal dimensions and port size with Marcel's cab and they are the same or very close, then those Legends sound like they would be a good choice as we know they work in Marcel's cab.

[DrNomis_44]

Note that it was rated at 350 ohms RMS. That 700W is 'program', so the original speakers are likely to be rated at around 80W RMS each (maybe 75W with an allowance for the HF speaker). 'Program' (or 'music') power is a rating deigned to give a maximum suitable amp output value to match with the cab. RMS is obviously based on a continuous, fixed amplitude, sine wave, and as bass (and guitar) signals aren't continuous or fixed amplitude, but dynamic and with gaps between, then you can get away with using a bigger amplifier, normally rated at up to twice the speaker RMS value, as the overall power level handles by the speakers will be roughly the same when used with an instrument like a guitar or bass (less so with synths that can give constant amplitude outputs). The wattage rating of a speaker is a measure of how much maximum average energy the voice coils can handle (normally tested for 1 hour these days) before they run into thermal problems and voice coil insulation starts melting.

The 2:1 power amp:speaker rating really works best for solid state power amps, where the rating (normally measured at around 5% THD) is very close to the maximum power the amp will output, even with serious amounts of distortion. With a valve amp, where the rating is still made at a clean level, there is still often a lot of extra power available once the power amp is overdriven, maybe an extra 80% or more, so you are best limiting a valve amp to the speaker RMS rating. So anything above 200W RMS should be fine.

If you can compare the internal dimensions and port size with Marcel's cab and they are the same or very close, then those Legends sound like they would be a good choice as we know they work in Marcel's cab.

Just had a look at the datasheet pdf I downloaded for those Eminence Legend speakers, and I think I will get a set of four of them for my Peavey 410TX bass cab next year when I can afford it.

Apparently there's a mod you can do to the crossover circuit board to make the cab sound less mid-scooped, which basically involves bypassing the inductor in the crossover, I'll have to look into it, bypassing the inductor makes the frequency response more wide range.

https://www.talkbass.com/threads/by-...ossover.78034/

[Simon Barden]

I'd leave it as it is until you get the new drivers in. You don't know how it will sound with both different drivers and your amp. Wait, see how it sounds and then make a choice. At least it's something you can probably test out with a crocodile clip link, so it doesn't need to be permanent (or even add a switch to select it in or out).

Does the mod shift the crossover frequency upwards or downwards? You need to be careful with shifting it downwards too far, as that passes a lot more energy to the HF driver. No idea what it's rated at but they normally aren't that highly rated. They don't need to be with a 3.5kHz crossover, but the lower the crossover frequency, the more energy they have to cope with.

[JimC]

Apparently there's a mod you can do to the crossover circuit board to make the cab sound less mid-scooped, which basically involves bypassing the inductor in the crossover, I'll have to look into it, bypassing the inductor makes the frequency response more wide range.

I'm fairly surprised at the described process not including tracing the circuit first. It's not generally that hard with a crossover.

If its a simple one inductor one capacitor crossover then bypassing the inductor turns the crossover into a high pass filter protecting the tweeter. Removing the tweeter as well turns the exercise into a very complicated way of wiring the woofer direct to the input socket.

It's not unusual to wire bass cabs, even some of the very best ones, with a high pass filter rather than a crossover to protect the tweeter. On a typical bass guitar driver the frequency response falls and the impedance rises strongly with frequency, so the results can be wholly satisfactory. It would be a different story with a mid driver in the mix.

Jim C

[DrNomis_44]

Those are good points you bring-up, maybe I could add a switch that bypasses or switches-in the inductor, but as Simon Barden says, maybe the best thing to do is to wait till the new speakers are installed and see how it sounds with the crossover operating normally.

@ Simon Barden I'm probably going to have to trace-out the circuit for the crossover to figure-out exactly what it's doing to the overall frequency response.

[Simon Barden]

I see that the guy who did the mod had already removed the tweeter (which seems to be universally considered as a bad unit) so you are really letting the drivers work as full range units and providing more treble. 800Hz is the common centre EQ frequency used by most bass amp with a single mid control, so 3.5kHz and above is really letting the low/mid treble back through that the HF driver won’t be providing. That Eminence driver looks to be giving useful output up to about 5kHz, after which it drops down quite quickly, so removing the crossover and the HF driver will make that treble available from the 10” drivers.

The bass and mid controls on guitar amps are normally up an octave from those on bass amps, plus your amp’s are just subtractive, so you may find a bass graphic EQ pedal (or a wider range pedal with more bands than say a Boss guitar graphic pedal has), useful in sculpting your bass sound.

[JimC]

On the one hand tweeters on bass rigs are highly polarising, and loved or loathed on TB, so I'd be wary of making judgments on that rig based on the comments. On the other hand though I was looking to see if I could find a circuit diagram for the crossover, and I found that Peavey issued two revised models of that cab, and the pr for both put crossover and tweeter changes first.

Were I doing this I would build the cab without tweeter or crossover and concentrate on tuning the ports and bass response. Only when happy there would I see if I felt an HF unit were needed.

[Marcel]

Okay, here we go, the outside dimensions of the Peavey 410TX bass cab are as follows:

Width = 615mm.

Depth = 435mm.

Height = 625mm.

All the speakers are indeed 10 inch in diameter, the cab itself seems to be made out of 20mm particle board, or, it could be 20mm plywood, hard to tell.

Hmmm, Seems my cab is a bit smaller, but not by much.

Mine is roughly 62cm x 62cm x 39cm. And nil fancy connector plate, just a simple molded metal plate large enough for two connectors and held in with 6 screws . Also my cab is covered with black marine carpet all over the top sides and back hence the measurement inaccuracy. Front is just painted black with the grill.

I doubt the minor size difference in the cabs would affect how it sounds with diff drivers too much. If it were me I'd be disconnecting that control and getting a nice new set of Eminence Legend drivers for your cab.

[Simon Barden]

Roughly 12% more internal volume than Marcel's then, which is not insignificant when looking at bass cab tuning. And the port size could be different. So I'd be a bit wary.

I'd enter the TS parameters for the Eminence into a cab calculator, and add the cab internal volume and port details into it and see what the results look like, and compare that to an ideal cab selection for the speakers.